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Sample records for midge chironomus tentans

  1. Cytochrome P450 genes from the aquatic midge Chironomus tentans: Atrazine-induced up-regulation of CtCYP6EX3 contributing to oxidative activation of chlorpyrifos

    Science.gov (United States)

    The open reading frames of 19 cytochrome P450 monooxygenase (CYP) genes were sequenced from Chironomus tentans, a commonly used freshwater invertebrate model. Functional analysis of CtCYP6EX3 confirmed its atrazine-induced oxidative activation for chlorpyrifos by using a nanoparticle-based RNA inter...

  2. Interlaboratory study of precision: Hyalella azteca and Chironomus tentans freshwater sediment toxicity assays

    Science.gov (United States)

    Burton, G.A.; Norberg-King, T. J.; Ingersoll, C.G.; Benoit, D.A.; Ankley, G.T.; Winger, P.V.; Kubitz, J.; Lazorchak, J.M.; Smith, M.E.; Greer, E.; Dwyer, F.J.; Call, D.J.; Day, K.E.; Kennedy, P.; Stinson, M.

    1996-01-01

    Standard 10-d whole-sediment toxicity test methods have recently been developed by the U.S. Environmental Protection Agency (EPA) for the amphipod Hyalella azteca and the midge Chironomus tentans. An interlaboratory evaluation of method precision was performed using a group of seven to 10 laboratories, representing government, academia, and environmental consulting firms. The test methods followed the EPA protocols for 4-d water-only reference toxicant (KCl) testing (static exposure) and for 10-d whole-sediment testing. Test sediments included control sediment, two copper-containing sediments, and a sediment contaminated primarily with polycyclic aromatic hydrocarbons. Reference toxicant tests resulted in H. azteca and C. tentans median lethal concentration (LC50) values with coefficents of variation (CVs) of 15.8 and 19.6%, respectively. Whole sediments which were moderately contaminated provided the best estimates of precision using CVs. Hyalella azteca and C. tentans tests in moderately contaminated sediments exhibited LC50 CVs of 38.9 and 13.5%, respectively. The CV for C. tentans growth was 31.9%. Only 3% (1 of 28) of samples exceeded acceptable interlaboratory precision limits for the H. azteca survival tests. No samples exceeded the intralaboratory precision limit for H. azteca or C. tentans survival tests. However, intralaboratory variability limits for C. tentans growth were exceeded by 80 and 100% of the laboratories for a moderately toxic and control sample, respectively. Interlaboratory variability limits for C. tentans survival were not exceeded by any laboratory. The results showed these test methods to have relatively low variance and acceptable levels of precision in interlaboratory comparisons.

  3. Chronic toxicity of the synthetic hormone 17alpha-ethinylestradiol to Chironomus tentans and Hyalella azteca.

    Science.gov (United States)

    Dussault, Eve B; Balakrishnan, Vimal K; Solomon, Keith R; Sibley, Paul K

    2008-12-01

    The chronic toxicity of the synthetic hormone 17alpha-ethinylestradiol (EE2) was investigated in two benthic invertebrates, the midge Chironomus tentans and the freshwater amphipod Hyalella azteca, in life-cycle water-only assays. In C. tentans, a 50% decrease in emergence was observed at a concentration of 1.5 mg/L; emergence was a more sensitive endpoint than survival, growth, or biomass. Reproduction was not significantly affected by EE2 exposure until a concentration of 3.1 mg/L, where emergence, and therefore reproduction, did not occur. In contrast, reproduction was the most sensitive endpoint in H. azteca (50% decrease in reproduction observed at a concentration of 0.36 mg/L). The sensitivity of the F1 generation to EE2 was also investigated with H. azteca, but was not different from the F0 generation. The data from the present study were combined with those from previous 10-d toxicity assays, to derive acute to chronic toxicity ratios (ACRs) for EE2. The ACRs calculated for EE2 were 13 for C. tentans and 16 for H. azteca, indicating that the application factors currently used in ecological risk assessment for the derivation of chronic toxicity are protective and conservative for these organisms. The results of the present study suggest that chronic toxicity was not mediated by disruption of endocrine pathways. Using a hazard quotient approach, the risk associated with sublethal exposure to EE2 was azteca and C. tentans, indicating that adverse effects are not expected, and that environmental exposure to EE2 likely poses a low risk to benthic invertebrates.

  4. Silver toxicity to Chironomus tentans in two freshwater sediments

    Energy Technology Data Exchange (ETDEWEB)

    Call, D.J.; Polkinghorne, C.N.; Markee, T.P.; Brooke, L.T.; Geiger, D.L. [Univ. of Wisconsin, Superior, WI (United States). Lake Superior Research Inst.; Gorsuch, J.W.; Robillard, K.A. [Eastman Kodak Co., Rochester, NY (United States)

    1999-01-01

    Sediment collected from two freshwater lakes, West Bearskin Lake (Cook, MN, USA) and Bond Lake (Douglas, WI, USA), was characterized for grain size, total organic carbon, (TOC), acid-volatile sulfides (AVS), simultaneously extracted metals (SEM), and iron (Fe). Both sediments had low levels of TOC. West Bearskin Lake sediment contained more small particles than Bond Lake, which was 95% sand. West Bearskin Lake also had higher SEM and had an Fe content that was approximately 30-fold greater than that of Bond Lake. These sediments were amended with AgNO{sub 3} in a series of concentrations, some of which were intended to exceed the total silver (Ag)-binding capacity of the sediments, allowing for the appearance of dissolved Ag in pore water (PW). Sediment toxicity tests were then designed such that the AgNO{sub 3} amendment levels would result in PW concentrations that bracketed the 10-d concentration causing 50% lethality for dissolved Ag of 0.057 mg/L, as determined in a toxicity test in water alone. The 10-d LC50 values for Chironomus tentans, based upon nominal additions of Ag to the sediments, were 2.75 and 1.17 g Ag per kilogram dry sediment for West Bearskin and Bond Lake sediments, respectively. An LC50 value based upon dissolved Ag in the PW was determined only for Bond Lake sediment and was approximately 275 times greater than the water-only LC50 value. This indicated that a high proportion of the dissolved fraction was not readily bioavailable to cause lethality. A reduction in PW pH and the displacement of other metals from sediment into PW with Ag additions to the sediment likely contributed to the observed mortalities and weight losses, particularly at the higher exposure levels. The concentrations of Ag in these sediments that resulted in biological effects are considerably higher than levels reported in the environment.

  5. CHRONIC EFFECTS OF THE HERBICIDE DIURON ON FRESHWATER CLADOCERANS,AMPHIPODS,MIDGES,MINNOWS,WORMS, AND SNAILS

    Science.gov (United States)

    The chronic effects of the herbicide diuron on survival and reproduction of Daphnia pulex, and survival and growth of the amphipod Hyalella azteca, the midge Chironomus tentans, juvenile and embro/larval fathead minnows, Pimephales promelas, annelid worms, Lumbriculus variegatus,...

  6. Response spectrum of pentachlorobenzene and fluoranthene for Chironomus tentans and Hyalella azteca.

    Science.gov (United States)

    Schuler, Lance J; Landrum, Peter F; Lydy, Michael J

    2007-06-01

    The whole-body residues of pentachlorobenzene (PCBz) and fluoranthene (FLU) in Hyalella azteca and Chironomus tentans were determined for a variety of chronic sublethal effects. The endpoints evaluated for H. azteca included 28-d growth and survival and 42-d growth, survival, and reproduction. Adverse effects to C. tentans also were determined at multiple endpoints including 10-d growth, cumulative pupation and emergence, and reproduction. The lowest-observed-effect residue (LOER) based on whole-body residues associated with growth was consistent between compounds and species tested with concentrations ranging from 0.17 to 0.33 micromol/g. For H. azteca, the most sensitive endpoints were growth at 0.23 micromol/g and reproduction at 0.11 micromol/g for PCBz and FLU, respectively. For C. tentans, the most sensitive endpoints were emergence, development and reproduction at 0.02 micromol/g, and development and reproduction at 0.15 micromol/g for PCBz and FLU, respectively. Compared to residues associated with acute lethality, the most sensitive sublethal endpoints were approximately 4 and 60 times lower for PCBz and FLU, respectively. The relative consistency of the sublethal endpoints suggests that body residues can be a valuable tool to evaluate bioaccumulation data as part of a risk assessment to predict adverse effects to biota.

  7. Bioaccumulation of the synthetic hormone 17alpha-ethinylestradiol in the benthic invertebrates Chironomus tentans and Hyalella azteca.

    Science.gov (United States)

    Dussault, Eve B; Balakrishnan, Vimal K; Borgmann, Uwe; Solomon, Keith R; Sibley, Paul K

    2009-09-01

    The present study investigated the bioaccumulation of the synthetic hormone 17alpha-ethinylestradiol (EE2) in the benthic invertebrates Chironomus tentans and Hyalella azteca, in water-only and spiked sediment assays. Water and sediment residue analysis was performed by LC/MS-MS, while biota extracts were analyzed using both LC/MS-MS and a recombinant yeast estrogen receptor assay. At the lowest exposure concentration, C. tentans accumulated less EE2 than H. azteca in the water-only assays (p=0.0004), but due to different slopes, this difference subsided with increasing concentrations; at the exposure concentration of 1mg/L, C. tentans had a greater body burden than H. azteca (p=0.02). In spiked sediments, C. tentans had the greatest EE2 accumulation (1.2+/-0.14 vs. 0.5+/-0.05 microg/gdw, n=4). Measurements in H. azteca indicated a negligible contribution from the sediments to the uptake of EE2 in this species. These differences were likely due to differences in the behavior and life history of the two species (epibenthic vs. endobenthic). Water-only bioaccumulation factors (BAFs) calculated at the lowest exposure concentration were significantly smaller in C. tentans than in H. azteca (31 vs. 142, respectively; pazteca (0.8 vs. 0.3; p<0.0001). Extracts of the exposed animals caused a response in a recombinant yeast estrogen receptor assay, thus confirming the estrogenic activity of the samples, presumably from EE2 and its estrogenic metabolites. The results of the present study suggest that consumption of invertebrate food items could provide an additional source of exposure to estrogenic substances in vertebrate predators.

  8. Examining the joint toxicity of chlorpyrifos and atrazine in the aquatic species: Lepomis macrochirus, Pimephales promelas and Chironomus tentans

    Energy Technology Data Exchange (ETDEWEB)

    Tyler Mehler, W.; Schuler, Lance J. [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University at Carbondale, Carbondale, IL 62901-6511 (United States); Lydy, Michael J. [Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University at Carbondale, Carbondale, IL 62901-6511 (United States)], E-mail: mlydy@siu.edu

    2008-03-15

    The joint toxicity of chlorpyrifos and atrazine was compared to that of chlorpyrifos alone to discern any greater than additive response using both acute toxicity testing and whole-body residue analysis. In addition, acetylcholinesterase (AChE) inhibition and biotransformation were investigated to evaluate the toxic mode of action of chlorpyrifos in the presence of atrazine. The joint toxicity of atrazine and chlorpyrifos exhibited no significant difference in Lepomis macrochirus compared to chlorpyrifos alone; while studies performed with Pimephales promelas and Chironomus tentans, did show significant differences. AChE activity and biotransformation showed no significant differences between the joint toxicity of atrazine and chlorpyrifos and that of chlorpyrifos alone. From the data collected, the combination of atrazine and chlorpyrifos pose little additional risk than that of chlorpyrifos alone to the tested fish species. - The joint toxicity between atrazine and chlorpyrifos caused greater than additive responses in invertebrates, but the interactions in vertebrates was less pronounced.

  9. Refining methods for conducting long-term sediment and water toxicity tests with Chironomus dilutus: Formation of a midge chronic testing work group

    Science.gov (United States)

    Standard methods have been established by USEPA, ASTM International, Environment Canada and Organization for Economic Cooperation and Development for conducting sediment toxicity tests with various species of midges including Chironomus dilutus. Short-term 10-day exposures are ty...

  10. Toxicity of eight metals to Malaysian freshwater midge larvae Chironomus javanus (Diptera, Chironomidae).

    Science.gov (United States)

    Shuhaimi-Othman, Mohammad; Yakub, Nadzifah; Umirah, Nur Shahirul; Abas, Ahmad

    2011-11-01

    Fourth instars larvae of freshwater midge Chironomus javanus (Diptera, Chironomidae) were exposed for a 4-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al) and manganese (Mn) concentrations. Mortality was assessed and median lethal concentrations (LC(50)) were calculated. LC(50) increased with the decrease in mean exposure times, for all metals. LC(50)s for 96 hours for Cu, Cd, Zn, Pb, Ni, Fe, Al and Mn were 0.17, 0.06, 5.57, 0.72, 5.32, 0.62, 1.43 and 5.27 mg/L, respectively. Metals bioconcentration in C. javanus increases with exposure to increasing concentrations and Cd was the most toxic to C. javanus, followed by Cu, Fe, Pb, Al, Mn, Zn and Ni (Cd > Cu > Fe > Pb > Al > Mn > Zn > Ni). Comparison of LC(50) values for metals for this species with those for other freshwater midges reveals that C. javanus is equally or more sensitive to metals than most other tested dipteran.

  11. Acute and chronic toxicity of imidacloprid to the aquatic invertebrates Chironomus tentans and Hyalella azteca under constant- and pulse-exposure conditions.

    Science.gov (United States)

    Stoughton, Sarah J; Liber, Karsten; Culp, Joseph; Cessna, Allan

    2008-05-01

    The toxicity of imidacloprid, a nicotinic mimic insecticide, to the aquatic invertebrates Chironomus tentans and Hyalella azteca, was first evaluated in static 96-hour tests using both technical material (99.2% pure) and Admire, a commercially available formulated product (240 g a.i. L(-1)). The 96-h lethal concentration (LC)50 values for technical imidacloprid and Admire were 65.43 and 17.44 microg/L, respectively, for H. azteca, and 5.75 and 5.40 microg/L, respectively, for C. tentans. Admire was subsequently used in 28-day chronic tests with both species. Exposure scenarios consisted of a constant- and a pulse-exposure regime. The pulse exposure lasted for four days, after which time the animals were transferred to clean water for the remaining 24 days of the study. Assessments were made on both day 10 and day 28. In the C. tentans under constant exposure, larval growth on day 10 was significantly reduced at 3.57 microg/L imidacloprid, the lowest-observed-effect concentration (LOEC). The no-observed-effect concentration (NOEC) and LOEC for the 28-day exposure duration (adult survival and emergence) were 1.14 and greater than 1.14 mug/L, respectively; the associated LC50 and LC25 were 0.91 and 0.59 microg/L, respectively. The LOEC for the pulse treatment was greater than 3.47 microg/L, but the day 10 LC25 was 3.03 microg/L. In the H. azteca tests, the day 10 and 28 constant exposure, as well as the day 28 pulse exposure, LOEC (survival) values were similar at 11.95, 11.46, and 11.93 microg/L, respectively. The day 10 and 28 constant exposure effective concentration (EC)25s (dry weight) were also similar, at 6.22 and 8.72 microg/L, respectively, but were higher than the pulse-exposure day 10 LOEC and EC25 (dry weight) values of 3.53 and 2.22 microg/L, respectively. Overall, C. tentans was more sensitive to acute and chronic imidacloprid exposure, but less sensitive to a single pulse, than H. azteca. Chronic, low-level exposure to imidacloprid may therefore reduce

  12. An inducible HSP70 gene from the midge Chironomus dilutus: Characterization and transcription profile under environmental stress

    Science.gov (United States)

    Karouna-Renier, N. K.; Rao, K.R.

    2009-01-01

    In the present study, we identified and characterized an inducible heat shock protein 70 (HSP70) from the midge Chironomus dilutus and investigated the transcriptional profile of the gene under baseline and environmentally stressful conditions. Using real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), we observed increased expression of CD-HSP70-1 in response to both heat shock and copper stress. We also investigated the expression of this gene during midge development. All C. dilutus developmental stages expressed CD-HSP70-1 under normal conditions, although at extremely low levels. Phylogenetic analysis of the amino acid sequence demonstrated distinct clustering of this gene with inducible HSP70s from other insect species. ?? 2008 The Authors.

  13. A Determination of Metallothionein in Larvae of Freshwater Midges (Chironomus riparius Using Brdicka Reaction

    Directory of Open Access Journals (Sweden)

    Rene Kizek

    2008-07-01

    Full Text Available Among wide spectrum of biomolecules induced by various stress factors low molecular mass protein called metallothionein (MT is suitable for assessment of the heavy metal environmental pollution. The aim of this work was to determine the metallothionein and total thiols content in larvae of freshwater midges (Chironomus riparius sampled from laboratory exposure to cadmium(II ions and from field studies using differential pulse voltammetry Brdicka reaction. Unique electrochemical instrument, stationary electrochemical analyser Autolab coupled with autosampler, was utilized for the analysis of the samples. The detection limit for MT was evaluated as 5 nM. The larvae exposed to two doses (50 ng/g or 50 μg/g of cadmium(II ions for fifteen days under laboratory controlled conditions were at the end of the exposure killed, homogenized and analysed. MT content in control samples was 1.2 μM, in larvae exposed to 50 ng Cd/g it was 2.0 μM and in larvae exposed to 50 μg Cd/g 2.9 μM. Moreover at field study chironomid larvae as well as sediment samples have been collected from eight field sites with different levels of pollution by heavy. The metals content (chromium, nickel, copper, zinc, arsenic, molybdenum, cadmium, tin and lead in the sediment and or MT content in the chironomid larvae were determined by inductively coupled plasma mass spectrometry or Brdicka reaction, respectively.

  14. Contaminated sediments and bioassay responses of three macroinvertebrates, the midge larva Chironomus riparius, the water louse Asellus aquaticus and the mayfly nymph Ephoron virgo

    NARCIS (Netherlands)

    Lange, de H.J.; Haas, de E.M.; Maas, H.; Peeters, E.T.H.M.

    2005-01-01

    Bioassays are widely used to estimate ecological risks of contaminated sediments. We compared the results of three whole sediment bioassays, using the midge larva Chironomus riparius, the water louse Asellus aquaticus, and the mayfly nymph Ephoron virgo. We used sediments from sixteen locations in t

  15. Contaminated sediments and bioassay responses of three macroinvertebrates, the midge larva Chironomus riparius, the water louse Asellus aquaticus and the mayfly nymph Ephoron virgo

    NARCIS (Netherlands)

    Lange, de H.J.; Haas, de E.M.; Maas, H.; Peeters, E.T.H.M.

    2005-01-01

    Bioassays are widely used to estimate ecological risks of contaminated sediments. We compared the results of three whole sediment bioassays, using the midge larva Chironomus riparius, the water louse Asellus aquaticus, and the mayfly nymph Ephoron virgo. We used sediments from sixteen locations in

  16. Toxicity of cadmium and lead on tropical midge larvae, Chironomus kiiensis Tokunaga and Chironomus javanus Kieffer (Diptera:Chironomidae)

    Institute of Scientific and Technical Information of China (English)

    Warrin Ebau; Che Salmah Md Rawi; Zubir Din; Salman Abdo Al-Shami

    2012-01-01

    Objective: To investigate the acute toxicity of cadmium and lead on larvae of two tropical Chironomid species, Chironomus kiiensis (C. kiiensis) Tokunaga and Chironomus javanus (C. javanus) Kieffer. Methods: Different larval instars (first-fourth) were exposed using a static non-replacement testing procedures to various concentrations of cadmium and lead. Results:In general, younger larvae (first and second instars) of both species were more sensitive to both metals than older larvae (third and forth instars). The toxic effects of the metals on C. kiiensis and C. javanus were influenced by the age of the larvae (first to fourth instars), types of metals (cadmium or lead) and duration of larval exposure (24, 48, 72 and 96 h) to the metals. Conclusions: Cadmium was more toxic to the chironomids than lead and C. javanus was significantly more sensitive to both metals than C. kiiensis (P<0.05).

  17. Identifying body residues of HCBP associated with 10-d mortality and partial life cycle effects in the midge, Chironomus riparius.

    Science.gov (United States)

    Hwang, H; Fisher, S W; Landrum, P F

    2001-05-01

    The relationship between the body residue of 2,2',4,4',5,5'-hexachlorobiphenyl (HCBP) and its effects, including 10-d mortality and chronic sublethal effects on the midge, Chironomus riparius, are examined in a partial life cycle assessment. The alga, Chlorella vulgaris, was loaded with 14C-labeled HCBP and fed to midges as the method for delivery of the toxicant. In a 10-d bioassay, median lethal body residue (LR50) was 0.57 (95% CI: 0.49-0.66) mmol/kg. In the partial life cycle test, midges were fed a mixture of 12C- and 14C-HCBP-laden algae and exposed in four separate tests to assess the different developmental stages representing 2nd to 3rd instar, 2nd to 4th, 2nd to pupa, and 2nd to adult stages. A variety of sublethal endpoints were monitored, including developmental time within a stadium, body concentration at the end of each stadium, body weight, and fecundity (the number of ova) for the female pupae and adults. Overall, midge body concentrations of HCBP increased with increasing exposure concentration. Body weight was not significantly affected by HCBP except during the 4th instar. Body residue also increased with each successive stadium. Developmental time increased significantly with increasing body concentration in 2nd to 4th, 2nd to pupa, and 2nd to adult tests, while there was no statistical significance in developmental time for the 2nd to 3rd instar test. The number of ova decreased significantly in adults with increasing body concentration of HCBP, with an average of 345 ova in controls, 289 ova at 0.028 mmol/kg of HCBP, and 258 ova at 0.250 mmol/kg. These data, which relate chronic endpoints to body residues, suggest that sublethal endpoints in invertebrates are useful for defining sublethal hazards of PCBs. These data also suggest that ecological consequences may result from relatively low body burdens of PCBs.

  18. Calculation and evaluation of sediment effect concentrations for the amphipod Hyalella azteca and the midge Chironomus riparius

    Science.gov (United States)

    Ingersoll, Christopher G.; Haverland, Pamela S.; Brunson, Eric L.; Canfield, Timothy J.; Dwyer, F. James; Henke, Chris; Kemble, Nile E.; Mount, David R.; Fox, Richard G.

    1996-01-01

    Procedures are described for calculating and evaluating sediment effect concentrations (SECs) using laboratory data on the toxicity of contaminants associated with field-collected sediment to the amphipod Hyalella azteca and the midge Chironomus riparius. SECs are defined as the concentrations of individual contaminants in sediment below which toxicity is rarely observed and above which toxicity is frequently observed. The objective of the present study was to develop SECs to classify toxicity data for Great Lake sediment samples tested with Hyalella azteca and Chironomus riparius. This SEC database included samples from additional sites across the United States in order to make the database as robust as possible. Three types of SECs were calculated from these data: (1) Effect Range Low (ERL) and Effect Range Median (ERM), (2) Threshold Effect Level (TEL) and Probable Effect Level (PEL), and (3) No Effect Concentration (NEC). We were able to calculate SECs primarily for total metals, simultaneously extracted metals, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The ranges of concentrations in sediment were too narrow in our database to adequately evaluate SECs for butyltins, methyl mercury, polychlorinated dioxins and furans, or chlorinated pesticides. About 60 to 80% of the sediment samples in the database are correctly classified as toxic or not toxic depending on type of SEC evaluated. ERMs and ERLs are generally as reliable as paired PELs and TELs at classifying both toxic and non-toxic samples in our database. Reliability of the SECs in terms of correctly classifying sediment samples is similar between ERMs and NECs; however, ERMs minimize Type I error (false positives) relative to ERLs and minimize Type II error (false negatives) relative to NECs. Correct classification of samples can be improved by using only the most reliable individual SECs for chemicals (i.e., those with a higher percentage of correct classification). SECs

  19. Relative sensitivity of an amphipod Hyalella azteca, a midge Chironomus dilutus, and a unionid mussel Lampsilis siliquoidea to a toxic sediment.

    Science.gov (United States)

    Ingersoll, Chris G; Kunz, James L; Hughes, Jamie P; Wang, Ning; Ireland, D Scott; Mount, David R; Hockett, J Russell; Valenti, Theodore W

    2015-05-01

    The objective of the present study was to evaluate the relative sensitivity of test organisms in exposures to dilutions of a highly toxic sediment contaminated with metals and organic compounds. One dilution series was prepared using control sand (low total organic carbon [TOC; azteca; 10-d and 28-d exposures), a midge (Chironomus dilutus; 20-d and 48-d exposures started with azteca were more sensitive endpoints in 28-d exposures than in 10-d exposures. Weight and biomass of L. siliquoidea were sensitive endpoints in both sand and West Bearskin Lake sediment dilutions. Metals, ammonia, oil, and other organic contaminants may have contributed to the observed toxicity.

  20. The effects of binary UV filter mixtures on the midge Chironomus riparius

    Energy Technology Data Exchange (ETDEWEB)

    Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis, E-mail: jlmartinez@ccia.uned.es

    2016-06-15

    Organic ultraviolet (UV) filters are used in a wide variety of products, including cosmetics, to prevent damage from UV light in tissues and industrial materials. Their extensive use has raised concerns about potential adverse effects in human health and aquatic ecosystems that accumulate these pollutants. To increase sun radiation protection, UV filters are commonly used in mixtures. Here, we studied the toxicity of binary mixtures of 4-methylbenzylidene camphor (4MBC), octyl-methoxycinnamate (OMC), and benzophenone-3 (BP-3), by evaluating the larval mortality of Chironomus riparius. Also molecular endpoints have been analyzed, including alterations in the expression levels of a gene related with the endocrine system (EcR, ecdysone receptor) and a gene related with the stress response (hsp70, heat shock protein 70). The results showed that the mortality caused by binary mixtures was similar to that observed for each compound alone; however, some differences in LC50 were observed between groups. Gene expression analysis showed that EcR mRNA levels increased in the presence of 0.1 mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10 mg/L of BP-3 or OMC. In contrast, the hsp70 mRNA levels increased after exposure to the combinations tested of 4MBC and BP-3 or OMC mixtures. These data suggest that 4MBC, BP-3, and OMC may have antagonist effects on EcR gene transcription and a synergistic effect on hsp70 gene activation. This is the first experimental study to show the complex patterned effects of UV filter mixtures on invertebrates. The data suggest that the interactions within these chemicals mixtures are complex and show diverse effects on various endpoints. - Highlights: • Chironomus riparius is sensitive to UV filter binary mixtures. • UV filters binary mixtures show antagonism on survival of 4th instar larvae. • BP-3 and OMC antagonize the stimulatory effect of 4MBC on EcR gene. • 4MBC, OMC, and BP-3 induce hsp70

  1. Energy-based modeling as a basis for the analysis of reproductive data with the midge (Chironomus riparius).

    Science.gov (United States)

    Ducrot, Virginie; Péry, Alexandre R R; Mons, Raphaël; Garric, Jeanne

    2004-01-01

    We propose a biologically based approach to analyze reproductive data for the midge (Chironomus riparius). We showed in a previous study that its larval development can be divided in two distinct phases regarding the use of energy: The somatic growth period and the gametic growth period. We hypothesize here the gametic period to be a crucial period for the energetic investment for reproduction. To test this, we performed several assays with different feeding programs. Our results confirmed that energetic investment for reproduction mainly occurs during the gametic growth period. We could then propose energy-based models to analyze reproductive data. We assumed the effects to result from a perturbation in the use of energy. Two models corresponding to different physiological modes of actions--decreased efficiency of feeding (i.e., feeding decrease model) or increased cost of egg production (i.e., egg-cost increase model)--were built and used for the analysis of data obtained after an exposure to an artificially copper-spiked sediment. During this experiment, different exposure patterns were performed to investigate whether effects on reproduction resulted mainly from an exposure that occurs during the gametic growth period or from an exposure that occurs during the somatic growth period. These exposure patterns led to similar effects on reproduction, which suggests that the toxicant-induced stress persists during the whole life cycle, even in case of exposure occurring only during part of it. Both the feeding decrease model and egg-cost increase model were able to describe the data. We showed that addition of copper in the sediment, even in low quantity (<6.5 mg/kg), might affect reproduction at the individual level. If no-effect concentrations were derived from these results, this may lead to an overprotective value. A relevant no-effect concentration could be derived from further investigations at the population level.

  2. The effects of binary UV filter mixtures on the midge Chironomus riparius.

    Science.gov (United States)

    Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis

    2016-06-15

    Organic ultraviolet (UV) filters are used in a wide variety of products, including cosmetics, to prevent damage from UV light in tissues and industrial materials. Their extensive use has raised concerns about potential adverse effects in human health and aquatic ecosystems that accumulate these pollutants. To increase sun radiation protection, UV filters are commonly used in mixtures. Here, we studied the toxicity of binary mixtures of 4-methylbenzylidene camphor (4MBC), octyl-methoxycinnamate (OMC), and benzophenone-3 (BP-3), by evaluating the larval mortality of Chironomus riparius. Also molecular endpoints have been analyzed, including alterations in the expression levels of a gene related with the endocrine system (EcR, ecdysone receptor) and a gene related with the stress response (hsp70, heat shock protein 70). The results showed that the mortality caused by binary mixtures was similar to that observed for each compound alone; however, some differences in LC50 were observed between groups. Gene expression analysis showed that EcR mRNA levels increased in the presence of 0.1mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10mg/L of BP-3 or OMC. In contrast, the hsp70 mRNA levels increased after exposure to the combinations tested of 4MBC and BP-3 or OMC mixtures. These data suggest that 4MBC, BP-3, and OMC may have antagonist effects on EcR gene transcription and a synergistic effect on hsp70 gene activation. This is the first experimental study to show the complex patterned effects of UV filter mixtures on invertebrates. The data suggest that the interactions within these chemicals mixtures are complex and show diverse effects on various endpoints.

  3. Chronic effects of Cd on the reproduction of the guppy (Poecilia reticulata) through Cd-accumulated midge larvae (Chironomus yoshimatsui)

    Energy Technology Data Exchange (ETDEWEB)

    Hatakeyama, S.; Yasuno, M.

    1987-12-01

    Chronic effects of Cd on the growth and reproduction of the guppy (Poecilia reticulata) were studied using a food chain model, midge larvae as prey and guppy as predator. The transfer rate of Cd from the midge to the guppy was between 0.5 and 1% during the 30-day experiment. Growth rate of the guppy fed Cd-accumulated midge larvae (270 micrograms/g dry wt) for 30 days was not impaired. Cumulative numbers of fry produced by the guppy fed Cd-accumulated midge larvae (210 micrograms/g) for 2 months decreased to ca. 80% of the control. Guppies had been fed the Cd-accumulated midges from 30 days old for 7 months. Cumulative numbers of fry produced by the guppy fed midge larvae-accumulated 500, 800, and 1300 micrograms Cd/g for 6 months decreased to 79, 65, and 55% of the control, respectively. Similar effects of Cd on the reproduction of guppy were shown between the guppies fed the Cd-accumulated midge larvae (500 micrograms Cd/g) and exposed to 10 or 20 micrograms Cd/liter for the 6 months. The Cd concentrations of the digestive tract, liver, and kidney increased strongly, indicating that such Cd accumulation was brought on mainly through the Cd-accumulated midges. Mortality of the female guppies fed larvae-accumulated 1300 micrograms Cd/g increased abruptly from the 6 months of the experiment, whereas no male guppy died during the experiment.

  4. Contaminants in stream sediments from seven United States metropolitan areas: part II--sediment toxicity to the amphipod Hyalella azteca and the midge Chironomus dilutus.

    Science.gov (United States)

    Kemble, Nile E; Hardesty, Douglas K; Ingersoll, Christopher G; Kunz, James L; Sibley, Paul K; Calhoun, Daniel L; Gilliom, Robert J; Kuivila, Kathryn M; Nowell, Lisa H; Moran, Patrick W

    2013-01-01

    Relationships between sediment toxicity and sediment chemistry were evaluated for 98 samples collected from seven metropolitan study areas across the United States. Sediment-toxicity tests were conducted with the amphipod Hyalella azteca (28 day exposures) and with the midge Chironomus dilutus (10 day exposures). Overall, 33 % of the samples were toxic to amphipods and 12 % of the samples were toxic to midge based on comparisons with reference conditions within each study area. Significant correlations were observed between toxicity end points and sediment concentrations of trace elements, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), or organochlorine (OC) pesticides; however, these correlations were typically weak, and contaminant concentrations were usually below sediment-toxicity thresholds. Concentrations of the pyrethroid bifenthrin exceeded an estimated threshold of 0.49 ng/g (at 1 % total organic carbon) in 14 % of the samples. Of the samples that exceeded this bifenthrin toxicity threshold, 79 % were toxic to amphipods compared with 25 % toxicity for the samples below this threshold. Application of mean probable effect concentration quotients (PECQs) based on measures of groups of contaminants (trace elements, total PAHs, total PCBs, OC pesticides, and pyrethroid pesticides [bifenthrin in particular]) improved the correct classification of samples as toxic or not toxic to amphipods compared with measures of individual groups of contaminants.

  5. Additive effects of predator cues and dimethoate on different levels of biological organisation in the non-biting midge Chironomus riparius.

    Science.gov (United States)

    Van Praet, Nander; De Jonge, Maarten; Stoks, Robby; Bervoets, Lieven

    2014-10-01

    The combined effects of a pesticide and predation risk on sublethal endpoints in the midge Chironomus riparius were investigated using a combination of predator-release kairomones from common carp (Cyprinus carpio) and alarm substances from conspecifics together with the pesticide dimethoate. Midge larvae were exposed for 30 days to three sublethal dimethoate concentrations (0.01, 0.1 and 0.25 mg L(-1)) in the presence or absence of predator cues. Sublethal endpoints were analysed at different levels of biological organisation. Available energy reserves, enzyme biomarkers, feeding rate and life history endpoints were investigated. Three endpoints were significantly affected by the two highest dimethoate concentrations, i.e. AChE activity, age at emergence and emergence success, with a significant decrease in response after exposure to 0.25, 0.1 and 0.01 mg L(-1) dimethoate, respectively. Four sublethal endpoints were significantly affected by predator stress: Total protein content, GST activity and biomass decreased only in the presence of the predation risk, while AChE activity further decreased significantly in the presence of predation cues and effects on AChE of combined exposure were additive. From this study we can conclude that sublethal life history characteristics should be included in ecotoxicity testing as well as natural environmental stressors such as predator stress, which might act additively with pollutants on fitness related endpoints.

  6. Spinosad and neem seed kernel extract as bio-controlling agents for malarial vector,Anopheles stephensi and non-biting midge,Chironomus circumdatus

    Institute of Scientific and Technical Information of China (English)

    Kumar AN; Murugan K; Madhiyazhagan P; Prabhu K

    2011-01-01

    Objective:Midge egg masses are reported to support non-pathogenic strains of the cholera pathogen,Vibrio cholera (V. cholera). Mosquito born diseases have been reported to cause millions of death worldwide. The present research reveals the toxicity effect of spinosad and neem seed kernel extract (NSKE)against different larval stages ofAnopheles stephensi (An. stephensi) andChironomus circumdatus (Ch. circumdatus).Methods: The neem seeds were collected from Marudamalai hills, Bharathiar University, Coimbatore, India. Neem seed kernels were powdered, extracted and diluted for different concentrations (2 ppm to10 ppm). Spinosad was purchased from Kalpatharu pesticide Limited, Coimbatore, Tamil Nadu, India and thoroughly mixed with distilled water to prepare various concentrations (0.01 to0.08 ppm) and used for bioassay.Results: The results depict that spinosad is more toxic in lower concentrations when compared toNSKE and mosquitoes are more susceptible than chironomids. Lethal concentrations were evaluated using the observed mortality. The lowest LC50 value obtained from spinosad againstAn. stephensi and Ch. circumdatus were0.002 05 ppm and0.008 91 ppm. This study investigated on effect of Spinosad andNSKE on the biology of mosquito. The immature stages of both species were susceptible to Spinosad andNSKE. Spinosad andNSKE in individual as well as combined treatment provided additional days in development for mosquitoes.Conclusions:The results conclude that Spinosad andNSKE are potential larvicides against An. stephensi andCh. circumdatus.

  7. Morpho-histological characterization of immature of the bioindicator midge Chironomus sancticaroli Strixino and Strixino (Diptera, Chironomidae

    Directory of Open Access Journals (Sweden)

    Vinicius Sobrinho Richardi

    2015-09-01

    Full Text Available ABSTRACTChironomidae immature are used as bioindicators of sediment quality in aquatic ecosystems and ecotoxicological assays. Histological descriptions for this family are outdated and limited and there are no studies with Neotropical species. The aim of this study was to describe the tissue architecture of several organs of the larva of Chironomus sancticaroli. For the description of the histological pattern, the larvae were fixed in Duboscq solution for insects at 56 °C, followed by routine histologic processing, infiltration in paraffin, and the sections were stained with Hematoxylin–Eosin. After examining the slides, the tube digestive, salivary gland, excretory, nervous, endocrine, circulatory, and integumentary systems and fat body were histologically characterized. The histology allows evaluation of cell morphology, and for being not expensive and easily accessible can be routinely used in biomonitoring. In addition, is a useful tool in ecotoxicological assays and allow to evaluate biomarkers at tissue and cell levels.

  8. The ultrastructure of the non-neurosecretory components in the brain of the midge, Chironomus riparious Mg. (diptera: nematocera).

    Science.gov (United States)

    Scales, M D; Credland, P F

    1978-02-24

    The ultrastruct of the neural sheath, glial cells and neurons in the brain of the neoimaginal male Chironomus riparius is described. The neural sheath comprises a neural lamella and underlying perineurium. The neural lamella consists of an amorphous matrix in which fine fibrils occur. The perineurium is composed of two cell types forming a continuous layer around the brain. The subjacent cortical layer, composed of the cell bodies of neurons and glial cells, varies considerably in thickness and surrounds the centrally located neuropiles. Three types of glial cells are distinguished on the basis of their positions and appearances. Five types of neurons are described which differ in size and relative frequency of organelles. Four types of axons, including those of neurosecretory cells, are distinguished by their size and content.

  9. Effects of clay minerals and organic matter in formulated sediments on the bioavailability of sediment-associated uranium to the freshwater midge, Chironomus dilutus

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Sarah E., E-mail: sarah.crawford@usask.ca [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3 (Canada); Liber, Karsten, E-mail: karsten.liber@usask.ca [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3 (Canada); School of Environment and Sustainability, 117 Science Place, University of Saskatchewan, Saskatoon, SK S7N 5C8 (Canada); Institute of Loess Plateau, 92 Wucheng Road, Shanxi University, Taiyuan, Shanxi 030006 (China)

    2015-11-01

    examined the role of two common sediment physicochemical properties in altering uranium bioavailability to midge larvae, Chironomus dilutus, using formulated sediments. • Bioaccumulation of U in C. dilutus decreased significantly as clay (kaolin) and organic matter (peat) content in formulated sediment increased. • Uranium concentrations in dissolved fractions (overlying water and pore water) were better predictors of U bioavailability than U concentrations in whole sediment. • These results can help improve risk assessment of U contaminated sediments and aid in the development of U sediment quality guidelines.

  10. Contaminants in stream sediments from seven United States metropolitan areas: part II—sediment toxicity to the amphipod Hyalella azteca and the midge Chironomus dilutus

    Science.gov (United States)

    Kemble, Nile E.; Hardesty, Douglas K.; Ingersoll, Christopher G.; Kunz, James L.; Sibley, Paul K.; Calhoun, Daniel L.; Gilliom, Robert J.; Kuivila, Kathryn; Nowell, Lisa H.; Moran, Patrick W.

    2013-01-01

    Relationships between sediment toxicity and sediment chemistry were evaluated for 98 samples collected from seven metropolitan study areas across the United States. Sediment-toxicity tests were conducted with the amphipod Hyalella azteca (28 day exposures) and with the midge Chironomus dilutus (10 day exposures). Overall, 33 % of the samples were toxic to amphipods and 12 % of the samples were toxic to midge based on comparisons with reference conditions within each study area. Significant correlations were observed between toxicity end points and sediment concentrations of trace elements, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), or organochlorine (OC) pesticides; however, these correlations were typically weak, and contaminant concentrations were usually below sediment-toxicity thresholds. Concentrations of the pyrethroid bifenthrin exceeded an estimated threshold of 0.49 ng/g (at 1 % total organic carbon) in 14 % of the samples. Of the samples that exceeded this bifenthrin toxicity threshold, 79 % were toxic to amphipods compared with 25 % toxicity for the samples below this threshold. Application of mean probable effect concentration quotients (PECQs) based on measures of groups of contaminants (trace elements, total PAHs, total PCBs,OCpesticides, and pyrethroid pesticides [bifenthrin in particular]) improved the correct classification of samples as toxic or not toxic to amphipods compared with measures of individual groups of contaminants. Sediments are a repository for many contaminants released into surface waters. Because of this, organisms inhabiting sediments may be exposed to a wide range of contaminants (United States Environmental Protection Agency (USEPA) United States Environmental Protection Agency 2000; American Society for Testing and Materials [ASTM] American Society for Testing and Materials International 2012). Contaminants of potential concern in sediments typically include trace elements (metals

  11. Overexpression of long non-coding RNAs following exposure to xenobiotics in the aquatic midge Chironomus riparius

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Guitarte, Jose-Luis, E-mail: jlmartinez@ccia.uned.es [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain); Planello, Rosario; Morcillo, Gloria [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain)

    2012-04-15

    Non-coding RNAs (ncRNAs) represent an important transcriptional output of eukaryotic genomes. In addition to their functional relevance as housekeeping and regulatory elements, recent studies have suggested their involvement in rather unexpected cellular functions. The aim of this work was to analyse the transcriptional behaviour of non-coding RNAs in the toxic response to pollutants in Chironomus riparius, a reference organism in aquatic toxicology. Three well-characterized long non-coding sequences were studied: telomeric repeats, Cla repetitive elements and the SINE CTRT1. Transcription levels were evaluated by RT-PCR after 24-h exposures to three current aquatic contaminants: bisphenol A (BPA), benzyl butyl phthalate (BBP) and the heavy metal cadmium (Cd). Upregulation of telomeric transcripts was found after BPA treatments. Moreover, BPA significantly activated Cla transcription, which also appeared to be increased by cadmium, whereas BBP did not affect the transcription levels of these sequences. Transcription of SINE CTRT1 was not altered by any of the chemicals tested. These data are discussed in the light of previous studies that have shown a response by long ncRNAS (lncRNAs) to cellular stressors, indicating a relationship with environmental stimuli. Our results demonstrated for the first time the ability of bisphenol A to activate non-coding sequences mainly located at telomeres and centromeres. Overall, this study provides evidence that xenobiotics can induce specific responses in ncRNAs derived from repetitive sequences that could be relevant in the toxic response, and also suggests that ncRNAs could represent a novel class of potential biomarkers in toxicological assessment.

  12. Differential sensitivity of Chironomus and human hemoglobin to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gaikwad, Pallavi S. [Stress Biology Research Laboratory, Department of Zoology, Savitribai Phule University, Pune, 411007 (India); Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085 (India); Panicker, Lata [Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085 (India); Mohole, Madhura; Sawant, Sangeeta [Bioinformatics Center, Savitribai Phule Pune University, Pune, 411007 (India); Mukhopadhyaya, Rita [Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085 (India); Nath, Bimalendu B., E-mail: bbnath@gmail.com [Stress Biology Research Laboratory, Department of Zoology, Savitribai Phule University, Pune, 411007 (India)

    2016-08-05

    Chironomus ramosus is known to tolerate high doses of gamma radiation exposure. Larvae of this insect possess more than 95% of hemoglobin (Hb) in its circulatory hemolymph. This is a comparative study to see effect of gamma radiation on Hb of Chironomus and humans, two evolutionarily diverse organisms one having extracellular and the other intracellular Hb respectively. Stability and integrity of Chironomus and human Hb to gamma radiation was compared using biophysical techniques like Dynamic Light Scattering (DLS), UV-visible spectroscopy, fluorescence spectrometry and CD spectroscopy after exposure of whole larvae, larval hemolymph, human peripheral blood, purified Chironomus and human Hb. Sequence- and structure-based bioinformatics methods were used to analyze the sequence and structural similarities or differences in the heme pockets of respective Hbs. Resistivity of Chironomus Hb to gamma radiation is remarkably higher than human Hb. Human Hb exhibited loss of heme iron at a relatively low dose of gamma radiation exposure as compared to Chironomus Hb. Unlike human Hb, the heme pocket of Chironomus Hb is rich in aromatic amino acids. Higher hydophobicity around heme pocket confers stability of Chironomus Hb compared to human Hb. Previously reported gamma radiation tolerance of Chironomus can be largely attributed to its evolutionarily ancient form of extracellular Hb as evident from the present study. -- Highlights: •Comparison of radiation tolerant Chironomus Hb and radiation sensitive Human Hb. •Amino acid composition of midge and human heme confer differential hydrophobicity. •Heme pocket of evolutionarily ancient midge Hb provide gamma radiation resistivity.

  13. Molecular Characterization and Expression Analysis of P38 MAPK Gene and Protein in Aquatic Midge, Chironomus riparius (Diptera: Chironomidae), Exposed to Environmental Contaminants.

    Science.gov (United States)

    Park, Sun-Young; Choi, Jinhee

    2017-04-01

    P38 Mitogen-activated protein kinase (MAPK), an important signaling protein involved in various cellular processes, including stress responses, has been well characterized in model organisms. P38 has been identified in a number of insects, including the genus Drosophila; however, its homologue in Chironomus riparius has not yet been identified. In this study, we identified and characterized p38 MAPK (Crp38) gene in C. riparius using a transcriptome database that was previously generated 454 GS-FLX pyrosequencing. Comparative and phylogenetic analyses were performed using the p38 homologue of other species, such as Drosophila melanogaster, Aedes aegypti, Bombyx mori, Caenorhabditis elegans, Homo sapiens, etc. Furthermore, to test its potential as a biomarker of environmental contamination, Crp38 gene expression was analyzed upon exposure to nonylphenol (NP), silver nanoparticles (AgNPs), and cadmium (Cd). Crp38 gene expression was up- or down-regulated depending on the concentration and exposure duration of chemicals. These results show the role of Crp38 gene in defense against environmental stresses, as well as its potential use as a biomarker for various environmental pollutants. We further synthesized p38 antibody based on the predicted amino acid sequence deduced from Crp38 cDNA and, using this customized antibody, examined p38 protein expression in Cd exposed C. riparius. Although transcriptional alteration was not translated to the protein level, this result showed the possible application of a protein level functional study using cDNA sequence information from next-generation sequencing database in nonmodel organisms.

  14. Effects of clay minerals and organic matter in formulated sediments on the bioavailability of sediment-associated uranium to the freshwater midge, Chironomus dilutus.

    Science.gov (United States)

    Crawford, Sarah E; Liber, Karsten

    2015-11-01

    It is well established that bioavailability influences metal toxicity in aquatic ecosystems. However, the factors and mechanisms that influence uranium (U) bioavailability and toxicity in sediment have not been thoroughly evaluated, despite evidence that suggests different sediment components can influence the sorption and interaction of some metals. Given that dissolved U is generally accepted as being the primary bioavailable fraction of U, it is hypothesized that adsorption and interaction of U with different sediment components will influence the bioavailability of U in sediment. We investigated the effects of key sediment physicochemical properties on the bioavailability of U to a model freshwater benthic invertebrate, Chironomus dilutus. Several 10-day spiked sediment bioaccumulation experiments were performed, exposing C. dilutus larvae to a variety of formulated sediments spiked with different concentrations of U (5, 50 and/or 200 mg U/kg d.w.). Mean accumulation of U in C. dilutus larvae decreased significantly from 1195 to 10 mg U/kg d.w. as kaolin clay content increased from 0% to 60% in sediment spiked with 50 mg U/kg d.w. Similarly, higher organic matter content also resulted in a significant reduction of U bioaccumulation in C. dilutus larvae, indicating a reduction in U bioavailability. Concentrations of U in both the overlying water and sediment pore water displayed a strong positive relationship to U bioaccumulation in C. dilutus larvae (r(2) = 0.77, p<0.001 and r(2) = 0.57, p < 0.001, respectively) for all experiments, while total U concentrations in the sediment had a poor relationship to U bioaccumulation (r(2) = 0.10, p = 0.028). Results from this research confirm that sediment clay and organic matter content play a significant role in altering U bioavailability, which is important in informing risk assessments of U contaminated sites and in the development of site-specific sediment quality guidelines for U.

  15. Effect of acute exposure to cadmium on the expression of heat-shock and hormone-nuclear receptor genes in the aquatic midge Chironomus riparius

    Energy Technology Data Exchange (ETDEWEB)

    Planello, R.; Martinez-Guitarte, J.L. [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain); Morcillo, G., E-mail: gmorcillo@ccia.uned.es [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain)

    2010-03-01

    Cadmium is a widespread and highly toxic pollutant of particular ecotoxicological relevance for aquatic ecosystems where it accumulates. To identify biomarkers for ecotoxicity monitoring, the effect of cadmium on the expression of different genes related to the stress response as well as to the ecdysone hormone-signalling pathway was studied in the aquatic larvae of Chironomus riparius (Diptera, Chironomidae), a standard test organism in aquatic toxicology testing. Reverse Transcription Polymerase Chain Reaction (RT-PCR) was used to evaluate the effects of acute and short-term cadmium exposures (10 mM CdCl{sub 2}, 12 h and 24 h) on the expression of hsp70, hsc70, hsp90 and hsp40 genes, as well as on that of the ecdysone hormonal-receptor genes (EcR and usp). A significant 3-fold increase in the level of hsp70 gene transcripts was induced by the treatment, whereas neither the other stress genes tested (hsp90 and hsp40) nor the constitutive form of hsp70, hsc70, was affected in the larvae exposed to cadmium. These results show that hsp70 is differentially activated to other environmentally regulated heat-shock genes, and constitutes a biomarker of exposure to this toxic metal. In addition, we also found that cadmium is able to alter the expression of the ecdysone receptor gene (EcR), whose mRNA level is significantly increased whereas usp levels remained unaltered. This finding, evidenced for the first time in invertebrates, supports the view that cadmium has the ability to mimic the effect of the hormone by the activation of the ecdysone nuclear receptor, which may partly explain the endocrine disruption capability that has been previously suggested for this toxic metal. Our research adds to the growing evidence implicating heavy metals, and cadmium in particular, as potential endocrine disruptive agents and may have significant implications for ecological risk assessment of endocrine-disrupting compounds in invertebrates.

  16. Extracellular electrical activity from the photoreceptors of midge

    Indian Academy of Sciences (India)

    A A Babrekar; G R Kulkarni; B B Nath; P B Vidyasagar

    2004-09-01

    The ontogeny of photosensitivity has been studied in a holometabolous insect, the midge Chironomus ramosus. The life cycle of midges shifts from an aquatic environment to a non-aquatic environment. Extracellular electrical activity of photoreceptor organs was recorded at larval and adult stages. We found an increase in photosensitivity as the larva metamorphosed to the adult stage. This is the first report of changes in photosensitivity during the development of any insect described in an ecological context.

  17. Evaluation of toxicity to the amphipod, Hyalella azteca, and to the midge, Chironomus dilutus; and bioaccumulation by the oligochaete, Lumbriculus variegatus, with exposure to PCB-contaminated sediments from Anniston, Alabama

    Science.gov (United States)

    Ingersoll, Christopher G.; Steevens, Jeffery A.; MacDonald, Donald D.; Brumbaugh, William G.; Coady, Matthew R.; Farrar, J. Daniel; Lotufo, Guilherme R.; Kemble, Nile E.; Kunz, James L.; Stanley, Jacob K.; Sinclair, Jesse A.; Ingersoll, Christopher G.; Steevens, Jeffery A.; MacDonald, Donald D.

    2014-01-01

    The U.S. Environmental Protection Agency (USEPA) requested that as part of the remedial investigation for the Anniston, Alabama Polychlorinated Biphenyl (PCB) Site (Anniston PCB Site), that Pharmacia Corporation and Solutia Inc. (P/S) perform long-term reproduction toxicity tests with the amphipod, Hyalella azteca, and the midge, Chironomus dilutus, and bioaccumulation tests with the oligochaete, Lumbriculus variegatus, using sediment samples collected from reference locations and from Operable Unit 4 of the Anniston PCB Site. The sediment toxicity testing and sediment bioaccumulation results will be used by ARCADIS U.S., Inc. (ARCADIS) as part of a weight-of-evidence assessment to evaluate risks and establish sediment remediation goals for contaminants to sediment-dwelling organisms inhabiting the Anniston PCB Site. The goal of this study was to characterize relations between sediment chemistry and sediment toxicity and relations between sediment chemistry and sediment bioaccumulation in samples of sediments collected from the Anniston PCB Site. A total of 32 samples were evaluated from six test sites and one reference site to provide a wide range in concentrations of chemicals of potential concern (COPCs) including PCBs in samples of whole sediment. The goal of this study was not to determine the extent of sediment contamination across the Anniston PCB Site. Hence, the test sites or samples collected from within a test site were not selected to represent the spatial extent of sediment contamination across the Anniston PCB Site. Sediment chemistry, pore-water chemistry, and sediment toxicity data were generated for 26 sediment samples from the Anniston PCB Site. All of the samples were evaluated to determine if they qualified as reference sediment samples. Those samples that met the chemical selection criteria and biological selection criteria were identified as reference samples and used to develop the reference envelope for each toxicity test endpoint. Physical

  18. Population variability in Chironomus (Camptochironomus) species (Diptera, Nematocera) with a Holarctic distribution: evidence of mitochondrial gene flow.

    Science.gov (United States)

    Martin, J; Guryev, V; Blinov, A

    2002-10-01

    Phylogenetic analysis of DNA sequences from mitochondrial (mt) genes (Cytochrome b and Cytochrome oxidase I) and one nuclear gene (globin 2b) was used for the investigation of Nearctic and Palearctic populations representing four Chironomus species of the subgenus Camptochironomus, namely C. biwaprimus, C. pallidivittatus, C. tentans sensu stricto and C. dilutus (the last two species constitute Holarctic C. tentans sensu lato). Phenograms constructed on the basis of mt sequences were not congruent with trees based on nuclear genes, or with morphological and cytological data. The mt tree divided the populations by continental region, rather than by the species groupings recognized by the other data sets. The incongruence is explained by mt gene flow resulting from hybridization between the sympatric species on each continent. Calculation of divergence times, based on the sequence data, suggest that C. tentans (s.l.) and C. pallidivittatus have both been in North America for about 2.5 My.

  19. Toxicity of inorganic and organic selenium to Daphnia magna (cladocera) and Chironomus riparius (diptera)

    Science.gov (United States)

    Ingersoll, Christopher G.; Dwyer, F.J.; May, T.W.

    1990-01-01

    Elevated concentrations of selenium (Se) have been previously measured in biota sampled from the Kesterson National Wildlife Refuge (KNWR) in the San Joaquin Valley of central California. We conducted acute and chronic toxicity tests with the cladoceran Daphnia magna and the midge Chironomus riparius to determine the toxicity or bioaccumulation of waterborne Se in a reconstituted water similar to the San Joaquin River. Daphnids were more acutely sensitive than midges to the toxic effects of inorganic Se. An organic form of Se (seleno-[L]-methionine) was extremely toxic to daphnids, but was relatively nontoxic to midges. In long-term exposure to a 6:1 mixture of selenate to selenite (a mixture representative of KNWR), the emergence time of adult midges was delayed at Se concentrations ≥ 837 μg/L. Daphnid reproduction and intrinsic rate of natural increase (r) were reduced at Se concentrations ≥ 348 μg/L and growth of adults was reduced at ≥ 156 μg/L. Whole body Mg, K and Na concentrations in daphnids were not affected by chronic Se exposure; however, whole body Ca concentration increased at intermediate Se exposure concentrations. In addition, whole body Cl concentration was reduced at 711 μg Se/L. Daphnids accumulated potentially toxic concentrations of Se from water that may adversely affect fish or waterfowl through the food chain.

  20. Low malathion concentrations influence metabolism in Chironomus sancticaroli (Diptera, Chironomidae in acute and chronic toxicity tests

    Directory of Open Access Journals (Sweden)

    Débora Rebechi

    2014-09-01

    Full Text Available Low malathion concentrations influence metabolism in Chironomus sancticaroli (Diptera, Chironomidae in acute and chronic toxicity tests. Organophosphate compounds are used in agro-systems, and in programs to control pathogen vectors. Because they are continuously applied, organophosphates often reach water sources and may have an impact on aquatic life. The effects of acute and chronic exposure to the organophosphate insecticide malathion on the midge Chironomus sancticaroli are evaluated. To that end, three biochemical biomarkers, acetylcholinesterase (AChE, alpha (EST-α and beta (EST-β esterase were used. Acute bioassays with five concentrations of malathion, and chronic bioassays with two concentrations of malathion were carried out. In the acute exposure test, AChE, EST-α and EST-β activities declined by 66, 40 and 37%, respectively, at 0.251 µg L-1 and more than 80% at 1.37, 1.96 and 2.51 µg L-1. In chronic exposure tests, AChE and EST-α activities declined by 28 and 15% at 0.251 µg L-1. Results of the present study show that low concentrations of malathion can influence larval metabolism, indicating high toxicity for Chironomus sancticaroli and environmental risk associated with the use of organophosphates.

  1. The protective nature of Chironomus luridus larval tubes against copper sulfate

    Directory of Open Access Journals (Sweden)

    M. Halpern

    2002-05-01

    Full Text Available The objective of this study was to determine whether the tubes in which Chironomus larvae dwell protect them against chemical toxicants. A laboratory culture of an Israeli benthic midge, Chironomus luridus, was exposed to copper sulfate. Two conditions were tested in bioassay experiments: larvae within silt tubes and larvae without tubes. The non toxic, anionic, fluorescent dye, fluorescein, was used to examine the effect of sub-lethal copper sulfate concentrations on the permeability of cuticular, gill and gut epithelia of the chironomids. Increased cell permeability, which is the cause of cell damage, was reflected by an increase in fluorescence intensity. Following exposure to copper sulfate, higher fluorescence was found in different body compartments: midgut, hindgut, tracheal gills, fat body and muscles, and the Malpighian tubules. The effect was significantly higher in tube-free larvae when compared to silt tube dwelling larvae. We conclude that in addition to its other functions in feeding, respiration, and anti-predation shelter, the Chironomus luridus tube protects its inhabitant from toxins such as copper sulfate.

  2. Chironomid midges as allergens: evidence from two species from West Bengal, Kolkata, India

    Directory of Open Access Journals (Sweden)

    Soumi Nandi

    2014-01-01

    Full Text Available Background & objectives: Arthropods of different taxonomic identity including chironomid midges are known to induce allergic response in humans. The present study was done to access two common chironomid species Chironomus circumdatus and Polypedilum nubifer for their sensitizing potential as an allergen in atopic patients and controls. Methods: Following preparation of allergenic extracts of the two chironomid species separately, 198 atopic patients attending an allergy clinic and 50 age matched controls were tested along with a routine panel of allergens to assess sensitization. Results: The skin prick test (SPT results revealed that 189 of the 198 patients (95.4% demonstrated sensitization to both the chironomid species. Higher levels of total IgE was observed in atopic subjects than in the control group. Interpretation & conclusions: The results suggest that the chironomid midges Chironomus circumdatus and Polypedilum nubifer can elicit sensitization in humans. A potential risk for allergic reactions by susceptible individuals exists due to these chironomid species, owing to their abundance and chances of contact with human beings. Further studies may be initiated to characterize the nature of the allergens and to assess their clinical relevance.

  3. Meadow-grass gall midge

    DEFF Research Database (Denmark)

    Hansen, Lars Monrad

    The area with meadow-grass (Poa pratensis, L.) grown for seed production in Den-mark is a significant proportion of the entire seed production. The meadow-grass gall midge (Mayetiola schoberi, Barnes 1958) is of considerable economic importance since powerful attacks can reduce the yield...... drastically. It overwinters as larvae in a puparium, in the soil, and begins to hatch on average in late April, but the time is de-pending on the temperature. Emergence of the meadow-grass gall midge in spring takes place over a 2-3 week period. Beginning of emergence of the meadow-grass gall midge takes...... maximum. Therefore, the spraying frequency could be lowered signifi-cantly and in many cases lowered to only one insecticide application in meadow-grass every year....

  4. Interlaboratory Evaluation of Hyalella Azteca and Chironomus Tentans Short-term and Long-term Sediment Toxicity Tests

    Science.gov (United States)

    This paper presents the results of interlaboratory toxicity tests on sediment toxicity methods for use in routine testing and this data has been presented in an EPA report and this is a summary of that data.

  5. Interlaboratory Evaluation of Hyalella Azteca and Chironomus Tentans Short-term and Long-term Sediment Toxicity Tests

    Science.gov (United States)

    This paper presents the results of interlaboratory toxicity tests on sediment toxicity methods for use in routine testing and this data has been presented in an EPA report and this is a summary of that data.

  6. A novel computational approach of image analysis to quantify behavioural response to heat shock in Chironomus Ramosus larvae (Diptera: Chironomidae

    Directory of Open Access Journals (Sweden)

    Bimalendu B. Nath

    2015-07-01

    Full Text Available All living cells respond to temperature stress through coordinated cellular, biochemical and molecular events known as “heat shock response” and its genetic basis has been found to be evolutionarily conserved. Despite marked advances in stress research, this ubiquitous heat shock response has never been analysed quantitatively at the whole organismal level using behavioural correlates. We have investigated behavioural response to heat shock in a tropical midge Chironomus ramosus Chaudhuri, Das and Sublette. The filter-feeding aquatic Chironomus larvae exhibit characteristic undulatory movement. This innate pattern of movement was taken as a behavioural parameter in the present study. We have developed a novel computer-aided image analysis tool “Chiro” for the quantification of behavioural responses to heat shock. Behavioural responses were quantified by recording the number of undulations performed by each larva per unit time at a given ambient temperature. Quantitative analysis of undulation frequency was carried out and this innate behavioural pattern was found to be modulated as a function of ambient temperature. Midge larvae are known to be bioindicators of aquatic environments. Therefore, the “Chiro” technique can be tested using other potential biomonitoring organisms obtained from natural aquatic habitats using undulatory motion as a behavioural parameter.

  7. Joint toxicity of a pyrethroid insecticide, cypermethrin, and a heavy metal, lead, to the benthic invertebrate Chironomus dilutus.

    Science.gov (United States)

    Mehler, W Tyler; Du, Juan; Lydy, Michael J; You, Jing

    2011-12-01

    Insecticides and heavy metals are frequently detected in the environment, but few studies have assessed the joint toxicity of organic and inorganic contaminants. Joint toxicity of a pyrethroid insecticide, cypermethrin, and a heavy metal, Pb(2+), was evaluated in the present study. An antagonistic toxic response was observed when the benthic invertebrate Chironomus dilutus was simultaneously exposed to the two contaminants in both water and sediment exposures. Pre-exposure bioassays with midges were also conducted, and toxicity of cypermethrin was significantly reduced for midges that were pre-exposed to Pb(2+). In addition, the impact of Pb(2+) on the bioavailability of cypermethrin to midges was measured using Tenax extraction. No significant difference was noted in the amount of Tenax-extractable cypermethrin when different amounts of Pb(2+) were added to sediment. Results suggested that altered organism sensitivity may contribute to the observed antagonistic interaction between cypermethrin and Pb(2+), whereas the influence of changes in toxicokinetic processes such as uptake, biotransformation, and elimination on the joint toxicity should be further studied. Finally, the decreased toxicity of cypermethrin when simultaneously applied with Pb(2+) may be one reason for the overestimation of sediment toxicity by cypermethrin alone in field-collected sediment. Copyright © 2011 SETAC.

  8. Toxicity of sediment-associated pesticides to Chironomus dilutus and Hyalella azteca.

    Science.gov (United States)

    Ding, Yuping; Weston, Donald P; You, Jing; Rothert, Amanda K; Lydy, Michael J

    2011-07-01

    Two hundred sediment samples were collected and their toxicity evaluated to aquatic species in a previous study in the agriculturally dominated Central Valley of California, United States. Pyrethroid insecticides were the main contributors to the observed toxicity. However, mortality in approximately one third of the toxic samples could not be explained solely by the presence of pyrethroids in the matrices. Hundreds of pesticides are currently used in the Central Valley of California, but only a few dozen are analyzed in standard environmental monitoring. A significant amount of unexplained sediment toxicity may be due to pesticides that are in widespread use that but have not been routinely monitored in the environment, and even if some of them were, the concentrations harmful to aquatic organisms are unknown. In this study, toxicity thresholds for nine sediment-associated pesticides including abamectin, diazinon, dicofol, fenpropathrin, indoxacarb, methyl parathion, oxyfluorfen, propargite, and pyraclostrobin were established for two aquatic species, the midge Chironomus dilutus and the amphipod Hyalella azteca. For midges, the median lethal concentration (LC₅₀) of the pesticides ranged from 0.18 to 964 μg/g organic carbon (OC), with abamectin being the most toxic and propargite being the least toxic pesticide. A sublethal growth endpoint using average individual ash-free dry mass was also measured for the midges. The no-observable effect concentration values for growth ranged from 0.10 to 633 μg/g OC for the nine pesticides. For the amphipods, fenpropathrin was the most toxic, with an LC₅₀ of 1-2 μg/g OC. Abamectin, diazinon, and methyl parathion were all moderately toxic (LC₅₀s 2.8-26 μg/g OC). Dicofol, indoxacarb, oxyfluorfen, propargite, and pyraclostrobin were all relatively nontoxic, with LC₅₀s greater than the highest concentrations tested. The toxicity information collected in the present study will be helpful in decreasing the

  9. Combined effects of copper and food on the midge Chironomus riparius in whole sediment bioassays

    NARCIS (Netherlands)

    Haas, de E.M.; Paumen, M.L.; Koelmans, A.A.; Kraak, M.H.S.

    2004-01-01

    Effects observed in whole-sediment bioassays must be seen as the joint effect of all sediment characteristics. In whole-sediment bioassays. however. adverse effects oil test organisms are usually attributed to the presence of contaminants and effects of food are often ignored. The aim of this study

  10. Differential sensitivity of Chironomus and human hemoglobin to gamma radiation.

    Science.gov (United States)

    Gaikwad, Pallavi S; Panicker, Lata; Mohole, Madhura; Sawant, Sangeeta; Mukhopadhyaya, Rita; Nath, Bimalendu B

    2016-08-05

    Chironomus ramosus is known to tolerate high doses of gamma radiation exposure. Larvae of this insect possess more than 95% of hemoglobin (Hb) in its circulatory hemolymph. This is a comparative study to see effect of gamma radiation on Hb of Chironomus and humans, two evolutionarily diverse organisms one having extracellular and the other intracellular Hb respectively. Stability and integrity of Chironomus and human Hb to gamma radiation was compared using biophysical techniques like Dynamic Light Scattering (DLS), UV-visible spectroscopy, fluorescence spectrometry and CD spectroscopy after exposure of whole larvae, larval hemolymph, human peripheral blood, purified Chironomus and human Hb. Sequence- and structure-based bioinformatics methods were used to analyze the sequence and structural similarities or differences in the heme pockets of respective Hbs. Resistivity of Chironomus Hb to gamma radiation is remarkably higher than human Hb. Human Hb exhibited loss of heme iron at a relatively low dose of gamma radiation exposure as compared to Chironomus Hb. Unlike human Hb, the heme pocket of Chironomus Hb is rich in aromatic amino acids. Higher hydophobicity around heme pocket confers stability of Chironomus Hb compared to human Hb. Previously reported gamma radiation tolerance of Chironomus can be largely attributed to its evolutionarily ancient form of extracellular Hb as evident from the present study.

  11. Chironomus plumosus larvae increase fluxes of denitrification products and diversity of nitrate-reducing bacteria in freshwater sediment

    DEFF Research Database (Denmark)

    Poulsen, Morten; W. V. Kofoed, Michael; H. Larsen, Lone

    2014-01-01

    Benthic invertebrates affect microbial processes and communities in freshwater sediment by enhancing sediment-water solute fluxes and by grazing on bacteria. Using microcosms, the effects of larvae of thewidespread midge Chironomus plumosus on the efflux of denitrification products (N2O and N2+ N2O......, respectively, which was mostly due to stimulation of sedimentary denitrification; incomplete denitrification in the guts accounted for up to 20% of the N2O efflux. Phylotype richness of the nitrate reductase gene narG was significantly higher in sediment with than without larvae. In the gut, 47 narG phylotypes...... nosZ wasdifferent in sediments with and without larvae. Hence, C. plumosus increases activity and diversity, but not overall abundance of nitrate-reducing bacteria, probably by providing additional ecological niches in its burrow and gut....

  12. Schmallenberg virus in Culicoides spp. biting midges, the Netherlands, 2011

    NARCIS (Netherlands)

    Elbers, A.R.W.; Meiswinkel, R.; Weezep, van E.; Sloet van Oldruitenborgh-Oosterbaan, M.M.; Kooi, E.A.

    2013-01-01

    To determine which species of Culicoides biting midges carry Schmallenberg virus (SBV), we assayed midges collected in the Netherlands during autumn 2011. SBV RNA was found in C. scoticus, C. obsoletus sensu stricto, and C. chiopterus. The high proportion of infected midges might explain the rapid

  13. Demonstration and Certification of Amphibian Ecological Risk Assessment Protocol. Cost and Performance Report (Version 2)

    Science.gov (United States)

    2009-07-01

    day benthic invertebrate toxicity tests conducted with the midge, Chironomus tentans, and the amphipod, Hyalella azteca . Actual unit costs for these...management decisions in wetlands often rely on site-specific benthic invertebrate toxicity testing using organisms such as the amphipod, H. azteca ...amphipod (H. azteca ), and the fathead minnow (Pimephales promelas). Although remediation has not yet occurred, the arsenic NOAEC from the amphibian

  14. Genes involved in cysteine metabolism of Chironomus tepperi are regulated differently by copper and by cadmium.

    Science.gov (United States)

    Jeppe, Katherine J; Carew, Melissa E; Long, Sara M; Lee, Siu F; Pettigrove, Vincent; Hoffmann, Ary A

    2014-05-01

    Freshwater invertebrates are often exposed to metal contamination, and changes in gene expression patterns can help understand mechanisms underlying toxicity and act as pollutant-specific biomarkers. In this study the expressions of genes involved in cysteine metabolism are characterized in the midge Chironomus tepperi during exposures to sublethal concentrations of cadmium and copper. These metals altered gene expression of the cysteine metabolism differently. Both metals decreased S-adenosylhomocysteine hydrolase expression and did not change the expression of S-adenosylmethionine synthetase. Cadmium exposure likely increased cystathionine production by up-regulating cystathionine-β-synthase (CβS) expression, while maintaining control level cysteine production via cystathionine-γ-lyase (CγL) expression. Conversely, copper down-regulated CβS expression and up-regulated CγL expression, which in turn could diminish cystathionine to favor cysteine production. Both metals up-regulated glutathione related expression (γ-glutamylcysteine synthase and glutathione synthetase). Only cadmium up-regulated metallothionein expression and glutathione S-transferase d1 expression was up-regulated only by copper exposure. These different transcription responses of genes involved in cysteine metabolism in C. tepperi point to metal-specific detoxification pathways and suggest that the transsulfuration pathway could provide biomarkers for identifying specific metals.

  15. Cadmium transport by the gut and Malpighian tubules of Chironomus riparius

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Erin M., E-mail: leonarem@mcmaster.ca [Department of Biology, McMaster University, Hamilton, ON, L8S 4K1 (Canada); Pierce, Laura M. [Department of Biology, McMaster University, Hamilton, ON, L8S 4K1 (Canada); Gillis, Patricia L. [Aquatic Ecosystem Protection Research Division, Environment Canada, Burlington, ON, L7R 4A6 (Canada); Wood, Chris M.; O' Donnell, Michael J. [Department of Biology, McMaster University, Hamilton, ON, L8S 4K1 (Canada)

    2009-05-05

    Many aquatic insects are very insensitive to cadmium in short-term laboratory studies. LC50 values for larvae of the midge Chironomus riparius are over 25,000 times the Criterion Maximum Concentration in the United States Environmental Protection Agency (U.S. EPA (2000)) species sensitivity distribution (SSD). Excretion or sequestration of cadmium may contribute to insensitivity and we have therefore examined cadmium transport by isolated guts and renal tissues of C. riparius larvae. Regional differences of Cd transport along the gut were identified using a Cd{sup 2+}-selective microelectrode in conjunction with the Scanning Ion-Selective Electrode Technique (SIET). Cd is transported into the anterior midgut (AMG) cells from the lumen and out of the cells into the hemolymph. The transport of Cd from the gut lumen to the hemolymph exposes other tissues such as the nervous system and muscles to Cd. The gut segments which remove Cd from the hemolymph at the highest rate are the posterior midgut (PMG) and the ileum. In addition, assays using an isolated Malpighian (renal) tubule preparation have shown that the Malpighian tubules (MT) both sequester and secrete Cd. For larvae bathed in 10 {mu}mol l{sup -1} Cd, the tubules can secrete the entire hemolymph burden of Cd in {approx}15 h.

  16. Leucine transport in membrane vesicles from Chironomus riparius larvae displays a mélange of crown-group features.

    Science.gov (United States)

    Parenti, P; Forcella, M; Pugliese, A; Giacchini, R; Rossaro, B; Hanozet, G M

    2001-10-01

    Leucine uptake into membrane vesicles from larvae of the midge Chironomus riparius was studied. The membrane preparation was highly enriched in typical brush border membrane enzymes and depleted of other membrane contaminants. In the absence of cations, there was a stereospecific uptake of l-leucine, which exhibited saturation kinetics. Parameters were determined both at neutral (Km 33 +/- 5 microM and Vmax 22.6 +/- 6.8 pmol/7s/mg protein) and alkaline (Km 46 +/- 5 microM and Vmax 15.5 +/- 2.5 pmol/7s/mg protein) pH values. At alkaline pH, external sodium increased the affinity for leucine (Km 17 +/- 1 microM) and the maximal uptake rate (Vmax 74.0 +/- 12.5 pmol/7s/mg protein). Stimulation of leucine uptake by external alkaline pH agreed with lumen pH measurements in vivo. Competition experiments indicated that at alkaline pH, the transport system readily accepts most L-amino acids, including branched, unbranched, and alpha-methylated amino acids, histidine and lysine, but has a low affinity for phenylalanine, beta-amino acids, and N-methylated amino acids. At neutral pH, the transport has a decreased affinity for lysine, glycine, and alpha-methylleucine. Taken together, these data are consistent with the presence in midges of two distinct leucine transport systems, which combine characters of the lepidopteran amino acid transport system and of the sodium-dependent system from lower neopterans.

  17. Assessment of thiamethoxam toxicity to Chironomus riparius.

    Science.gov (United States)

    Saraiva, Althiéris S; Sarmento, Renato A; Rodrigues, Andreia C M; Campos, Diana; Fedorova, Ganna; Žlábek, Vladimír; Gravato, Carlos; Pestana, João L T; Soares, Amadeu M V M

    2017-03-01

    The insecticide thiamethoxam (TMX) is a systemic neonicotinoid widely used for pest control in several agricultural crops. TMX mimics the action of acetylcholine causing uncontrolled muscular contraction eventually leading to insect death. TMX is being found in freshwater ecosystems at concentrations of up to 225µg/L. Still, chronic toxicity data for freshwater invertebrates is limited. Therefore, the aim of this study was to evaluate the acute and chronic effects (at organismal and biochemical levels) of TMX on the freshwater insect Chironomus riparius. C. riparius life history responses were significantly affected by TMX exposure, namely with a decrease in growth and delay in emergence. Concerning the biochemical responses, after a short exposure (48h) to TMX, our results showed that low concentrations of TMX significantly reduced CAT activity and LPO levels of C. riparius. No effects were observed in AChE, GST and ETS activities. Effects in terms of survival, development rates and biochemical responses of C. riparius exposed to low concentrations of TMX observed in this study suggest potential deleterious effects of this neonicotinoid on aquatic insects inhabiting freshwaters environments near agricultural areas.

  18. Transcriptome profiling of Chironomus kiinensis under phenol stress using Solexa sequencing technology.

    Directory of Open Access Journals (Sweden)

    Chuanwang Cao

    Full Text Available Phenol is a major pollutant in aquatic ecosystems due to its chemical stability, water solubility and environmental mobility. To date, little is known about the molecular modifications of invertebrates under phenol stress. In the present study, we used Solexa sequencing technology to investigate the transcriptome and differentially expressed genes (DEGs of midges (Chironomus kiinensis in response to phenol stress. A total of 51,518,972 and 51,150,832 clean reads in the phenol-treated and control libraries, respectively, were obtained and assembled into 51,014 non-redundant (Nr consensus sequences. A total of 6,032 unigenes were classified by Gene Ontology (GO, and 18,366 unigenes were categorized into 238 Kyoto Encyclopedia of Genes and Genomes (KEGG categories. These genes included representatives from almost all functional categories. A total of 10,724 differentially expressed genes (P value <0.05 were detected in a comparative analysis of the expression profiles between phenol-treated and control C. kiinensis including 8,390 upregulated and 2,334 downregulated genes. The expression levels of 20 differentially expressed genes were confirmed by real-time RT-PCR, and the trends in gene expression that were observed matched the Solexa expression profiles, although the magnitude of the variations was different. Through pathway enrichment analysis, significantly enriched pathways were identified for the DEGs, including metabolic pathways, aryl hydrocarbon receptor (AhR, pancreatic secretion and neuroactive ligand-receptor interaction pathways, which may be associated with the phenol responses of C. kiinensis. Using Solexa sequencing technology, we identified several groups of key candidate genes as well as important biological pathways involved in the molecular modifications of chironomids under phenol stress.

  19. Potential impact of Chironomus plumosus larvae on hypolimnetic oxygen in the central basin of Lake Erie

    Science.gov (United States)

    Soster, Frederick M.; Matisoff, Gerald; Schloesser, Donald W.; Edwards, William J.

    2015-01-01

    Previous studies have indicated that burrow-irrigating infauna can increase sediment oxygen demand (SOD) and impact hypolimnetic oxygen in stratified lakes. We conducted laboratory microcosm experiments and computer simulations with larvae of the burrowing benthic midge Chironomus plumosus to quantify burrow oxygen uptake rates and subsequent contribution to sediment oxygen demand in central Lake Erie. Burrow oxygen uptake and water flow velocities through burrows were measured using oxygen microelectrodes and hot film anemometry, respectively. Burrow oxygen consumption averaged 2.66 × 10− 10 (SE = ± 7.82 × 10− 11) mol O2/burrow/s at 24 °C and 9.64 × 10− 10 (SE = ± 4.86 × 10− 10) mol O2/burrow/s at 15 °C. In sealed microcosm experiments, larvae increased SOD 500% at 24 °C (density = 1508/m2) and 375% at 15 °C (density = 864/m2). To further evaluate effects of densities of C. plumosus burrows on SOD we developed a 3-D transport reaction model of the process. Using experimental data and chironomid abundance data in faunal surveys in 2009 and 2010, we estimated that bioirrigation by a population of 140 larvae/m2 could account for between 2.54 × 10− 11 mol/L/s (model results) and 5.58 × 10− 11 mol/L/s (experimental results) of the average 4.22 × 10− 11 mol/L/s oxygen depletion rate between 1970 and 2003, which could have accounted for 60–132% of the oxygen decline. At present, it appears that the population density of this species may be an important factor in development of hypoxic or anoxic conditions in central Lake Erie.

  20. [Inversion polymorphism in the population of Camptochironomus tentans from Kaliningrad city].

    Science.gov (United States)

    Petrova, N A; Vinokurova, N V; Danilova, M V; Sharton, A Iu

    2011-01-01

    This paper present the map of polytene chromosomes and inversion polymorphism of widely distributed Chironomidae species, Camptochironomus tentans, from the most western locality of Russia--Kaliningrad city. Chromosomes banding pattern is designated according to Beermann, 1955. Only one larva (2.9%) had a standard banding pattern, and karyotypes of the rest (97.1%) were polymorphic. We have found 2.0 heterozygous inversions per individual, and the frequency of hetero- and homozygous inversions, taken together, amounted to 2.2 per individual. 17 inversion banding patterns and 20 genotypic combinations of these patterns were found. It was shown that the most frequent inversions in this population were identical to these in European populations.

  1. Molecular cloning of soluble trehalase from Chironomus riparius larvae, its heterologous expression in Escherichia coli and bioinformatic analysis.

    Science.gov (United States)

    Forcella, Matilde; Mozzi, Alessandra; Bigi, Alessandra; Parenti, Paolo; Fusi, Paola

    2012-10-01

    Trehalase is involved in the control of trehalose concentration, the main blood sugar in insects. Here, we describe the molecular cloning of the cDNA encoding for the soluble form of the trehalase from the midge larvae of Chironomus riparius, a well-known bioindicator of the quality of freshwater environments. Molecular cloning was achieved through multiple alignment of Diptera trehalase sequences, allowing the synthesis of internal homology-based primers; the complete open reading frame(ORF) was subsequently obtained through RACE-PCR(where RACE is rapid amplification of cDNA ends). The cDNA contained the 5' untranslated region (UTR), the 3' UTR including a poly(A) tail and the ORF of 1,725 bp consisting of 574 amino acid residues with a predicted molecular mass of 65,778 Da. Recombinant trehalase was successfully expressed in Escherichia coli as a His-tagged protein and purified on Ni-NTA affinity chromatography. Primary structure analysis showed a series of characteristic features shared by all insect trehalases, while three-dimensional structure prediction yielded the typical glucosidase fold, the two key residues involved in the catalytic mechanism being conserved. Production of recombinant insect trehalases opens the way to structural characterizations of the catalytic site, which might represent, among others, an element for reconsidering the enzyme as a target in pest insects' control.

  2. Transcriptional deregulation of genetic biomarkers in Chironomus riparius larvae exposed to ecologically relevant concentrations of di(2-ethylhexyl) phthalate (DEHP)

    Science.gov (United States)

    Morcillo, Gloria; Planelló, Rosario

    2017-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental pollutant used worldwide as a plasticizer and solvent in many formulations. Based on available toxicological data, it has been classified as toxic for reproduction and as an endocrine disruptor. Despite this, ecotoxicological studies in aquatic wildlife organisms are still scarce. In the present work, the toxic molecular alterations caused by DEHP in aquatic larvae of the midge Chironomus riparius have been studied, by analyzing the transcriptional activity of genes related to some vital cellular pathways, such as the ribosomal machinery (rpL4, rpL13), the cell stress response (hsc70, hsp70, hsp40, hsp27), the ecdysone hormone pathway (EcR), the energy metabolism (GAPDH), and detoxication processes (CYP4G). Environmentally relevant concentrations (10−3 to 105 μg/L) and exposure conditions (24 to 96 h) have been tested, as well as the toxic effects after DEHP withdrawal. Although the compound caused no mortality, significant changes were detected in almost all the studied biomarkers: e.g. strong repression of hsp70; general inhibition of EcR; GAPDH activity loss in long exposures; among others. Our data show a general transcriptional downregulation that could be associated with an adaptive response to cell damage. Besides, the activity of the compound as an ecdysone antagonist and its delayed effects over almost all the biomarkers analyzed are described as novel toxic targets in insects. PMID:28166271

  3. Reproductive isolation and ecological niche partition among larvae of the morphologically cryptic sister species Chironomus riparius and C. piger.

    Directory of Open Access Journals (Sweden)

    Markus Pfenninger

    Full Text Available BACKGROUND: One of the central issues in ecology is the question what allows sympatric occurrence of closely related species in the same general area? The non-biting midges Chironomus riparius and C. piger, interbreeding in the laboratory, have been shown to coexist frequently despite of their close relatedness, similar ecology and high morphological similarity. METHODOLOGY/PRINCIPAL FINDINGS: In order to investigate factors shaping niche partitioning of these cryptic sister species, we explored the actual degree of reproductive isolation in the field. Congruent results from nuclear microsatellite and mitochondrial haplotype analyses indicated complete absence of interspecific gene-flow. Autocorrelation analysis showed a non-random spatial distribution of the two species. Though not dispersal limited at the scale of the study area, the sister species occurred less often than expected at the same site, indicating past or present competition. Correlation and multiple regression analyses suggested the repartition of the available habitat along water chemistry gradients (nitrite, conductivity, CaCO(3, ultimately governed by differences in summer precipitation regime. CONCLUSIONS: We show that these morphologically cryptic sister species partition their niches due to a certain degree of ecological distinctness and total reproductive isolation in the field. The coexistence of these species provides a suitable model system for the investigation of factors shaping the distribution of closely related, cryptic species.

  4. A multi-platform metabolomics approach demonstrates changes in energy metabolism and the transsulfuration pathway in Chironomus tepperi following exposure to zinc

    Energy Technology Data Exchange (ETDEWEB)

    Long, Sara M., E-mail: hoskins@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia); Tull, Dedreia L., E-mail: dedreia@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Jeppe, Katherine J., E-mail: k.jeppe@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia); Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, The University of Melbourne, 3010 (Australia); De Souza, David P., E-mail: desouzad@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Dayalan, Saravanan, E-mail: sdayalan@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Pettigrove, Vincent J., E-mail: vpet@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, The University of Melbourne, 3010 (Australia); McConville, Malcolm J., E-mail: malcolmm@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Hoffmann, Ary A., E-mail: ary@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia); School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia)

    2015-05-15

    Highlights: • An integrated metabolomics approach was applied to examine zinc exposure in midges. • Changes in carbohydrate and energy metabolism were observed using GC–MS. • Transsulfuration pathway is affected by zinc exposure. • Heavy metals other than zinc affect the transsulfuration pathways differently. - Abstract: Measuring biological responses in resident biota is a commonly used approach to monitoring polluted habitats. The challenge is to choose sensitive and, ideally, stressor-specific endpoints that reflect the responses of the ecosystem. Metabolomics is a potentially useful approach for identifying sensitive and consistent responses since it provides a holistic view to understanding the effects of exposure to chemicals upon the physiological functioning of organisms. In this study, we exposed the aquatic non-biting midge, Chironomus tepperi, to two concentrations of zinc chloride and measured global changes in polar metabolite levels using an untargeted gas chromatography–mass spectrometry (GC–MS) analysis and a targeted liquid chromatography–mass spectrometry (LC–MS) analysis of amine-containing metabolites. These data were correlated with changes in the expression of a number of target genes. Zinc exposure resulted in a reduction in levels of intermediates in carbohydrate metabolism (i.e., glucose 6-phosphate, fructose 6-phosphate and disaccharides) and an increase in a number of TCA cycle intermediates. Zinc exposure also resulted in decreases in concentrations of the amine containing metabolites, lanthionine, methionine and cystathionine, and an increase in metallothionein gene expression. Methionine and cystathionine are intermediates in the transsulfuration pathway which is involved in the conversion of methionine to cysteine. These responses provide an understanding of the pathways affected by zinc toxicity, and how these effects are different to other heavy metals such as cadmium and copper. The use of complementary

  5. Gall midges (Diptera: Cecidomyiidae) new to the Danish fauna

    DEFF Research Database (Denmark)

    Haarder, Simon; Bruun, Hans Henrik; Harris, Keith M.

    2016-01-01

    ), Piceacecis abietiperda (Henschel), Rabdophaga strobilina (Bremi), Taxomyia taxi (Inchbald) and a probably undescribed species of Contarinia Rondani. Thus, 363 fully identified gall midge species are now documented from Denmark along with 25 species, which have been identified to genus level only. The species...

  6. Estimating Culicoides sonorensis biting midge abundance using digital image analysis.

    Science.gov (United States)

    Osborne, C J; Mayo, C E; Mullens, B A; Maclachlan, N J

    2014-12-01

    ImageJ is an open-source software tool used for a variety of scientific objectives including cell counting, shape analysis and image correction. This technology has previously been used to estimate mosquito abundance in surveillance efforts. However, the utility of this application for estimating abundance or parity in the surveillance of Culicoides spp. (Diptera: Ceratopogonidae) has not yet been tested. Culicoides sonorensis (Wirth and Jones), a biting midge often measuring 2.0-2.5 mm in length, is an economically important vector of ruminant arboviruses in California. Current surveillance methods use visual sorting for the characteristics of midges and are very time-intensive for large studies. This project tested the utility of ImageJ as a tool to assist in gross trap enumeration as well as in parity analysis of C. sonorensis in comparison with traditional visual methods of enumeration using a dissecting microscope. Results confirmed that automated counting of midges is a reliable means of approximating midge numbers under certain conditions. Further evaluation confirmed accurate and time-efficient parity analysis in comparison with hand sorting. The ImageJ software shows promise as a tool that can assist and expedite C. sonorensis surveillance. Further, these methods may be useful in other insect surveillance activities.

  7. Nucleolar organizer (NO) size as a measure of instantaneous growth in Chironomus riparius larvae (Diptera: Chironomidae) : a tool for monitoring individual and population responses to stress

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.P.; Ciborowski, J.J.; Wytrykush, C. [Windsor Univ., Windsor, ON (Canada)

    2009-07-01

    This presentation reported on 2 laboratory experiments that were conducted using Chironomus riparius larvae to relate nucleolar growth (NO) size to chironomid growth. In one experiment, 5 treatments varied in diet quality only, which was manipulated by providing midge larvae with 1.0 mg of food per individual per day, but varying the ratio of Tetramin to non-nutritious methyl-cellulose. A second experiment followed a 2 x 2 factorial design. The factors were growth period and diet quality. Diet quality and growth period were found to influence the individual biomass considerably. NO size was related to the quality of the diet provided at the end of the experiment, regardless of larval biomass. Therefore, NO size appears to be related to growth rate at time of collection rather than larval size. The authors proposed using NO size of larvae in natural populations as a measure of growth on which to base estimates of secondary production and as a new way to monitor individual and population responses to environmental stress. Preliminary field measurements of larval production and NO size from oil sands-affected and reference wetlands were found to be consistent with laboratory results.

  8. Chronic toxicity of azoxystrobin to freshwater amphipods, midges, cladocerans, and mussels in water-only exposures

    Science.gov (United States)

    Kunz, James L.; Ingersoll, Christopher G.; Smalling, Kelly; Elskus, Adria; Kuivila, Kathryn

    2017-01-01

    Understanding the effects of fungicides on nontarget organisms at realistic concentrations and exposure durations is vital for determining potential impacts on aquatic ecosystems. Environmental concentrations of the fungicide azoxystrobin have been reported up to 4.6 μg/L in the United States and 30 μg/L in Europe. The objective of the present study was to evaluate the chronic toxicity of azoxystrobin in water-only exposures with an amphipod (Hyalella azteca; 42-d exposure), a midge (Chironomus dilutus; 50-d exposure), a cladoceran (Ceriodaphnia dubia; 7-d exposure), and a unionid mussel (Lampsilis siliquoidea; 28-d exposure) at environmentally relevant concentrations. The potential photo-enhanced toxicity of azoxystrobin accumulated by C. dubiaand L. siliquoidea following chronic exposures to azoxystrobin was also evaluated. The 20% effect concentrations (EC20s) based on the most sensitive endpoint were 4.2 μg/L for H. aztecareproduction, 12 μg/L for C. dubia reproduction and C. dilutus emergence, and >28 μg/L for L. siliquoidea. Hyalella azteca was more sensitive to azoxystrobin compared with the other 3 species in the chronic exposures. No photo-enhanced toxicity was observed for either C. dubia or L. siliquoidea exposed to ultraviolet light in control water following azoxystrobin tests. The results of the present study indicate chronic effects of azoxystrobin on 3 of 4 invertebrates tested at environmentally relevant concentrations. The changes noted in biomass and reproduction have the potential to alter the rate of ecological processes driven by aquatic invertebrates. Environ Toxicol Chem 2017;9999:1–8. Published 2017 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

  9. Biting Midges (Diptera: Ceratopogonidae: Culicoides Latr.) associated with livestock farms in the Faroe Islands

    DEFF Research Database (Denmark)

    Nielsen, Søren Achim; Holm, Høgni; Overgaard Nielsen, Boy

    2017-01-01

    A large number of biting midges (Culicoides) were collected in light traps operating simultaneously outside and indside 25 Faroese byres. The catch comprised two species: C. (Culicoides) impunctatus Goetghebuer, 1920, accounting for >98% of all biting midges trapped, and C. (Oecacta) pseudoheliop......A large number of biting midges (Culicoides) were collected in light traps operating simultaneously outside and indside 25 Faroese byres. The catch comprised two species: C. (Culicoides) impunctatus Goetghebuer, 1920, accounting for >98% of all biting midges trapped, and C. (Oecacta...

  10. Collective Behaviour without Collective Order in Wild Swarms of Midges

    Science.gov (United States)

    Attanasi, Alessandro; Cavagna, Andrea; Del Castello, Lorenzo; Giardina, Irene; Melillo, Stefania; Parisi, Leonardo; Pohl, Oliver; Rossaro, Bruno; Shen, Edward; Silvestri, Edmondo; Viale, Massimiliano

    2014-01-01

    Collective behaviour is a widespread phenomenon in biology, cutting through a huge span of scales, from cell colonies up to bird flocks and fish schools. The most prominent trait of collective behaviour is the emergence of global order: individuals synchronize their states, giving the stunning impression that the group behaves as one. In many biological systems, though, it is unclear whether global order is present. A paradigmatic case is that of insect swarms, whose erratic movements seem to suggest that group formation is a mere epiphenomenon of the independent interaction of each individual with an external landmark. In these cases, whether or not the group behaves truly collectively is debated. Here, we experimentally study swarms of midges in the field and measure how much the change of direction of one midge affects that of other individuals. We discover that, despite the lack of collective order, swarms display very strong correlations, totally incompatible with models of non-interacting particles. We find that correlation increases sharply with the swarm's density, indicating that the interaction between midges is based on a metric perception mechanism. By means of numerical simulations we demonstrate that such growing correlation is typical of a system close to an ordering transition. Our findings suggest that correlation, rather than order, is the true hallmark of collective behaviour in biological systems. PMID:25057853

  11. Collective behaviour without collective order in wild swarms of midges.

    Directory of Open Access Journals (Sweden)

    Alessandro Attanasi

    2014-07-01

    Full Text Available Collective behaviour is a widespread phenomenon in biology, cutting through a huge span of scales, from cell colonies up to bird flocks and fish schools. The most prominent trait of collective behaviour is the emergence of global order: individuals synchronize their states, giving the stunning impression that the group behaves as one. In many biological systems, though, it is unclear whether global order is present. A paradigmatic case is that of insect swarms, whose erratic movements seem to suggest that group formation is a mere epiphenomenon of the independent interaction of each individual with an external landmark. In these cases, whether or not the group behaves truly collectively is debated. Here, we experimentally study swarms of midges in the field and measure how much the change of direction of one midge affects that of other individuals. We discover that, despite the lack of collective order, swarms display very strong correlations, totally incompatible with models of non-interacting particles. We find that correlation increases sharply with the swarm's density, indicating that the interaction between midges is based on a metric perception mechanism. By means of numerical simulations we demonstrate that such growing correlation is typical of a system close to an ordering transition. Our findings suggest that correlation, rather than order, is the true hallmark of collective behaviour in biological systems.

  12. Genotoxic effect of Phenanthrene on Chironomus sancticaroli (Diptera: Chironomidae

    Directory of Open Access Journals (Sweden)

    Gisele dos Santos Morais

    2014-08-01

    Full Text Available Phenanthrene, a Polycyclic Aromatic Hydrocarbon, remains adsorbed to sedimentary particles in aquatic environments. It affects mainly benthic organisms, and is considered potentially genotoxic. In ecotoxicology, species of Chironomus Meigen, 1803 are widely known as bioindicators of the effects of chemicals on aquatic organisms. This study investigates the effects of phenanthrene on the size of the head capsule of Chironomus sancticaroli Strixino & Strixino, 1981 larvae after chronic (eight days exposure, and DNA damage after acute (96 hours and chronic exposure (eight days, under laboratory conditions. DNA damage, evaluated using the alkaline comet assay, detected effects for both exposure periods, indicating that phenanthrene is toxic for C. sancticaroli. For the acute exposure, we analyzed five concentrations of phenanthrene, between 0.16 mg.l-1 and 1.60 mg.l-1, detecting significant differences (Kruskall-Wallis test with p < 0.05 in the degree of DNA damage in all groups. These effects were not dose-dependent. For the chronic exposure, two concentrations (0.16 mg.l-1, 0.83 mg.l-1 were analyzed, and DNA damage was observed in both. Again, the effects were not dose-dependent. This indicates that phenanthrene is genotoxic to larvae of C. sancticaroli even at low concentrations. The size of the head capsule was evaluated after chronic exposure to concentrations of 0.16 mg.l-1 and 0.83 mg.l-1. Significant differences (ANOVA test with p < 0.05 were detected in the two concentrations, and a reduction in the size of the larval head capsule was observed. This suggests that phenanthrene causes delay in larval development. These results indicate that phenanthrene affects the development of and causes DNA damage in C. sancticaroli larvae. Therefore, we suggest that C. sancticaroli can be used as a biological indicator for environmental contamination with phenanthrene.

  13. Redescription of larva, pupa and imago male of Chironomus (Chironomus) salinarius Kieffer from the saline rivers of the Lake Elton basin (Russia), its karyotype and ecology.

    Science.gov (United States)

    Orel Zorina, Oksana V; Istomina, Albina G; Kiknadze, Iya I; Zinchenko, Tatiana D; Golovatyuk, Larisa V

    2014-07-29

    Cytology and ecology of Chironomus (Chironomus) salinarius Kieffer, 1915 (Diptera, Chironomidae) was examined from material collected in the saline rivers of the Lake Elton basin (Volgograd region, Russia). Larvae of salinarius-type were identified as C. salinarius on the basis of their karyotype. The species is redescribed on the basis of all metamorphic stages. The reared imago and karyotype were obtained from larvae of the same population. The karyotype of C. salinarius, detailed mapping of the 5 chromosome arms A, C, D, E, F and characteristics of chromosome polymorphism are provided. Information on distribution and ecology of C. salinarius from the saline rivers (total mineralization 6.8-31.6 g l-1) of the Lake Elton basin is also given. Chironomus salinarius is a common in the saline rivers and occurs in sediments with high silt content. On the basis of recent samplings C. salinarius appears to be very abundant in saline, mesotrophic as well as in eutrophic rivers. Chironomus salinarius accounted for 49-66% of total abundance of zoobenthos in water with salinity up to 13-31.6 g l-1.

  14. Rapid Spread of Schmallenberg Virus-infected Biting Midges (Culicoides spp.) across Denmark in 2012

    DEFF Research Database (Denmark)

    Rasmussen, Lasse Dam; Kirkeby, Carsten; Bødker, Rene;

    2014-01-01

    Detection of Schmallenberg virus RNA, using real-time RT-PCR, in biting midges (Culicoides spp.) caught at 48 locations in 2011 and four well-separated farms during 2012 in Denmark, revealed a remarkably rapid spread of virus-infected midges across the country. During 2012, some 213 pools of obso...

  15. Biology of a Pine Needle Sheath Midge, Contarinia Acuta Gagne (Diptera: Cecidomyiidae), on Loblolly Pine

    Science.gov (United States)

    Julie C. Weatherby; John C. Moser; Raymond J. Gagné; Huey N. Wallace

    1989-01-01

    The biology of a pine needle sheath midge, Contarinia acuta Gagné is described for a new host in Louisiana. This midge was found feeding within the needle sheath on elongating needles of loblolly pine, P. taeda L. Needle droop and partial defoliation were evident on heavily infested trees. Overwintering C. acuta...

  16. Chromosomal organization of the ribosomal RNA genes in the genus Chironomus (Diptera, Chironomidae

    Directory of Open Access Journals (Sweden)

    Larisa Gunderina

    2015-05-01

    Full Text Available Chromosomal localization of ribosomal RNA coding genes has been studied by using FISH (fluorescence in situ hybridization in 21 species from the genus Chironomus Meigen, 1803. Analysis of the data has shown intra- and interspecific variation in number and location of 5.8S rDNA hybridization sites in 17 species from the subgenus Chironomus and 4 species from the subgenus Camptochironomus Kieffer, 1914. In the majority of studied species the location of rDNA sites coincided with the sites where active NORs (nucleolus organizer regions were found. The number of hybridization sites in karyotypes of studied chironomids varied from 1 to 6. More than half of the species possessed only one NOR (12 out of 21. Two rDNA hybridization sites were found in karyotypes of five species, three – in two species, and five and six sites – in one species each. NORs were found in all chromosomal arms of species from the subgenus Chironomus with one of them always located on arm G. On the other hand, no hybridization sites were found on arm G in four studied species from the subgenus Camptochironomus. Two species from the subgenus Chironomus – Ch. balatonicus Devai, Wuelker & Scholl, 1983 and Ch. “annularius” sensu Strenzke, 1959 – showed intraspecific variability in the number of hybridization signals. Possible mechanisms of origin of variability in number and location of rRNA genes in the karyotypes of species from the genus Chironomus are discussed.

  17. Biological responses of midge (Chironomus riparius) and lamprey (Lampetra fluviatilis) larvae in ecotoxicity assessment of PCDD/F-, PCB- and Hg-contaminated river sediments.

    Science.gov (United States)

    Salmelin, J; Karjalainen, A K; Hämäläinen, H; Leppänen, M T; Kiviranta, H; Kukkonen, J V K; Vuori, K M

    2016-09-01

    We evaluated the utility of chironomid and lamprey larval responses in ecotoxicity assessment of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/F)-, polychlorinated biphenyls (PCB)- and mercury (Hg)-contaminated river sediments. Sediment samples were collected from the River Kymijoki with a known industrial pollution gradient. Sediment for the controls and lamprey larvae were obtained from an uncontaminated river nearby. Contamination levels were verified with sediment and tissue PCDD/F, PCB and Hg analyses. Behaviour of sediment-exposed chironomid and lamprey larvae were measured with Multispecies Freshwater Biomonitor© utilizing quadrupole impedance conversion technique. In addition, mortality, growth and head capsule deformity incidence of chironomids were used as ecotoxicity indicators. WHOPCDD/F+PCB-TEQ in the R. Kymijoki sediments ranged from the highest upstream 22.36 ng g(-1) dw to the lowest 1.50 ng g(-1) near the river mouth. The sum of PCDD/Fs and PCBs correlated strongly with Hg sediment concentrations, which ranged from contaminated sediments and was negatively related to sediment ∑PCDD/Fs, WHOPCDD/F+PCB-TEQ and Hg. There were no significant differences in larval mortality or chironomid mentum deformity incidence between the sediment exposures. The distinct behavioural patterns of both species indicate overall applicability of behavioural MFB measurements of these species in sediment toxicity bioassays. Chironomids spent less and lampreys more time in locomotion in the most contaminated sediment compared to the reference, albeit statistically significant differences were not detected. Lamprey larvae had also a greater activity range in some of the contaminated sediments than in the reference. High pollutant levels in lamprey indicate risks for biomagnification in the food webs, with potential health risks to humans consuming fish.

  18. Culicoides midges (Diptera: Ceratopogonidae as vectors of orbiviruses in Slovakia

    Directory of Open Access Journals (Sweden)

    Adela Sarvašová

    2014-09-01

    Full Text Available In recent years, rapid spread of Culicoides-borne pathogens such as bluetongue (BT and Schmallenberg viruses have been reported in Europe. In this study we examined the Culicoides populations in farms with wild and domestic ruminants in Eastern Slovakia with the aim to confirm the presence of biting midges serving as potential vectors of important pathogens. The main vector complexes were the Obsoletus complex (54%; n=4,209 and the Pulicaris complex (23%; n=1,796. To estimate the relative abundance of the cryptic species of the Obsoletus complex (Culicoides obsoletus, Culicoides scoticus and Culicoides montanus, we performed the multiplex polymerase chain reaction (PCR based on ITS-2 and ITS-1 segments, on 125 midges randomly sampled. The relative abundance of C. obsoletus ranged from 5.26% in the farm with wild ruminants to 85.71% in another farm with cattle and sheep. A total of 112 pools of parous and gravid females belonging to the Obsoletus and Pulicaris complexes were tested for virus detection by the real-time reverse transcription polymerase chain reaction (RT-PCR for BT virus, as well as for the Epizootic Hemorrhagic Disease Virus (EHDV, with negative results.

  19. Growth of immature Chironomus calligraphus (Diptera, Chironomidae in laboratory conditions

    Directory of Open Access Journals (Sweden)

    Rita de Cássia S.A. Canteiro

    2011-12-01

    Full Text Available Chironomidae larvae are important macroinvertebrates in limnic environments, but little knowledge exists about their biometrics development characteristics. This study aims to describe the immature Chironomus calligraphus Goeldi, 1905 under laboratory conditions by the accomplishment of thirteen egg masses from eggs eclosion to adults emergency, at controlled room temperature (25ºC and photoperiod (12-12h. Larvae were feed ad libitum with "Alcon Basic - MEP 200 Complex" fish food and commercial dehydrated Spirulina. The postures had a mean length of 9 ± 1 mm (n = 13 and 348 ± 66 eggs. The brownish colored eggs with elliptical shape had length of 160.3 ± 17.7 µm (n = 130, being arranged as an organized string in a pseudo spiral form. The time duration from the first to the four instars were three, four, four and eight days, and the average length of a cephalic capsule to each one of the instars (66.3 ± 12.3 µm, 102.9 ± 22.1 µm, 159 ± 24.6 µm, 249.2 ± 29.7 µm, n = 456 were significantly different (ANOVA, p Larvas de Chironomidae são importantes componentes emambientes límnicos, mas pouca informação está disponívelsobre as características biométricas em seu desenvolvimento. Este estudo objetivou descrever os imaturos de Chironomus calligraphus Goeldi, 1905 em condições de laboratório, através do acompanhamento de treze posturas da espécie desde aeclosão dos ovos até a emergência dos adultos, sob temperatura (25ºC e fotoperíodo controlados (12-12 h. As larvas foram alimentadas com ração para peixes "Alcon Basic - MEP 200 Complex" e Spirulina comercial desidratada. A postura apresentou comprimento médio de 9 ± 1 mm (n = 13 e348 ± 66 ovos. Estes, de cor amarronzada e formato elíptico, apresentaram comprimento de 160,3 ± 17,7 µm (n = 130, arranjados como uma fita em formato pseudo-espiralado. Aduração do primeiro ao quarto estágio foi de três, quatro,quatro e oito dias, e os comprimentos médios da c

  20. Identity and diversity of blood meal hosts of biting midges (Dipterea: Ceratopogonidae: Culicoides Latreille) in Denmark

    DEFF Research Database (Denmark)

    Lassen, Sandra; Nielsen, Søren Achim; Kristensen, Michael

    2012-01-01

    the species of the collected biting midges (GenBank accessions JQ683259-JQ683374). The blood meals were first screened with a species-specific cytochrome b primer pair for cow and if negative with a universal cytochrome b primer pair followed by sequencing to identify mammal or avian blood meal hosts. RESULTS...... and diversity of blood meals taken from vertebrate hosts in wild-caught Culicoides biting midges near livestock farms. METHODS: Biting midges were collected at weekly intervals for 20 weeks from May to October 2009 using light traps at four collection sites on the island Sealand, Denmark. Blood-fed female...... biting midges were sorted and head and wings were removed for morphological species identification. The thoraxes and abdomens including the blood meals of the individual females were subsequently subjected to DNA isolation. The molecular marker cytochrome oxidase I (COI barcode) was applied to identify...

  1. Molecular identification of bloodmeals from biting midges (Diptera: Ceratopogonidae; Culicoides Latreille) in Denmark

    DEFF Research Database (Denmark)

    Lassen, Sandra Boline; Nielsen, Søren A; Skovgård, Henrik

    2011-01-01

    . Their choice of host for blood feeding is sparsely described. The aim of the present study was to establish methods for the identification of bloodmeal hosts and determine the identity and diversity of bloodmeals of vertebrate hosts from wild-caught biting midges near livestock farms. The study includes some...... of the most common and abundant species of biting midges in Denmark: Culicoides obsoletus, Culicoides scoticus, Culicoides pulicaris and Culicoides punctatus. We collected 8,378 biting midges including nine species of Culicoides of which blood-fed specimens were found from six species. We identified 251 blood...... engorged biting midges, and hosts were identified in 115 of 125 analysed specimens (90%). Cow, roe deer, horse, mallard and wood pigeon were identified as hosts. The most abundant host species was cow, which constituted 73.9% of the total identified bloodmeals, but the common wood pigeon was found...

  2. Papular dermatitis induced in guinea pigs by the biting midge Culicoides sonorensis (Diptera: Ceratopogonidae)

    Science.gov (United States)

    Histological, ultrastructural, and virological examinations were performed on abdominal skin from guinea pigs after a blood meal by colony-bred biting midges, Culicoides sonorensis. Small, superficial, cutaneous, crateriform ulcers with necrosis of superficial dermis developed at feeding sites and ...

  3. Biting Midges of the Genus Culicoides in South Carolina Zoos

    Science.gov (United States)

    Nelder, Mark P.; Swanson, Dustin A.; Adler, Peter H.; Grogan, William L.

    2010-01-01

    Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) were collected during the summer of 2007 at the Greenville and Riverbanks Zoos in South Carolina with Centers for Disease Control and Prevention (CDC) traps equipped with ultraviolet or incandescent lights and baited with carbon dioxide. Sixteen species of Culicoides were collected, four of which represented more than 80%. They were Culicoides guttipennis (Coquillett), Culicoides mulrenanni Beck, Culicoides obsoletus (Meigen), and Culicoides sanguisuga (Coquillett). C. guttipennis was found on a dead colobus monkey and a dead golden-headed lion tamarin; Culicoides husseyi Wirth & Blanton was collected from an unidentified, abandoned bird's nest. Ultraviolet light-equipped traps captured significantly more Culicoides specimens than traps with incandescent light. Half of the collected species previously have been associated with vertebrate pathogens, indicating a potential risk to captive animals. PMID:20569132

  4. Toxicity of uranium, molybdenum, nickel, and arsenic to Hyalella azteca and Chironomus dilutus in water-only and spiked-sediment toxicity tests.

    Science.gov (United States)

    Liber, Karsten; Doig, Lorne E; White-Sobey, Suzanne L

    2011-07-01

    A series of laboratory spiked-sediment toxicity tests with the amphipod Hyalella azteca and the midge Chironomus dilutus were undertaken to determine acute and chronic toxicity thresholds for uranium (U), molybdenum (Mo), nickel (Ni), and arsenic (As) based on both whole-sediment (total) and pore water exposure concentrations. Water-only toxicity data were also generated from separate experiments to determine the toxicities of these metals/metalloids under our test conditions and to help evaluate the hypothesis that pore water metal concentrations are better correlated with sediment toxicity to benthic organisms than whole-sediment metal concentrations. The relative toxicity of the four elements tested differed depending on which test species was used and whether whole-sediment or pore water metal concentrations were correlated with effects. Based on measured whole-sediment concentrations, Ni and As were the two most acutely toxic elements to H. azteca with 10-d LC50s of 521 and 532 mg/kg d.w., respectively. Measured pore water concentrations indicated that U and Ni were the two most acutely toxic elements, with 10-d LC50s to H. azteca of 2.15 and 2.05 mg/L, respectively. Based on pore water metal concentrations, the no-observed-effect concentrations (NOECs) for growth were (H. azteca and C. dilutus, respectively) 0.67 and 0.21 mg/L for U, azteca and C. dilutus, respectively) 2.99 and 0.48 mg/L for U, 0.37 and 2.33 mg/L for Ni, and 58.99 and 0.42 mg/L for As. For U and Ni, results from 96-h water-only acute toxicity tests correlated well with pore water metal concentrations in acutely toxic metal-spiked sediment. This was not true for As where metalloid concentrations in overlying water (diffusion from sediment) may have contributed to toxicity. The lowest whole-sediment LOEC reported here for As was 6.6- and 4-fold higher than the Canadian Council of Ministers of the Environment interim sediment quality guideline and the Canadian Nuclear Safety Commission (CNSC

  5. Ion-selective microelectrode measurements of Tl⁺ and K⁺ transport by the gut and associated epithelia in Chironomus riparius.

    Science.gov (United States)

    Belowitz, Ryan; O'Donnell, Michael J

    2013-08-15

    Thallium (Tl) is a non-essential metal that is mobilized through industrial processes, subsequently entering aquatic environments where it can exert toxic effects. Although the aquatic larvae of the midge, Chironomus riparius, are exceptionally tolerant toward many waterborne non-essential metals, few studies have looked at the cellular mechanism of this tolerance. Tl⁺ and K⁺ share the same charge and have similar ionic radii, resulting in competition between these ions for K⁺ transporters. Using a recently developed Tl⁺-selective microelectrode in conjunction with the scanning ion selective electrode technique (SIET) and a two-microelectrode holder, measurements of K⁺ and Tl⁺ fluxes were made along the anal papillae and also along the isolated gut tract and Malpighian tubules (MTs) of C. riparius larvae. The MTs are a site of Tl⁺ secretion (i.e. from hemolymph into the tubule lumen). The major K⁺ transporting regions of the gut were the caecae, anterior midgut (AMG) and posterior midgut (PMG) in Tl⁺-naïve larvae, and Tl⁺ was also transported in the same direction at these locations. When the bathing saline concentration of Tl⁺ was increased to 50 μmol l⁻¹, K⁺ transport was inhibited at the AMG and PMG. Larvae exposed to 300 μmol l⁻¹ waterborne Tl⁺ for 48 h prior to ion flux measurements absorbed Tl⁺ (lumen to hemolymph) across the caecae, AMG and PMG. K⁺ secretion at the caecae was unaffected by Tl⁺ exposure, consistent with separate pathways for Tl⁺ and K⁺ transport across the caecae. By contrast, K⁺ flux at the AMG and PMG of Tl⁺-exposed larvae was impaired, suggesting that interference of Tl⁺ on K⁺ transport across these tissues may contribute to Tl⁺ toxicity. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Culicoides biting midges, arboviruses and public health in Europe.

    Science.gov (United States)

    Carpenter, Simon; Groschup, Martin H; Garros, Claire; Felippe-Bauer, Maria Luiza; Purse, Bethan V

    2013-10-01

    The emergence of multiple strains of bluetongue virus (BTV) and the recent discovery of Schmallenberg virus (SBV) in Europe have highlighted the fact that exotic Culicoides-borne arboviruses from remote geographic areas can enter and spread rapidly in this region. This review considers the potential for this phenomenon to impact on human health in Europe, by examining evidence of the role of Culicoides biting midges in the zoonotic transmission and person-to-person spread of arboviruses worldwide. To date, the only arbovirus identified as being primarily transmitted by Culicoides to and between humans is Oropouche virus (OROV). This member of the genus Orthobunyavirus causes major epidemics of febrile illness in human populations of South and Central America and the Caribbean. We examine factors promoting sustained outbreaks of OROV in Brazil from an entomological perspective and assess aspects of the epidemiology of this arbovirus that are currently poorly understood, but may influence the risk of incursion into Europe. We then review the secondary and rarely reported role of Culicoides in the transmission of high-profile zoonotic infections, while critically reviewing evidence of this phenomenon in endemic transmission and place this in context with the presence of other potential vector groups in Europe. Scenarios for the incursions of Culicoides-borne human-to-human transmitted and zoonotic arboviruses are then discussed, along with control measures that could be employed to reduce their impact. These measures are placed in the context of legislative measures used during current and ongoing outbreaks of Culicoides-borne arboviruses in Europe, involving both veterinary and public health sectors.

  7. Life Cycle of Gall Midge on Red Chilli in West Sumatra

    Directory of Open Access Journals (Sweden)

    Munzir Busniah

    2014-01-01

    Full Text Available Study of the life cycle of the gall midge (Asphondylia capsici Barnes (Diptera: Cecidomyiidae has been performed in pepper (Capsicum annuum L.. The experiment was conducted in laboratory experiments carried out at the Laboratory of Plant Pest Disease, Faculty of Agriculture, University of Andalas Padang, from January to June 2012. The objective was to study the life cycle of the gall midge in pepper. Gall midge egg white, elongated round, length 0,69 and width 0,35 mm. Early instar larvae rounded elongated, transparent color and a whitish or yellowish white. Instar larva up getting flattened by the color yellow to brownish yellow. The larvae live in the chilies. Pupa brown to blackish brown, 3.0 mm long and 2.3 mm wide, located in the chilies. Pradewasa stage lasted 22 days. Imago brown or blackish brown. Imago body length of males and females is almost the same, at 2.8 mm, but the body of the female imago fatter than the males. Imago males live longer (35 hours compared with female imago (32 hours. Imago female fecundity is 124 eggs. The life cycle of gall midge on pepper plants 25 days.

  8. Phylogeography of the Asian rice gall midge Orseolia oryzae (Wood Mason) (Diptera: Cecidomyiidae) in Thailand.

    Science.gov (United States)

    Janique, Solene; Sriratanasak, Wantana; Ketsuwan, Kulchana; Jairin, Jirapong; Jeratthitikul, Ekgachai

    2017-02-01

    The Asian rice gall midge (RGM) Orseolia oryzae (Wood Mason) (Diptera: Cecidomyiidae) is a major pest of rice, leading to yield losses in Thailand and many Asian countries. Despite an increasing number of reported midge outbreaks and the presence of many susceptible rice varieties, only a few studies have focused on the genetic variation of the midges. Therefore, we analyzed the phylogeography among Thai RGM populations covering north, northeast and central Thailand. Two mitochondrial DNA genes, cytochrome C oxidase I (COI) and 12S, and a non-coding repeat region (RR) situated just before COI were amplified. Overall, the haplotype diversity for COI and 12S genes of the Thai population was high, but the nucleotide diversity was quite low. Altogether, the phylogenetic tree and pairwise F st values indicated that Thai RGM populations recently expanded and were homogeneously distributed throughout the country, except for some populations in the north, which most likely became recently isolated from the main population. Two non-coding repeat motifs, that were recently observed in the mitogenome of RGM in India, were absent in Thai populations and replaced by an 89 bp non-coding sequence. Tandem nucleotide repeats of the sequence TA were also observed. The repeat copy number varied from 2 to 11 and was not correlated with geographical repartition of the midge. Finally, COI barcoding divergence between Indian and Thai populations was high (6.3% in average), giving insights into the potential existence of an RGM species complex in Asia.

  9. Understanding and exploiting olfaction for the surveillance and control of Culicoides biting midges

    Science.gov (United States)

    Culicoides midges (Diptera: Ceratopogonidae) are found worldwide with the exception of only a few countries including New Zealand, Patagonia, the Hawaiian Isles and Antarctica. They are a nuisance pest to human beings, but transmit a number of diseases that mainly affect livestock. Like many haema...

  10. Celticecis, a Genus of Gall Midges (Diptera: Cecidomyiidae), Newly Reported for the Western Palearctic Region

    Science.gov (United States)

    Raymond J. Gagné; John C. Moser

    1997-01-01

    Many Holarctic genera of trees and shrubs are host over much of their ranges to particular genera of Cecidomyiidae. As examples, willows host gall midges of Rabdophaga and Iteomyia, oaks host Macrodiplosis and Polystepha, and birches host Semudobia in both the Nearctic and...

  11. Culicoides midge bites modulate the host response and impact on bluetongue virus infection in sheep.

    Science.gov (United States)

    Pages, Nonito; Bréard, Emmanuel; Urien, Céline; Talavera, Sandra; Viarouge, Cyril; Lorca-Oro, Cristina; Jouneau, Luc; Charley, Bernard; Zientara, Stéphan; Bensaid, Albert; Solanes, David; Pujols, Joan; Schwartz-Cornil, Isabelle

    2014-01-01

    Many haematophagous insects produce factors that help their blood meal and coincidently favor pathogen transmission. However nothing is known about the ability of Culicoides midges to interfere with the infectivity of the viruses they transmit. Among these, Bluetongue Virus (BTV) induces a hemorrhagic fever- type disease and its recent emergence in Europe had a major economical impact. We observed that needle inoculation of BTV8 in the site of uninfected C. nubeculosus feeding reduced viraemia and clinical disease intensity compared to plain needle inoculation. The sheep that developed the highest local inflammatory reaction had the lowest viral load, suggesting that the inflammatory response to midge bites may participate in the individual sensitivity to BTV viraemia development. Conversely compared to needle inoculation, inoculation of BTV8 by infected C. nubeculosus bites promoted viraemia and clinical symptom expression, in association with delayed IFN- induced gene expression and retarded neutralizing antibody responses. The effects of uninfected and infected midge bites on BTV viraemia and on the host response indicate that BTV transmission by infected midges is the most reliable experimental method to study the physio-pathological events relevant to a natural infection and to pertinent vaccine evaluation in the target species. It also leads the way to identify the promoting viral infectivity factors of infected Culicoides in order to possibly develop new control strategies against BTV and other Culicoides transmitted viruses.

  12. Culicoides midge bites modulate the host response and impact on bluetongue virus infection in sheep.

    Directory of Open Access Journals (Sweden)

    Nonito Pages

    Full Text Available Many haematophagous insects produce factors that help their blood meal and coincidently favor pathogen transmission. However nothing is known about the ability of Culicoides midges to interfere with the infectivity of the viruses they transmit. Among these, Bluetongue Virus (BTV induces a hemorrhagic fever- type disease and its recent emergence in Europe had a major economical impact. We observed that needle inoculation of BTV8 in the site of uninfected C. nubeculosus feeding reduced viraemia and clinical disease intensity compared to plain needle inoculation. The sheep that developed the highest local inflammatory reaction had the lowest viral load, suggesting that the inflammatory response to midge bites may participate in the individual sensitivity to BTV viraemia development. Conversely compared to needle inoculation, inoculation of BTV8 by infected C. nubeculosus bites promoted viraemia and clinical symptom expression, in association with delayed IFN- induced gene expression and retarded neutralizing antibody responses. The effects of uninfected and infected midge bites on BTV viraemia and on the host response indicate that BTV transmission by infected midges is the most reliable experimental method to study the physio-pathological events relevant to a natural infection and to pertinent vaccine evaluation in the target species. It also leads the way to identify the promoting viral infectivity factors of infected Culicoides in order to possibly develop new control strategies against BTV and other Culicoides transmitted viruses.

  13. Papular Dermatitis Induced in Guinea Pig by Biting Midge Culicoides Sonorensis (Diptera: Ceratopogonidaie)

    Science.gov (United States)

    Histological, ultrastructural, and virological examinations were performed on abdominal skin from guinea pigs after a blood meal by colony-bred biting midges, Culicoides sonorensis. Small, superficial, cutaneous, crateriform ulcers with necrosis of superficial dermis developed at feeding sites and h...

  14. An expanded surface-water palaeotemperature inference model for use with fossil midges from eastern Canada

    NARCIS (Netherlands)

    Walker, I.R.; Levesque, A.J.; Cwynar, L.C.; Lotter, A.F.

    1997-01-01

    Using an expanded surface sample data set, representing lakes distributed across a transect from southernmost Canada to the Canadian High Arctic, a revised midge-palaeotemperature inference model was developed for eastern Canada.Modelling trials with weighted averaging (with classical and inverse de

  15. Origin and development of the tergotrochanteral muscle in Chironomus (Diptera: Nematocera).

    Science.gov (United States)

    Lebart-Pedebas, M C

    1992-01-01

    The origin and the development of the tubular tergo-trochanteral muscle (TTD) was studied by light and electron microscopy in Chironomus (Diptera: Nematocera). Unlike the flight muscles, the TTD was found to develop from myoblasts located around a larval axon, without contribution from a larval muscle. The myoblasts fuse together to form myotubes. Innervation of the TTD arises from the larval axon. The myotubes send out sarcoplasmic extensions towards the axon branches issued from the larval axon. The first differentiated synapses are described. The TTD begins to grow later than the flight muscles. The implications of this developmental lag are discussed.

  16. Analysis of SSH library of rice variety Aganni reveals candidate gall midge resistance genes.

    Science.gov (United States)

    Divya, Dhanasekar; Singh, Y Tunginba; Nair, Suresh; Bentur, J S

    2016-03-01

    The Asian rice gall midge, Orseolia oryzae, is a serious insect pest causing extensive yield loss. Interaction between the gall midge and rice genotypes is known to be on a gene-for-gene basis. Here, we report molecular basis of HR- (hypersensitive reaction-negative) type of resistance in Aganni (an indica rice variety possessing gall midge resistance gene Gm8) through the construction and analysis of a suppressive subtraction hybridization (SSH) cDNA library. In all, 2,800 positive clones were sequenced and analyzed. The high-quality ESTs were assembled into 448 non-redundant gene sequences. Homology search with the NCBI databases, using BlastX and BlastN, revealed that 73% of the clones showed homology to genes with known function and majority of ESTs belonged to the gene ontology category 'biological process'. Validation of 27 putative candidate gall midge resistance genes through real-time PCR, following gall midge infestation, in contrasting parents and their derived pre-NILs (near isogenic lines) revealed induction of specific genes related to defense and metabolism. Interestingly, four genes, belonging to families of leucine-rich repeat (LRR), heat shock protein (HSP), pathogenesis related protein (PR), and NAC domain-containing protein, implicated in conferring HR+ type of resistance, were found to be up-regulated in Aganni. Two of the reactive oxygen intermediates (ROI)-scavenging-enzyme-coding genes Cytosolic Ascorbate Peroxidase1, 2 (OsAPx1 and OsAPx2) were found up-regulated in Aganni in incompatible interaction possibly suppressing HR. We suggest that Aganni has a deviant form of inducible, salicylic acid (SA)-mediated resistance but without HR.

  17. Origin and development of the dorso-ventral flight muscles in Chironomus (Diptera; Nematocera).

    Science.gov (United States)

    Lebart-Pedebas, M C

    1990-01-01

    The origin and development of the dorso-ventral flight muscles (DVM) was studied by light and electron microscopy in Chironomus (Diptera; Nematocera). Chironomus was chosen because unlike Drosophila, its flight muscles develop during the last larval instar, before the lytic process of metamorphosis. Ten fibrillar DVM were shown to develop from a larval muscle associated with myoblasts. This muscle is connected to the imaginal leg disc so that its cavity communicates with the adepithelial cells present in the disc; but no migration of myoblasts seems to take place from the imaginal leg disc towards the larval muscle or vice versa. At the beginning of the last larval instar, the myoblasts were always present together with the nerves in the larval muscle. In addition, large larval muscle cells incorporated to the imaginal discs were observed to border on the area occupied by adepithelial cells, and are probably involved in the formation of 4 other fibrillar DVM with adepithelial cells. Three factors seem to determine the number of DVM fibres: the initial number of larval fibres in the Anlage, the fusions of myoblasts with these larval fibres and the number of motor axons in the Anlage. The extrapolation of these observations to Drosophila, a higher dipteran, is discussed.

  18. Sediment microbes and biofilms increase the bioavailability of chlorpyrifos in Chironomus riparius (Chironomidae, Diptera).

    Science.gov (United States)

    Widenfalk, Anneli; Lundqvist, Anna; Goedkoop, Willem

    2008-10-01

    In a microcosm study, the importance of different sources of organic matter (humic acids, sterile sediment, sediment, and a microbial extract) for the bioavailability of the hydrophobic pesticide chlorpyrifos to Chironomus riparius larvae was quantified. In the last two treatments biofilms were allowed to grow before (14)C-chlorpyrifos addition. Chlorpyrifos accumulation was quantified after 25 h of exposure and after 21 h of depuration. Larval accumulation was twice as high in the microbial extract treatment (447+/-79 microg/kg ww larvae) and 1.7 times higher in the sediment treatment (371+/-33 microg/kg). After depuration, chlorpyrifos accumulation in larval tissue showed even higher differences; 3.1 times higher tissue concentrations in the microbial extract treatment (218+/-21 microg/kg) and 2.2 times higher in the sediment treatment (156+/-35 microg/kg). In contrast, chlorpyrifos accumulation in the humic acid and sterile sediment did not differ from that in controls. These results show that living microbes and biofilms, by creating a microenvironment and providing food for larvae, markedly increase the bioavailability of chlorpyrifos to Chironomus riparius.

  19. Compact genome of the Antarctic midge is likely an adaptation to an extreme environment

    Science.gov (United States)

    Kelley, Joanna L.; Peyton, Justin T.; Fiston-Lavier, Anna-Sophie; Teets, Nicholas M.; Yee, Muh-Ching; Johnston, J. Spencer; Bustamante, Carlos D.; Lee, Richard E.; Denlinger, David L.

    2014-01-01

    The midge, Belgica antarctica, is the only insect endemic to Antarctica, and thus it offers a powerful model for probing responses to extreme temperatures, freeze tolerance, dehydration, osmotic stress, ultraviolet radiation and other forms of environmental stress. Here we present the first genome assembly of an extremophile, the first dipteran in the family Chironomidae, and the first Antarctic eukaryote to be sequenced. At 99 megabases, B. antarctica has the smallest insect genome sequenced thus far. Although it has a similar number of genes as other Diptera, the midge genome has very low repeat density and a reduction in intron length. Environmental extremes appear to constrain genome architecture, not gene content. The few transposable elements present are mainly ancient, inactive retroelements. An abundance of genes associated with development, regulation of metabolism and responses to external stimuli may reflect adaptations for surviving in this harsh environment. PMID:25118180

  20. An Attractant of the Aphidophagous Gall Midge Aphidoletes aphidimyza From Honeydew of Aphis gossypii.

    Science.gov (United States)

    Watanabe, Hiroshi; Yano, Eizi; Higashida, Keita; Hasegawa, Syouichi; Takabayashi, Junji; Ozawa, Rika

    2016-02-01

    Many natural enemies of insects use honeydew as a volatile cue to locate hosts or prey, as an oviposition stimulant, and as an arrestant for foraging. The aphidophagous gall midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae) has predacious larval stages and can be used to control aphid populations, especially in greenhouses. Previous studies have shown that the honeydew, excreted by the aphid Myzus persicae, attracts A. aphidimyza, but the crucial attractants have not been identified. Using an olfactometer, we studied behavioral responses of female A. aphidimyza to volatiles emitted from honeydew excreted by the aphid Aphis gossypii on eggplants. The volatiles attracted female midges and induced oviposition. Moreover, using gas chromatography coupled with mass spectrometry (GC/MS), we identified phenylacetaldehyde as the attractant compound in the honeydew, although it did not induce oviposition in olfactometer experiments.

  1. A fossil biting midge (Diptera: Ceratopogonidae) from early Eocene Indian amber with a complex pheromone evaporator

    Science.gov (United States)

    Stebner, Frauke; Szadziewski, Ryszard; Rühr, Peter T.; Singh, Hukam; Hammel, Jörg U.; Kvifte, Gunnar Mikalsen; Rust, Jes

    2016-10-01

    The life-like fidelity of organisms captured in amber is unique among all kinds of fossilization and represents an invaluable source for different fields of palaeontological and biological research. One of the most challenging aspects in amber research is the study of traits related to behaviour. Here, indirect evidence for pheromone-mediated mating behaviour is recorded from a biting midge (Ceratopogonidae) in 54 million-year-old Indian amber. Camptopterohelea odora n. sp. exhibits a complex, pocket shaped structure on the wings, which resembles the wing folds of certain moth flies (Diptera: Psychodidae) and scent organs that are only known from butterflies and moths (Lepidoptera) so far. Our studies suggests that pheromone releasing structures on the wings have evolved independently in biting midges and might be much more widespread in fossil as well as modern insects than known so far.

  2. Compact genome of the Antarctic midge is likely an adaptation to an extreme environment.

    Science.gov (United States)

    Kelley, Joanna L; Peyton, Justin T; Fiston-Lavier, Anna-Sophie; Teets, Nicholas M; Yee, Muh-Ching; Johnston, J Spencer; Bustamante, Carlos D; Lee, Richard E; Denlinger, David L

    2014-08-12

    The midge, Belgica antarctica, is the only insect endemic to Antarctica, and thus it offers a powerful model for probing responses to extreme temperatures, freeze tolerance, dehydration, osmotic stress, ultraviolet radiation and other forms of environmental stress. Here we present the first genome assembly of an extremophile, the first dipteran in the family Chironomidae, and the first Antarctic eukaryote to be sequenced. At 99 megabases, B. antarctica has the smallest insect genome sequenced thus far. Although it has a similar number of genes as other Diptera, the midge genome has very low repeat density and a reduction in intron length. Environmental extremes appear to constrain genome architecture, not gene content. The few transposable elements present are mainly ancient, inactive retroelements. An abundance of genes associated with development, regulation of metabolism and responses to external stimuli may reflect adaptations for surviving in this harsh environment.

  3. New records of non-biting midges (Diptera: Chironomidae, Orthocladiinae from Mallorca, Spain

    Directory of Open Access Journals (Sweden)

    Viktor Baranov

    2016-09-01

    Full Text Available Ten species of non-biting midges belonging to the subfamily Orthocladiinae were found in samples from predominantly madicolous habitats in Mallorca, Spain. One species, Bryophaenocladius nidorum (Edwards, 1929, has not previously been recorded from Spain, while Smittia pratorum (Goetghebuer, 1927, Bryophaenocladius inconstans (Brundin, 1947, Orthocladius (O. maius Goetghebuer, 1942, Paracladius conversus (Walker, 1856 and Paraphaenocladius impensus (Walker, 1856 are recorded for the first time from the Balearic Islands.

  4. Comparison of different light sources for trapping Culicoides biting midges, mosquitoes and other dipterans.

    Science.gov (United States)

    González, Mikel; Alarcón-Elbal, Pedro María; Valle-Mora, Javier; Goldarazena, Arturo

    2016-08-15

    The response of Culicoides biting midges, mosquitoes and other dipterans to different wavelengths was evaluated in a farm meadow in northern Spain. A total of 9449 specimens of 23 species of Culicoides, 5495 other ceratopogonids (non-biting midges), 602 culicids and 12428 other mixed dipterans were captured. Centers for Disease Control and Prevention (CDC) suction light traps fitted with five light emitting diodes (LEDs) (white, green, red, blue, ultraviolet) were run for 15 consecutive nights. Significantly more Culicoides were collected in those traps fitted with green, blue or ultraviolet (UV) lights than in red and white-baited LED traps for the most abundant species captured: C. punctatus (37.5%), C. cataneii (26.5%) and C. obsoletus/C. scoticus (20.4%). Similar results were obtained for non-Culicoides ceratopogonids, mosquitoes and other mixed dipterans. Wavelengths in green (570nm) resulted effective for targeting some Culicoides species, culicids and other midges. In a second trial, the effectiveness of 4-W white and UV tubes was compared to traps fitted with UV LED and a standard incandescent light bulb. More specimens of all taxa were collected with fluorescent black light (UV) traps than with the other light sources, except culicids, which were recovered in high numbers from fluorescent white light traps.

  5. Carotenoids in unexpected places: gall midges, lateral gene transfer, and carotenoid biosynthesis in animals.

    Science.gov (United States)

    Cobbs, Cassidy; Heath, Jeremy; Stireman, John O; Abbot, Patrick

    2013-08-01

    Carotenoids are conjugated isoprenoid molecules with many important physiological functions in organisms, including roles in photosynthesis, oxidative stress reduction, vision, diapause, photoperiodism, and immunity. Until recently, it was believed that only plants, microorganisms, and fungi were capable of synthesizing carotenoids and that animals acquired them from their diet, but recent studies have demonstrated that two arthropods (pea aphid and spider mite) possess a pair of genes homologous to those required for the first step of carotenoid biosynthesis. Absent in all other known animal genomes, these genes appear to have been acquired by aphids and spider mites in one or several lateral gene transfer events from a fungal donor. We report the third case of fungal carotenoid biosynthesis gene homologs in an arthropod: flies from the family Cecidomyiidae, commonly known as gall midges. Using phylogenetic analyses we show that it is unlikely that lycopene cyclase/phytoene synthase and phytoene desaturase homologs were transferred singly to an ancient arthropod ancestor; instead we propose that genes were transferred independently from related fungal donors after divergence of the major arthropod lineages. We also examine variation in intron placement and copy number of the carotenoid genes that may underlie function in the midges. This trans-kingdom transfer of carotenoid genes may represent a key innovation, underlying the evolution of phytophagy and plant-galling in gall midges and facilitating their extensive diversification across plant lineages.

  6. Does gall midge larvae cause pre-dispersal seed mortality and limit cornflower population growth?

    Science.gov (United States)

    Koprdova, Stanislava; Bellanger, Solène; Skuhrovec, Jiří; Darmency, Henri

    2015-11-01

    Many kinds of pests can reduce seed production. Some directly attack seeds before they are released, and some are hosted by the fruit and impact seed ripening and viability indirectly. Pre-dispersal seed mortality may have strong effects on plant population dynamics and evolution. Our goals were to determine to what extent insect-mediated pre-dispersal seed mortality contributes to population-level declines of cornflower, Centaurea cyanus L. We recorded occurrence and abundance of seed-feeding insects on flower heads in twelve cornflower populations. We measured flower head size, number of disc florets, seed production, and seed viability and germination. Larger flower heads had proportionally fewer healthy seeds. Although we observed no visible damage to the C. cyanus seed, the presence of gall midge (Cecidomyiidae) larvae inside the flower head correlated with four times fewer viable seeds. It seems that gall midges could have a significant impact on ovule fertilization, seed abortion and viability of fully developed cornflower seeds. The higher rate of aborted seeds in the presence of gall midge larvae could have been because the larvae extracted resources from the seeds, or because the larvae repelled pollinators. The viability of apparently healthy seeds was 40% lower in flower heads that contained larvae and/or aborted seed. Insect-mediated pre-dispersal mortality could select against evolution toward larger flower head, and have detrimental consequences on seed number, viability and germination, all of which could limit the spread of C. cyanus populations.

  7. Identifying primary stressors impacting macroinvertebrates in the Salinas River (California, USA): Relative effects of pesticides and suspended particles

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, B.S. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)]. E-mail: anderson@ucdavis.edu; Phillips, B.M. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Hunt, J.W. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Connor, V. [Division of Water Quality, State Water Resources Control Board, 1001 I. Street, Sacramento, CA 95814 (United States); Richard, N. [Division of Water Quality, State Water Resources Control Board, 1001 I. Street, Sacramento, CA 95814 (United States); Tjeerdema, R.S. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)

    2006-06-15

    Laboratory dose-response experiments with organophosphate and pyrethroid pesticides, and dose-response experiments with increasing particle loads were used to determine which of these stressors were likely responsible for the toxicity and macroinvertebrate impacts previously observed in the Salinas River. Experiments were conducted with the amphipod Hyalella azteca, the baetid mayfly Procloeon sp., and the midge Chironomus dilutus (Shobanov, formerly Chironomus tentans). The results indicate the primary stressor impacting H. azteca was pesticides, including chlorpyrifos and permethrin. The mayfly Procloeon sp. was sensitive to chlorpyrifos and permethrin within the range of concentrations of these pesticides measured in the river. Chironomus dilutus were sensitive to chlorpyrifos within the ranges of concentrations measured in the river. None of the species tested were affected by turbidity as high as 1000 NTUs. The current study shows that pesticides are more important acute stressors of macroinvertebrates than suspended sediments in the Salinas River. - Pesticides are the primary stressor impacting macroinvertebrates in sections of the lower Salinas River.

  8. Dynamics and recovery of a sediment-exposed Chironomus riparius population: A modelling approach.

    Science.gov (United States)

    Diepens, Noël J; Beltman, Wim H J; Koelmans, Albert A; Van den Brink, Paul J; Baveco, Johannes M

    2016-06-01

    Models can be used to assess long-term risks of sediment-bound contaminants at the population level. However, these models usually lack the coupling between chemical fate in the sediment, toxicokinetic-toxicodynamic processes in individuals and propagation of individual-level effects to the population. We developed a population model that includes all these processes, and used it to assess the importance of chemical uptake routes on a Chironomus riparius population after pulsed exposure to the pesticide chlorpyrifos. We show that particle ingestion is an important additional exposure pathway affecting C. riparius population dynamics and recovery. Models ignoring particle ingestion underestimate the impact and the required recovery times, which implies that they underestimate risks of sediment-bound chemicals. Additional scenario studies showed the importance of selecting the biologically relevant sediment layer and showed population effects in the long term.

  9. [Seasonal variability of the karyotype structure of Chironomus plumosus (Diptera, Chironomidae) from a biotope of Kaliningrad].

    Science.gov (United States)

    Petrova, N A; Vinokurova, N V; Danilova, M V; Maslova, V V

    2007-01-01

    Chironomus plumosus larvae from the polluted Shkolnoe lake, Kaliningrad, have 2n = 8 and 2n = 8 + B. In winter season we found 11 types of hetero- and homozygous inversions in A, B, C, D, E, and F arms whereas in summer season we registered 7 types of the same inversions in A, B, C, D, and E arms. All inversions with exception of the inversion in arm C correspond to Hardy-Weinberg equilibrium. The arm IVG shows homozygous increase of centromeric heterochromatin more frequently in summer than in winter (34.4% as compared with 1.8%). The arm E has asynapsis 2 times less frequently in summer than in winter (21.4% as compared with 44.6%).

  10. The Evolution of SINEs and LINEs in the genus Chironomus (Diptera).

    Science.gov (United States)

    Papusheva, Ekaterina; Gruhl, Mary C; Berezikov, Eugene; Groudieva, Tatiana; Scherbik, Svetlana V; Martin, Jon; Blinov, Alexander; Bergtrom, Gerald

    2004-03-01

    Genomic DNA amplification from 51 species of the family Chironomidae shows that most contain relatives of NLRCth1 LINE and CTRT1 SINE retrotransposons first found in Chironomus thummi. More than 300 cloned PCR products were sequenced. The amplified region of the reverse transcriptase gene in the LINEs is intact and highly conserved, suggesting active elements. The SINEs are less conserved, consistent with minimal/no selection after transposition. A mitochondrial gene phylogeny resolves the Chironomus genus into six lineages (Guryev et al. 2001). LINE and SINE phylogenies resolve five of these lineages, indicating their monophyletic origin and vertical inheritance. However, both the LINE and the SINE tree topologies differ from the species phylogeny, resolving the elements into "clusters I-IV" and "cluster V" families. The data suggest a descent of all LINE and SINE subfamilies from two major families. Based on the species phylogeny, a few LINEs and a larger number of SINEs are cladisitically misplaced. Most misbranch with LINEs or SINEs from species with the same families of elements. From sequence comparisons, cladistically misplaced LINEs and several misplaced SINEs arose by convergent base substitutions. More diverged SINEs result from early transposition and some are derived from multiple source SINEs in the same species. SINEs from two species (C. dorsalis, C. pallidivittatus), expected to belong to the clusters I-IV family, branch instead with cluster V family SINEs; apparently both families predate separation of cluster V from clusters I-IV species. Correlation of the distribution of active SINEs and LINEs, as well as similar 3' sequence motifs in CTRT1 and NLRCth1, suggests coevolving retrotransposon pairs in which CTRT1 transposition depends on enzymes active during NLRCth1 LINE mobility.

  11. Assessment of potential biomarkers, metallothionein and vitellogenin mRNA expressions in various chemically exposed benthic Chironomus riparius larvae

    Science.gov (United States)

    Park, Kiyun; Kwak, Inn-Sil

    2012-12-01

    The objective of this study was conducted to identify the possibility of using Chironomus metallothionein (MT) and vitellogenin (VTG) as biomarkers of stress caused by endocrinedisrupting chemicals (EDCs), heavy metals, herbicides and veterinary antibiotics. We characterized the MT and VTG cDNA in Chironomus riparius and evaluated their mRNA expression profiles following exposure to different environmental pollutants. The gene expression analysis showed that the MT mRNA levels increased significantly after long-term exposure to cadmium (Cd), copper (Cu), Lead (Pb), di(2-ethylhexyl) phthalate (DEHP), and 2,4-dichlorophenoxyacetic acid (2,4-D). Moreover, the VTG mRNA expression increased significantly in C. riparius larvae exposed to BPA, NP, DEHP, Cd, 2,4-D and fenbendazole. Evaluation of the long-term effects of environmental pollutants revealed up regulation of Chironomus MT mRNA in response to DEHP exposure among EDCs, and the level of the VTG mRNA was increased significantly following treatment with Cd and herbicide 2,4-D at all concentrations in a dose-dependent manner. These results indicate that VTG could be used as a potential biomarker of herbicide and Cd as well as EDCs, while MT was a potential biomarker of heavy metals such as Cd, Cu, and Pb in aquatic environments.

  12. From Midges to Spiders: Mercury Biotransport in Riparian Zones Near the Buffalo River Area of Concern (AOC), USA.

    Science.gov (United States)

    Pennuto, C M; Smith, M

    2015-12-01

    Riparian communities can receive environmental contaminants from adjacent aquatic 'donor' habitats. We investigated mercury biotransport from aquatic to terrestrial habitats via aquatic insect emergence and uptake by riparian spiders at sites within and upstream of the Buffalo River Area of Concern (AOC), a site with known sediment Hg contamination. Mercury concentration in emerging midges was roughly 10× less than contaminated sediment levels with the AOC, but biomagnification factors from midges to spiders ranged from 2.0 to 2.65 between sites. There was a significantly negative body mass:total mercury relationship in spiders (p Spiders contained significantly more mercury than their midge prey and spiders upstream of the AOC had higher mercury concentrations than spiders from within the AOC. Collectively, these data indicate that riparian spiders can be good mercury sentinels in urban environments, and that riparian communities upstream from the AOC may be at greater risk to mercury than has been previously considered.

  13. Schmallenberg virus circulation in culicoides in Belgium in 2012: field validation of a real time RT-PCR approach to assess virus replication and dissemination in midges.

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    Nick De Regge

    Full Text Available Indigenous Culicoides biting midges are suggested to be putative vectors for the recently emerged Schmallenberg virus (SBV based on SBV RNA detection in field-caught midges. Furthermore, SBV replication and dissemination has been evidenced in C. sonorensis under laboratory conditions. After SBV had been detected in Culicoides biting midges from Belgium in August 2011, it spread all over the country by the end of 2011, as evidenced by very high between-herd seroprevalence rates in sheep and cattle. This study investigated if a renewed SBV circulation in midges occurred in 2012 in the context of high seroprevalence in the animal host population and evaluated if a recently proposed realtime RT-PCR approach that is meant to allow assessing the vector competence of Culicoides for SBV and bluetongue virus under laboratory conditions was applicable to field-caught midges. Therefore midges caught with 12 OVI traps in four different regions in Belgium between May and November 2012, were morphologically identified, age graded, pooled and tested for the presence of SBV RNA by realtime RT-PCR. The results demonstrate that although no SBV could be detected in nulliparous midges caught in May 2012, a renewed but short lived circulation of SBV in parous midges belonging to the subgenus Avaritia occured in August 2012 at all four regions. The infection prevalence reached up to 2.86% in the south of Belgium, the region where a lower seroprevalence was found at the end of 2011 than in the rest of the country. Furthermore, a frequency analysis of the Ct values obtained for 31 SBV-S segment positive pools of Avaritia midges showed a clear bimodal distribution with peaks of Ct values between 21-24 and 33-36. This closely resembles the laboratory results obtained for SBV infection of C. sonorensis and implicates indigenous midges belonging to the subgenus Avaritia as competent vectors for SBV.

  14. Schmallenberg virus circulation in culicoides in Belgium in 2012: field validation of a real time RT-PCR approach to assess virus replication and dissemination in midges.

    Science.gov (United States)

    De Regge, Nick; Madder, Maxime; Deblauwe, Isra; Losson, Bertrand; Fassotte, Christiane; Demeulemeester, Julie; Smeets, François; Tomme, Marie; Cay, Ann Brigitte

    2014-01-01

    Indigenous Culicoides biting midges are suggested to be putative vectors for the recently emerged Schmallenberg virus (SBV) based on SBV RNA detection in field-caught midges. Furthermore, SBV replication and dissemination has been evidenced in C. sonorensis under laboratory conditions. After SBV had been detected in Culicoides biting midges from Belgium in August 2011, it spread all over the country by the end of 2011, as evidenced by very high between-herd seroprevalence rates in sheep and cattle. This study investigated if a renewed SBV circulation in midges occurred in 2012 in the context of high seroprevalence in the animal host population and evaluated if a recently proposed realtime RT-PCR approach that is meant to allow assessing the vector competence of Culicoides for SBV and bluetongue virus under laboratory conditions was applicable to field-caught midges. Therefore midges caught with 12 OVI traps in four different regions in Belgium between May and November 2012, were morphologically identified, age graded, pooled and tested for the presence of SBV RNA by realtime RT-PCR. The results demonstrate that although no SBV could be detected in nulliparous midges caught in May 2012, a renewed but short lived circulation of SBV in parous midges belonging to the subgenus Avaritia occured in August 2012 at all four regions. The infection prevalence reached up to 2.86% in the south of Belgium, the region where a lower seroprevalence was found at the end of 2011 than in the rest of the country. Furthermore, a frequency analysis of the Ct values obtained for 31 SBV-S segment positive pools of Avaritia midges showed a clear bimodal distribution with peaks of Ct values between 21-24 and 33-36. This closely resembles the laboratory results obtained for SBV infection of C. sonorensis and implicates indigenous midges belonging to the subgenus Avaritia as competent vectors for SBV.

  15. Entomopathogenic fungus as a biological control for an important vector of livestock disease: the Culicoides biting midge.

    Directory of Open Access Journals (Sweden)

    Minshad Ali Ansari

    Full Text Available BACKGROUND: The recent outbreak of bluetongue virus in northern Europe has led to an urgent need to identify control measures for the Culicoides (Diptera: Ceratopogonidae biting midges that transmit it. Following successful use of the entomopathogenic fungus Metarhizium anisopliae against larval stages of biting midge Culicoides nubeculosus Meigen, we investigated the efficacy of this strain and other fungi (Beauveria bassiana, Isaria fumosorosea and Lecanicillium longisporum as biocontrol agents against adult C. nubeculosus in laboratory and greenhouse studies. METHODOLOGY/FINDINGS: Exposure of midges to 'dry' conidia of all fungal isolates caused significant reductions in survival compared to untreated controls. Metarhizium anisopliae strain V275 was the most virulent, causing a significantly decrease in midge survival compared to all other fungal strains tested. The LT(50 value for strain V275 was 1.42 days compared to 2.21-3.22 days for the other isolates. The virulence of this strain was then further evaluated by exposing C. nubeculosus to varying doses (10(8-10(11 conidia m(-2 using different substrates (horse manure, damp peat, leaf litter as a resting site. All exposed adults were found to be infected with the strain V275 four days after exposure. A further study exposed C. nubeculosus adults to 'dry' conidia and 'wet' conidia (conidia suspended in 0.03% aq. Tween 80 of strain V275 applied to damp peat and leaf litter in cages within a greenhouse. 'Dry' conidia were more effective than 'wet' conidia, causing 100% mortality after 5 days. CONCLUSION/SIGNIFICANCE: This is the first study to demonstrate that entomopathogenic fungi are potential biocontrol agents against adult Culicoides, through the application of 'dry' conidia on surfaces (e.g., manure, leaf litter, livestock where the midges tend to rest. Subsequent conidial transmission between males and females may cause an increased level of fungi-induced mortality in midges thus

  16. Identification of female-produced sex pheromone of the honey locust gall midge, Dasineura gleditchiae.

    Science.gov (United States)

    Molnár, Béla; Kárpáti, Zsolt; Szocs, Gábor; Hall, David R

    2009-06-01

    The honey locust gall midge, Dasineura gleditchiae Osten Sacken 1866 (Diptera: Cecidomyiidae) is the main pest of ornamental varieties of the honey locust tree, Gleditsia triacanthos L., in North America, and is now becoming a pest of concern in Europe. Female midges were observed to emerge in the early morning with their ovipositor extended until they mated. Volatiles were collected from virgin females in a closed-loop stripping apparatus and analyzed by gas chromatography (GC) coupled to electroantennographic (EAG) recording from the antenna of a male midge. A single EAG response was observed, which was assumed to be to the major component of the female sex pheromone. This was identified as (Z)-2-acetoxy-8-heptadecene by comparison of its mass spectrum and GC retention times on different columns with those of synthetic standards and by micro-analytical reactions. This compound was synthesized, and the individual enantiomers were produced by kinetic resolution with lipase from Candida antarctica. Analysis of the naturally-produced compound on a cyclodextrin GC column indicated it was the (R)-enantiomer. In EAG dose-response measurements, the (R)-enantiomer alone or in the racemic mixture evoked significant responses from the antennae of male D. gleditchiae, whereas the (S)-enantiomer did not. In field trapping tests, the (R)-enantiomer attracted male D. gleditchiae. The racemic compound was equally attractive, but the (S)-enantiomer was not attractive. Both the pure (R)-enantiomer or racemic (Z)-2-acetoxy-8-heptadecene, applied to red rubber septa in a dose range of 3-30 microg, constitute a strongly attractive bait in sticky traps for monitoring the flight of D. gleditchiae.

  17. Wing pattern variation in the Patagonian biting midge, Forcipomyia (Forcipomyia multipicta Ingram & Macfie (Diptera, Ceratopogonidae

    Directory of Open Access Journals (Sweden)

    Gustavo R. SPINELLI

    2012-01-01

    Full Text Available Examination of the type-series and non-type specimens of the Patagonian biting midge, Forcipomyia (Forcipomyia multipicta Ingram & Macfie (Diptera: Ceratopogonidae, revealed considerable variation in wing patterns of both sexes. One pattern includes several distinct light spot areas, whereas another pattern (e.g, in the holotype only features marginal light spots in cell r3, while other light spots are barely perceptible or absent. The cause(s of the differential lack of dark macrotrichia in certain areas of the wing membrane in specimens of some series could not be attributed either to their age, sex, or method of preservation.

  18. Community analysis of biting midges (Culicoides Latr.) on livestock farms in Denmark

    DEFF Research Database (Denmark)

    Nielsen, S. A.; Banta, G.; Rasmussen, Anne-Marie;

    2014-01-01

    This study presents descriptive statistics and community analysis of adult biting midges trapped at 16 livestock farms by means of light traps on Zealand and Lolland-Falster, Denmark. A total of 9,047 male and female Culicoides divided into 24 species, were caught. Biotic and abiotic factors...... ranging from presence of different host species (cattle or sheep/goats), presence of small woody areas or wetlands in the surrounding landscape, and agricultural practice (organic or conventional) were included in the community analysis. Only differences in the Culicoides communities between conventional...

  19. Two torymid species (Hymenoptera: Chalcidoidea, Torymidae developing on Artemisia gall midges (Diptera: Cecidomyiidae

    Directory of Open Access Journals (Sweden)

    Lotfalizadeh Hossein

    2015-12-01

    Full Text Available Two parasitoid wasps, Torymus artemisiae Mayr and Torymoides violaceus (Nikol’skaya, were reared on Artemisia herba-alba (Asteraceae galles, in central Iran. Torymus artemisiae and T. violaceus were developed from the gall midges: Rhopalomyia navasi Tavares and R. hispanica Tavares, respectively. The occurrence of these two parasitic wasps in Iran, and their associations with R. navasi and R. hispanica, are new. Data on the wasps’ biological associations and geographical distribution are provided. The parasitoid compositions of the genus Rhopalomyia (Diptera: Cecidomyiidae were also discussed.

  20. Bluetongue virus isolations from midges belonging to the Obsoletus complex (Culicoides, Diptera: Ceratopogonidae) in Italy.

    Science.gov (United States)

    Savini, G; Goffredo, M; Monaco, F; Di Gennaro, A; Cafiero, M A; Baldi, L; de Santis, P; Meiswinkel, R; Caporale, V

    2005-07-30

    Between July and September 2002 there were outbreaks of bluetongue on three sheep holdings in the communities of San Gregorio Magno (Salerno, Campania), Laviano (Salerno, Campania) and Carpino (Foggia, Puglia), and the involvement of bluetongue virus (btv) was confirmed serologically and virologically. The mortality rate was at least 11 per cent and involved btv serotype 2 (btv-2) and serotype 9 (btv-9). These holdings were also surveyed for the Culicoides (Diptera: Ceratopogonidae) vectors; approximately 10,000 midges belonging to 15 species were captured, but they did not include a single specimen of the classical Afro-Asiatic bluetongue vector, Culicoides imicola. Species belonging to the Obsoletus complex dominated the light-trap collections, and Culicoides obsoletus Meigen, Culicoides scoticus Downes and Kettle and Culicoides dewulfi Goetghebuer constituted 90 per cent of all the Culicoides species captured. Fifty-six pools of the Obsoletus complex (excluding C dewulfi), each containing 100 individual midges and containing only parous and gravid females, were assayed for virus. btv-2 was isolated from three pools from San Gregorio Magno and Carpino, and btv-9 was isolated from one pool from Laviano. These results indicate that a species other than C imicola is involved in the current re-emergence of bluetongue in the Mediterranean Basin, but whether it is C obsoletus sensu stricto or C scoticus, or both, is uncertain.

  1. Homosexual Pairing within a Swarm-Based Mating System: The Case of the Chironomid Midge

    Directory of Open Access Journals (Sweden)

    Athol J. McLachlan

    2011-01-01

    Full Text Available Homosexuality has been dubbed the Darwinian paradox, because it raises the question of how behaviour that would seem to reduce the chance of successful mating can be maintained by natural selection. This question rests on the assumption that same sex mating is the result of active choice of partner, hardwired into the mating behaviour, but there is an alternative explanation for such behaviour. I refer to the possibility that same-sex mating is the result, not of adaptive behaviour at all, but rather of errors due to imprecise sensory machinery. Such an explanation finds support within the mating system of insects with swarm-based mating systems. To explore this case, I turn to the common chironomid midge. I show that homosexual pairing here, exclusively involving male/male pairs, is common. I attempt to show that this observation, together with data on insect predators of swarming midges, can be used to penetrate the mysteries of this fascinating but elusive mating system.

  2. Wild swarms of midges linger at the edge of an ordering phase transition

    Science.gov (United States)

    Giardina, Irene

    2014-03-01

    The most notable hallmark of collective behavior in biological systems is the emergence of order: individuals synchronize their state, giving the stunning impression that the group behaves as one. Birds flocks, fish schools and mammal herds are just a few common examples of polarized animal groups. Mating swarms of mosquitoes and midges, on the other hand, do not display global order and it is therefore unclear whether swarms are a true instance of collective behavior or a mere epiphenomenon of the independent response of each insect to an environmental stimulus. The crucial task for a group, however, is not simply to achieve an ordered state, but to respond collectively to the environmental stimuli. For this to happen, correlation must be large, namely individuals must be able to influence each other's behavioral changes on a group scale. In this work, we experimentally study wild swarms of midges and find that, despite the lack of collective order, swarms display strong correlation, comparable to that found in highly ordered groups of vertebrates. Correlation is orders of magnitude larger in natural swarms than in random systems, indicating the existence of large clusters of insects responding together. We also find that the total amount of correlation, i.e. the susceptibility, increases sharply with the swarm density, a distinctive mark of an incipient ordering phase transition. Swarms, however, live at the near-critical edge of this transition, never plunging in the ordered phase, suggesting that their size and density are tuned to maximize collective response.

  3. Characterization of Viral Communities of Biting Midges and Identification of Novel Thogotovirus Species and Rhabdovirus Genus

    Directory of Open Access Journals (Sweden)

    Sarah Temmam

    2016-03-01

    Full Text Available More than two thirds of emerging viruses are of zoonotic origin, and among them RNA viruses represent the majority. Ceratopogonidae (genus Culicoides are well-known vectors of several viruses responsible for epizooties (bluetongue, epizootic haemorrhagic disease, etc.. They are also vectors of the only known virus infecting humans: the Oropouche virus. Female midges usually feed on a variety of hosts, leading to possible transmission of emerging viruses from animals to humans. In this context, we report here the analysis of RNA viral communities of Senegalese biting midges using next-generation sequencing techniques as a preliminary step toward the identification of potential viral biohazards. Sequencing of the RNA virome of three pools of Culicoides revealed the presence of a significant diversity of viruses infecting plants, insects and mammals. Several novel viruses were detected, including a novel Thogotovirus species, related but genetically distant from previously described tick-borne thogotoviruses. Novel rhabdoviruses were also detected, possibly constituting a novel Rhabdoviridae genus, and putatively restricted to insects. Sequences related to the major viruses transmitted by Culicoides, i.e., African horse sickness, bluetongue and epizootic haemorrhagic disease viruses were also detected. This study highlights the interest in monitoring the emergence and circulation of zoonoses and epizooties using their arthropod vectors.

  4. [Nuclear protein matrix from giant nuclei of Chironomus plumosus determinates polythene chromosome organization].

    Science.gov (United States)

    Makarov, M S; Chentsov, Iu S

    2010-01-01

    Giant nuclei from salivary glands of Chironomus plumosus were treated in situ with detergent, 2 M NaCl and nucleases in order to reveal residual nuclear matrix proteins (NMP). It was shown, that preceding stabilization of non-histone proteins with 2 mM CuCl2 allowed to visualize the structure of polythene chromosomes at every stage of the extraction of histones and DNA. Stabilized NPM of polythene chromosomes maintains their morphology and banding patterns, which is observed by light and electron microscopy, whereas internal fibril net or residual nucleoli are not found. In stabilized NPM of polythene chromosomes, topoisomerase IIalpha and SMC1 retain their localization that is typical of untreated chromosomes. NPM of polythene chromosomes also includes sites of DNA replication, visualized with BrDU incubation, and some RNA-components. So, we can conclude that structure of NPM from giant nuclei is equal to NPM from normal interphase nuclei, and that morphological features of polythene chromosomes depend on the presence of NMP.

  5. Bioavailability-based toxicity endpoints of bifenthrin for Hyalella azteca and Chironomus dilutus.

    Science.gov (United States)

    Harwood, Amanda D; Landrum, Peter F; Lydy, Michael J

    2013-01-01

    Recent studies have determined that techniques, such as solid phase microextraction (SPME) fibers and Tenax beads, can predict bioaccumulation and potentially could predict toxicity for several compounds and species. Toxicity of bifenthrin was determined using two standard sediment toxicity tests with the benthic species Hyalella azteca and Chironomus dilutus in three reference sediments with different characteristics. The objectives of the current study were to establish bioavailability-based median lethal concentrations (LC50) and median effect concentrations (EC50) of the pyrethroid insecticide bifenthrin, compare their ability to assess toxicity to the use of whole sediment concentrations, as well as to make comparisons of the concentrations derived using each method in order to make assessments of accuracy and extrapolation potential. Four metrics were compared including SPME fiber concentration, pore water concentration derived using SPMEs, 6 h Tenax extractable concentration, and 24 h Tenax extractable concentration. The variation among the LC50s and EC50s in each sediment derived using bioavailability-based methods was comparable to variation among organic carbon normalized sediment concentrations, but improved over whole sediment concentrations. There was a significant linear relationship between SPME or Tenax and organic carbon normalized sediment concentrations. Additionally, there was a significant relationship between the SPME and Tenax concentrations across sediments. The significant linear relationship between SPME and Tenax concentrations further demonstrates that these bioavailability-based endpoints are interrelated. This study derived bioavailability-based benchmarks that may prove to be more accurate than sediment-based ones in predicting toxicity across sediment types.

  6. Ecotoxicological multilevel-evaluation of the effects of fenbendazole exposure to Chironomus riparius larvae.

    Science.gov (United States)

    Park, Kiyun; Bang, Hyun Woo; Park, Jungan; Kwak, Inn-Sil

    2009-10-01

    Veterinary antibiotics may find their way into the aquatic environment through direct or indirect pathways due to their widespread use. Fenbendazole is a benzimidazole anthelmintic that is widely used in veterinary medicine. To evaluate the potential ecological risk of fenbendazole, we examined the molecular and biochemical responses of biomarker genes such as heat shock proteins (HSPs), cytochrome P450 (CYP450), glutathione S-transferases (GSTs) and hemoglobins (Hbs) in Chironomus riparius for long periods. The expression of HSP70, HSP40, HSP90 and CYP450 in C. riparius increased significantly after exposure to all concentrations of fenbendazole evaluated, while the levels of GST and HbA only increased in C. riparius exposed to relatively high concentrations of fenbendazole (30 microg L(-1)). HbB expression did not differ significantly between the control and treatment groups. Exposure to 30 microg L(-1) fenbendazole had significant effects on the survival, growth, sex balance of emergent adults and development of mouthpart deformity in C. riparius. These results should constitute an important contribution to the understanding of the toxicology of fenbendazole in C. riparius. Moreover, the responses of the biomarker genes also provide valuable information that will aid in understanding the effects of fenbendazole in aquatic ecosystems.

  7. Ecotoxicological assessment of grey water treatment systems with Daphnia magna and Chironomus riparius.

    Science.gov (United States)

    Hernández Leal, L; Soeter, A M; Kools, S A E; Kraak, M H S; Parsons, J R; Temmink, H; Zeeman, G; Buisman, C J N

    2012-03-15

    In order to meet environmental quality criteria, grey water was treated in four different ways: 1) aerobic 2) anaerobic+aerobic 3) aerobic+activated carbon 4) aerobic+ozone. Since each treatment has its own specific advantages and disadvantages, the aim of this study was to compare the ecotoxicity of differently treated grey water using Chironomus riparius (96 h test) and Daphnia magna (48 h and 21d test) as test organisms. Grey water exhibited acute toxicity to both test organisms. The aerobic and combined anaerobic+aerobic treatment eliminated mortality in the acute tests, but growth of C. riparius was still affected by these two effluents. Post-treatment by ozone and activated carbon completely removed the acute toxicity from grey water. In the chronic toxicity test the combined anaerobic+aerobic treatment strongly affected D. magna population growth rate (47%), while the aerobic treatment had a small (9%) but significant effect. Hence, aerobic treatment is the best option for biological treatment of grey water, removing most of the toxic effects of grey water. If advanced treatment is required, the treatment with either ozone or GAC were shown to be very effective in complete removal of toxicity from grey water.

  8. Transcriptional changes induced by in vivo exposure to pentachlorophenol (PCP) in Chironomus riparius (Diptera) aquatic larvae.

    Science.gov (United States)

    Morales, Mónica; Martínez-Paz, Pedro; Martín, Raquel; Planelló, Rosario; Urien, Josune; Martínez-Guitarte, José Luis; Morcillo, Gloria

    2014-12-01

    Pentachlorophenol (PCP) has been extensively used worldwide as a pesticide and biocide and is frequently detected in the aquatic environment. In the present work, the toxicity of PCP was investigated in Chironomus riparius aquatic larvae. The effects following short- and long-term exposures were evaluated at the molecular level by analyzing changes in the transcriptional profile of different endocrine genes, as well as in genes involved in the stress response and detoxification. Interestingly, although no differences were found after 12- and 24-h treatments, at 96-h exposures PCP was able to induce significant increases in transcripts from the ecdysone receptor gene (EcR), the early ecdysone-inducible E74 gene, the estrogen-related receptor gene (ERR), the Hsp70 gene and the CYP4G gene. In contrast, the Hsp27 gene appeared to be downregulated, while the ultraspiracle gene (usp) (insect ortholog of the retinoid X receptor) was not altered in any of the conditions assayed. Moreover, Glutathione-S-Transferase (GST) activity was not affected. The results obtained show the ability of PCP to modulate transcription of different biomarker genes from important cellular metabolic activities, which could be useful in genomic approaches to monitoring. In particular, the significant upregulation of hormonal genes represents the first evidence at the genomic level of the potential endocrine disruptive effects of PCP on aquatic invertebrates. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Growth of Chironomus dilutus larvae exposed to ozone-treated and untreated oil sands process water

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J.; Wiseman, S.; Franz, E.; Jones, P.; Liber, K.; Giesy, J. [Saskatchewan Univ., Saskatoon, SK (Canada); Gamal El-Din, M.; Marin, J. [Alberta Univ., Edmonton, AB (Canada)

    2010-07-01

    Oil sand processing operations require large quantities of freshwater and produce large volumes of oil sands process water (OSPW) which must be stored on-site. This presentation reviewed various treatment methods for remediating OSPW in order to eliminate downstream toxicity. Naphthenic acids are the most important target fractions for treatment because they are primarily responsible for the acute toxicity of OSPW. Although ozonation has shown promise for reducing OSPW toxicity, the effects of ozonation on aquatic invertebrates remain unknown. This study investigated the effects of exposure to untreated and ozonated OSPW in Chironomus dilutus larvae. OSPW was treated with either a 50 or 80 mg O{sub 3}/L dose of ozonation. The effects of ozonation levels on C. dilutus survival and growth were examined. The study showed that after a 10-day exposure, there were pronounced effects on survival of larvae exposed to ozone-treated or untreated OSPW. Larvae exposed to OSPW were 64-77 percent smaller than their respective controls, but the mean wet mass of organisms exposed to 50 mg O{sub 3}/L ozonated OSPW was not much different from that of the controls. Larvae exposed to 80 mg O{sub 3}/L ozone-treated OSPW were 40 percent smaller than the freshwater controls, and the mean wet mass was also much larger than the untreated OSPW. It was concluded that the toxicity of OSPW to benthic invertebrates may be reduced by ozone treatment.

  10. Phenotypic differentiation and phylogenetic signal of wing shape in western European biting midges, Culicoides spp., of the subgenus Avaritia

    DEFF Research Database (Denmark)

    Muñoz-Muñoz, F.; Talavera, S.; Carpenter, S.

    2014-01-01

    In the past decade biting midges of the subgenus Avaritia (Diptera: Ceratopogonidae) have been popular subjects of applied entomological studies in Europe owing to their implication as biological vectors in outbreaks of bluetongue and Schmallenberg viruses. This study uses a combination of cytoch...

  11. Histopathological effects of cypermethrin and Bacillus thuringiensis var. israelensis on midgut of Chironomus calligraphus larvae (Diptera: Chironomidae).

    Science.gov (United States)

    Lavarías, Sabrina; Arrighetti, Florencia; Siri, Augusto

    2017-06-01

    Pesticides are extensively used for the control of agricultural pests and disease vectors, but they also affect non-target organisms. Cypermethrin (CYP) is a synthetic pyrethroid used worldwide. Otherwise, bioinsecticides like Bacillus thuringiensis var. israelensis (Bti) have received great attention as an environmentally benign and desirable alternative. In order to evaluate the toxicity of those pesticides, Chironomus calligraphus was selected due to its high sensitivity to some toxicants. Third and fourth instars larvae were exposed to serial dilutions of CYP and Bti to determine LC50 values. In order to evaluate the potentially histopathological alterations as biomarkers, after 96-h of exposure, live larvae were fixed for histological analysis of the mid region of digestive tract. The 96-h LC50 values were 0.52 and 1.506μg/L for CYP and Bti, respectively. Midgut histological structure of the control group showed a single layer of cubical cells with microvilli in their apical surface and a big central nucleus. The midgut epithelium of larvae exposed to a low concentration of CYP (0.037μg/L) showed secretion activity and vacuolization while at high concentration (0.3μg/L) cells showed a greater disorganization and a more developed fat body. On the other hand, Bti caused progressive histological damage in this tissue. Chironomus calligraphus is sensitive to Bti and CYP toxicity like other Chironomus species. The histopathological alterations could be a valuable tool to assess toxicity mechanism of different pesticides. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Functional Validation of Apoptosis Genes IAP1 and DRONC in Midgut Tissue of the Biting Midge Culicoides sonorensis (Diptera: Ceratopogonidae) by RNAi

    Science.gov (United States)

    Background: Culicoides biting midges transmit multiple ruminant viruses, including bluetongue virus and epizootic hemorrhagic disease virus, causing significant economic burden worldwide due to trade restrictions and production loss. To limit the spread of these viruses, control strategies focus on ...

  13. Hypoxia and anoxia effects on alcohol dehydrogenase activity and hemoglobin content in Chironomus riparius Meigen, 1804

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    Valentina Grazioli

    2016-02-01

    Full Text Available The metabolic effects of low oxygen content on alcohol-dehydrogenase (ADH activity and hemoglobin (Hb concentration were investigated in IV-instar larvae of Chironomus riparius (Diptera: Chironomidae from an Italian stream. Two series of short-term (48 h experiments were carried out: exposure to (1 progressive hypoxia (95 to 5% of oxygen saturation and (2 anoxia (at <5% of oxygen saturation. In (1, Hb amount increased with increasing oxygen depletion up to a critical value of oxygenation (about 70% of oxygen saturation. Below this percentage, the Hb amount declined to values comparable with those present in the control. The respiration rate (R remained almost constant at oxygen saturation >50% and decreased significantly only after 48 h of treatment (= <5% of oxygen saturation reaching values <100 mmolO2 gAFDW-1 h-1. ADH activity showed two phases of growth, within the first 14 h and over 18 h of exposure. Overall, we inferred that i Hb might function as short-term oxygen storage, enabling animals to delay the on-set of anaerobiosis; and ii alcoholic fermentation co-occurs for a short time with aerobic respiration, becoming the prevalent metabolic pathway below 5% of oxygen saturation (<1 mg L-1. These considerations were supported also by results from anoxia exposure (2. In such condition, larvae were visibly stressed, becoming immobile after few minutes of incubation, and ADH reached higher values than in the hypoxia treatment (2.03±0.15 UADH mg prot-1. Overall, this study showed a shift from aerobic to anaerobic activity in C. riparius larvae exposed to poorly oxygenated water with an associated alteration of ADH activity and the Hb amount. Such metabolites might be valid candidate biomarkers for the environmental monitoring of running waters.

  14. Factors that alter the biochemical biomarkers of environmental contamination in Chironomus sancticaroli (Diptera, Chironomidae

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    Débora Rebechi-Baggio

    Full Text Available ABSTRACT Changes in physiology of the nervous system and metabolism can be detected through the activity of acetylcholinesterase (AChE, alpha esterase (EST-a and beta esterase (EST-ß in chironomids exposed to pollutants. However, to understand the real effect of xenobiotics on organisms, it is important to investigate how certain factors can interfere with enzyme activity. We investigated the effects of different temperatures, food stress and two steps of the enzymatic protocol on the activity of AChE, EST-a and EST-ß in Chironomus sancticaroli. In experiment of thermal stress individuals from the egg stage to the fourth larval instar were exposed to different temperatures (20, 25 and 30 °C. In food stress experiment, larvae were reared until IV instar in a standard setting (25 °C and 0.9 g weekly ration, but from fourth instar on they were divided into groups and offered different feeding regimes (24, 48 and 72 h with/without food. In sample freezing experiment, a group of samples was processed immediately after homogenization and another after freezing for 30 days. To test the effect of centrifugation on samples, enzyme activity was quantified from centrifuged and non-centrifuged samples. The activity of each enzyme reached an optimum at a different temperature. The absence of food triggered different changes in enzyme activity depending on the period of starvation. Freezing and centrifugation of the samples significantly reduced the activity of three enzymes. Based on these results we conclude that the four factors studied had an influence on AChE, EST-a and EST-ß and this influence should be considered in ecotoxicological approaches.

  15. Genome Instability of Chironomus riparius Mg. (Diptera, Chironomidae from Polluted Water Basins in Bulgaria

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    Julia Ilkova

    2014-04-01

    Full Text Available Larvae of Chironomus riparius Mg. (Chironomidae, Diptera collected from two polluted water basins in Bulgaria, the Maritsa and Chaya Rivers (adjacent to Plovdiv and Asenovgrad respectively, a small pool (near Plovdiv plus controls reared in the laboratory were studied. High concentrations of the heavy metals Pb, Cu and Cd were recorded in the sediments of the polluted stations. Marked somatic structural chromosome aberrations were found in C. riparius salivary polytene chromosomes from the field stations and their frequency was significantly higher (p<0.01 compared to the control. The observed somatic chromosome changes are discussed as a response of the chironomid genome to aquatic pollution. A new cytogenetic index based on the number of aberrations found in larvae from polluted regions in comparison with the control was applied to the data to more easily evaluate the degree of heavy metal pollution in aquatic ecosystems. Our study of a polluted site near the River Chaya showed that the somatic index was very high at 3.35 for 2010 and 11.66 for 2013 compared to 0.5 in the control. The cytogenetic index was effective in showing that all studied sites were highly polluted in comparison with the control. To determine the mechanism involved in the concentration of aberration breakpoints within specific regions of the chironomid polytene chromosome the FISH method was applied. The localization of a transposable element TFB1 along the polytene chromosomes of C. riparius was analyzed and the sites of localization were compared with breakpoints of chromosome aberrations. A significant correlation (p<0.05 was found which shows that most of the aberrations do not appear randomly but are concentrated in sites rich in transposable elements.

  16. A Key to the Pupal Exuviae of the Midges (Diptera: Chironomidae) of Everglades National Park, Florida

    Science.gov (United States)

    Jacobsen, Richard E.

    2008-01-01

    A key has been developed for identifying the pupal exuviae of 132 taxa of chironomid midges collected in Everglades National Park, as well as 18 additional species from freshwater habitats adjacent to the Park. Descriptions and illustrations are based upon voucher specimens from extensive collections of chironomid pupal exuviae for faunal surveys and biomonitoring research conducted in ENP and surrounding freshwater areas from 1998 to 2007. The key includes taxonomic comments for confirming identifications, as well as brief summaries of the distribution and ecology of each species in southern Florida waters. Information is also provided on the morphology of chironomid pupal exuviae, recommended references for identifying pupal exuviae, techniques for making slides, and methods to confirm proper identification.

  17. Culicoides biting midges at the National Zoological Gardens of South Africa : research communication

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    K. Labuschagne

    2007-09-01

    Full Text Available Culicoides biting midges (Diptera: Ceratopogonidae are responsible for the transmission of a large number of pathogens to livestock and wild animals. In this study the presence of the genus, using light traps based at four different sites within the National Zoological Gardens of South Africa, was investigated during 2002-2004. In total, 37 species were recorded, including large numbers of Culicoides imicola Kieffer, 1913, which is responsible for the transmission of economically important arboviruses in South Africa, Europe, Middle and Far East. These results are discussed with reference to the wider Culicoides fauna in the Onderstepoort area of South Africa, their vector competence as well as biosecurity at the National Zoological Gardens.

  18. Sugar-feeding behaviour and longevity of European Culicoides biting midges.

    Science.gov (United States)

    Kaufmann, C; Mathis, A; Vorburger, C

    2015-03-01

    Most haematophagous insect vectors can also use sugar as an energy source; thus their sugar-feeding behaviour influences their longevity and blood-feeding rate and hence their vectorial capacity. Scant information is available on the sugar-feeding behaviour of Culicoides Latreille biting midges (Diptera: Ceratopogonidae), which are vectors of bluetongue and Schmallenberg viruses. The longevity of laboratory-reared Culicoides nubeculosus (Meigen) under fluctuating temperatures (16 and 28 °C) and with access to water or water and blood was on average 6.4 days and 8.9 days, respectively, which was around one third of the lifespan of siblings with access to sugar or sugar and blood (22.2 days and 27.1 days, respectively). Access to honeydew significantly increased the midge's longevity, whereas the provision of extrafloral nectaries had no impact. Females with access to sugar produced a significantly higher number of eggs (65.5 ± 5.2) than their starved sisters (45.4 ± 8.4). More than 80% of field-caught female Culicoides from the two most abundant European groups, Obsoletus (n = 2243) and Pulicaris (n = 805), were fructose-positive. Fructose-positivity was high in all physiological stages and no seasonal variability was noted. The high rate of natural sugar feeding of Culicoides offers opportunities for the development of novel control strategies using toxic sugar baits and for the monitoring of vector-borne diseases using sugar-treated FTA (nucleic acid preservation) cards in the field. © 2014 The Royal Entomological Society.

  19. Moonlight receptor of the "1-h-midge" Clunio marinus studied by micro-XRF

    Science.gov (United States)

    Falkenberg, G.; Fleissner, Ge; Neumann, D.; Wellenreuther, G.; Alraun, P.; Fleissner, Gue

    2013-10-01

    Melanin is a pigment widely occurring in animals, plants, fungi and algae. It does not only colour skin, hair and eyes but serves mainly as photoprotectant and prevents overload with minerals induced by inflammations, infections and degenerative diseases. Therefore, the mechanisms underlying melanisation gained increasing interest in the field of biomedical research and clinic. So far, the processes of melanogenesis are only partly analysed, nearly nothing is known on a putative switch between melanins of different types. Here we offer a model organism to study these mechanisms as part of a naturally cycling change of transparency of the retinal shielding pigment. A marine midge, Clunio marinus, living in coastal regions, underlies a complex timing of its development by solar and lunar climatic periodicities, which synchronise biological clocks. The question was how the animals can discriminate changing sunlight from moonlight intensities. For the first time, we could show a "moonlight window" in the larval ocelli of this midge, and propose a hypothesis on the underlying mechanisms. Driven by a lunar clock the image forming ocelli become transparent and convert during moonlit nights to a sensitive photometer, which can record the dynamics of environmental light. High resolution X-ray fluorescence (XRF) measurements of the distribution of trace minerals in single melanosomes combined with their fine structural details in various states of the lunar cycle provide a first insight into the enzymatic pathways for the generation of a dark melanin (like eumelanin) and a light coloured melanin (like phaeomelanin). Essential advantage of this approach is the spatial and temporal resolution of the metals associated with melanisation processes, which could never before be demonstrated in these details. The data may stimulate further research projects in biomedicine.

  20. Dehydration, rehydration, and overhydration alter patterns of gene expression in the Antarctic midge, Belgica antarctica.

    Science.gov (United States)

    Lopez-Martinez, Giancarlo; Benoit, Joshua B; Rinehart, Joseph P; Elnitsky, Michael A; Lee, Richard E; Denlinger, David L

    2009-05-01

    We investigated molecular responses elicited by three types of dehydration (fast, slow and cryoprotective), rehydration and overhydration in larvae of the Antarctic midge, Belgica antarctica. The larvae spend most the year encased in ice but during the austral summer are vulnerable to summer storms, osmotic stress from ocean spray and drying conditions due to wind and intense sunlight. Using suppressive subtractive hybridization (SSH), we obtained clones that were potentially responsive to dehydration and then used northern blots to evaluate the gene's responsiveness to different dehydration rates and hydration states. Among the genes most responsive to changes in the hydration state were those encoding heat shock proteins (smHsp, Hsp70, Hsp90), antioxidants (superoxide dismutase, catalase), detoxification (metallothionein, cytochrome p450), genes involved in altering cell membranes (fatty acid desaturase, phospholipase A2 activating protein, fatty acyl CoA desaturase) and the cytoskeleton (actin, muscle-specific actin), and several additional genes including a zinc-finger protein, pacifastin and VATPase. Among the three types of dehydration evaluated, fast dehydration elicited the strongest response (more genes, higher expression), followed by cryoprotective dehydration and slow dehydration. During rehydration most, but not all, genes that were expressed during dehydration continued to be expressed; fatty acid desaturase was the only gene to be uniquely upregulated in response to rehydration. All genes examined, except VATPase, were upregulated in response to overhydration. The midge larvae are thus responding quickly to water loss and gain by expressing genes that encode proteins contributing to maintenance of proper protein function, protection and overall cell homeostasis during times of osmotic flux, a challenge that is particularly acute in this Antarctic environment.

  1. To bite or not to bite! A questionnaire-based survey assessing why some people are bitten more than others by midges

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    Weeks Emma NI

    2010-05-01

    Full Text Available Abstract Background The Scottish biting midge, Culicoides impunctatus, responsible for more than 90% of biting attacks on human beings in Scotland, is known to demonstrate a preference for certain human hosts over others. Methods In this study we used a questionnaire-based survey to assess the association between people's perception of how badly they get bitten by midges and their demographic, lifestyle and health related characteristics. Results Most people (85.8% reported being bitten sometimes, often or always with only 14.2% reporting never being bitten by midges when in Scotland. There was no association between level of bites received and age, smoking, diet, exercise, medication, eating strongly flavoured foods or alcohol consumption. However, there was a strong association between the probability of being bitten and increasing height (in men and BMI (in women. A large proportion of participants (33.8% reported experiencing a bad/severe reaction to midge bites while 53.1% reported a minor reaction and 13.1% no reaction at all. Also, women tend to react more than men to midge bites. Additionally, the results indicated that the susceptibility to being bitten by midges is hereditary. Conclusions This study suggests that midges prefer to bite men that are tall and women that have a large BMI, and that the tendency for a child to be bitten or not could be inherited from their parent. The study is questionnaire-based; therefore, the interpretation of the results may be limited by the subjectivity of the answers given by the respondents. Although the results are relevant only to the Scottish biting midge, the approach used here could be useful for investigating human-insect interactions for other insects, particularly those which transmit pathogens that cause disease.

  2. The Biting Midge Culicoides sonorensis (Diptera: Ceratopogonidae Is Capable of Developing Late Stage Infections of Leishmania enriettii.

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    Veronika Seblova

    Full Text Available Despite their importance in animal and human health, the epidemiology of species of the Leishmania enriettii complex remains poorly understood, including the identity of their biological vectors. Biting midges of the genus Forcipomyia (Lasiohelea have been implicated in the transmission of a member of the L. enriettii complex in Australia, but the far larger and more widespread genus Culicoides has not been investigated for the potential to include vectors to date.Females from colonies of the midges Culicoides nubeculosus Meigen and C. sonorensis Wirth & Jones and the sand fly Lutzomyia longipalpis Lutz & Nevia (Diptera: Psychodidae were experimentally infected with two different species of Leishmania, originating from Australia (Leishmania sp. AM-2004 and Brazil (Leishmania enriettii. In addition, the infectivity of L. enriettii infections generated in guinea pigs and golden hamsters for Lu. longipalpis and C. sonorensis was tested by xenodiagnosis. Development of L. enriettii in Lu. longipalpis was relatively poor compared to other Leishmania species in this permissive vector. Culicoides nubeculosus was not susceptible to infection by parasites from the L. enriettii complex. In contrast, C. sonorensis developed late stage infections with colonization of the thoracic midgut and the stomodeal valve. In hamsters, experimental infection with L. enriettii led only to mild symptoms, while in guinea pigs L. enriettii grew aggressively, producing large, ulcerated, tumour-like lesions. A high proportion of C. sonorensis (up to 80% feeding on the ears and nose of these guinea pigs became infected.We demonstrate that L. enriettii can develop late stage infections in the biting midge Culicoides sonorensis. This midge was found to be susceptible to L. enriettii to a similar degree as Lutzomyia longipalpis, the vector of Leishmania infantum in South America. Our results support the hypothesis that some biting midges could be natural vectors of the L

  3. Screening of oomycete fungi for their potential role in reducing the biting midge (Diptera: Ceratopogonidae) larval populations in Hervey Bay, Queensland, Australia.

    Science.gov (United States)

    Stephen, Kirsty; Kurtböke, D Ipek

    2011-05-01

    Biting midges are globally distributed pests causing significant economic losses and transmitting arbovirus diseases to both animals and humans. Current biological and chemical control strategies for biting midge target destruction of adult forms, but strategies directed at immature stages of the insect have yet to be explored in Australia. In the present study, coastal waters of Hervey Bay region in Queensland, Australia were screened to detect the habitats of biting midge at immature stages. These results were then correlated to local environmental conditions and naturally occurring entomopathogenic fungal flora, in particular the Oomycete fungi, to determine their reducing effect on insect immature stages in the search for biological control agents in the region. The dominant species of biting midge found within this study was Culicoides subimmaculatus occuring between mean high water neaps and mean high water spring tide levels. Within this intertidal zone, the presence of C. subimmaculatus larvae was found to be influenced by both sediment size and distance from shore. Halophytophthora isolates colonized both dead and alive pupae. However, the association was found to be surface colonization rather than invasion causing the death of the host. Lack of aggressive oomycete fungal antagonists towards midge larvae might correlate with increased incidences of biting midge infestations in the region.

  4. Screening of Oomycete Fungi for Their Potential Role in Reducing the Biting Midge (Diptera: Ceratopogonidae Larval Populations in Hervey Bay, Queensland, Australia

    Directory of Open Access Journals (Sweden)

    D. Ipek Kurtböke

    2011-05-01

    Full Text Available Biting midges are globally distributed pests causing significant economic losses and transmitting arbovirus diseases to both animals and humans. Current biological and chemical control strategies for biting midge target destruction of adult forms, but strategies directed at immature stages of the insect have yet to be explored in Australia. In the present study, coastal waters of Hervey Bay region in Queensland, Australia were screened to detect the habitats of biting midge at immature stages. These results were then correlated to local environmental conditions and naturally occurring entomopathogenic fungal flora, in particular the Oomycete fungi, to determine their reducing effect on insect immature stages in the search for biological control agents in the region. The dominant species of biting midge found within this study was Culicoides subimmaculatus occuring between mean high water neaps and mean high water spring tide levels. Within this intertidal zone, the presence of C. subimmaculatus larvae was found to be influenced by both sediment size and distance from shore. Halophytophthora isolates colonized both dead and alive pupae. However, the association was found to be surface colonization rather than invasion causing the death of the host. Lack of aggressive oomycete fungal antagonists towards midge larvae might correlate with increased incidences of biting midge infestations in the region.

  5. BLOOD-SUCKING MIDGES FROM THE GENUS Culicoides (Diptera: Ceratopogonidae) ACT AS FILED VECTORS OF HUMAN AND ANIMAL DISEASES (review)

    OpenAIRE

    2015-01-01

    Bluetongue and Shmallenberg diseases, the arboviral infections of ruminants, caused by Bluetongue virus (BTV) of Orbivirus genus (Reoviridae) and so-called Shmallenberg virus (SBV) preliminarily attributed as a member of Orthobunyavirus genus (Bunyaviridae), respectively, are mainly transmitted by blood-sucking midges from Culicoides genus. They are widely distributed, with a total of over 80 species documented in Russia (V.M. Glukhova, 1989), including the Far North territories. Of them, a t...

  6. Ribosomal genes as early targets of cadmium-induced toxicity in Chironomus riparius larvae

    Energy Technology Data Exchange (ETDEWEB)

    Planello, R. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain); Martinez-Guitarte, J.L. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain); Morcillo, G. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain)]. E-mail: gmorcillo@ccia.uned.es

    2007-02-01

    Cadmium is a widespread environmental pollutant that causes severe impacts in organisms. Although the effects of cadmium on aquatic insects have been studied in terms of their toxicity and changes in developmental parameters, little is known about its molecular and genetic effects. We have investigated the alterations in the pattern of gene expression provoked by acute exposure to cadmium in Chironomus riparius Mg. (Diptera, Chironomidae), a sentinel organism widely used in aquatic toxicity testing. The early cytotoxic effects were evaluated using immunocytochemistry and specific fluorescent probes in fourth instar larvae after 12 h of 10 mM cadmium treatments; under these conditions no significant effect on larvae mortality was detected until after 36 h of exposure. The changes in the pattern of gene expression were analysed by means of DNA/RNA hybrid antibodies in the polytene chromosomes from salivary gland cells. A decrease in the activity of the nucleolus is especially remarkable, accompanied by a significant reduction in size and the modification in nucleolar architecture, as shown by FISH. The inhibition of rDNA transcription was further evaluated by Northern blot analysis, which showed a marked decrease in the level of preribosomal rRNA (54% 45S 12 h). However, the BR genes, whose products are the giant polypeptides that constitute the silk-like secretion for constructing housing tubes, remain active. Simultaneously, decondensation and activation take place at some chromosomal regions, especially at the centromeres. The changes observed in the pattern of gene expression do not resemble those found after heat shock or other cell stressors. These data provide the first evidence that cadmium interacts with ribosomal genes and results in a drastic impairment of the functional activity of the nucleolus, an essential organelle for cellular survival. Therefore, the depletion of ribosomes would be a long-term effect of Cd-induced cellular damage. These findings may

  7. Survival, reproduction, and arsenic body burdens in Chironomus riparius exposed to arsenate and phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Mogren, Christina L., E-mail: christina.mogren@email.ucr.edu [Department of Entomology, University of California, Riverside, 900 University Ave, Riverside, CA 92521 (United States); Kiparski, Guntram R. von; Parker, David R. [Department of Environmental Science, University of California, Riverside, 900 University Ave, Riverside, CA 92521 (United States); Trumble, John T. [Department of Entomology, University of California, Riverside, 900 University Ave, Riverside, CA 92521 (United States)

    2012-05-15

    Despite the increasing awareness of arsenic (As) contamination in surface waters worldwide, little is known about how As alone and in the presence of other chemicals affects aquatic insects. Larvae of Chironomus riparius were exposed in a laboratory investigation to factorial combinations of 0, 0.13, 2.0, 5.3, and 13 {mu}mol As l{sup -1} and 0, 0.15, and 15 {mu}mol PO{sub 4} l{sup -1} throughout development from first instar to pupal emergence. The time between male and female emergence increased from 1.8 {+-} 0.17 days to 2.9 {+-} 0.34 days with exposure at higher As levels. The highest As exposure also decreased the number of eggs per egg mass, which may affect population maintenance. For these parameters, there was no effect from PO{sub 4}, and no interaction between As and PO{sub 4}. Total As determination of larval and adult tissues was conducted using Hydride Generated Atomic Absorption Spectroscopy (HGAAS) and revealed concentrations ranging from 2.48 {+-} 0.363 to 30.5 {+-} 0.473 {mu}g/g and 1.03 {+-} 0.286 to 8.97 {+-} 0.662 {mu}g/g, respectively, indicating elimination of approximately 72% of total As body burdens between the fourth instar and adult stages. There was no effect of PO{sub 4}, indicating PO{sub 4} does not alter uptake of As in C. riparius. The potential for movement of As to terrestrial systems exists, though trophic transfer may be more likely during the aquatic larval stage. - Highlights: Black-Right-Pointing-Pointer We evaluate how sublethal concentrations of As and P affect C. riparius. Black-Right-Pointing-Pointer High As exposure significantly increased the time between male and female emergence. Black-Right-Pointing-Pointer High As exposure significantly decreased the number of eggs per egg mass. Black-Right-Pointing-Pointer Fourth instar larvae eliminate 72% of As body burdens before the adult stage.

  8. [Chromosomal variation in Chironomus plumosus L. (Diptera, Chironomidae) from populations of Bryansk region, Saratov region (Russia), and Gomel region (Belarus)].

    Science.gov (United States)

    Belyanina, S I

    2015-02-01

    Cytogenetic analysis was performed on samples of Chironomus plumosus L. (Diptera, Chironomidae) taken from waterbodies of various types in Bryansk region (Russia) and Gomel region (Belarus). Karyotypes of specimens taken from stream pools of the Volga were used as reference samples. The populations of Bryansk and Gomel regions (except for a population of Lake Strativa in Starodubskii district, Bryansk region) exhibit broad structural variation, including somatic mosaicism for morphotypes of the salivary gland chromosome set, decondensation of telomeric sites, and the presence of small structural changes, as opposed to populations of Saratov region. As compared with Saratov and Bryansk regions, the Balbiani ring in the B-arm of chromosome I is repressed in populations of Gomel region. It is concluded that the chromosome set of Ch. plumosus in a range of waterbodies of Bryansk and Gomel regions is unstable.

  9. Germ line transformation and in vivo labeling of nuclei in Diptera: report on Megaselia abdita (Phoridae) and Chironomus riparius (Chironomidae).

    Science.gov (United States)

    Caroti, Francesca; Urbansky, Silvia; Wosch, Maike; Lemke, Steffen

    2015-06-01

    To understand how and when developmental traits of the fruit fly Drosophila melanogaster originated during the course of insect evolution, similar traits are functionally studied in variably related satellite species. The experimental toolkit available for relevant fly models typically comprises gene expression and loss as well as gain-of-function analyses. Here, we extend the set of available molecular tools to piggyBac-based germ line transformation in two satellite fly models, Megaselia abdita and Chironomus riparius. As proof-of-concept application, we used a Gateway variant of the piggyBac transposon vector pBac{3xP3-eGFPafm} to generate a transgenic line that expresses His2Av-mCherry as fluorescent nuclear reporter ubiquitously in the gastrulating embryo of M. abdita. Our results open two phylogenetically important nodes of the insect order Diptera for advanced developmental evolutionary genetics.

  10. Control of nitrous oxide emission from Chironomus plumosus larvae by nitrate and temperatur

    DEFF Research Database (Denmark)

    Stief, Peter; Polerecky, Lubos; Poulsen, Morten

    2010-01-01

    of Chironomus plumosus in field and laboratory experiments. Larvae collected from lake sediments emitted between 2 and 73 pmol N2O ind.-1 h-1 during the warm season, but took up maximally 227 pmol N2O ind.21 h21 during winter. Larvae kept in laboratory microcosms emitted between 14 and 122 pmol N2O ind.-1 h-1......, and N2O uptake was never observed. For both types of larvae, the rate of N2O emission was stimulated by temperature (when the NO3- concentration in the water column was higher than 25–50 µmol L-1) and by NO3- (when the temperature was higher than 4–10°C). Modeling based on experimentally determined...

  11. Setting the reference for the use of Chironomus sancticaroli (Diptera: Chironomidae as bioindicator: Ontogenetic pattern of larval head structures

    Directory of Open Access Journals (Sweden)

    Débora Rebechi

    2012-04-01

    Full Text Available Species of Chironomidae are widely used as bioindicators of water quality, since their larvae undergo morphological deformities when in contact with sediment contaminated with chemicals. In this work we endeavored to study the morphology of head structures (antennae, mandible, mentum, pecten epipharyngis, ventromental plate and premandible throughout the development of the four larval instars of Chironomus sancticaroli Strixino & Strixino, 1981, which can be used in environmental impact analyses. Our results show that it is possible to differentiate among larval instars by doing a quantitative analysis on the number of striae on the ventromental plates. The six structures analyzed changed during larval ontogeny. These changes are part of the ontogeny of the immature stages not exposed to xenobiotics. We believe that the morphological pattern defined in this work can be used for comparisons with ontogenetic changes observed in field studies conducted in polluted environments.

  12. Warm Mediterranean mid-Holocene summers inferred from fossil midge assemblages

    Science.gov (United States)

    Samartin, Stéphanie; Heiri, Oliver; Joos, Fortunat; Renssen, Hans; Franke, Jörg; Brönnimann, Stefan; Tinner, Willy

    2017-02-01

    Understanding past climate trends is key for reliable projections of global warming and associated risks and hazards. Uncomfortably large discrepancies between vegetation-based summer temperature reconstructions (mainly based on pollen) and climate model results have been reported for the current interglacial, the Holocene. For the Mediterranean region these reconstructions indicate cooler-than-present mid-Holocene summers, in contrast with expectations based on climate models and long-term changes in summer insolation. We present new quantitative and replicated Holocene summer temperature reconstructions based on fossil chironomid midges from the northern central Mediterranean region. The Holocene thermal maximum is reconstructed 9,000-5,000 years ago and estimated to have been 1-2 °C warmer in mean July temperature than the recent pre-industrial period, consistent with glacier and marine records, and with transient climate model runs. This combined evidence implies that widely used pollen-based summer temperature reconstructions in the Mediterranean area are significantly biased by precipitation or other forcings such as early land use. Our interpretation can resolve the previous discrepancy between climate models and quantitative palaeotemperature records for millennial-scale Holocene summer temperature trends in the Mediterranean region. It also suggests that pollen-based evidence for cool mid-Holocene summers in other semi-arid to arid regions of the Northern Hemisphere may have to be reconsidered, with potential implications for global-scale reconstructions.

  13. Biting midges (Diptera: Ceratopogonidae from Martín García Island, Argentina

    Directory of Open Access Journals (Sweden)

    María M Ronderos

    2011-09-01

    Full Text Available Nearly 230 species of biting midges have been recorded or described from Argentina; 38 of them are known from the Buenos Aires province and only one is cited from Martín García Island. This paper presents the results raised from six collecting trips which took place on the island during spring 2005, summer 2006 and autumn 2009. Diverse sampling sites including permanent and temporary aquatic environments were chosen, most of the ten sampling sites were ponds of diverse origin, some of these environments were covered with floating vegetation as Lemna gibba, Lemna minuscule, Salvinia biloba, Salvinia minima, Azolla filiculoides, Limnobium laevigatum, Pistia stratiotes, Spirodela intermedia, Wolffiella oblonga and Wolffia columbiana. Other sites were placed in urban and suburban areas. Adults were collected with sweep nets at sunrise and sunset and with light traps at intervals of four to five hours at night, depending on electricity availability on the island. Larvae and pupae were collected with different implements depending on characteristics of each surveyed aquatic habitat. In free standing water, they were captured with small sieves or hand pipettes and micropipettes, flotation techniques were utilized for sampling vegetated areas, free and rooted floating hydrophytes were extracted for removing insects among them. Thirteen species of Ceratopogonidae were collected, three of Atrichopogon Kieffer, three of Forcipomyia Meigen, two of Dasyhelea Kieffer, four of Culicoides Latreille, and one of Bezzia Kieffer, all representing new records from the island. Rev. Biol. Trop. 59 (3: 1183-1194. Epub 2011 September 01.

  14. Distinct contractile and cytoskeletal protein patterns in the Antarctic midge are elicited by desiccation and rehydration.

    Science.gov (United States)

    Li, Aiqing; Benoit, Joshua B; Lopez-Martinez, Giancarlo; Elnitsky, Michael A; Lee, Richard E; Denlinger, David L

    2009-05-01

    Desiccation presents a major challenge for the Antarctic midge, Belgica antarctica. In this study, we use proteomic profiling to evaluate protein changes in the larvae elicited by dehydration and rehydration. Larvae were desiccated at 75% relative humidity (RH) for 12 h to achieve a body water loss of 35%, approximately half of the water that can be lost before the larvae succumb to dehydration. To evaluate the rehydration response, larvae were first desiccated, then rehydrated for 6 h at 100% RH and then in water for 6 h. Controls were held continuously at 100% RH. Protein analysis was performed using 2-DE and nanoscale capillary LC/MS/MS. Twenty-four identified proteins changed in abundance in response to desiccation: 16 were more abundant and 8 were less abundant; 84% of these proteins were contractile or cytoskeletal proteins. Thirteen rehydration-regulated proteins were identified: 8 were more abundant and 5 were less abundant, and 69% of these proteins were also contractile or cytoskeletal proteins. Additional proteins responsive to desiccation and rehydration were involved in functions including stress responses, energy metabolism, protein synthesis, glucogenesis and membrane transport. We conclude that the major protein responses elicited by both desiccation and rehydration are linked to body contraction and cytoskeleton rearrangements.

  15. Evaluation of mentum deformities of Chironomus spp. (Chironomidae: Diptera) larvae using modified toxic score index (MTSI) to assess the environmental stress in Juru River Basin, Penang, Malaysia.

    Science.gov (United States)

    Al-Shami, Salman Abdo; Salmah, Mad Rawi Che; Hassan, Ahmad Abu; Azizah, Mohd Nor Siti

    2011-06-01

    Morphological mentum deformities which represent sublethal effect of exposure to different types of pollutants were evaluated in Chironomus spp. larvae inhabiting three polluted rivers of Juru River Basin in northwestern peninsular Malaysia. Using mentum deformity incidences, the modified toxic score index (MTSI) was developed based on Lenat's toxic score index (TSI). The suggested MTSI was compared with TSI in terms of its effectiveness to identify different pollutants including heavy metals. The MTSI showed stronger relationship to total deformity incidence expressed as percentage. Additionally, the multivariate RDA model showed higher capability of MTSI to explain the variations in heavy metal contents of the river sediments. The MTSI was recommended in bioassessment of water and sediment quality using the mentum deformities of Chironomus spp. larvae from aquatic ecosystems receiving anthropogenic, agricultural, or industrial discharges.

  16. The importance of excretion by Chironomus larvae on the internal loads of nitrogen and phosphorus in a small eutrophic urban reservoir

    Directory of Open Access Journals (Sweden)

    R. Henry

    Full Text Available Measurements of ammonium and phosphate excretion by the Chironomus larvae were conducted in order to evaluate the importance of these chironomids for the internal loads of a small eutrophic urban reservoir. Ammonium and phosphate excretion rates by Chironomus larvae of small size (6-10 mm total length were significantly higher than those of the Chironomids having medium (9-11 mm and large (11-16 mm sizes. A dependence in relation to temperature was recorded for the ammonium and phosphate excretions that was significantly higher at 25 °C than at 20 and 15 °C. Through a linear relation between biomass (dry weight and total length and, between excretion and biomass and, data on chironomids densities, after an intense sampling in 33 sites distributed all along the reservoir bottom, the mean phosphate and ammonium excretion rates corresponded to 2,014 ± 5,134 µg.m-2/day and 1,643 ± 3,974 µg.m-2/day, respectively. Considering the mean biomass (34 mg.m-2 of Chironomus, the lake area (88,156 m² and the mean excretion rates, the contribution of benthic chironomids to the internal loads would be 181 KgP and 147 KgN. for the sampling months (October-November 1998. These values showed that the internal loads by excretion from Chironomus larvae correspond to approximately 33% of the external loads of phosphorus in the lake and, in the case of nitrogen, to only 5%.

  17. Study on the sensitivity of three oat varieties to the saddle gall midge, haplodiplosis margina ta (von Roser) (Diptera: cecidomyiidae).

    Science.gov (United States)

    Censier, F; Chavalle, S; G, San Martin Y Gomez; De Proft, M; Bodson, B

    2013-01-01

    The saddle gall midge, Haplodiplosis marginota (von Roser, 1840) is a univoltine pest of cereals which occurs in Europe. The larvae feed on stems and attractive saddle-shaped depressions, driving to important yield losses when the galls are numerous. After 40 years without any reporting, large populations of H. marginata and important damage have been observed since 2010 in wheat crops in Belgium, especially in the Flemish Polders where clay soils and intensive farming of cereals favour heavy infestations. According to some research conducted in the 1960s during the last outbreak, oat (Avena sativa L.) is known to be one of the less favourable hosts to the saddle gall midge. Our study was performed in order to assess the host sensitivity of three oat varieties currently grown in Belgium: EVITA, EFFEKTIv and FREDDY. Therefore, oat varieties were sown on infested soil in two separate enclosures in a glasshouse. In the first enclosure, only the three oat varieties were grown; in the second one, these three oat varieties were grown together with two varieties of spring wheat: GRANNY and KWS CHAMSIN. TWO parameters were measured: the percentage of leaves with laid eggs, and the number of galls per stem. The percentage of leaves with eggs showed that the infestation was significantly lower on oats when they were in presence of wheat. The egg infestation was also significantly higher on wheat than on oat, which means oat is a much less favourable host plant than spring wheat for egg laying. Oat varieties were significantly different from each other regarding the number of galls per stem, but with very little damage compared to wheat. The FREDDY variety even seemed to be completely resistant to saddle gall midge, as no galls were observed although there was a similar percentage of leaves with eggs for the three oat varieties. Cropping oat could thus contribute to reduce infestations of H. morginato.

  18. A new species of predaceous midge in the Patagonian genus Austrosphaeromias with a redescription of A. chilensis (Diptera, Ceratopogonidae

    Directory of Open Access Journals (Sweden)

    Gustavo R. Spinelli

    2015-03-01

    Full Text Available A new species of predaceous midge, Austrosphaeromias setosa sp. nov., is described and illustrated from adult males and females collected in the Patagonian-Andean region of Argentina and Chile. Based on examination of the type species of Austrosphaeromias Spinelli, 1997 and recently collected specimens from near the type-locality, the female and previously unknown male of Austrosphaeromias chilensis (Ingram & Macfie, 1931 are also described and illustrated. Descriptions are accompanied by color photographs and illustrations of key features of females and males of both species. We also provide a key to adult females and males of the four species of Austrosphaeromias.

  19. Follicular cell differentiation in polytrophic ovaries of a moth midge, Tinearia alternata.

    Science.gov (United States)

    Mazurkiewicz, Marta; Kubrakiewicz, Janusz

    2008-01-01

    Dipteran ovaries consist of structural-functional units termed egg chambers. Each egg chamber is composed of a cluster of germ cells enveloped by a simple somatic follicular epithelium. With the progress of oogenesis, initially an almost uniform population of follicular cells (FCs) becomes diversified into a few subgroups, which significantly differ in their function and behaviour. From the extensive genetic and molecular studies on Drosophila it became evident that the mode of diversification of FCs and the interactions between distinct FC subpopulations and the germ-line cells are essential for a proper course of oogenesis and the generation of oocyte/embryo polarity. Recent comparative studies showed that major dipteran lineages may significantly differ in the mode of FC differentiation. The most essential difference occurs in the ability of the FCs to undertake migrations within the egg chamber. In contrast to long distance, invasive migrations characteristic of distinct FC subgroups in the egg chambers of the most derived flies (Brachycera), including Drosophila, the FCs in the ovaries of more ancestral Nematocera lack migratory activity and change their location only within the epithelial layer. Comparative analyses indicate that the FCs in the representatives of particular evolutionary lineages within Nematocera may differ in their behaviour during oogenesis. In this report we describe the FC differentiation pathway in the egg chambers of a moth midge, T. alternata (Psychodomorpha). Comparison with representatives of craneflies (Nematocera: Polyneura) showed that differences in the behaviour of FCs and in the number of FC subpopulations between Polyneura and Psychodomorpha, may depend on different oogenesis dynamics. In spite of the observed differences, some functional homologies between distinct subsets of the FCs in dipteran ovaries are postulated.

  20. Insecticide management strategies for control of swede midge (Diptera: Cecidomyiidae) on cole crops.

    Science.gov (United States)

    Hallett, Rebecca H; Chen, Mao; Sears, Mark K; Shelton, Anthony M

    2009-12-01

    Insecticide field trials were conducted in Ontario, Canada, and New York state to identify insecticides effective against the swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae), a new invasive pest in North America. Field trials indicated that foliar applications of lambda-cyhalothrin, permethrin, acetamiprid, chlorpyrifos, and dimethoate could provide control of C. nasturtii. Foliar insecticide applications were effective in keeping damage within marketable limits in all cabbage and some broccoli trials during the early phase of regional colonization by C. nasturtii (2001-2002). However by 2005-2006, treatments were rarely able to maintain damage levels within marketable limits. Low efficacy suggested the possibility of insecticide resistance in Canadian C. nasturtii populations, but laboratory assays revealed no evidence for resistance. Thus, eventual control failures on a season-long basis were apparently due to very high populations during later phases of colonization in Ontario. Early season applications (e.g., seed treatments, greenhouse plug tray drenches and/or band sprays) of neonicotinoid insecticides proved effective for 3-5 wk after transplanting in New York. These early season treatments would require supplemental control with foliar insecticides, but would reduce the number of foliar applications required and thus reduce insecticide usage. Our results suggest that acceptable control with foliar insecticides will be difficult where C. nasturtii populations are high, because of multiple and overlapping generations, and difficulty in achieving adequate spray coverage. An integrated pest management program that uses cultural control methods and host plant resistance, with judicious use of insecticides, is needed for sustainable management of this newly invasive pest.

  1. Respiration of midges (Diptera; Chironomidae) in British Columbian lakes: oxy-regulation, temperature and their role as palaeo-indicators

    DEFF Research Database (Denmark)

    Brodersen, Klaus Peter; Pedersen, Ole; Walker, Ian R.;

    2008-01-01

    1. The specific respiration rate of 13 chironomid taxa and Chaoborus were measured to test the hypothesis of the relation between a species' ability to regulate their oxygen uptake and their distributional patterns among nine study lakes in British Columbia, Canada. 2. Respiration patterns...... of individual taxa were modelled using piecewise linear regression with break point and simple hyperbolic functions. Three types of respiration curves were identified: (i) classical oxy-conformers (e.g. littoral Cricotopus) which cannot sustain a sufficient oxygen uptake with decreasing oxygen availability; (ii......) oxy-regulators (e.g. profundal Chironomus) which can regulate and maintain a constant respiration until a certain critical point and (iii) oxy-stressors (Micropsectra) which increase their respiration rate with decreasing oxygen availability until a critical point. 3. Respiration was measured at two...

  2. Application of an embryonated chicken egg model to assess the vector competence of Australian Culicoides midges for bluetongue viruses.

    Science.gov (United States)

    VAN DER Saag, M R; Ward, M P; Kirkland, P D

    2017-09-01

    Culicoides biting midges (Diptera: Ceratopogonidae) are vectors of a number of globally important arboviruses that affect livestock, including bluetongue virus (BTV), African horse sickness virus and the recently emerged Schmallenberg virus. In this study, a model using embryonated chicken eggs (ECEs) was utilized to undertake vector competence studies of Australian Culicoides spp. for 13 laboratory-adapted or wild-type virus strains of BTV. A total of 7393 Culicoides brevitarsis were reared from bovine dung, and 3364 Culicoides were induced to feed from ECEs infected with different strains of BTV. Of those, 911 (27%) survived the putative extrinsic incubation period of 9-12 days. In some trials, virus was also transmitted onward to uninfected ECEs, completing the transmission cycle. This model does not rely on the use of colonized midges and has the capacity to assess the vector competence of field-collected insects with strains of virus that have not previously been passaged in laboratory culture systems. There is also potential for this model to be used in investigations of the competence of Culicoides spp. for other arboviruses. © 2017 The Royal Entomological Society.

  3. CHANGES OF GLYCEROL CONTENT IN DIAPAUSE LARVAEOF THE ORANGE WHEAT BLOSSOM MIDGE, SITODIPLOSIS MOSELLANA (GEHIN) IN VARIOUS SEASONS

    Institute of Scientific and Technical Information of China (English)

    Jun-xiangWu; FengYuan

    2004-01-01

    The glycerol contents in diapause larvae of the orange wheat blossom midge, Sitodiplosis mosellana (Gehin), collected from various seasons, were measured. The results showed that there was less glycerol content in larvae during living on the wheat head. Content of glycerol began to increase significantly when the larvae left the wheat head and entered the soil. A change trend of upper- lower- upper- lower in larvae glycerol contents during diapause in soil was observed from June to April of next year. More glycerol could be examined in larvae collected in summer and winter than in spring and autumn. There was not more glycerol in cocooned larvae than that in non-cocooned larvae during various seasons from the point of statistics. Comparing the glycerol content of larvae being diapause in the first year with that of larvae in the second year, there was yet no obvious difference when larvae were collected in the same season belonged to different years. Therefore, it is shown that the content of glycerol in larvae of the wheat midge in diapause is affected mainly by the seasons or diapause intensity.

  4. Identification, expression, and characterization of a major salivary allergen (Cul s 1) of the biting midge Culicoides sonorensis relevant for summer eczema in horses

    Science.gov (United States)

    Salivary proteins of Culicoides biting midges are thought to play a key role in the induction of summer eczema (SE), a seasonal recurrent allergic dermatitis in horses. The present study describes the identification of a candidate allergen in artificially collected saliva of the North American speci...

  5. Pyrosequencing Reveals the Predominance of Pseudomonadaceae in Gut Microbiome of a Gall Midge

    Directory of Open Access Journals (Sweden)

    Raman Bansal

    2014-06-01

    midge, and provides a foundation for future studies to elucidate the roles of gut microbes in Hessian fly virulence and biology.

  6. A comparison of the sublethal and lethal toxicity of four pesticides in Hyalella azteca and Chironomus dilutus.

    Science.gov (United States)

    Hasenbein, Simone; Connon, Richard E; Lawler, Sharon P; Geist, Juergen

    2015-08-01

    Laboratory toxicity testing is the primary tool used for surface water environmental risk assessment; however, there are critical information gaps regarding the sublethal effects of pesticides. In 10-day exposures, we assessed the lethal and sublethal (motility and growth) toxicities of four commonly used pesticides, bifenthrin, permethrin, cyfluthrin, and chlorpyrifos, on two freshwater invertebrates, Chironomus dilutus and Hyalella azteca. Pyrethroids were more toxic than the organophosphate chlorpyrifos in both species. Bifenthrin was most toxic to H. azteca survival and growth. Cyfluthrin was most toxic to C. dilutus. However, cyfluthrin had the greatest effect on motility on both H. azteca and C. dilutus. The evaluated concentrations of chlorpyrifos did not affect C. dilutus motility or growth, but significantly impacted H. azteca growth. Motility served as the most sensitive endpoint in assessing sublethal effects at low concentrations for both species, while growth was a good indicator of toxicity for all four pesticides for H. azteca. The integration of sublethal endpoints in ambient water monitoring and pesticide regulation efforts could improve identification of low-level pesticide concentrations that may eventually cause negative effects on food webs and community structure in aquatic environments.

  7. Influence of Chironomus riparius (Diptera, Chironomidae) and Tubifex tubifex (Annelida, Oligochaeta) on oxygen uptake by sediments. Consequences of uranium contamination

    Energy Technology Data Exchange (ETDEWEB)

    Lagauzere, S. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire (IRSN), DEI/SECRE/LRE, Cadarache 186, BP 3, F-13115 Cedex, Saint Paul Lez Durance (France)], E-mail: lagauzere@gmail.com; Pischedda, L.; Cuny, P. [Laboratoire de Microbiologie, Geochimie et Ecologie Marines, UMR 6117 CNRS/COM/Universite de la Mediterranee, Campus de Luminy, Case 901, F-13288 Cedex 09, Marseille (France); Gilbert, F. [EcoLab, Laboratoire d' Ecologie Fonctionnelle, UMR 5245 CNRS/INP/Universite Paul Sabatier, 29 Rue Jeanne Marvig, F-31055 Cedex 4, Toulouse (France); Stora, G. [Laboratoire de Microbiologie, Geochimie et Ecologie Marines, UMR 6117 CNRS/COM/Universite de la Mediterranee, Campus de Luminy, Case 901, F-13288 Cedex 09, Marseille (France); Bonzom, J.-M. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire (IRSN), DEI/SECRE/LRE, Cadarache 186, BP 3, F-13115 Cedex, Saint Paul Lez Durance (France)

    2009-04-15

    The diffusive oxygen uptake (DOU) of sediments inhabited by Chironomus riparius and Tubifex tubifex was investigated using a planar oxygen optode device, and complemented by measurements of bioturbation activity. Additional experiments were performed within contaminated sediments to assess the impact of uranium on these processes. After 72 h, the two invertebrate species significantly increased the DOU of sediments (13-14%), and no temporal variation occurred afterwards. Within contaminated sediments, it was already 24% higher before the introduction of the organisms, suggesting that uranium modified the sediment biogeochemistry. Although the two species firstly reacted by avoidance of contaminated sediment, they finally colonized it. Their bioturbation activity was reduced but, for T. tubifex, it remained sufficient to induce a release of uranium to the water column and an increase of the DOU (53%). These results highlight the necessity of further investigations to take into account the interactions between bioturbation, microbial metabolism and pollutants. - This study highlights the ecological importance of bioturbation in metal-contaminated sediments.

  8. Effects of phenol on metabolic activities and transcription profiles of cytochrome P450 enzymes in Chironomus kiinensis larvae.

    Science.gov (United States)

    Cao, C W; Sun, L L; Niu, F; Liu, P; Chu, D; Wang, Z Y

    2016-02-01

    Phenol, also known as carbolic acid or phenic acid, is a priority pollutant in aquatic ecosystems. The present study has investigated metabolic activities and transcription profiles of cytochrome P450 enzymes in Chironomus kiinensis under phenol stress. Exposure of C. kiinensis larvae to three sublethal doses of phenol (1, 10 and 100 µM) inhibited cytochrome P450 enzyme activity during the 96 h exposure period. The P450 activity measured after the 24 h exposure to phenol stress could be used to assess the level (low or high) of phenol contamination in the environment. To investigate the potential of cytochrome P450 genes as molecular biomarkers to monitor phenol contamination, the cDNA of ten CYP6 genes from the transcriptome of C. kiinensis were identified and sequenced. The open reading frames of the CYP6 genes ranged from 1266 to 1587 bp, encoding deduced polypeptides composed of between 421 and 528 amino acids, with predicted molecular masses from 49.01 to 61.94 kDa and isoelectric points (PI) from 6.01 to 8.89. Among the CYP6 genes, the mRNA expression levels of the CYP6EW3, CYP6EV9, CYP6FV1 and CYP6FV2 genes significantly altered in response to phenol exposure; therefore, these genes could potentially serve as biomarkers in the environment. This study shows that P450 activity combined with one or multiple CYP6 genes could be used to monitor phenol pollution.

  9. Can mouth part deformities of Chironomus riparius serve as indicators for water and sediment pollution? A laboratory approach

    Energy Technology Data Exchange (ETDEWEB)

    Langer-Jaesrich, Miriam; Koehler, Heinz R. [Animal Physiological Ecology Dept., Univ. of Tuebingen (Germany); Gerhardt, Almut [LimCo International, Ibbenbueren (Germany)

    2010-04-15

    Purpose: The significance of chironomids mouthpart deformities as suitable indicators for pollutant contamination of natural waters and sediments has been investigated and discussed for several decades. Uncertainties still exist as further laboratory studies, with different pollutants and with the same experimental design are required. Materials and methods In this study, the effects of four substances (i.e., nickel chloride, chlorpyrifos, imidacloprid and thiacloprid) were tested on the mouthpart deformity rates and patterns in Chironomus riparius. These compounds were investigated either individually or in mixtures. Results and discussion No significant increase in the frequency of mouthpart deformities was found using different single substance treatments when compared to the controls. Consequently no concentration-effect relationships between substance concentration and deformity frequency were detected. In mixture experiments an increase in mouthpart deformities of C. riparius exposed to imidacloprid-thiacloprid mixtures was detected. This indicated that the effects of single substances and mixtures on mouthpart deformity frequency may differ considerably. Conclusions The findings in this study from different laboratory approaches in combination with the published literature questions the reliability of chironomids mouthpart deformities as indicators of freshwater and sediment contamination by toxic substances. (orig.)

  10. DNA damage and transcriptional changes induced by tributyltin (TBT) after short in vivo exposures of Chironomus riparius (Diptera) larvae.

    Science.gov (United States)

    Morales, Mónica; Martínez-Paz, Pedro; Ozáez, Irene; Martínez-Guitarte, José Luis; Morcillo, Gloria

    2013-08-01

    Tributyltin (TBT) is a widespread environmental contaminant in aquatic systems whose adverse effects in development and reproduction are related to its well-known endocrine-disrupting activity. In this work, the early molecular effects of TBT in Chironomus riparius (Diptera) were evaluated by analyzing its DNA damaging potential and the transcriptional response of different endocrine-related genes. Twenty-four-hour in vivo exposures of the aquatic larvae, at environmentally relevant doses of TBT, revealed genotoxic activity as shown by significant increases in DNA strand breaks quantified with the comet assay. TBT was also able to induce significant increases in transcripts from the ecdysone receptor gene (EcR), the ultraspiracle gene (usp) (insect ortholog of the retinoid X receptor), the estrogen-related receptor (ERR) gene and the E74 early ecdysone-inducible gene, as measured by real-time RT-PCR. In contrast, the expression of the vitellogenin (vg) gene remained unaltered, while the hsp70 gene appeared to be down-regulated. The ability of TBT to up-regulate hormonal target genes provides the first evidence, at genomic level, of its endocrine disruptive effects and also suggests a mechanism of action that mimics ecdysteroid hormones in insects. These data reveal for the first time the early genomic effects of TBT on an insect genome.

  11. Role of ingestion route in the perfluoroalkyl substance bioaccumulation by Chironomus plumosus larvae in sediments amended with carbonaceous materials.

    Science.gov (United States)

    Zhai, Yawei; Xia, Xinghui; Zhao, Xiuli; Dong, Haiyang; Zhu, Baotong; Xia, Na; Dong, Jianwei

    2016-01-25

    The role of ingestion route in the bioaccumulation of six types of perfluoroalkyl substances (PFASs) by Chironomus plumosus larvae in sediments amended with four types of carbonaceous materials (CMs) was studied. The results showed that the body burden of PFASs decreased in the presence of CMs at mass ratios of 0.2-2%, regardless of ingestion. PFASs accumulated by the larvae with ingestion exposure were higher than those without ingestion, and the role of ingestion route was altered in the presence of CMs. The contribution of ingestion route to PFAS bioaccumulation was 2.7-31.6% without CMs, and it increased to more than 61.4% in the presence of fullerene at mass ratios of 0.2-2%. The enhancement of the ingestion route contribution caused by CMs is due to the fact that the CMs can be ingested and CM-associated PFASs can be partly desorbed in larvae. The maximum desorption efficiency of perfluorooctanoic acid was 20.8% from fullerene by the larval digestive juice. This study suggests that CM-associated PFASs could be accumulated partly by organisms, and the ecological risk of PFASs might increase in some cases with the presence of CMs. This should be considered when applying CMs in PFAS and other hydrophobic organic compound pollution remediation. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. FLUID AND ION SECRETION BY MALPIGHIAN TUBULES OF LARVAL CHIRONOMIDS, Chironomus riparius: EFFECTS OF REARING SALINITY, TRANSPORT INHIBITORS, AND SEROTONIN.

    Science.gov (United States)

    Zadeh-Tahmasebi, Melika; Bui, Phuong; Donini, Andrew

    2016-10-01

    Larvae of Chironomus riparius respond to ion-poor and brackish water (IPW, BW) conditions by activating ion uptake mechanisms in the anal papillae and reducing ion absorption at the rectum, respectively. The role that the Malpighian tubules play in ion and osmoregulation under these conditions is not known in this species. This study examines rates of fluid secretion and major cation composition of secreted fluid from tubules of C. riparius reared in IPW, freshwater (FW) and BW. Fluid secretion of tubules from FW and BW larvae was similar but tubules from IPW larvae secrete fluid at higher rates, are more sensitive to serotonin stimulation, and the secreted fluid contains less Na(+) . Therefore in IPW, tubules work in concert with anal papillae to eliminate excess water while conserving Na(+) in the hemolymph. Tubules do not appear to play a significant role in ion/osmoregulation under BW. Serotonin immunoreactivity in the nervous system and gastrointestinal tract of larval C. riparius was similar to that seen in mosquito larvae with the exception that the hindgut was devoid of staining. Hemolymph serotonin titer was similar in FW and IPW; hence, serotonin is not responsible for the observed high rates of fluid secretion in IPW. Instead, it is suggested that serotonin may work in a synergistic manner with an unidentified hormonal factor in IPW. Ion transport mechanisms in the tubules of C. riparius are pharmacologically similar to those of other insects.

  13. New species records of Culicoides biting midges (Diptera: Ceratopogonidae) for the state of Rondônia in Brazilian Amazon.

    Science.gov (United States)

    Carvalho, Luis Paulo Costa; Farias, Emanuelle de Sousa; Gil, Luiz Herman Soares; Pessoa, Felipe Arley Costa; Medeiros, Jansen Fernandes

    2017-01-01

    Culicoides biting midges are small insects that are proven vectors of pathogens that cause disease in animals and humans. There are 1,368 species of Culicoides in the world, including 149 species in Brazil and 122 species in the Brazilian Amazon Basin. This study documents specimens that were collected between 2013 and 2015 in the municipalities of Alvorada d'Oeste, Buritis, Cacoal, Costa Marques, Espigão d'Oeste, Guajará-Mirim, Pimenta Bueno, Porto Velho and São Francisco Guaporé. Collections were performed using HP light traps in forest, pasture and peridomicilie environments. Species newly recorded in Rondônia State include Culicoides carpenteri Wirth & Blanton, 1953; C. dasyophrus Macfie, 1940; C. eublepharus Macfie, 1948; C. galindoi Wirth & Blanton, 1953; C. heliconiae Fox & Hoffman, 1944; and C. ignacioi Forattini, 1957. This is the first record in Brazil of C. darlingtonae Wirth & Blanton, 1971.

  14. Biting midges (Diptera: Ceratopogonidae from Martín García Island, Argentina

    Directory of Open Access Journals (Sweden)

    María M Ronderos

    2011-09-01

    Full Text Available Nearly 230 species of biting midges have been recorded or described from Argentina; 38 of them are known from the Buenos Aires province and only one is cited from Martín García Island. This paper presents the results raised from six collecting trips which took place on the island during spring 2005, summer 2006 and autumn 2009. Diverse sampling sites including permanent and temporary aquatic environments were chosen, most of the ten sampling sites were ponds of diverse origin, some of these environments were covered with floating vegetation as Lemna gibba, Lemna minuscule, Salvinia biloba, Salvinia minima, Azolla filiculoides, Limnobium laevigatum, Pistia stratiotes, Spirodela intermedia, Wolffiella oblonga and Wolffia columbiana. Other sites were placed in urban and suburban areas. Adults were collected with sweep nets at sunrise and sunset and with light traps at intervals of four to five hours at night, depending on electricity availability on the island. Larvae and pupae were collected with different implements depending on characteristics of each surveyed aquatic habitat. In free standing water, they were captured with small sieves or hand pipettes and micropipettes, flotation techniques were utilized for sampling vegetated areas, free and rooted floating hydrophytes were extracted for removing insects among them. Thirteen species of Ceratopogonidae were collected, three of Atrichopogon Kieffer, three of Forcipomyia Meigen, two of Dasyhelea Kieffer, four of Culicoides Latreille, and one of Bezzia Kieffer, all representing new records from the island. Rev. Biol. Trop. 59 (3: 1183-1194. Epub 2011 September 01.Alrededor de 230 especies de ceratopogónidos han sido registradas o descritas en Argentina, 38 de ellas son conocidas para la provincia de Buenos Aires y sólo una ha sido previamente citada para la Isla Martín García. En este trabajo se presentan los resultados obtenidos a partir de muestreos realizados en seis viajes a la isla

  15. A simulation approach to assessing sampling strategies for insect pests: an example with the balsam gall midge.

    Directory of Open Access Journals (Sweden)

    R Drew Carleton

    Full Text Available Estimation of pest density is a basic requirement for integrated pest management in agriculture and forestry, and efficiency in density estimation is a common goal. Sequential sampling techniques promise efficient sampling, but their application can involve cumbersome mathematics and/or intensive warm-up sampling when pests have complex within- or between-site distributions. We provide tools for assessing the efficiency of sequential sampling and of alternative, simpler sampling plans, using computer simulation with "pre-sampling" data. We illustrate our approach using data for balsam gall midge (Paradiplosis tumifex attack in Christmas tree farms. Paradiplosis tumifex proved recalcitrant to sequential sampling techniques. Midge distributions could not be fit by a common negative binomial distribution across sites. Local parameterization, using warm-up samples to estimate the clumping parameter k for each site, performed poorly: k estimates were unreliable even for samples of n ∼ 100 trees. These methods were further confounded by significant within-site spatial autocorrelation. Much simpler sampling schemes, involving random or belt-transect sampling to preset sample sizes, were effective and efficient for P. tumifex. Sampling via belt transects (through the longest dimension of a stand was the most efficient, with sample means converging on true mean density for sample sizes of n ∼ 25-40 trees. Pre-sampling and simulation techniques provide a simple method for assessing sampling strategies for estimating insect infestation. We suspect that many pests will resemble P. tumifex in challenging the assumptions of sequential sampling methods. Our software will allow practitioners to optimize sampling strategies before they are brought to real-world applications, while potentially avoiding the need for the cumbersome calculations required for sequential sampling methods.

  16. Comparison of single- and multi-scale models for the prediction of the Culicoides biting midge distribution in Germany

    Directory of Open Access Journals (Sweden)

    Renke Lühken

    2016-05-01

    Full Text Available This study analysed Culicoides presence-absence data from 46 sampling sites in Germany, where monitoring was carried out from April 2007 until May 2008. Culicoides presence-absence data were analysed in relation to land cover data, in order to study whether the prevalence of biting midges is correlated to land cover data with respect to the trapping sites. We differentiated eight scales, i.e. buffer zones with radii of 0.5, 1, 2, 3, 4, 5, 7.5 and 10 km, around each site, and chose several land cover variables. For each species, we built eight single-scale models (i.e. predictor variables from one of the eight scales for each model based on averaged, generalised linear models and two multiscale models (i.e. predictor variables from all of the eight scales based on averaged, generalised linear models and generalised linear models with random forest variable selection. There were no significant differences between performance indicators of models built with land cover data from different buffer zones around the trapping sites. However, the overall performance of multi-scale models was higher than the alternatives. Furthermore, these models mostly achieved the best performance for the different species using the index area under the receiver operating characteristic curve. However, as also presented in this study, the relevance of the different variables could significantly differ between various scales, including the number of species affected and the positive or negative direction. This is an even more severe problem if multi-scale models are concerned, in which one model can have the same variable at different scales but with different directions, i.e. negative and positive direction of the same variable at different scales. However, multi-scale modelling is a promising approach to model the distribution of Culicoides species, accounting much more for the ecology of biting midges, which uses different resources (breeding sites, hosts, etc. at

  17. Evolutionary ecotoxicology of perfluoralkyl substances (PFASs) inferred from multigenerational exposure: a case study with Chironomus riparius (Diptera, Chironomidae).

    Science.gov (United States)

    Stefani, F; Rusconi, M; Valsecchi, S; Marziali, L

    2014-11-01

    A multigeneration toxicity test on Chironomus riparius was performed with the aim of investigating the evolutionary consequences of exposure to perfluoralkyl substances (perfluorooctane sulfonic acid, PFOS; perfluorooctanoic acid, PFOA; perfluorobutane sulfonate, PFBS). Six-hundred larvae were bred per treatment and per generation until emergence and egg deposition under a nominal concentration of 10μg/L of contaminants. Newborn larvae were used to start the next generation. Evolution of genetic variability was evaluated along a total of 10 consecutive generations based on 5 microsatellite loci. Analysis of life-history traits (survival, sex ratio and reproduction) was also carried out. Rapid genetic variability reduction was observed in all treatments, including controls, across generations due to the test conditions. Nevertheless, an increased mutation rate determined a stronger conservation of genetic variability in PFOS and, at minor extent, in PFBS exposed populations compared to controls. No significant effects were induced by exposure to PFOA. Direct mutagenicity or induced stress conditions may be at the base of increased mutation rate, indicating the potential risk of mutational load caused by exposure to PFOS and PFBS. The test provided the opportunity to evaluate the use of approximate Bayesian computation (ABC) and coalescent approaches in evolutionary ecotoxicology. A weak performance was evidenced for ABC, either in terms of bias or dispersion of effective population sizes and of estimates of mutation rate. On the contrary, coalescent simulations proved the sensitivity of traditional genetic endpoints (i.e. heterozygosity and number of alleles) to the alteration of mutation rate, but not to erosion of genetic effective size.

  18. Effects of exposure to high concentrations of waterborne Tl on K and Tl concentrations in Chironomus riparius larvae.

    Science.gov (United States)

    Belowitz, Ryan; Leonard, Erin M; O'Donnell, Michael J

    2014-11-01

    Thallium (Tl) is a non-essential metal which is released into the environment primarily as the result of anthropogenic activities such as fossil fuel burning and smelting of ores. The ionic radius of monovalent Tl⁺ is similar to that of K⁺ and Tl⁺ may thus interfere with K⁺-dependent processes. We determined that the acute (48 h) lethal concentration where 50% of the organisms do not survive (LC₅₀) of Tl for 4th instar Chironomus riparius larvae was 723 μmol L⁻¹. Accumulation of Tl by the whole animal was saturable, with a maximum accumulation (Jmax) of 4637 μmol kg⁻¹ wet mass, and K(D) of 670 μmol Tl l⁻¹. Tl accumulation by the gut appeared saturable at the lowest four Tl concentrations, with a Jmax of 2560 μmol kg⁻¹ wet mass and a K(D) of 54.5 μmol Tl l⁻¹. The saturable accumulation at the gut may be indicative of a limited capacity for intracellular detoxification, such as storage in lysosomes or complexation with metal-binding proteins. Tl accumulation by the hemolymph was found to be linear and Tl concentrations in the hemolymph were ~75% of the exposure concentration at Tl exposures >26.9 μmol L⁻¹. There was not a significant decrease in whole animal, gut or hemolymph K during exposure to waterborne Tl at any of the concentrations tested (up to 1500 μmol L⁻¹). The avoidance of hypokalemia by C. riparius larvae may contribute to survival during acute waterborne exposures to Tl. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Bioconcentration of perfluoroalkyl substances by Chironomus plumosus larvae in water with different types of dissolved organic matters.

    Science.gov (United States)

    Wen, Wu; Xia, Xinghui; Chen, Xi; Wang, Haotian; Zhu, Baotong; Li, Husheng; Li, Yang

    2016-06-01

    The effects of four types of dissolved organic matters (DOM) on the bioconcentration of perfluoroalkyl substances (PFASs) in Chironomus plumosus larvae have been studied. The PFASs included perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorododecanoic acid (PFDoA). The DOM included humic acid (HA), fulvic acid (FA), tannic acid (TA), and a protein, peptone (PEP), and their concentrations ranged from 0 to 50 mg L(-1). The results showed that, upon bioconcentration equilibrium, the body burdens of longer perfluoroalkyl chain PFASs (PFOS, PFDA, PFUnA and PFDoA) decreased with PEP and HA concentrations while increased with FA and TA concentrations. When FA and TA concentrations increased from 0 to 50 mg L(-1), body burdens of these PFASs increased by 7.5%-148.8% and 5.7%-37.1%, respectively. However, the DOM had no significant impact on the body burdens of shorter perfluoroalkyl chain PFASs (PFOA and PFNA). All of the four types of DOM lowered not only the uptake rate constants (ku) of PFASs due to the decrease of freely dissolved PFAS concentrations, but also the elimination rate constants (ke) due to the inhibition effect of DOM on the PFAS elimination from the larvae. The reduction in the two constants varied with both DOM and PFAS types. In the presence of PEP and HA with larger molecular weights, the ku values decreased more than ke, leading to the decreased body burdens of longer perfluoroalkyl chain PFASs. As for FA and TA with smaller molecular weights, the ke values decreased more than ku, resulting in increased body burdens of longer perfluoroalkyl chain PFASs. This study suggests that the effects of DOM on PFAS bioconcentration depend not only on the concentration but also on the molecule weight of DOM, which should be considered in the bioavailability assessment of PFASs.

  20. Alteration in the expression of antioxidant and detoxification genes in Chironomus riparius exposed to zinc oxide nanoparticles.

    Science.gov (United States)

    Gopalakrishnan Nair, Prakash M; Chung, Ill Min

    2015-12-01

    Zinc oxide nanoparticles (ZnONPs) are widely used in several commercial products due to their unique physicochemical properties. However, their release into the aquatic environments through various anthropogenic activities will lead to toxic effect in aquatic organisms. Although several investigations have been reported on the effect of ZnONPs in aquatic organisms using traditional end points such as survival, growth, and reproduction, the molecular level end points are faster and sensitive. In this study, the expression of different genes involved in oxidative stress response, detoxification, and cellular defense was studied in an ecotoxicologically important bio-monitoring organism Chironomus riparius in order to understand the subcellular effects of ZnONPs. The fourth instar larvae were exposed to 0, 0.2, 2, 10, and 20 mg/L of ZnONPs and Zn ions (in the form of ZnSO4.7H2O) for 24 and 48 h period. The expression of CuZn superoxide dismutase, manganese superoxide dismutase, catalase, phospholipid hydroperoxide glutathione peroxidase, thioredoxin reductase 1 and delta-3, sigma-4 and epsilon-1 classes of glutathione S-transferases, cytochrome p4509AT2, and heat shock protein 70 were studied using real-time polymerase chain reaction method. Gene expression results showed that the expression of genes related to oxidative stress response was more pronounced as a result of ZnONPs exposure as compared to Zn ions. The mRNA expression of genes involved in detoxification and cellular protection was also modulated. Significantly higher expression levels of oxidative stress-related genes shows that oxidative stress is an important mechanism of toxicity as a result of ZnONPs exposure in C. riparius.

  1. 饶河口岸吸血蚊蠓本底调查%Baseline investigation on bloodsucking mosquitoes and midges at Raohe port in China

    Institute of Scientific and Technical Information of China (English)

    李永久; 于巍; 张阳; 刘国平

    2011-01-01

    目的 调查黑龙江省饶河口岸吸血蚊、蠓的种类分布和种群组成.方法 采用人帐诱、诱虫灯诱和网捕法采集吸血蚊、蠓,收集相关文献.结果 2008-2009年在饶河口岸采获吸血蚊、蠓90214只,计6属63种,其中蚊类4属28种;蠓类2属35种,哈尔巴岭库蠓为饶河口岸首次记录的蠓种;优势蚊种为刺扰伊蚊(84.94%);吸血蠓的主要种类是兴安库蠓(37.19%)、不显库蠓(20.03%)和刺螫库蠓(20.04%).不同生境、场所的主要蚊、蠓种类组成有所不同.结论 为黑龙江省饶河口岸吸血蚊、蠓本底、虫媒病和防制研究提供了科学依据.%Objective To investigate the species distribution and population composition of bloodsucking mosquitoes and midges at Raohe port in Heilongjiang province. Methods Bed curtains, light traps and insect nets were used to collect mosquitoes and bloodsucking midges. Results From 2008 to 2009, 90 214 mosquitoes and bloodsucking midges were captured in the region, which belonged to 63 species of 6 genera, 2 families, including 28 species, 4 genera of Culicoidae and 35 species, 2 genera of Ceratopogonidae. Culicoides haerbalingeruis were recorded for the first time at Raohe port. The predominant species of mosquitoes was Aedes vaxans (84.94%). The predominant species of bloodsucking midges were Culicoides sinanoennis (37.19%), C. Obsoletus (20.03%) and C. Punctatus (20.04%). The population composition of mosquitoes and bloodsucking midges varied in different habitats. Conclusion This investigation provided baseline data on bloodsucking mosquitoes and midges for formulation of the prevention and control strategies.

  2. Spatial and temporal variability in midge (Nematocera) assemblages in shallow Finnish lakes (60-70 deg N) : community-based modelling of past environmental change

    Energy Technology Data Exchange (ETDEWEB)

    Luoto, T.

    2010-07-01

    Multi- and intralake datasets of fossil midge assemblages in surface sediments of small shallow lakes in Finland were studied to determine the most important environmental factors explaining trends in midge distribution and abundance. The aim was to develop palaeoenvironmental calibration models for the most important environmental variables for the purpose of reconstructing past environmental conditions. The developed models were applied to three high-resolution fossil midge stratigraphies from southern and eastern Finland to interpret environmental variability over the past 2000 years, with special focus on the Medieval Climate Anomaly (MCA), the Little Ice Age (LIA) and recent anthropogenic changes. The midge-based results were compared with physical properties of the sediment, historical evidence and environmental reconstructions based on diatoms (Bacillariophyta), cladocerans (Crustacea: Cladocera) and tree rings. The results showed that the most important environmental factor controlling midge distribution and abundance along a latitudinal gradient in Finland was the mean July air temperature (TJul). However, when the dataset was environmentally screened to include only pristine lakes, water depth at the sampling site became more important. Furthermore, when the dataset was geographically scaled to southern Finland, hypolimnetic oxygen conditions became the dominant environmental factor. The results from an intralake dataset from eastern Finland showed that the most important environmental factors controlling midge distribution within a lake basin were river contribution, water depth and submerged vegetation patterns. In addition, the results of the intralake dataset showed that the fossil midge assemblages represent fauna that lived in close proximity to the sampling sites, thus enabling the exploration of within-lake gradients in midge assemblages. Importantly, this within-lake heterogeneity in midge assemblages may have effects on midge-based temperature

  3. Multiple stressor effects on water quality in Poplar Bay, Lake of the Woods, Canada: a midge-based assessment of hypolimnetic oxygen conditions over the last two centuries

    Directory of Open Access Journals (Sweden)

    Jamie C. Summers

    2012-01-01

    Full Text Available Chironomid and Chaoborus (midge remains preserved in a dated sediment core from Poplar Bay, Lake of the Woods (LOW, Ontario, Canada, were used to assess the effects of multiple stressors (e.g., recent warming and shoreline development on water quality over the past ~200 years. As monitoring data for LOW do not extend beyond recent decades, paleolimnological methods are used to reconstruct long-term limnological trends and to establish pre-disturbance conditions. The effects of recent warming and shoreline development on Poplar Bay water quality are examined using an index of hypolimnetic oxygen (O2 status based on the ratio of Chaoborus to chironomid remains (chaob:chir and a midge-inferred volume-weighted hypolimnetic oxygen (VWHO model. Our paleolimnological data indicate that hypolimnetic [O2] in Poplar Bay have been historically hypoxic (1-4 mg O2 L-1 but have declined further (generally <2 mg O2 L-1 over the last few decades. Significant relationships between air temperature and midge data indicate that substantial warming starting in the late-1970s has triggered a marked response in the midge assemblages that pre-dates the onset of cottage development (mid-1990s. These findings complement a diatom-based study on the same sediment core, likewise suggesting that recent warming has played a prominent role in structuring limnetic communities. However, it is likely that the full, compounded effects of recent warming and shoreline development have not yet been realized. Our study highlights the complexity of multiple stressor systems, such as Poplar Bay, and emphasizes the benefits of using multiple, independent lines of paleoenvironmental evidence in gaining a more complete understanding of historical water quality.

  4. An automated overlying water-renewal system for sediment toxicity studies

    Energy Technology Data Exchange (ETDEWEB)

    Rand, G.M.; Wheat, J.V.; Carriger, J.F.; Lee, T.A

    2003-04-01

    A new system is described for sediment toxicity testing. - An automated water-renewal toxicity test system is described for exposing benthic invertebrates to whole sediments. The system will intermittently deliver laboratory or on-site water for overlying water replacement in sediment exposures. A range of cycle rates can be used to produce different volume additions of overlying water per day to exposure chambers. The system can be used with six different treatments and eight replicates per treatment producing 48 exposure chambers. Three formulated sediments with variable organic carbon (1.5%, 7.5%) and sand (14%, 63%) content were prepared to test the system exposing amphipods, Hyalella azteca and midges, Chironomus tentans in 10 day whole sediment tests. Intermittent water flow was used with a 90 min cycle time to create two volume additions of laboratory water per 24 h in exposure chambers (180 ml sediment, 320 ml water). Overlying water quality conditions, and survival and growth of both species were consistent and within acceptable limits for the testing requirements of the U.S. EPA guidelines for sediments with freshwater invertebrates.

  5. Comparative chronic toxicity of imidacloprid, clothianidin, and thiamethoxam to Chironomus dilutus and estimation of toxic equivalency factors.

    Science.gov (United States)

    Cavallaro, Michael C; Morrissey, Christy A; Headley, John V; Peru, Kerry M; Liber, Karsten

    2017-02-01

    Nontarget aquatic insects are susceptible to chronic neonicotinoid insecticide exposure during the early stages of development from repeated runoff events and prolonged persistence of these chemicals. Investigations on the chronic toxicity of neonicotinoids to aquatic invertebrates have been limited to a few species and under different laboratory conditions that often preclude direct comparisons of the relative toxicity of different compounds. In the present study, full life-cycle toxicity tests using Chironomus dilutus were performed to compare the toxicity of 3 commonly used neonicotinoids: imidacloprid, clothianidin, and thiamethoxam. Test conditions followed a static-renewal exposure protocol in which lethal and sublethal endpoints were assessed on days 14 and 40. Reduced emergence success, advanced emergence timing, and male-biased sex ratios were sensitive responses to low-level neonicotinoid exposure. The 14-d median lethal concentrations for imidacloprid, clothianidin, and thiamethoxam were 1.52 μg/L, 2.41 μg/L, and 23.60 μg/L, respectively. The 40-d median effect concentrations (emergence) for imidacloprid, clothianidin, and thiamethoxam were 0.39 μg/L, 0.28 μg/L, and 4.13 μg/L, respectively. Toxic equivalence relative to imidacloprid was estimated through a 3-point response average of equivalencies calculated at 20%, 50%, and 90% lethal and effect concentrations. Relative to imidacloprid (toxic equivalency factor [TEF] = 1.0), chronic (lethality) 14-d TEFs for clothianidin and thiamethoxam were 1.05 and 0.14, respectively, and chronic (emergence inhibition) 40-d TEFs were 1.62 and 0.11, respectively. These population-relevant endpoints and TEFs suggest that imidacloprid and clothianidin exert comparable chronic toxicity to C. dilutus, whereas thiamethoxam induced comparable effects only at concentrations an order of magnitude higher. However, the authors caution that under field conditions, thiamethoxam readily degrades to

  6. TOXICITY OF TWO HERBICIDES 2,4 -D DIMETHYLAMINE AND BENSULFURON METHYL TO RICE FIELD CHIRONOMUS KIIENSIS (TOKUNAGA) ( DIPTERA: CHIRONOMIDAE)

    Institute of Scientific and Technical Information of China (English)

    Al-Shami S A; Che Salmah M R; Siti Azizah M N; Abu Hassan A; Azmi M

    2006-01-01

    Fourth instar larvae of Chironomus kiiensis(Tokunaga) were exposed to various concentrations of two commonly used herbicides: 2,4 - D Dimethylamine and Bensulfuron methyl in the rice fields. The bioassay experiment was carried out in a rearing unit in the laboratory at a room temperature ( (27 ± 2) ℃ ). A thin layer of sand sediments and tissue papers were provided as substrate in each unit. Each concentration of all herbicides was prepared in 250 mL distilled water. The experiment was performed in triplicate and 20 chironomid larvae were placed in each rearing unit. The larvae were fed with fish food (Sanyuichiban(R)) at 2 d intervals and all units were aerated by air pumps. The experiment was monitored every 24 h for mortality of C. kiiensis. The 2,4 - D Dimethylamine bioassay was carried out for 24 h while Bensulfuron methyl was run for 72 h. Dead larvae, pupae and living or dead adults were counted and removed daily.The LC50 of 2,4 - D Dimethylamine was 2 638 mg ai L-1, more than 2 000 times higher than the recommended dose of 0.753 mg ai L-1 used for controlling weeds in the rice field. Bensulfuron methyl was more toxic than the 2,4 - D Dimethylamine. The LC50 of the Bensulfuron methyl was recorded at 1.29 mg ai L-1, and approximately was more 20 times than that of the recommended dose of 0. 057 mg ai L-1. Bensulfuron methyl was found to be slow acting. The mortality of the larvae was only observed after 72 h. However, this herbicide interfered with the emergence of C. kiiensis to adults at and above the recommended dose used in the rice fields. Based on their LC50 values, this study showed that applying these herbicides in the rice fields at doses recommended by the manufacturers was safe for C. kiiensis and presumably to other living organisms in the water.

  7. Spatial uniformity in depth optima of midges: evidence from sedimentary archives of shallow Alpine and boreal lakes

    Directory of Open Access Journals (Sweden)

    Tomi P. Luoto

    2012-01-01

    Full Text Available In this study, water depth optima, i.e. habitat preferences within a depth gradient, were estimated for mutual midge (Diptera: Nematocera; Ceratopogonidae, Chironomidae taxa in surface sediment intralake data sets from eastern Finland and Austrian Alps and in a regional data set across Finland. The aim was to investigate how the optima and tolerances differ in these data sets and to discuss whether the possible causal factor for deviance is related to local adaptation, taxa representativeness, or some other factor. A total of 20 mutual taxa were found from the data sets and the estimated optima and tolerances were highly similar, with the exception of three taxa, which had deviating optima in the Austrian lake. The reason for these differences was most likely that the optima were poorly estimated in the Austrian lake due to low abundances and number of occurrences of these taxa. No evidence for intraspecific niche separation or local habitat adaptation was found between the Austrian and Finnish sites, although, interspecific variation in habitats was evident. Therefore, water depth optima estimated from representative number of specimens may be applicable for various ecological, limnological, and paleolimnological purposes. However, when the optima are applied outside the data set’s coverage, the results should be interpreted with caution. In addition, the given optima are not applicable in sites deeper than the sites in the data sets.

  8. Chironomus plumosus' påvirkning af næringsstofflukse i restaurerede søer

    DEFF Research Database (Denmark)

    Kristensen, Thomas Boll; Reitzel, Kasper; Andersen, Frede Østergaard;

    Den interne næringsstofbelastning af en række danske søer har betydet at disse søer er forblevet i en uklar, algedomineret tilstand til trods for reduktioner i mængden af tilførte næringsstoffer. I mange tilfælde er der derfor efterfølgende lavet et eller flere restaureringsindgreb for at skabe e....... plumosus efter længere tid vil øge bindingen af fosfor.   Andersen,F.Ø.; Jørgensen,M.; Jensen, H.S. (2006). The influence of Chironomus plumosus larvae on nutrient fluxes and phosphorus fractions in aluminum treated lake sediment. Water, Air, and Soil Pollution: Focus....

  9. Karyotype characteristics and polymorphism peculiarities of Chironomus bernensis Wülker & Klötzli, 1973 (Diptera, Chironomidae from the Central Caucasus and Ciscaucasia

    Directory of Open Access Journals (Sweden)

    Mukhamed Kh. Karmokov

    2015-06-01

    Full Text Available Data about the karyotype characteristics, features of chromosomal polymorphism and larval morphology of populations of Chironomus bernensis Wülker & Klötzli, 1973 (Diptera, Chironomidae from the Central Caucasus (the northern macroslope and Ciscaucasia are presented. The characteristics of the pericentromeric regions of the long chromosomes of this species from Caucasian populations were very similar to the ones from some European populations (from Poland and Italy, but differed from Swiss and Siberian populations. In the North Caucasian populations 10 banding sequences were found: two in arms A, C, and E, and one in arms B, D, F, and G. Nine of them were already known for this species, and one, berC2, is described for the first time. Cytogenetic distances between all the studied populations of Ch. bernensis show that close geographical location of all studied populations from the Central Caucasus and Ciscaucasia is reflected in their similar cytogenetic structure, but on the other hand, that they are more closely related to populations from Europe than to populations from Western Siberia. At the same time, all studied larvae from Caucasian populations have a four-bladed premandible, instead of a two-bladed one, as in the description of Ch. bernensis from Switzerland (Wülker and Klötzli 1973, Polukonova 2005c. These peculiarities may indicate the relative isolation of the Caucasus from the viewpoint of microevolution. Further research on karyological and morphological characteristics of Chironomus bernensis from geographically distant regions is necessary as there is a possibility that the presently known species is actually polytypic and consists of several sibling species.

  10. In Situ Estuarine and Marine Toxicity Testing: A Review, Including Recommendations for Future Use in Ecological Risk Assessment

    Science.gov (United States)

    2009-09-01

    39 Lavoie et al. (2001) used the freshwater amphipod Hyallela azteca , as well as the cladoceran Daphnia magna, in caged exposures as part of an...54 pp., June 2003. Chappie DJ and Burton GA, Jr., 1997. Optimization of in situ bioassays with Hyalella azteca and Chironomus tentans. Environ

  11. Biting midges of the subfamily Forcipomyiinae (Diptera: Ceratopogonidae) from the Middle East, with keys and descriptions of new species.

    Science.gov (United States)

    Alwin-Kownacka, Alicja; Szadziewski, Ryszard; Szwedo, Jacek

    2016-10-05

    Middle East biting midges of the genera Atrichopogon Kieffer and Forcipomyia Meigen, subfamily Forcipomyiinae Lenz, covering 41 species are reviewed. Two new species are described and illustrated: Forcipomyia (F.) siverekensis Alwin & Szadziewski sp. nov. and Forcipomyia (Microhelea) borkenti Alwin & Szadziewski sp. nov. The list includes 16 species of Atrichopogon and 25 of Forcipomyia. Nine species previously described by Vimmer and Kieffer from the Middle East are treated as nomina dubia and not included in the list.        Keys to identification of Atrichopogon and Forcipomyia species of the Middle East are also provided.

  12. Two gall midge pests (Diptera:Cecidomyiidae) attacking avocados%两种危害鳄梨的瘿蚊科害虫

    Institute of Scientific and Technical Information of China (English)

    焦克龙; 王学利; 牛春敬; 卜文俊

    2014-01-01

    苜蓿波瘿蚊(Asphondylia websteri Felt)和鳄梨布瘿蚊(Bruggmanniella perseae Gagné)是世界已知的两种严重危害鳄梨幼果的地区性害虫,均未有在中国发生或入侵的报道。本文提供了这两种瘿蚊害虫的鉴定依据,并提供详细的形态特征、生物学特性以及危害特点等信息,为进一步研究、检疫和防治这类害虫提供参考。%Avocados(Persea americana) have high economic values, so avocado pests should be given attention. Asphondylia websteri Felt and Bruggmanniella perseae Gagné are two of regional pests severely attacking young fruits of avocados only known in the world, neither of which were reported for the occurrence or invasion in China. Identification of the two gall midge pests with morphological characteristics, biological and damage features is provided fi rst in China in the present paper to fully understand the economic importance and to give a reference for further research, quarantine and control of the avocado gall midge pests.

  13. Identification of human-derived volatile chemicals that interfere with attraction of the Scottish biting midge and their potential use as repellents.

    Science.gov (United States)

    Logan, James G; Seal, Nicola J; Cook, James I; Stanczyk, Nina M; Birkett, Michael A; Clark, Suzanne J; Gezan, Salvador A; Wadhams, Lester J; Pickett, John A; Mordue, A Jennifer

    2009-03-01

    The Scottish biting midge, Culicoides impunctatus (Diptera: Ceratopogonidae), is a major pest in Scotland, causing a significant impact to the Scottish tourist and forestry industries. C. impunctatus is a generalist feeder, preferring to feed on large mammals, and is notorious for its attacks on humans. Until now, there was anecdotal evidence for differential attraction of female host-seeking C. impunctatus to individual human hosts, and the mechanism for this phenomenon was unknown. Using extracts of human odor collected by air entrainment, electroantennogram recordings to identify the physiologically active components, followed by behavioral assays, we show, for the first time, the differential attraction of female C. impunctatus to human odors and the chemical basis for this phenomenon. Certain chemicals, found in greater amounts in extracts that cause low attractiveness to midges, elicit a repellent effect in laboratory assays and repellency trials in the field. Differences in the production of these natural human-derived compounds could help to explain differential "attractiveness" between different human hosts. A mixture of two compounds in particular, 6-methyl-5-hepten-2-one and geranylacetone [(E)-6,10-dimethylundeca-5,9-dien-2-one], showed significant repellency (87, 77.4, 74.2, and 31.6% at hours 0, 1, 2, and 3, respectively) in the field and have the potential to be developed as novel repellents.

  14. Two new species of gall midges (Diptera, Cecidomyiidae) associated with Erythroxylum ovalifolium Peyr. (Erythroxylaceae) from the Barra de Maricá restinga, Maricá, Rio de Janeiro, Brazil

    OpenAIRE

    Maia,VC; Fernandes,SPC

    2011-01-01

    Two new species of gall midges (Diptera, Cecidomyiidae) Dasineura ovalifoliae and Clinodiplosis maricaensis are described based on material from the Barra de Maricá restinga, Maricá, Rio de Janeiro, Brazil. Both species are associated with Erythroxylum ovalifolium Peyr. (Erythroxylaceae). The former is the gall inducer and the latter an inquiline.

  15. Two new species of gall midges (Diptera, Cecidomyiidae associated with Erythroxylum ovalifolium Peyr. (Erythroxylaceae from the Barra de Maricá restinga, Maricá, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    VC Maia

    Full Text Available Two new species of gall midges (Diptera, Cecidomyiidae Dasineura ovalifoliae and Clinodiplosis maricaensis are described based on material from the Barra de Maricá restinga, Maricá, Rio de Janeiro, Brazil. Both species are associated with Erythroxylum ovalifolium Peyr. (Erythroxylaceae. The former is the gall inducer and the latter an inquiline.

  16. Identification, characterization and expression profiles of Chironomus riparius glutathione S-transferase (GST) genes in response to cadmium and silver nanoparticles exposure

    Energy Technology Data Exchange (ETDEWEB)

    Nair, Prakash M. Gopalakrishnan [School of Environmental Engineering and Graduate School of Energy and Environmental System Engineering, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743 (Korea, Republic of); Choi, Jinhee, E-mail: jinhchoi@uos.ac.kr [School of Environmental Engineering and Graduate School of Energy and Environmental System Engineering, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743 (Korea, Republic of)

    2011-02-15

    In this study, we report the identification and characterization of 13 cytosolic GST genes in Chironomus riparius from Expressed Sequence Tags (ESTs) database generated using pyrosequencing. Comparative and phylogenetic analyses were undertaken with Drosophila melanogaster and Anopheles gambiae GSTs and 3 Delta, 4 Sigma, 1 each in Omega, Epsilon, Theta, Zeta and 2 unclassified classes of GSTs were identified and characterized. The relative mRNA expression levels of all of the C. riparius GSTs (CrGSTs) genes under different developmental stages were varied with low expression in the larval stage. The antioxidant role of CrGSTs was studied by exposing fourth instar larvae to a known oxidative stress inducer Paraquat and the relative mRNA expression to different concentrations of cadmium (Cd) and silver nanoparticles (AgNPs) for various time intervals were also studied. All the CrGSTs showed up- or down regulation to varying levels based upon the concentration, and duration of exposure. The highest mRNA expression was noticed in Delta3, Sigma4 and Epsilon1 GST class in all treatments. These results show the role of CrGST genes in defense against oxidative stress and its potential as a biomarker to Cd and AgNPs exposure.

  17. Are gall midge species (Diptera, Cecidomyiidae host-plant specialists? Espécies de moscas galhadoras (Diptera, Cecidomyiidae são especialistas em plantas hospedeiras?

    Directory of Open Access Journals (Sweden)

    Marco Antonio A. Carneiro

    2009-01-01

    Full Text Available Despite the speciose fauna of gall-inducing insects in the Neotropical region, little is known about their taxonomy. On the other hand, gall morphotypes associated with host species have been extensively used as a surrogate of the inducer species worldwide. This study reviewed the described gall midges and their galls to test the generalization on the use of gall morphotypes as surrogates of gall midge species in the Brazilian fauna. We compiled taxonomic and biological data for 196 gall midge species recorded on 128 host plant species. Ninety two percent of those species were monophagous, inducing galls on a single host plant species, whereas only 5.6% species were oligophagous, inducing galls on more than one congeneric host plant species. Only four species induced galls on more than one host plant genus. We conclude that gall morphotypes associated with information on the host plant species and attacked organs are reliable surrogates of the gall-inducing species.Apesar do elevado número de espécies da fauna de insetos indutores de galhas na região Neotropical, muito pouco espécies foram descritas. Por outro lado, o morfotipo da galha associado com a espécie da planta hospedeira é em todo o mundo amplamente utilizado como um indicador da espécie de inseto indutor. Este estudo revê as espécies de cecidommídeos descritos e suas galhas para verificar a generalização do uso da morfologia da galha como indicador da espécie de cecidomíideo na fauna brasileira. Nós compilamos dados biológicos e taxonômicos de 196 espécies de cecidomiídeos em 128 espécies de plantas no Brasil. Noventa e dois porcento destas espécies foram monófagas, induzindo galhas em uma única espécie de planta hospedeira, enquanto somente 5,6% das espécies foram oligófagas, induzindo galhas em mais de uma espécie de planta do mesmo gênero. Somente quatro espécies induzem galhas em espécies de plantas de gêneros diferentes. Nós concluímos que o morfo

  18. Tagging and mapping of a rice gall midge resistance gene, Gm8, and development of SCARs for use in marker-aided selection and gene pyramiding.

    Science.gov (United States)

    Jain, A; Ariyadasa, R; Kumar, A; Srivastava, M N; Mohan, M; Nair, S

    2004-11-01

    Using amplified fragment length polymorphisms (AFLPs) and random amplified polymorphic DNAs (RAPDs), we have tagged and mapped Gm8, a gene conferring resistance to the rice gall midge (Orseolia oryzae), a major insect pest of rice, onto rice chromosome 8. Using AFLPs, two fragments, AR257 and AS168, were identified that were linked to the resistant and susceptible phenotypes, respectively. Another resistant phenotype-specific marker, AP19(587), was also identified using RAPDs. SCAR primers based on the sequence of the fragments AR257 and AS168 failed to reveal polymorphism between the resistant and the susceptible parents. However, PCR using primers based on the regions flanking AR257 revealed polymorphism that was phenotype-specific. In contrast, PCR carried out using primers flanking the susceptible phenotype-associated fragment AS168 produced a monomorphic fragment. Restriction digestion of these monomorphic fragments revealed polymorphism between the susceptible and resistant parents. Nucleotide BLAST searches revealed that the three fragments show strong homology to rice PAC and BAC clones that formed a contig representing the short arm of chromosome 8. PCR amplification using the above-mentioned primers on a larger population, derived from a cross between two indica rice varieties, Jhitpiti (resistant parent) and TN1 (susceptible parent), showed that there is a tight linkage between the markers and the Gm8 locus. These markers, therefore, have potential for use in marker-aided selection and pyramiding of Gm8 along with other previously tagged gall midge resistance genes [ Gm2, Gm4(t), and Gm7].

  19. Effects of in vivo exposure to UV filters (4-MBC, OMC, BP-3, 4-HB, OC, OD-PABA) on endocrine signaling genes in the insect Chironomus riparius.

    Science.gov (United States)

    Ozáez, Irene; Martínez-Guitarte, José Luis; Morcillo, Gloria

    2013-07-01

    There is increasing evidence indicating that several UV filters might have endocrine disruptive effects. Numerous studies have evaluated hormonal effects in vertebrates, mainly reporting estrogenic and androgenic activities in mammals and fishes. There is only limited knowledge about potential endocrine activity in invertebrate hormonal systems. In this work, the effects on endocrine signaling genes of six frequently used UV filters were investigated in Chironomus riparius, a reference organism in aquatic toxicology. The UV filters studied were: octyl-p-methoxycinnamate (OMC) also called 2-ethylhexyl-4-methoxycinnamate (EHMC); 4-methylbenzylidene camphor (4-MBC); benzophenone-3 (BP-3); 4-hidroxybenzophenone (4-HB); octocrylene (OC); and octyldimethyl-p-aminobenzoate (OD-PABA). After in vivo exposure at different dosages, expression levels of the genes coding for the ecdysone receptor (EcR), the ultraspiracle (usp, ortholog of the RXR) and the estrogen-related receptor (ERR) were quantified by Real Time PCR. The EcR gene was significantly upregulated by 4-MBC, OMC/EHMC and OD-PABA, with a dose-related response following 24h exposure. In contrast, the benzophenones, BP-3 and 4-HB, as well as OC did not alter this gene at the same exposure conditions. The transcription profiles of the usp and ERR genes were not significantly affected, except for BP-3 that inhibited the usp gene at the highest concentration. To our knowledge, this is the first experimental evidence in invertebrates of a direct effect of UV filters on endocrine-related genes, and is consistent with the known effects on vertebrate hormonal receptor genes. The capability of 4-MBC, OMC/EHMC and OD-PABA to stimulate the expression of the ecdysone receptor, a key transcription factor for the ecdysone-genomic response in arthropods, suggests the possibility of a broad and long-term effect on this hormonal pathway. These findings strengthen the need for further research about the ecotoxicological implications

  20. Assessing the effects of fluoxetine on Physa acuta (Gastropoda, Pulmonata) and Chironomus riparius (Insecta, Diptera) using a two-species water-sediment test

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Argueello, Paloma [Laboratory for Ecotoxicology, Department of the Environment, INIA, Crta, A Coruna km 7, 28040 Madrid (Spain)], E-mail: arguello@inia.es; Fernandez, Carlos; Tarazona, Jose V. [Laboratory for Ecotoxicology, Department of the Environment, INIA, Crta, A Coruna km 7, 28040 Madrid (Spain)

    2009-03-01

    Fluoxetine has been tested in a two-species water-sediment system, which allowed a two-generation study with Chironomus riparius and a partial life-cycle with the freshwater snail Physa acuta to be performed at the same time. The design considered the continuous application of fluoxetine to overlaying water for nominal concentrations of 31.25, 62.5, 125 and 250 {mu}g/L. A fifth treatment (87.5 {mu}g/L) level consisted of pulse applications once a week. Measures of water and sediment concentrations were determined once a week and at the end of experiment (day 44), respectively. The fate study demonstrated that water dissipation can be explained by partitioning of fluoxetine to sediment. At the end of experiment, the percentage of detected fluoxetine was up to 10-fold higher in sediment than in overlaying water. The employed two-species test allowed distinguishing, in the same exposure conditions, effects due to waterborne exposure together ingestion at the sediment surface (freshwater grazing snail P. acuta) and exposure by burrowing activities (sediment-dwelling insect larvae C. riparius). The effect assessment showed a stimulation of P. acuta reproduction at lower concentrations (31.25 and 62.5 {mu}g/L), while the opposite effect was observed at the highest treatment (250 {mu}g/L). Additional studies should be conducted to establish if the statistically significant differences observed in F0 sex ratio at the 62.5 {mu}g/L and F1 adult emergence at 31.25 {mu}g/L of C. riparius have a toxicological significance. This study showed that fluoxetine can affect reproduction of freshwater molluscs. The results of the present study may contribute to knowledge on ecotoxicology of pharmaceuticals, about which little data is available. The possible consequences and implications for targeting the environmental risk assessment of fluoxetine are discussed.

  1. Individual-based model of Chironomus riparius population dynamics over several generations to explore adaptation following exposure to uranium-spiked sediments.

    Science.gov (United States)

    Beaudouin, Rémy; Dias, Victor; Bonzom, Jean Marc; Péry, Alexandre

    2012-05-01

    Natural populations are chronically exposed to various pollutants over many generations. It is thus crucial to understand and quantify adaptive dynamics of stressed populations in order to increase the relevance of ecotoxicological risk assessment. However, long-term consequences to population exposure are not much studied yet. The present study investigated evolutionary responses of Chironomus riparius populations exposed to uranium (heavy metal pollutant) and to assess the underlying mechanisms. To fulfil our objective, we produced data with organisms exposed to four relevant concentrations of uranium through eight successive generations. We built an individual-based (IBM) model of C. riparius population dynamics to analyse these data and to test several assumptions about the mechanisms involved in the phenotypic changes. The IBM was based on a dynamic energy budget (DEB) model for C. riparius by Pery et al. (2002). DEB models account mathematically for the acquisition and use of energy to describe and predict growth, maintenance, development and reproduction of living organisms. The IBM accounted for the influence of the test conditions on the observations over eight generations and highlighted some trait evolution such as time to emergence and adult size in control conditions. The model was then used to analyse the exposed population data. Our results showed that exposure to uranium led to a phenotypic selection via a differential survival characterised by longer time to emergence and smaller larval maximal size. As a general conclusion, IBMs based on DEB-based modelling developed to analyse multi-generation experiments are very promising for understanding and quantifying long term selection and tolerance mechanisms in a population under toxic stress.

  2. Effects of Lumbriculus variegatus (Annelida, Oligochaete) bioturbation on zinc sediment chemistry and toxicity to the epi-benthic invertebrate Chironomus tepperi (Diptera: Chironomidae).

    Science.gov (United States)

    Colombo, Valentina; Pettigrove, Vincent J; Hoffmann, Ary A; Golding, Lisa A

    2016-09-01

    Classical laboratory-based single-species sediment bioassays do not account for modifications to toxicity from bioturbation by benthic organisms which may impact predictions of contaminated sediment risk to biota in the field. This study aims to determine the effects of bioturbation on the toxicity of zinc measured in a standard laboratory bioassay conducted with chironomid larvae (Chironomus tepperi). The epi-benthic chironomid larvae were exposed to two different levels of sediment contamination (1600 and 1980 mg/kg of dry weight zinc) in the presence or absence of annelid worms (Lumbriculus variegatus) which are known to be tolerant to metal and to have a large impact on sediment properties through bioturbation. Chironomids had 5-6x higher survival in the presence of L. variegatus which shows that bioturbation had a beneficial effect on the chironomid larvae. Chemical analyses showed that bioturbation induced a flux of zinc from the pore water into the water column, thereby reducing the bioavailability of zinc in pore water to the chironomid larvae. This also suggested that pore water was the major exposure path for the chironomids to metals in sediment. During the study, annelid worms (Oligochaetes) produced a thin layer of faecal pellets at the sediment surface, a process known to: (i) create additional adsorption sites for zinc, thus reducing its availability, (ii) increase the microbial abundance that in turn could represent an additional food source for opportunistic C. tepperi larvae, and (iii) modify the microbial community's structure and alter the biogeochemical processes it governs thus indirectly impact zinc toxicity. This study represents a contribution in recognising bioturbating organisms as "ecological engineers" as they directly and indirectly influence metal bioavailability and impact other sediment-inhabiting species. This is significant and should be considered in risk assessment of zinc levels (and other metals) in contaminated sediment

  3. Cationic lipid-formulated DNA vaccine against hepatitis B virus: immunogenicity of MIDGE-Th1 vectors encoding small and large surface antigen in comparison to a licensed protein vaccine.

    Directory of Open Access Journals (Sweden)

    Anne Endmann

    Full Text Available Currently marketed vaccines against hepatitis B virus (HBV based on the small (S hepatitis B surface antigen (HBsAg fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible strategies to improve the efficacy of HBV vaccines. Here, we evaluated the immunogenicity of SAINT-18-formulated MIDGE-Th1 vectors encoding the S or the large (L protein of HBsAg in mice and pigs. In both animal models, vectors encoding the secretion-competent S protein induced stronger humoral responses than vectors encoding the L protein, which was shown to be retained mainly intracellularly despite the presence of a heterologous secretion signal. In pigs, SAINT-18-formulated MIDGE-Th1 vectors encoding the S protein elicited an immune response of the same magnitude as the licensed protein vaccine Engerix-B, with S protein-specific antibody levels significantly higher than those considered protective in humans, and lasting for at least six months after the third immunization. Thus, our results provide not only the proof of concept for the SAINT-18-formulated MIDGE-Th1 vector approach but also confirm that with a cationic-lipid formulation, a DNA vaccine at a relatively low dose can elicit an immune response similar to a human dose of an aluminum hydroxide-adjuvanted protein vaccine in large animals.

  4. On the study of the transmission networks of blood parasites from SW Spain: diversity of avian haemosporidians in the biting midge Culicoides circumscriptus and wild birds.

    Science.gov (United States)

    Ferraguti, Martina; Martínez-de la Puente, Josué; Ruiz, Santiago; Soriguer, Ramón; Figuerola, Jordi

    2013-07-15

    Blood-sucking flying insects play a key role in the transmission of pathogens of vector-borne diseases. However, at least for the case of avian malaria parasites, the vast majority of studies focus on the interaction between parasites and vertebrate hosts, but there is a lack of information regarding the interaction between the parasites and the insect vectors. Here, we identified the presence of malaria and malaria-like parasite lineages harbored by the potential vector Culicoides circumscriptus (Kieffer). Also, we identified some nodes of the transmission network connecting parasite lineages, potential insect vectors and avian hosts by comparing Haemoproteus and Plasmodium lineages isolated from insects with those infecting wild birds in this and previous studies. Using a molecular approach, we analysed the presence of blood parasites in a total of 97 biting midges trapped in the Doñana National Park (SW Spain) and surrounding areas. Also, 123 blood samples from 11 bird species were analyzed for the presence of blood parasite infections. Blood parasites Haemoproteus and Plasmodium were identified by amplification of a 478 bp fragment of the mitochondrial cytochrome b gen. Thirteen biting midges harboured blood parasites including six Haemoproteus and two Plasmodium lineages, supporting the potential role of these insects on parasite transmission. Moreover, ten (8.1%) birds carried blood parasites. Seven Plasmodium and one Haemoproteus lineages were isolated from birds. Overall, six new Haemoproteus lineages were described in this study. Also, we identified the transmission networks of some blood parasites. Two Haemoproteus lineages, hCIRCUM03 and GAGLA03, were identical to those isolated from Corvus monedula in southern Spain and Garrulus glandarius in Bulgaria, respectively. Furthermore, the new Haemoproteus lineage hCIRCUM05 showed a 99% similarity with a lineage found infecting captive penguins in Japan. The comparison of the parasite lineages isolated in

  5. Tolerance of freshwater test organisms to formulated sediments for use as control materials in whole-sediment toxicity tests

    Energy Technology Data Exchange (ETDEWEB)

    Kemble, N.E.; Dwyer, F.J.; Ingersoll, C.G. [Geological Survey, Columbia, MO (United States). Environmental and Contaminants Research Center; Dawson, T.D. [Integrated Laboratory Systems, Duluth, MN (United States); Norberg-King, T.J. [Environmental Protection Agency, Duluth, MN (United States). Mid-Continent Ecological Div.

    1999-02-01

    A method is described for preparing formulated sediments for use in toxicity testing. Ingredients used to prepare formulated sediments included commercially available silt, clay, sand, humic acid, dolomite, and {alpha}-cellulose (as a source of organic carbon). {alpha}-Cellulose was selected as the source of organic carbon because it is commercially available, consistent from batch to batch, and low in contaminant concentrations. The tolerance of freshwater test organisms to formulated sediments for use as control materials in whole-sediment toxicity testing was evaluated. Sediment exposures were conducted for 10 d with the amphipod Hyalella azteca, the midges Chironomus riparius and C. tentans, and the oligochaete Lumbriculus variegatus and for 28 d with H. azteca. Responses of organisms in formulated sediments was compared with a field-collected control sediment that has routinely been used to determine test acceptability. Tolerance of organisms to formulated sediments was evaluated by determining responses to varying levels of {alpha}-cellulose, to varying levels of grain size, to evaluation of different food types, or to evaluation of different sources of overlying water. In the 10-d exposures, survival of organisms exposed to the formulated sediments routinely met or exceeded the responses of test organisms exposed to the control sediment and routinely met test acceptability criteria required in standard methods. Growth of amphipods and oligochaetes in 10-d exposures with formulated sediment was often less than growth of organisms in the field-collected control sediment. Additional research is needed, using the method employed to prepare formulated sediment, to determine if conditioning formulated sediments before starting 10-d tests would improve the growth of amphipods. In the 28-d exposures, survival of H. azteca was low when reconstituted water was used as the source of overlying water. However, when well water was used as the source of overlying water in

  6. Toxicological evaluation of sediment samples from Burns Harbor, Porter County, Indiana

    Energy Technology Data Exchange (ETDEWEB)

    Ward, J.A.; Pinza, M.R.; Barrows, M.E.; Karls, R.K.; Word, J.Q. [Battelle/Marine Sciences Lab., Sequim, WA (United States)

    1994-05-01

    The US Army Corps of Engineers (USACE) Chicago District is authorized to maintain the water depths in Burns Harbor at navigable levels. In order to maintain these levels, sediments must be dredged and disposed of at approved disposal sites. To make a 404 (b) 1 open-water disposal evaluation, the dredged sediment may be evaluated through a series of toxicological tests to assess its potential for causing an adverse environmental effect. Battelle/Marine Sciences Laboratory (MSL) was contracted by USACE to perform these freshwater toxicity tests. The tests were designed to simulate conditions that organisms living within an aquatic dredged material disposal site might experience during disposal operations, and included both bedded-sediment (solid-phase) and suspended-sediment (elutriate) tests. Test samples were collected by USACE personnel and composited into three test treatments representing potential dredging areas (Management Units {number_sign}1, {number_sign}2, and {number_sign}3). Four toxicological tests were conducted in support of this program. The solid-phase tests included the amphipod, Hyalella azteca, and the midge, Chironomus tentans. The elutriate tests included the fathead minnow, Pimephales promelas, and the daphnid, Daphnia magna. Testing was conducted following standard procedures provided by USACE which are consistent with ASTM protocols and the Evaluation of Dredged Material Proposed for Discharge in Inland and Near Coastal Waters -- Testing Manual (Draft) Inland Testing Manual (EPA/USACE 1993), known as the ``Draft Inland Testing Manual.`` The suitability of sediment representing the management units for open-water disposal was evaluated following the guidelines contained in the Draft Inland Testing Manual.

  7. The protective effect of rapid cold-hardening develops more quickly in frozen versus supercooled larvae of the Antarctic midge, Belgica antarctica.

    Science.gov (United States)

    Kawarasaki, Yuta; Teets, Nicholas M; Denlinger, David L; Lee, Richard E

    2013-10-15

    During the austral summer, larvae of the terrestrial midge Belgica antarctica (Diptera: Chironomidae) experience highly variable and often unpredictable thermal conditions. In addition to remaining freeze tolerant year-round, larvae are capable of swiftly increasing their cold tolerance through the rapid cold-hardening (RCH) response. The present study compared the induction of RCH in frozen versus supercooled larvae. At the same induction temperature, RCH occurred more rapidly and conferred a greater level of cryoprotection in frozen versus supercooled larvae. Furthermore, RCH in frozen larvae could be induced at temperatures as low as -12°C, which is the lowest temperature reported to induce RCH. Remarkably, as little as 15 min at -5°C significantly enhanced larval cold tolerance. Not only is protection from RCH acquired swiftly, but it is also quickly lost after thawing for 2 h at 2°C. Because the primary difference between frozen and supercooled larvae is cellular dehydration caused by freeze concentration of body fluids, we also compared the effects of acclimation in dehydrated versus frozen larvae. Because slow dehydration without chilling significantly increased larval survival to a subsequent cold exposure, we hypothesize that cellular dehydration caused by freeze concentration promotes the rapid acquisition of cold tolerance in frozen larvae.

  8. Expression of genes involved in energy mobilization and osmoprotectant synthesis during thermal and dehydration stress in the Antarctic midge, Belgica antarctica.

    Science.gov (United States)

    Teets, Nicholas M; Kawarasaki, Yuta; Lee, Richard E; Denlinger, David L

    2013-02-01

    The Antarctic midge, Belgica antarctica, experiences sub-zero temperatures and desiccating conditions for much of the year, and in response to these environmental insults, larvae undergo rapid shifts in metabolism, mobilizing carbohydrate energy reserves to promote synthesis of low-molecular-mass osmoprotectants. In this study, we measured the expression of 11 metabolic genes in response to thermal and dehydration stress. During both heat and cold stress, we observed upregulation of phosphoenolpyruvate carboxykinase (pepck) and glycogen phosphorylase (gp) to support rapid glucose mobilization. In contrast, there was a general downregulation of pathways related to polyol, trehalose, and proline synthesis during both high- and low-temperature stress. Pepck was likewise upregulated in response to different types of dehydration stress; however, for many of the other genes, expression patterns depended on the nature of dehydration stress. Following fast dehydration, expression patterns were similar to those observed during thermal stress, i.e., upregulation of gp accompanied by downregulation of trehalose and proline synthetic genes. In contrast, gradual, prolonged dehydration (both at a constant temperature and in conjunction with chilling) promoted marked upregulation of genes responsible for trehalose and proline synthesis. On the whole, our data agree with known metabolic adaptations to stress in B. antarctica, although a few discrepancies between gene expression patterns and downstream metabolite contents point to fluxes that are not controlled at the level of transcription.

  9. Toxicity of Trinitrotoluene to Sheepshead Minnows in Water Exposures

    Science.gov (United States)

    2010-02-06

    more toxic than TNT to an amphipod Hyalella azteca (2 times) and the cladoceran Ceriodaphia dubia (30 times) (Griest et al., 1998). Substantial...the aquatic amphipod Hyalella Azteca . Ecotoxicol. Environ. Saf. 70, 38–46. Smock, L.A., Stoneburner, D.L., Clark, J.R., 1976. The toxic effects of...tetranitro-1,3,5,7-tetrazocine in sediments to Chironomus tentans and Hyalella azteca : low-dose hormesis and high-dose mortality. Environ. Toxicol. Chem. 21

  10. Palaeoclimatological and palaeolimnological records from fossil midges and tree-rings: the role of the North Atlantic Oscillation in eastern Finland through the Medieval Climate Anomaly and Little Ice Age

    Science.gov (United States)

    Luoto, Tomi P.; Helama, Samuli

    2010-08-01

    Hydrological changes and air temperature variability are reconstructed from the sediments of Lake Pieni-Kauro, eastern Finland during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA) using transfer functions derived from midge (Insecta: Nematocera)-based calibration models. The reconstructions are compared with a regional tree-ring chronology and sediment physical properties are determined to track depositional changes. An objective of the study is to examine the long-term relationship between the North Atlantic Oscillation (NAO) and climate (temperature, precipitation). Our results show that the MCA was characterized by warm and dry summer conditions, which were accompanied by changes in the sediment magnetic susceptibility values most likely representing major forest fires during the tree-ring indicated MCA megadrought. However, the midge-based stream flow reconstruction shows increased values during the MCA, thus implying enhanced spring floods after snowy winters. During the LIA, the tree-ring data indicate that a generally wetter climate prevailed during summers, but the stream flow reconstruction indicates less snowy winters. In the terms of long-term climatology, the present results show support to the concept that the NAO has a positive correlation between winter precipitation and annual temperature and a negative correlation between summer precipitation in eastern Finland. Thus, the results may serve as important background data for global change assessments.

  11. Sellers' Revisited: A Big Data Reassessment of Historical Outbreaks of Bluetongue and African Horse Sickness due to the Long-Distance Wind Dispersion of Culicoides Midges.

    Science.gov (United States)

    Durr, Peter A; Graham, Kerryne; van Klinken, Rieks D

    2017-01-01

    The possibility that outbreaks of bluetongue (BT) and African horse sickness (AHS) might occur via long-distance wind dispersion (LDWD) of their insect vector (Culicoides spp.) was proposed by R. F. Sellers in a series of papers published between 1977 and 1991. These investigated the role of LDWD by means of visual examination of the wind direction of synoptic weather charts. Based on the hypothesis that simple wind direction analysis, which does not allow for wind speed, might have led to spurious conclusions, we reanalyzed six of the outbreak scenarios described in Sellers' papers. For this reanalysis, we used a custom-built Big Data application ("TAPPAS") which couples a user-friendly web-interface with an established atmospheric dispersal model ("HYSPLIT"), thus enabling more sophisticated modeling than was possible when Sellers undertook his analyzes. For the two AHS outbreaks, there was strong support from our reanalysis of the role of LDWD for that in Spain (1966), and to a lesser degree, for the outbreak in Cyprus (1960). However, for the BT outbreaks, the reassessments were more complex, and for one of these (western Turkey, 1977) we could discount LDWD as the means of direct introduction of the virus. By contrast, while the outbreak in Cyprus (1977) showed LDWD was a possible means of introduction, there is an apparent inconsistency in that the outbreaks were localized while the dispersion events covered much of the island. For Portugal (1956), LDWD from Morocco on the dates suggested by Sellers is very unlikely to have been the pathway for introduction, and for the detection of serotype 2 in Florida (1982), LDWD from Cuba would require an assumption of a lengthy survival time of the midges in the air column. Except for western Turkey, the BT reanalyses show the limitation of LDWD modeling when used by itself, and indicates the need to integrate susceptible host population distribution (and other covariate) data into the modeling process. A further

  12. Sellers’ Revisited: A Big Data Reassessment of Historical Outbreaks of Bluetongue and African Horse Sickness due to the Long-Distance Wind Dispersion of Culicoides Midges

    Directory of Open Access Journals (Sweden)

    Peter A. Durr

    2017-07-01

    Full Text Available The possibility that outbreaks of bluetongue (BT and African horse sickness (AHS might occur via long-distance wind dispersion (LDWD of their insect vector (Culicoides spp. was proposed by R. F. Sellers in a series of papers published between 1977 and 1991. These investigated the role of LDWD by means of visual examination of the wind direction of synoptic weather charts. Based on the hypothesis that simple wind direction analysis, which does not allow for wind speed, might have led to spurious conclusions, we reanalyzed six of the outbreak scenarios described in Sellers’ papers. For this reanalysis, we used a custom-built Big Data application (“TAPPAS” which couples a user-friendly web-interface with an established atmospheric dispersal model (“HYSPLIT”, thus enabling more sophisticated modeling than was possible when Sellers undertook his analyzes. For the two AHS outbreaks, there was strong support from our reanalysis of the role of LDWD for that in Spain (1966, and to a lesser degree, for the outbreak in Cyprus (1960. However, for the BT outbreaks, the reassessments were more complex, and for one of these (western Turkey, 1977 we could discount LDWD as the means of direct introduction of the virus. By contrast, while the outbreak in Cyprus (1977 showed LDWD was a possible means of introduction, there is an apparent inconsistency in that the outbreaks were localized while the dispersion events covered much of the island. For Portugal (1956, LDWD from Morocco on the dates suggested by Sellers is very unlikely to have been the pathway for introduction, and for the detection of serotype 2 in Florida (1982, LDWD from Cuba would require an assumption of a lengthy survival time of the midges in the air column. Except for western Turkey, the BT reanalyses show the limitation of LDWD modeling when used by itself, and indicates the need to integrate susceptible host population distribution (and other covariate data into the modeling process

  13. "Mid-G" region sequences of the glycoprotein gene of Austrian infectious hematopoietic necrosis virus isolates form two lineages within European isolates and are distinct from American and Asian lineages.

    Science.gov (United States)

    Kolodziejek, Jolanta; Schachner, Oskar; Dürrwald, Ralf; Latif, Muna; Nowotny, Norbert

    2008-01-01

    Infectious hematopoietic necrosis virus (IHNV) is one of the most important pathogens of salmonid fish. In this study a comprehensive phylogenetic analysis of the genetic evolution and variety of Austrian IHNV strains, as well as selected strains ensuring worldwide coverage, is presented. The phylogenetic investigation is based on sequences comprising the "mid-G" region of the G gene, and it includes all currently available IHNV sequences of the G gene with a length of at least 615 bp. Austrian IHNVs are located--together with other European IHNV isolates--in two clusters of genogroup M (M-Eur1 and M-Eur2) and are clearly separated from American and Asian lineages. The genetic clustering, however, could not be linked to certain clinical symptoms or significant differences in the mortality rates.

  14. A key, based on wing patterns of biting midges (genus Culicoides Latreille - Diptera: Ceratopogonidae in the Iberian Peninsula, for use in epidemiological studies

    Directory of Open Access Journals (Sweden)

    Rawlings, Peter

    1996-12-01

    Full Text Available The identity of vectors of disease are often required speedily in epidemiological studies but with a precision which excludes as many other species as possible. Identification keys usually require the examination of many different parts of the suspected vector to pinpoint the species. This consumes considerable time and resources, so epidemiologists tend to ignore them. Asimplified approach to identification is proposed, using the characteristics of a single part of the body (the wings of biting midges of the genus Culicoides. The level of differentiation was epidemiologically valuable. The monoclave could not differentiate all the species from each other but more than one third (20/58 of identifications were for single species, and a further 12/58 identifications gave only two possibilities, making 55.2% of identifications to an accuracy of at most one of two species. The diagnosis of vector species was reached in a maximum of six decision points. The only notable exception to valuable differentiation was the four species in the Culicoides obsoletus group which had almost identical female wing patterns. The ready availability of simple keys, which can be used by anyone without formal training in taxonomy, for all the species of a group in a region should encourage greater standardisation of identifications in all studies, including those not primarily aimed at systematics. These monoclaves can also serve as the primary tools to build computerised image-recognition systems for genera, families and orders of insects.Con frequencia en los estudios epidemiológicos hace falta conocer con rapidez, pero también con precisión, la identidad de los vectores. Por lo general los procedimientos de identificación y las claves exigen el examen de un elevado número de partes diferentes del vector sospechoso. Este enfoque consume mucho tiempo y recursos por lo que tiende a ser evitado por los epidemiólogos. Se propone un sistema simplificado para la

  15. The origin of speciation: Trace metal kinetics over natural water/sediment interfaces and the consequences for bioaccumulation

    NARCIS (Netherlands)

    Vink, J.P.M.

    2009-01-01

    The speciation of heavy metals was measured over a variety of natural and undisturbed water/sediment interfaces. Simultaneously, two benthic species (oligochaete Limnodrilus spp. and the midge Chironomus riparius) were exposed to these sediments. Under occurring redox conditions, free ion activities

  16. The origin of speciation: Trace metal kinetics over natural water/sediment interfaces and the consequences for bioaccumulation

    NARCIS (Netherlands)

    Vink, J.P.M.

    2009-01-01

    The speciation of heavy metals was measured over a variety of natural and undisturbed water/sediment interfaces. Simultaneously, two benthic species (oligochaete Limnodrilus spp. and the midge Chironomus riparius) were exposed to these sediments. Under occurring redox conditions, free ion activities

  17. Habitat selection by chironomid larvae: fast growth requires fast food

    NARCIS (Netherlands)

    Haas, de E.M.; Wagner, C.; Koelmans, A.A.; Kraak, M.H.S.; Admiraal, W.

    2006-01-01

    1. Sediments have been considered as a habitat, a cover from predators and a source of food, but also as a source of potential toxic compounds. Therefore, the choice of a suitable substrate is essential for the development of chironomids. 2. For the midge Chironomus riparius (Meigen 1804) the growth

  18. 茂兰国家自然保护区常见蚊蠓昼夜活动节律的初步观察%A Preliminary Study on Nyctohemeral Activity Rhythm of Mosquito and Midge in Maolan National Nature Conservation Area in Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    刘鉴; 吴家红; 李金福; 闫妍

    2011-01-01

    Objective: To observe nyctohemeral activity rhythm of common mosquitoes and midges in Maolan national nature conservation area. Methods: A 24 h continuous survey was carried out by u-sing human baited net trap, insect net capture and light trap methods. Results: Most of the captures were midges which amounted to 338 under 5 genera and were dominated by Culicoides. The collected mosquitoes were 117 of 5 species under 4 genera. The total amount of mosquitoes and midges was 455. Conclusions: Round-the-clock activity rhythm and dynamic distribution of mosquitoes and midges a-round the residential areas of Wengang village are generally clarified.%目的:观察茂兰国家自然保护区常见蚊、蠓的昼夜活动规律.方法:采用人帐诱法、网捕法、灯诱法进行24 h连续调查,在解剖镜下对所采集的蚊蠓进行种属鉴定;根据采集蚊蠓数初步分析蚊蠓昼夜活动规律.结果:采集到的蠓数量最多,有5属338只,以库蠓为主;蚊虫为4属5种117只,共计455只;蚊虫活动高峰在日出前(晨)和日落后(昏),昏峰大于晨峰.结论:初步了解茂兰国家自然保护区翁昂乡常见蚊蠓昼夜活动节律以及动态分布.

  19. 物理和摇蚊幼虫组合扰动对内源磷再生和形态转化的协同作用%Synergistic Effect of Physical and Chironomus plumosus Combined Disturbance on Regeneration and Transformation of Internal Phosphorus

    Institute of Scientific and Technical Information of China (English)

    史晓丹; 李大鹏; 王忍; 黄勇

    2015-01-01

    To explain the synergistic effect of physical and Chironomus plumosus combined disturbance on the regeneration and transformation of internal phosphorus, laboratory static incubation experiments were carried out with the sediments and overlying water from a eutrophic river in Suzhou. Rhizon samplers were used to acquire the pore water. In the experiment, we compared the variation of different phosphorus forms in the overlying water, the pore water and sediments under the Chironomus plumosus disturbance and the combined disturbance. The results indicated that the amount of different forms of phosphorus ( TP, PP, DTP, DIP) in the overlying water under combined disturbance was higher than that under Chironomus plumosus combination disturbance. It was attributed to the significant increase of the microbial activity in the sediments. Compared with Chironomus plumosus disturbance, the amount of DIP and ferrous decreased with the greater magnitude and range. It was attributed to the superposition effect of the physical and benthos disturbance on the penetration depth of the dissolved oxygen. In addition, the amount of NH4 Cl-P decreased remarkably in the 0-2 cm sediment while Fe/Al-P increased obviously. Furthermore, the variation magnitude of NH4 Cl-P and Fe/Al-P was higher under combined disturbance than that under Chironomus plumosus disturbance, which suggested the superposition effect of the physical and benthos disturbance on the regeneration and migration of phosphorus.%为探讨物理和摇蚊幼虫组合扰动对内源磷再生和形态转化的协同作用,选取了苏州某富营养化河道为研究对象。利用室内静态培养试验和Rhizon间隙水采样技术,着重对比了单纯的摇蚊幼虫扰动和组合扰动下,上覆水、间隙水、沉积物中磷形态数量分布的变化规律。结果表明,组合扰动下,上覆水中不同形态磷含量( TP、 PP、 DTP、 DIP)均处于较高水平,明显高于摇蚊幼虫扰动。这可归因于微

  20. Acute toxicity, critical body residues, Michaelis-Menten analysis of bioaccumulation, and ionoregulatory disturbance in response to waterborne nickel in four invertebrates: Chironomus riparius, Lymnaea stagnalis, Lumbriculus variegatus and Daphnia pulex.

    Science.gov (United States)

    Leonard, Erin M; Wood, Chris M

    2013-06-01

    We investigated the bioaccumulation and acute toxicity (48 h or 96 h) of Ni in four freshwater invertebrate species in two waters with hardness of 40 (soft water) and 140 mg L(-1) as CaCO(3) (hard water). Sensitivity order (most to least) was Lymnaea stagnalis > Daphnia pulex > Lumbriculus variegatus > Chironomus riparius. In all cases water hardness was protective against acute Ni toxicity with LC(50) values 3-3.5× higher in the hard water vs. soft water. In addition, higher water hardness significantly reduced Ni bioaccumulation in these organisms suggesting that competition by Ca and Mg for uptake at the biotic ligand may contribute to higher metal resistance. CBR50 values (Critical Body Residues) were less dependent on water chemistry (i.e. more consistent) than LC(50) values within and across species by ~2 fold. These data support one of the main advantages of the Tissue Residue Approach (TRA) where tissue concentrations are generally less variable than exposure concentrations with respect to toxicity. Whole body Ni bioaccumulation followed Michaelis-Menten kinetics in all organisms, with greater hardness tending to decrease B(max) with no consistent effect on K(d). Across species, acute Ni LC(50) values tended to increase with both K(d) and B(max) values - i.e. more sensitive species exhibited higher binding affinity and lower binding capacity for Ni, but there was no correlation with body size. With respect to biotic ligand modeling, log K(NiBL) values derived from Ni bioaccumulation correlated well with log K(NiBL) values derived from toxicity testing. Both whole body Na and Mg levels were disturbed, suggesting that disruption of ionoregulatory homeostasis is a mechanism of acute Ni toxicity. In L. stagnalis, Na depletion was a more sensitive endpoint than mortality, however, the opposite was true for the other organisms. This is the first study to show the relationship between Na and Ni. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Morphological deformities in Chironomus spp. (Diptera: Chironomidae) larvae as a tool for impact assessment of anthropogenic and environmental stresses on three rivers in the Juru river system, Penang, Malaysia.

    Science.gov (United States)

    Al-Shami, Salman; Rawi, Che Salmah M; Nor, Siti Azizah M; Ahmad, Abu Hassan; Ali, Arshad

    2010-02-01

    Morphological deformities in parts of the head capsule of Chironomus spp. larvae inhabiting three polluted rivers (Permatang Rawa [PRR], Pasir [PR], and Kilang Ubi [KUR]) in the Juru River Basin, northeastern peninsular Malaysia, were studied. Samples of the fourth-instar larvae at one location in each river were collected monthly from November 2007 to March 2008 and examined for deformities of the mentum, antenna, mandible, and epipharyngis. At each sample location, in situ measurements of water depth, river width, water pH, dissolved oxygen, and water temperature were made. Samples of river water and benthic sediments were also collected monthly from each larval sample location in each river and taken to the laboratory for appropriate analysis. Total suspended solids (TSSs), ammonium-N, nitrate-N, phosphate-P, chloride, sulfate, and aluminum content in water were analyzed. Total organic matter and nonresidual metals in the sediment samples were also analyzed. Among the three rivers, the highest mean deformity (47.17%) was recorded in larvae collected from KUR that received industrial discharges from surrounding garment and rubber factories, followed by PRR (33.71%) receiving primarily residues of fertilizers and pesticides from adjacent rice fields, and PR (30.34%) contaminated primarily by anthropogenic wastes from the surrounding residential areas. Among the various head capsule structures, deformity of the mentum was strongly reflective of environmental stress and amounted to 27.9, 20.87, and 30.19% in the PRR, PR, and KUR, respectively. Calculated Lenat's toxic score index satisfactorily explained the influence of prevailing environmental variables on the severity of mentum deformities. Redundancy analysis and forward selection selected TSSs, sediment Zn, Mn, Cu, and Ni, and water pH, dissolved oxygen, water temperature, total organic matter, nitrate-N, chloride, phosphate-P, ammonium-N, sulfate, and aluminum as parameters that significantly affected some

  2. Studies on Entomophthora culicis ( Zygomycetes: Entomophthorales) infecting Chironomus sp. ( Diptera: Chironomidae) in Guangdong Province%广东省侵染摇蚊的库蚊虫霉研究

    Institute of Scientific and Technical Information of China (English)

    贾春生; 洪波

    2011-01-01

    This paper presents the first description of aspects of Entomophthora culicis infecting Chironomus sp. in China, including disease symptoms and occurrence dynamics. The primary conidia of E. culicis are campanulate,measure ( 14.6 ± 1.5 ) μm × ( 10. 8 ± 1.2 ) μm and have a distinct apical point. Secondary conidia are similar to primary ones but are smaller, measuring ( 11.0 ± 1.1 ) μm × ( 8.0 ± 0. 5 ) μm. Resting spores are ( 29. 3 ± 1.9 ) μm in size and spherical to subspherical in shape. Infected insects are fixed to the substrate by rhizoids. The sporulating mycelium is greenish and covers the host completely. The infection rate of E. culicis was obviously different in three trees. The infection rate varied between seasons, being lowest in summer (0) and highest in spring (90. 2% ). There was no significant change in infection rate (93.5%-95.7% ) from 2006 to 2009.%在中国首次报道了侵染摇蚊的库蚊虫霉(Entomophtora culichs)的形态特征、侵染症状以及发生动态等.库蚊虫霉初生分生孢子,钟罩形,顶部有一明显小尖突,(14.6±1.5)μm×(10.8±1.2)μm.次生分生孢子形似初生分生孢子,但略小,(11.0±1.1)μm×(8.0±0.5)μm.休眠孢子,球形至亚球形,直径(29.3±1.9)μm.被侵染摇蚊尸体以假根附着于基物上,通体覆盖着绿色的真菌子实层.库蚊虫霉侵染率在不同植物上明显不同.库蚊虫霉侵染率随季节不同波动很大,春季最高达90.2%,其次为秋季和冬季,夏季最低为0.2006-2009年库蚊虫霉侵染率为93.5%~95.7%,年际之间变动不大.

  3. Comparative effects of butyl benzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP) on the aquatic larvae of Chironomus riparius based on gene expression assays related to the endocrine system, the stress response and ribosomes.

    Science.gov (United States)

    Planelló, Rosario; Herrero, Oscar; Martínez-Guitarte, José Luis; Morcillo, Gloria

    2011-09-01

    In this work, the effects of butyl benzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP), two of the most extensively used phthalates, were studied in Chironomus riparius under acute short-term treatments, to compare their relative toxicities and identify genes sensitive to exposure. The ecotoxicity of these phthalates was assessed by analysis of the alterations in gene expression profiles of selected inducible and constitutive genes related to the endocrine system, the cellular stress response and the ribosomal machinery. Fourth instar larvae, a model system in aquatic toxicology, were experimentally exposed to five increasing concentrations (0.01, 0.1, 1, 10, and 100mg/L) of DEHP and BBP for 24h. Gene expression was analysed by the changes in levels of transcripts, using RT-PCR techniques with specific gene probes. The exposures to DEHP or BBP were able to rapidly induce the hsp70 gene in a concentration-dependent manner, whereas the cognate form hsc70 was not altered by either of these chemicals. Transcription of ribosomal RNA as a measure of cell viability, quantified by the levels of ITS2, was not affected by DEHP, but was slightly, yet significantly, downregulated by BBP at the highest concentrations tested. Finally, as these phthalates are classified as endocrine disruptor chemicals (EDCs), their potential effect on the ecdysone endocrine system was studied by analysing the two genes, EcR and usp, of the heterodimeric ecdysone receptor complex. It was found that BBP provoked the overexpression of the EcR gene, with significant increases from exposures of 0.1mg/L and above, while DEHP significantly decreased the activity of this gene at the highest concentration. These data are relevant as they show for the first time the ability of phthalates to interfere with endocrine marker genes in invertebrates, demonstrating their potential capacity to alter the ecdysone signalling pathway. Overall, the study clearly shows a differential gene-toxin interaction

  4. Comparative Study of the Morphology of the Ovipositor of Platygaster diplosisae (Hymenoptera: Platygasteridae and Aprostocetus procerae (Hymenoptera: Eulophidae Two Parasitoids Associated with the African Rice Gall Midge, Orseolia oryzivora (Diptera: Cecidomyiidae

    Directory of Open Access Journals (Sweden)

    Souleymane Nacro

    2009-01-01

    Full Text Available We studied the morphology of the ovipositor of Platygaster diplosisae (Hymenoptera: Platygasteridae and Aprostocetus procerae (= Tetrastichus pachydiplosisae (Hymenoptera: Eulophidae, two parasitoids associated with the African rice gall midge (AFRGM, and Orseolia oryzivora (Diptera: Cecidomyiidae. Scanning electron microscope techniques were used for this study. The ovipositor of P. diplosisae was short (40 μm, and most of the sensillae found on it were mechanoreceptors and located on the distal portion of the 3rd valvulae. These sensillae may be involved in selection of an egg or larval host. The shortness of this ovipositor may be an adaptation to a host whose egg envelope thickness is not more than 0.7 μm. The ovipositor of A. procerae was 30 times (1.2 mm the length of the P. diplosisae ovipositor. It was not only well equipped with mechanoreceptive sensillae, but these sensillae were very diverse and distributed along the length of the valvulae. The 10 denticulations of the lancet of this ovipositor allow this parasitoid to exploit hosts that are not otherwise readily accesible. These two parasitoids share the same resource by infesting different life stages of the host. The ovipositor of each species of parasitoid enhanced resource sharing, due to its length and its sensillae type and distribution.

  5. Evaluation of Metal Toxicity in Streams Affected by Abandoned Mine Lands, Upper Animas River Watershed, Colorado

    Science.gov (United States)

    Besser, John M.; Allert, Ann L.; Hardesty, Douglas K.; Ingersoll, Christopher G.; May, Thomas W.; Wang, Ning; Leib, Kenneth J.

    2001-01-01

    water; (3) to develop site-specific thresholds for toxicity of Zn and Cu in stream water; and (4) to develop models of the contributions of Cu and Zn to toxicity of stream water, which may be used to characterize toxicity before and after planned remediation efforts. We evaluated the toxicity of metal-contaminated sediments by conducting sediment toxicity tests with two species of benthic invertebrates, the midge, Chironomus tentans. and the amphipod, Hyalella azteca. Laboratory toxicity tests with both taxa, exposed to fine stream-bed sediments collected in September 1997, showed some evidence of sediment toxicity, as survival of midge larvae in sediments from Cement Creek (C48) and lower Mineral Creek (M34), and growth of amphipods in sediments from these sites and three Animas River sites (A68, Animas at Silverton; A72, Animas below Silverton, and A73, Animas at Elk Park) were significantly reduced compared to a reference site, South Mineral Creek (SMC) . Amphipods were also exposed to site water and fine stream-bed sediment, separately and in combination, during the late summer low flow period (August-September) of 1998. In these studies, stream water, with no sediment present, from all five sites tested (same sites as above, except C48) caused 90% to 100% mortality of amphipods. In contrast, significant reductions in survival of amphipods occurred at two sites (A72 and SMC) in exposures with field-collected sediment plus stream water, and at only one site (A72) in exposures with sediments and clean overlying water. Concentrations of Zn, Pb, Cu, and Cd were high in both sediment and pore water (interstitial water) from most sites tested, but greatest sediment toxicity was apparently associated with greater concentrations of Fe and/or Al in sediments. These results suggest that fine stream-bed sediments of the more contaminated stream reaches of the upper Animas River watershed are toxic to benthic invertebrates, but that these impacts are less serious than tox

  6. Two new species and a new record of biting midges from Emei Mountain, China (Ceratopogonidae, Diptera)%峨嵋山发现蠓类二新种及一新纪录(双翅目:蠓科)

    Institute of Scientific and Technical Information of China (English)

    邓成玉; 廖忠友; 张有植; 莫东平; 虞以新

    2011-01-01

    The present paper deals with two new species and a new record of biting midges from Mt. Emei, Emei County,Sichuan Province, China. All specimens were collected with net trap during Sept. 15-29 , 2010 from Mt. Emei ( 29. 5°N,103. 3°E ), Sichuan Province, and are deposited in the Collection of Medical Entomology of Beijing Institution of Microbiology and Epidemiology ( 20 Dongdajie Ave. , Fengtai Dis. , Beijing 100071 , China ).1 Atrichopogon emeiensis Deng, Liao et Yu, sp. nov. ♂ ( Fig. 1 )Compound eyes bare, wing length 2. 07 mm, width 0. 55 mm. Scutellum with 6 long bristles, hind tibia with 9 terminal bristles.This new species is quite specific in very short antenna segment 15 , differing distinctly from that of other species of the genus. The new species is closely allied to Atrichopogon schizonyx Giles et Wirth, 1982 and Atrichopogon setosilateralis Borkent et Picado, 2004 , but eyes are pubescent in the allied species, distinctly differing from the new species.Type: holotype ♂ .2 Stilobezzia lijiangi Yu, Zhang et Mo, sp. nov. ♂♀ ( Fig. 2 )Compound eyes bare, wing unmarked, surface without macrotrichia; length ♂ 1. 09 mm, ♀ 1. 15 mm;width ♂ 0. 32 mm ♀ 0. 45 mm, Scutellum with 4 long bristles, hind tibia with 5 terminal bristles.The male of new species is somewhat related to Stilobezzia blaesopira Yu et Deng, 2005. and St. unifaciatus Tokunaga, 1963 , especially in the aedeagus, but distinctly different from the related species in the wing surface without macrotrichia and mid leg TR >3. Types: holotype ♂ , paratype ♀ .3 Stilobezzia robusta Das Gupta et Wirth, 1968 ( Fig. 3 ) New record in China. Material exanmined : 1 ♂ .Distribution : Malaysia ; China.%2010年9月中下旬在四川省峨眉县峨眉山(29.5°N,103.3°E)西南麓进行了挥网采集,获得蠓类2亚科10属11种,其中有2个新种:峨眉裸蠓(Atrichopogon emeiensis Deng,Liao et Yu sp.nov.)和李江柱蠓(Stilobezzia lijiangi Yu,Zhang et Mo,sp.nov.);以及1

  7. Phermonal Control of Biting Midges (Culicoides SPP).

    Science.gov (United States)

    1982-04-28

    Associate Professor, Dept. of Entomology and Nematology , Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611...Microbiology University of Maryland College Park, MD 20742 Or. Donald W. Hall Associate Professor Department of Entomology & Nematology University of

  8. Culicoides Biting Midges (Diptera: Ceratopogonidae) of Kenya

    Science.gov (United States)

    1990-03-01

    Culicoides are vectors of viral diseases in do- mestic animals and humans. Isolation of half of the known Simbu group arboviruses has been made from...53 (male, femalej. Holotype: 0, Zika Forest, Uganda, C. Khamala, light trap, 17-V-66 (BMNH). Paratypes: 1 0, 1 6, Kakamega Forest, Kenya, C... vector potential than imicola and others. Precipitin tests of seven blood-engorged females gave one positive for sheep. They isolated bluetongue-l

  9. Toxicity to freshwater organisms from oils and oil spill chemical treatments in laboratory microcosms

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, S.; Klerks, P.L.; Nyman, J.A

    2003-04-01

    Toxicity of oil and diesel fuel to freshwater biota may be increased by use of oil spill cleaning agents. - Toxicity and temporal changes in toxicity of freshwater-marsh-microcosms containing South Louisiana Crude (SLC) or diesel fuel and treated with a cleaner or dispersant, were investigated using Chironomus tentans, Daphnia pulex, and Oryzias latipes. Bioassays used microcosm water (for D. pulex and O. latipes) or soil slurry (for C. tentans) taken 1,7, 31, and 186 days after treatment. SLC was less toxic than diesel, chemical additives enhanced oil toxicity, the dispersant was more toxic than the cleaner, and toxicities were greatly reduced by day 186. Toxicities were higher in the bioassay with the benthic species than in those with the two water-column species. A separate experiment showed that C. tentans' sensitivity was intermediate to that of Tubifex tubifex and Hyallela azteca. Freshwater organisms, especially benthic invertebrates, thus appear seriously effected by oil under the worst-case-scenario of our microcosms. Moreover, the cleaner and dispersant tested were poor response options under those conditions.

  10. Invisible face of boron pollution in fluvial ecosystem: the level in the tissues of sentinel and nectonic organisms.

    Science.gov (United States)

    Arslan, Naime

    2013-10-01

    Turkey is the largest producer of borate products in the world. Among four largest boron mines in Turkey two of them are located in basins of Orhaneli and Emet Streams. In this study, boron levels in abiotic (water-sediment) and some biotic elements (sentinel organisms; Asellus aquaticus, Gammarus pulex, Chironomus tentans, Limnodrilus hoffmeisteri and nektonic organism; Squalius cii) of Orhaneli and Emet Streams were investigated and their ranks among the food chain were demonstrated. Since Orhaneli and Emet Streams confluence to form Mustafakemalpaşa Brook which feeds Uluabat Lake which is one of the most important Ramsar fields of the world, Boron levels in those two streams have importance in terms of both continuances of aquatic systems. Present study results have shown that boron levels in water of both streams are much higher (vary between 8.64 and 16.73 mg L(-1)) than not only Turkish Standard but also limits determined by WHO, US EPA, and NAS. Boron levels determined in sediments of two streams vary between 18.05 and 36.7 mg kg(-1). The highest boron level in the biotic elements was determined in liver of Squalius cii (34.64 mg kg(-1)), it is followed by Limnodrilus hoffmeisteri (2.84 mg kg(-1)), Chironomus tentans (2.11 mg kg(-1)), and Gammarus pulex (1.98 mg kg(-1)).

  11. TINJAUAN YURIDIS TENTAN G BADAN HAM ASEAN DALAM SISTEM HUKUM NASIONAL INDONESIA

    Directory of Open Access Journals (Sweden)

    Heribertus Jaka Triyana

    2012-02-01

    Full Text Available The AICHR seems to fail to contribute positively in enforcing protection, fulfillment, and implementation of human rights at national level since its terms of references and structural composition differs from the commonly-recognised regional institutions. Legal gaps, legal vacuum, legal overlapping and conflicts of authorities with national authorities are indicators that hinder its future works. Kemampuan AICHR dalam menjamin perlindungan, pemenuhan dan pemajuan hak asasi manusia di level nasional diragukan karena kewenangan AICHR yang limitatif dan tidak mengikuti pakem seperti yang dimiliki oleh komisi HAM di Eropa dan Afrika. Ketimpangan hukum, kekosongan hukum, tumpang-tindih aturan, dan konflik kewenangan dengan otoritas nasional menjadi faktor penghambat pelaksanaan kewenangan AICHR.

  12. 中朝俄边境吸血蠓及一新种(双翅目:蠓科)%Fauna and a new species of hematophagous midges in the borders of North Korea, Russia and China(Diptera:Ceratopogonidea)

    Institute of Scientific and Technical Information of China (English)

    任清明; 王峰; 王旭; 邵锴; 刘国平

    2016-01-01

    该文报道了采自东北中朝俄边境17个市(县)的吸血蠓3属71种,其中包括1新种,饶河库蠓(Culicoieds raoheensis Ren et Liu sp. nov.)。中朝边境7个市(县)分布3属42种,中俄边境10个市(县)分布2属54种。饶河库蠓与千山库蠓(Culicoides qianshanensis Fei,1982)相近似,但后者触须第3节有感觉器窝,触角嗅觉器分布在3~15节与本新种明显不同。新种模式标本保存在沈阳军区疾病预防控制中心(沈阳110034)。%This paper reports 3 genera and 71 species of hematophagous midges in 17 cities and counties of bordering area of North Korea, Russia and China, among which a new species Culicoides moheensis Ren et Liu sp. nov. was described. Three genera and 42 species were distributed in the 7 cities and counties of China⁃North Korea borders; and 2 genera 54 species in 10 cities and counties of China⁃Russia borders. Culicoides raoheensis Ren et Liu, sp. nov. is similar to C. qianshanensis Fei, 1982, but distinctly different in the palpus third segment with a large and deep sensory pit, antenna sensilla coeloconica present on segments 3-15 of female C. qinashanensis Fei, 1982. The type specimen is deposited at the Shenyang Command Center for Disease Control and Prevention(Shenyang 110034,China).

  13. Organic waste compounds in streams: Occurrence and aquatic toxicity in different stream compartments, flow regimes, and land uses in southeast Wisconsin, 2006–9

    Science.gov (United States)

    Baldwin, Austin K.; Corsi, Steven R.; Richards, Kevin D.; Geis, Steven W.; Magruder, Christopher

    2013-01-01

    -water-indicator compounds, among others. Urban runoff and storm-related leaks of sanitary sewers and (or) septic systems may be important sources of these and other compounds to the streams. The Kinnickinnic River, a highly urbanized site, had the highest detection rates and concentrations of compounds of all the sampled sites. The Milwaukee River near Cedarburg—one of the least urban sites—and the Outer Milwaukee Harbor site had the lowest detection rates and concentrations. Aquatic-toxicity benchmarks were exceeded for 12 of the 25 compounds with known benchmarks. The compounds with the greatest benchmark exceedances were the PAHs, both in terms of exceedance frequency (up to 93 percent for some compounds in sediment samples) and magnitude (concentrations up to 1,024 times greater than the benchmark value). Other compounds with toxicity-benchmark exceedances include Bis(2-ethylhexyl) phthalate (a plasticizer), 2-Methylnapthalene (a component of fuel and oil), phenol (an antimicrobial disinfectant with diverse uses), and 4-Nonylphenol (sum of all isomers; a detergent metabolite, among other uses). Analyzed as a mixture, the suite of PAH compounds were found to be potentially toxic for most non-base-flow samples. Bioassay tests were conducted on samples from 14 streams: Ceriodaphnia dubia in base-flow samples, Ceriodaphnia dubia and Hyallela azteca in pore-water samples, and Hyallela azteca and Chironomus tentans in sediment samples. The greatest adverse effect was observed in tests with Chironomus tentans from sediment samples. The weight of Chironomus tentans after exposure to sediments decreased with increased OWC concentrations. This was most evident in the relation between PAH results and Chironomus tentans bioassay results for the majority of samples; however, solvents and flame retardants appeared to be important for one site each. These results for PAHs were consistent with assessment of PAH potency factors for sediment, indicating that PAHs were likely to have adverse effects

  14. AcEST: BP917171 [AcEST

    Lifescience Database Archive (English)

    Full Text Available YMU001_000097_B09 441 Adiantum capillus-veneris mRNA. clone: YMU001_000097_B09. BP91717...1 CL1480Contig1 Show BP917171 Clone id YMU001_000097_B09 Library YMU01 Length 441 Definition Adiantum ca...pillus-veneris mRNA. clone: YMU001_000097_B09. Accession BP917171 Tissue type prothallium Developmental stag...leic Acids Res. 25:3389-3402. Query= BP917171|Adiantum capillus-veneris mRNA, clo...G 211 >sp|Q03376|BAR3_CHITE Balbiani ring protein 3 OS=Chironomus tentans GN=BR3 PE=2 SV=1 Length = 17

  15. An assessment of the toxicity of phthalate esters to freshwater benthos. 1. Aqueous exposures.

    Science.gov (United States)

    Call, D J; Markee, T P; Geiger, D L; Brooke, L T; VandeVenter, F A; Cox, D A; Genisot, K I; Robillard, K A; Gorsuch, J W; Parkerton, T F; Reiley, M C; Ankley, G T; Mount, D R

    2001-08-01

    Tests were performed with the freshwater invertebrates Hyalella azteca, Chironomus tentans, and Lumbriculus variegatus to determine the acute toxicity of six phthalate esters, including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butylbenzyl phthalate (BBP), di-n-hexyl phthalate (DHP), and di-2-ethylhexyl phthalate (DEHP). It was possible to derive 10-d LC50 (lethal concentration for 50% of the population) values only for the four lower molecular weight esters (DMP, DEP, DBP, and BBP), for which toxicity increased with increasing octanol-water partition coefficient (Kow) and decreasing water solubility. The LC50 values for DMP, DEP, DBP, and BBP were 28.1, 4.21, 0.63, and 0.46 mg/L for H. azteca; 68.2, 31.0, 2.64, and > 1.76 mg/L for C. tentans; and 246, 102, 2.48, and 1.23 mg/L for L. variegatus, respectively. No significant survival reductions were observed when the three species were exposed to either DHP or DEHP at concentrations approximating their water solubilities.

  16. Midges as palaeoindicators of lake productivity, eutrophication and hypolimnetic oxygen

    DEFF Research Database (Denmark)

    Brodersen, K. P.; Quinlan, R.

    2006-01-01

    palaeolimnology. The recent advances in quantitative reconstructions using chironomid transfer functions and numerical analyses are presented and compared. A consensus ranking of species trophic optima and respiratory adaptations from published data sets showed good agreement. Factors such as lake depth......, stratification patterns, water level change, sediment conditions, submerged vegetation and ecological thresholds are all important for interpretation of palaeolimnological trajectories. We use previously published and new data to document how these factors determine, change or preserve the "lake identity" over......The sedimentary record from lakes can be used as an archive of past environmental changes and for events related to anthropogenic activities in the catchment area. In this paper, we review the more recent studies on zoobenthos responses to changes in lake productivity and to altered sublittoral...

  17. Biting Midges (Ceratopogonidae: Culicoides Latreille) Recorded from Farms in Sweden

    DEFF Research Database (Denmark)

    Nielsen, S. A.; Nielsen, B.O.; Chirico, J.

    2009-01-01

    In light of the emergence of bluetongue in Northern Europe, populations of Culicoides species were monitored in and around several Swedish livestock farms (surveillance in 2007 and 2008). The position of the sampling sites ranged from about latitude 55° N to about 68° N. Thirty-three Culicoides...... species were recorded, of which 30 were new to Sweden. The species recorded, and their relative abundance and spatial distribution on sites are detailed. Species incriminated as vectors of bluetongue virus were predominant. (Texte intégral)...

  18. Revision of early taxa of Australian gall midges (Diptera: Cecidomyiidae).

    Science.gov (United States)

    Kolesik, Peter; Gagné, Raymond J

    2016-12-07

    Australian Cecidomyiidae described by Schiner (1868), Skuse (1888, 1890), Koebele (1893), Felt (1915), Edwards (1916) and Rübsaamen (1916), totalling 111 species and three subgenera, are revised. Chastomera Skuse, 1888 is confirmed to be a junior synonym of Haplusia Karsch, 1878 and Gonioclema Skuse, 1888 and Necrophlebia Skuse, 1888 are declared nomina dubia. Twenty-two species are placed to genus, an additional four species are placed to supertribe or subfamily, all of them redescribed. The remaining species are declared junior synonyms or nomina dubia. Diadiplosis koebelei (Koebele, 1893) is a new junior synonym of Diadiplosis plumbea (Skuse, 1888). Dasineura tomentosa Dorchin, 2011 is a new junior synonym of Dasineura frauenfeldi (Schiner, 1868). Sphenolasioptera Kolesik & Gagné gen. nov. (Cecidomyiinae: Lasiopterini) is erected to contain Sphenolasioptera vastatrix (Skuse, 1888) n. comb. The following genera are recorded from Australia for the first time: Ledomyia Kieffer (Cecidomyiinae: Ledomyiini), represented by L. vitulans (Skuse), n. comb.; Bremia Rondani (Cecidomyiinae: Aphidoletini), represented by B. actiosa (Skuse) n. comb. and B. oreas (Skuse) n. comb.; Divellepidosis Fedotova & Sidorenko (Porricondylinae: Porricondylini), represented by D. pallidina (Skuse) n. comb. and D. indubitata (Skuse) n. comb. Additions are made to the key to genera of Cecidomyiinae of Australia and Papua New Guinea (Kolesik 2014) to accomodate Bremia, Ledomyia and Sphenolasioptera.

  19. Specifically Designed Constructed Wetlands: A Novel Treatment Approach for Scrubber Wastewater

    Energy Technology Data Exchange (ETDEWEB)

    John H. Rodgers Jr; James W. Castle; Chris Arrington: Derek Eggert; Meg Iannacone

    2005-09-01

    A pilot-scale wetland treatment system was specifically designed and constructed at Clemson University to evaluate removal of mercury, selenium, and other constituents from flue gas desulfurization (FGD) wastewater. Specific objectives of this research were: (1) to measure performance of a pilot-scale constructed wetland treatment system in terms of decreases in targeted constituents (Hg, Se and As) in the FGD wastewater from inflow to outflow; (2) to determine how the observed performance is achieved (both reactions and rates); and (3) to measure performance in terms of decreased bioavailability of these elements (i.e. toxicity of sediments in constructed wetlands and toxicity of outflow waters from the treatment system). Performance of the pilot-scale constructed wetland treatment systems was assessed using two criteria: anticipated NPDES permit levels and toxicity evaluations using two sentinel toxicity-testing organisms (Ceriodaphnia dubia and Pimephales promelas). These systems performed efficiently with varied inflow simulations of FGD wastewaters removing As, Hg, and Se concentrations below NPDES permit levels and reducing the toxicity of simulated FGD wastewater after treatment with the constructed wetland treatment systems. Sequential extraction procedures indicated that these elements (As, Hg, and Se) were bound to residual phases within sediments of these systems, which should limit their bioavailability to aquatic biota. Sediments collected from constructed wetland treatment systems were tested to observe toxicity to Hyalella azteca or Chironomus tetans. Complete survival (100%) was observed for H. azteca in all cells of the constructed wetland treatment system and C. tentans had an average of 91% survival over the three treatment cells containing sediments. Survival and growth of H. azteca and C. tentans did not differ significantly between sediments from the constructed wetland treatment system and controls. Since the sediments of the constructed

  20. An assessment of the toxicity of phthalate esters to freshwater benthos. 2. Sediment exposures.

    Science.gov (United States)

    Call, D J; Cox, D A; Geiger, D L; Genisot, K I; Markee, T P; Brooke, L T; Polkinghorne, C N; VandeVenter, F A; Gorsuch, J W; Robillard, K A; Parkerton, T F; Reiley, M C; Ankley, G T; Mount, D R

    2001-08-01

    Seven phthalate esters were evaluated for their 10-d toxicity to the freshwater invertebrates Hyalella azteca and Chironomus tentans in sediment. The esters were diethyl phthalate (DEP), di-n-butyl phthalate (DBP), di-n-hexyl phthalate (DHP), di-(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), and a commercial mixture of C7, C9, and C11 isophthalate esters (711P). All seven esters were tested in a sediment containing 4.80% total organic carbon (TOC), and DBP alone was tested in two additional sediments with 2.45 and 14.1% TOC. Sediment spiking concentrations for DEP and DBP were based on LC50 (lethal concentration for 50% of the population) values from water-only toxicity tests, sediment organic carbon concentration, and equilibrium partitioning (EqP) theory. The five higher molecular weight phthalate esters (DHP, DEHP, DINP, DIDP, 711P), two of which were tested and found to be nontoxic in water-only tests (i.e., DHP and DEHP), were tested at single concentrations between 2,100 and 3,200 mg/kg dry weight. Preliminary spiking studies were performed to assess phthalate ester stability under test conditions. The five higher molecular weight phthalate esters in sediment had no effect on survival or growth of either C. tentans or H. azteca, consistent with predictions based on water-only tests and EqP theory. The 10-d LC50 values for DBP and H. azteca were >17,400, >29,500, and >71,900 mg/kg dry weight for the low, medium, and high TOC sediments, respectively. These values are more than 30x greater than predicted by EqP theory and may reflect the fact that H. azteca is an epibenthic species and not an obligative burrower. The 10-d LC50 values for DBP and C. tentans were 826, 1,664, and 4.730 mg/kg dry weight for the low, medium, and high TOC sediments, respectively. These values are within a factor of two of the values predicted by EqP theory. Pore-water 10-d LC50 values for DBP (dissolved fraction) and C. tentans in the three

  1. On the tensile strength of insect swarms

    Science.gov (United States)

    Ni, Rui; Ouellette, Nicholas T.

    2016-08-01

    Collective animal groups are often described by the macroscopic patterns they form. Such global patterns, however, convey limited information about the nature of the aggregation as a whole. Here, we take a different approach, drawing on ideas from materials testing to probe the macroscopic mechanical properties of mating swarms of the non-biting midge Chironomus riparius. By manipulating ground-based visual features that tend to position the swarms in space, we apply an effective tensile load to the swarms, and show that we can quasi-statically pull single swarms apart into multiple daughter swarms. Our results suggest that swarms surprisingly have macroscopic mechanical properties similar to solids, including a finite Young’s modulus and yield strength, and that they do not flow like viscous fluids.

  2. How Many Insects Does It Take to Make a Swarm?

    Science.gov (United States)

    Ouellette, Nicholas

    2014-03-01

    Aggregations of social animals, such as flocks of birds, schools of fish, or swarms of insects, are beautiful, natural examples of self-organized behavior far from equilibrium. They tend to display a range of emergent properties, from enhanced sensing to the rapid propagation of information throughout the aggregate. Many classes of models have been proposed to describe these systems, including agent-based models that specify explicit social forces between individuals and continuum models that abstract the interactions between individuals into some smooth advecting velocity field. Assessing these various modeling approaches requires comparison with empirical data. We will discuss measurements of laboratory mating swarms of the non-biting midge Chironomus riparius in the context of model assessment. In particular, we focus on the question of the small-number limit: how large must the population be before collective properties emerge?

  3. The interaction of actinide and lanthanide ions with hemoglobin and its relevance to human and environmental toxicology

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Amit, E-mail: amitk@barc.gov.in [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Ali, Manjoor [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Ningthoujam, Raghumani S. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Gaikwad, Pallavi [Department of Zoology, Savitribai Phule Pune University, Pune 411 007, Mumbai (India); Kumar, Mukesh [Solid State, Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Nath, Bimalendu B. [Department of Zoology, Savitribai Phule Pune University, Pune 411 007, Mumbai (India); Pandey, Badri N. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2016-04-15

    Highlights: • The sites of Ln and An interaction in Hb depend upon their charge-to-ionic-radii ratio. • Th(IV), Ce(IV) and U(VI) altered structure and oxygen-binding of Hb. • Spectroscopic studies determined binding characteristics of actinides. • Metal–Hb interaction was tested in an environmentally-important aquatic midge, Chironomus. - Abstract: Due to increasing use of lanthanides/actinides in nuclear and civil applications, understanding the impact of these metal ions on human health and environment is a growing concern. Hemoglobin (Hb), which occurs in all the kingdom of living organism, is the most abundant protein in human blood. In present study, effect of lanthanides and actinides [thorium: Th(IV), uranium: U(VI), lanthanum: La(III), cerium: Ce(III) and (IV)] on the structure and function of Hb has been investigated. Results showed that these metal ions, except Ce(IV) interacted with carbonyl and amide groups of Hb, which resulted in the loss of its alpha-helix conformation. However, beyond 75 μM, these ions affected heme moiety. Metal–heme interaction was found to affect oxygen-binding of Hb, which seems to be governed by their closeness with the charge-to-ionic-radius ratio of iron(III). Consistently, Ce(IV) being closest to iron(III), exhibited a greater effect on heme. Binding constant and binding stoichiometry of Th(IV) were higher than that of U(VI). Experiments using aquatic midge Chironomus (possessing human homologous Hb) and human blood, further validated metal–Hb interaction and associated toxicity. Thus, present study provides a biochemical basis to understand the actinide/lanthanide-induced interference in heme, which may have significant implications for the medical and environmental management of lanthanides/actinides toxicity.

  4. Assessment of nonpoint-source runoff in a stream using in situ and laboratory approaches

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, K.A.; Burton, G.A. Jr.

    1999-12-01

    Anthropogenic activities that change a watershed can cause adverse impacts to receiving water. Agricultural and urban runoff are the two leading causes of surface-water impairment in the US. When assessing pollutant sources and their effects on aquatic ecosystems, and prior to implementing source controls, it is necessary to define the systems stressors and receptors of exposure. Toxicity assays are a key component to integrative assessments that include habitat (physical), chemical, and indigenous community characterization. Traditional toxicity assay methods and the use of water-quality criteria are often inappropriate because of exposure design and effect assumptions. Hyalella azteca and Chironomus tentans were exposed in situ for varying time periods during both low- and high-flow conditions to determine the effect of urban and agricultural runoff. Short-term chronic and acute toxicity of urban and agricultural runoff was then measured in the laboratory and related to in situ test results. Nonpoint-source (NPS) runoff from urban areas was often more acutely toxic to organisms in the laboratory as compared to in situ results. Conversely, toxicity to the organisms was greater at the agricultural site during in situ exposures when compared to laboratory. In situ assays were an essential and integral component of NPS runoff assessments. They provided unique information that complemented laboratory toxicity, habitat, benthic community, and physicochemical characterizations.

  5. Effect of zeolite on toxicity of ammonia in freshwater sediments: Implications for toxicity identification evaluation procedures

    Energy Technology Data Exchange (ETDEWEB)

    Besser, J.M.; Ingersoll, C.G. [Geological Survey, Columbia, MO (United States); Leonard, E.N.; Mount, D.R. [Environmental Protection Agency, Duluth, MN (United States). Mid-Continent Ecology Div.

    1998-11-01

    Techniques for reducing ammonia toxicity in freshwater sediments were investigated as part of a project to develop toxicity identification and evaluation (TIE) procedures for whole sediments. Although ammonia is a natural constituent of freshwater sediments, pollution can lead to ammonia concentrations that are toxic to benthic invertebrates, and ammonia can also contribute to the toxicity of sediments that contain more persistent contaminants. The authors investigated the use of amendments of a natural zeolite mineral, clinoptilolite, to reduce concentrations of ammonia in sediment pore water. Zeolites have been widely used for removal of ammonia in water treatment and in aqueous TIE procedures. The addition of granulated zeolite to ammonia-spiked sediments reduced pore-water ammonia concentrations and reduced ammonia toxicity to invertebrates. Amendments of 20% zeolite (v/v) reduced ammonia concentrations in pore water by {ge}70% in spiked sediments with ammonia concentrations typical of contaminated freshwater sediments. Zeolite amendments reduced toxicity of ammonia-spiked sediments to three taxa of benthic invertebrates (Hyalella azteca, Lumbriculus variegatus, and Chironomus tentans), despite their widely differing sensitivity to ammonia toxicity. In contrast, zeolite amendments did not reduce acute toxicity of sediments containing high concentrations of cadmium or copper or reduce concentrations of these metals in pore waters. These studies suggest that zeolite amendments, used in conjunction with toxicity tests with sensitive taxa such as H. azteca, may be an effective technique for selective reduction of ammonia toxicity in freshwater sediments.

  6. Effect of zeolite on toxicity of ammonia in freshwater sediments: Implications for toxicity identification evaluation procedures

    Science.gov (United States)

    Besser, J.M.; Ingersoll, C.G.; Leonard, E.N.; Mount, D.R.

    1998-01-01

    Techniques for reducing ammonia toxicity in freshwater sediments were investigated as part of a project to develop toxicity identification and evaluation (TIE) procedures for whole sediments. Although ammonia is a natural constituent of freshwater sediments, pollution can lead to ammonia concentrations that are toxic to benthic invertebrates, and ammonia can also contribute to the toxicity of sediments that contain more persistent contaminants. We investigated the use of amendments of a natural zeolite mineral, clinoptilolite, to reduce concentrations of ammonia in sediment pore water. Zeolites have been widely used for removal of ammonia in water treatment and in aqueous TIE procedures. The addition of granulated zeolite to ammonia-spiked sediments reduced pore-water ammonia concentrations and reduced ammonia toxicity to invertebrates. Amendments of 20% zeolite (v/v) reduced ammonia concentrations in pore water by ???70% in spiked sediments with ammonia concentrations typical of contaminated freshwater sediments. Zeolite amendments reduced toxicity of ammonia-spiked sediments to three taxa of benthic invertebrates (Hyalella azteca, Lumbriculus variegatus, and Chironomus tentans), despite their widely differing sensitivity to ammonia toxicity. In contrast, zeolite amendments did not reduce acute toxicity of sediments containing high concentrations of cadmium or copper or reduce concentrations of these metals in pore waters. These studies suggest that zeolite amendments, used in conjunction with toxicity tests with sensitive taxa such as H. azteca, may be an effective technique for selective reduction of ammonia toxicity in freshwater sediments.

  7. Caenorhabditis elegans NONO-1: Insights into DBHS protein structure, architecture, and function.

    Science.gov (United States)

    Knott, Gavin J; Lee, Mihwa; Passon, Daniel M; Fox, Archa H; Bond, Charles S

    2015-12-01

    Members of the Drosophila behavior/human splicing (DBHS) protein family have been characterized in the vertebrates Homo sapiens and Mus musculus, and the invertebrates Drosophila melanogaster and Chironomus tentans. Collectively, both vertebrate and invertebrate DBHS proteins function throughout gene regulation, largely but not always, within the nucleus. In this study, we report a structural and bioinformatic analysis of the DBHS protein family to guide future studies into DBHS protein function. To explore the structural plasticity of the family, we describe the 2.4 Å crystal structure of Caenorhabditis elegans non-POU domain-containing octamer-binding protein 1 (NONO-1). The structure is dimeric, with a domain arrangement consistent with mammalian DBHS proteins. Comparison with the DBHS structures available from H. sapiens reveals that there is inherent domain flexibility within the homologous DBHS region. Mapping amino acid similarity within the family to the NONO-1 dimer highlights the dimer interface, coiled-coil oligomerization motif, and putative RNA binding surfaces. Surprisingly, the interior surface of RNA recognition motif 2 (RRM2) that faces a large internal void is highly variable, but the external β2-β3 loops of RRM2 show remarkable preservation. Overall, the DBHS region is under strong purifying selection, whereas the sequences N- and C-terminal to the DBHS region are less constrained. The findings described in this study provide a molecular basis for further investigation into the mechanistic function of the DBHS protein family in biology.

  8. Using a triad approach in the assessment of hazardous waste site leaching from a Superfund site to an adjacent stream

    Energy Technology Data Exchange (ETDEWEB)

    Leppanen, C.J. [Univ. of Maine, Orono, ME (United States). Dept. of Biochemistry, Microbiology, and Molecular Biology; Blanner, P.M.; Allan, R.S.; Maier, K.J. [Univ. of Memphis, TN (United States); Benson, W.H. [Univ. of Mississippi, University, MS (United States)

    1998-10-01

    A triad approach was used in the evaluation of sediment in the Wolf River adjacent to the North Hollywood Dump, a federally listed Superfund site. Chemical analyses were done for 18 organochlorine pesticides, 21 polychlorinated biphenyl (PCB) congeners, and 10 metals. Sediment toxicity was evaluated with freshwater invertebrates. Chironomus tentans and Hyalella azteca. Benthic macroinvertebrate diversity and abundance were assessed with a family-level biotic index. Mean Al, Ba, Cd, Cu, Fe, Ni, Pb, and Zn concentrations were significantly higher in sediments collected in the spring. Both spring and fall sediments exhibited toxicity downstream from, adjacent to, and upstream from the dump, with toxicity significantly higher in fall sediments; however, a consistent trend was not observed. Toxicity was typically greater in the fall, and metal concentrations were typically higher in spring sediments, suggesting that metals were not responsible for the toxicity. Sediment-associated organochlorine pesticide and PCB congener concentrations were all below detectable limits, suggesting that these potential contaminants are not contributing to the observed toxicity. No differences were found in benthic macroinvertebrate community structure, which was composed of predominantly pollution-tolerant families, among seasons or river reaches, which appear to be limited by the physical characteristics of the river. Sediments in urban reaches of the Wolf River appear to be degraded; the North Hollywood Dump cannot be isolated as a source of toxicity in this study. In situ testing, sediment toxicity identification and evaluation testing, acid-volatile sulfide analyses, or artificial substrate work would be appropriate to follow.

  9. Acute toxicity of metals and reference toxicants to a freshwater ostracod, Cypris subglobosa Sowerby, 1840 and correlation to EC{sub 50} values of other test models

    Energy Technology Data Exchange (ETDEWEB)

    Khangarot, B.S., E-mail: bkhangarot@hotmail.com [Ecotoxicology Division, Indian Institute of Toxicology Research (Formerly: Industrial Toxicology Research Centre), Post Box No. 80, Mahatma Gandhi Marg, Lucknow 226001 (India); Das, Sangita [Ecotoxicology Division, Indian Institute of Toxicology Research (Formerly: Industrial Toxicology Research Centre), Post Box No. 80, Mahatma Gandhi Marg, Lucknow 226001 (India)

    2009-12-30

    The ostracod Cypris subglobosa Sowerby, 1840 static bioassay test on the basis of a 48 h of 50% of immobilization (EC{sub 50}) has been used to measure the toxicity of 36 metals and metalloids and 12 reference toxicants. Among the 36 metals and metalloids, osmium (Os) was found to be the most toxic in the test while boron (B), the least toxic. The EC{sub 50} values of this study revealed positive linear relationship with the established test models of cladoceran (Daphnia magna), sludge worm (Tubifex tubifex), chironomid larvae (Chironomus tentans), protozoan (Tetrahymena pyriformis), fathead minnow (Pimephales promelas), bluegill sunfish (Lepomis macrochirus), and aquatic macrophyte duckweed (Lemna minor). Correlation coefficients (r{sup 2}) for 17 physicochemical properties of metals or metal ions and EC{sub 50}s (as pM) were examined by linear regression analysis. The electronegativity, ionization potential, melting point, solubility product of metal sulfides (pK{sub sp}), softness parameter and some other physicochemical characteristics were significantly correlated with EC{sub 50}s of metals to C. subglobosa. The reproducibility of toxicity test was determined using 12 reference toxicants. The coefficient of variability of the EC{sub 50}s ranged from 6.95% to 55.37% and variability was comparable to that noticed for D. magna and other aquatic test models. The study demonstrated the need to include crustacean ostracods in a battery of biotests to detect the presence of hazardous chemicals in soils, sewage sludges, sediments and aquatic systems.

  10. Combined effects of Cu and UVR on survival and melanin synthesis in Chironomus riparius larvae

    NARCIS (Netherlands)

    de Baat, M.L.; van Gemert, M.; Verweij, R.A.; Loayza Muro, R.A.; Kraak, M.H.S.

    2012-01-01

    The tropical Andes encompass vast areas with altitudes above 4000 m, where the combination of high UV radiation and metal pollution creates environments that challenge the survival and persistence of aquatic life. Since the pigment melanin counteracts the negative effects of UVR, and has the additio

  11. Combined effects of Cu and UVR on survival and melanin synthesis in Chironomus riparius larvae

    NARCIS (Netherlands)

    de Baat, M.L.; van Gemert, M.; Verweij, R.A.; Loayza Muro, R.A.; Kraak, M.H.S.

    2012-01-01

    The tropical Andes encompass vast areas with altitudes above 4000 m, where the combination of high UV radiation and metal pollution creates environments that challenge the survival and persistence of aquatic life. Since the pigment melanin counteracts the negative effects of UVR, and has the

  12. Bioconcentration and acute toxicity of polycyclic musks in two benthic organisms (Chironomus riparius and Lumbriculus variegatus)

    NARCIS (Netherlands)

    Artola-Garicano, E.; Sinnige, T.L.; Holsteijn, I. van; Vaes, W.H.J.; Hermens, J.L.M.

    2003-01-01

    In the current study, the bioconcentration behavior and acute toxicity of two polycyclic musks, Tonalide® 7-acetyl-1,1,3,4,4,6,-hexamethyl-1,2,3,4,-tetrahydronaphthalene (AHTN) and Galaxolide® 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexa-methyl-cyclopenta[γ]-2- benzopyran (HHCB), were studied in two benth

  13. Bioconcentration and acute toxicity of polycyclic musks in two benthic organisms (Chironomus riparius and Lumbriculus variegatus)

    NARCIS (Netherlands)

    Artola-Garicano, E.; Sinnige, T.L.; Holsteijn, I. van; Vaes, W.H.J.; Hermens, J.L.M.

    2003-01-01

    In the current study, the bioconcentration behavior and acute toxicity of two polycyclic musks, Tonalide® 7-acetyl-1,1,3,4,4,6,-hexamethyl-1,2,3,4,-tetrahydronaphthalene (AHTN) and Galaxolide® 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexa-methyl-cyclopenta[γ]-2- benzopyran (HHCB), were studied in two

  14. Ecotoxicological assessment of grey water treatment systems with Daphnia magna and Chironomus riparius

    NARCIS (Netherlands)

    Hernádez Leal, L.; Soeter, A.M.; Kools, S.A.E.; Kraak, M.H.S.; Parsons, J.R.; Temmink, H.; Zeeman, G.; Buisman, C.J.N.

    2012-01-01

    In order to meet environmental quality criteria, grey water was treated in four different ways: 1) aerobic 2) anaerobic + aerobic 3) aerobic + activated carbon 4) aerobic + ozone. Since each treatment has its own specific advantages and disadvantages, the aim of this study was to compare the ecotoxi

  15. Ecotoxicological assessment of grey water treatment systems with Daphnia magna and Chironomus riparius

    NARCIS (Netherlands)

    Hernádez Leal, L.; Soeter, A.M.; Kools, S.A.E.; Kraak, M.H.S.; Parsons, J.R.; Temmink, H.; Zeeman, G.; Buisman, C.J.N.

    2012-01-01

    In order to meet environmental quality criteria, grey water was treated in four different ways: 1) aerobic 2) anaerobic + aerobic 3) aerobic + activated carbon 4) aerobic + ozone. Since each treatment has its own specific advantages and disadvantages, the aim of this study was to compare the

  16. Rapid genetic erosion in pollutant-exposed experimental chironomid populations

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Carsten [Abteilung Okologie und Evolution, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: cnowak@senckenberg.de; Vogt, Christian [Abteilung Aquatische Okotoxikologie, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: vogt@bio.uni-frankfurt.de; Pfenninger, Markus [Abteilung Okologie und Evolution, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: pfenninger@bio.uni-frankfurt.de; Schwenk, Klaus [Abteilung Okologie und Evolution, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: k.schwenk@bio.uni-frankfurt.de; Oehlmann, Joerg [Abteilung Aquatische Okotoxikologie, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: oehlmann@bio.uni-frankfurt.de; Streit, Bruno [Abteilung Okologie und Evolution, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: streit@bio.uni-frankfurt.de; Oetken, Matthias [Abteilung Aquatische Okotoxikologie, Institut fuer Okologie, Evolution und Diversitaet, J. W. Goethe-Universitaet Frankfurt am Main, Siesmayerstrasse 70, 60054 Frankfurt am Main (Germany)], E-mail: oetken@bio.uni-frankfurt.de

    2009-03-15

    Few studies have evaluated how effectively environmental contamination may reduce genetic diversity of a population. Here, we chose a laboratory approach in order to test if tributyltin (TBT) exposure at environmentally relevant concentrations leads to reduced genetic variation in the midge Chironomus riparius. Two TBT-exposed and two unexposed experimental populations were reared simultaneously in the laboratory for 12 generations. We recorded several life-history traits in each generation and monitored genetic variation over time using five variable microsatellite markers. TBT-exposed strains showed increased larval mortality (treatments: 43.8%; controls: 27.8%), slightly reduced reproductive output, and delayed larval development. Reduction of genetic variation was strongest and only significant in the TBT-exposed strains (treatments: -45.9%, controls: -24.4% of initial heterozygosity) after 12 generations. Our findings document that chemical pollution may lead to a rapid decrease in genetic diversity, which has important implications for conservation strategies and ecological management in polluted environments. - Chronic TBT exposure reduces allelic variation at five variable microsatellite loci in experimental populations of Chironomus riparius.

  17. Bamboo stumps as mosquito larval habitats in Darjeeling Himalayas,India:A spatial scale analysis

    Institute of Scientific and Technical Information of China (English)

    Gautam Aditya; Rakesh Tamang; Dipendra Sharma; Francis Subba; Goutam K.Saha

    2008-01-01

    Bamboo stumps can be a congenial breeding habitat of the mosquitoes.In view of this,a preliminary assessment of the dipteran immatures inhabiting the stumps of bamboo groves in the Darjeeling Himalayas was carried out at a spatial scale.Of the 104 stumps of Dendrocalamus hamiltoni surveyed,70 were found to host immatures of three dipteran species,the mosquitoes Aedes aegypti and Culex quinquefasciatus and the midges Chironomus sp.in varying densities.Though the stumps varied in diameter,in each stump on average 12.1 immatures were found.The abundance of the immatures was positively correlated with the diameter of the stumps (r = +0.382;P < 0.001) but negatively with the pH of the water present in the stumps (r = -0.336;P < 0.01).The coefficient of association was found to be +8.4 for the Ae.aegypti and Chironomus immatures,while in the rest of the species pair the association seemed to be independent.Thus it can be concluded that the stumps in the bamboo groves of Darjeeling Himalayas provides a favourable habitat for the mosquito and chironomid immatures.

  18. Impact of a flood disaster on sediment toxicity in a major river system--the Elbe flood 2002 as a case study.

    Science.gov (United States)

    Oetken, Matthias; Stachel, Burkhard; Pfenninger, Markus; Oehlmann, Jörg

    2005-03-01

    The ecotoxicological implications of a flooding disaster were investigated with the exceptional Elbe flood in August 2002 as an example. Sediment samples were taken shortly after the flood at 37 sites. For toxicity assessment the midge Chironomus riparius (Insecta) and the mudsnail Potamopyrgus antipodarum (Gastropoda) were exposed to the sediment samples for 28 days. For a subset of 19 sampling sites, the contamination level and the biological response of both species were also recorded before the flood in 2000. The direct comparison of biological responses at identical sites revealed significant differences for samples taken before and immediately after the flood. After flood sediments of the river Elbe caused both higher emergence rates in the midge and higher numbers of embryos in the mudsnail. Contrary to expectations the toxicity of the sediments decreased after the flood, probably because of a dilution of toxic substances along the river Elbe and a reduction in bioavailability of pollutants as a result of increasing TOC values after the flood.

  19. Toxicity of sediments from lead-zinc mining areas to juvenile freshwater mussels (Lampsilis siliquoidea) compared to standard test organisms.

    Science.gov (United States)

    Besser, John M; Ingersoll, Christopher G; Brumbaugh, William G; Kemble, Nile E; May, Thomas W; Wang, Ning; MacDonald, Donald D; Roberts, Andrew D

    2015-03-01

    Sediment toxicity tests compared chronic effects on survival, growth, and biomass of juvenile freshwater mussels (28-d exposures with Lampsilis siliquoidea) to the responses of standard test organisms-amphipods (28-d exposures with Hyalella azteca) and midges (10-d exposures with Chironomus dilutus)-in sediments from 2 lead-zinc mining areas: the Tri-State Mining District and Southeast Missouri Mining District. Mussel tests were conducted in sediments sieved to toxic responses (reduced 10% or more relative to reference sites) in Tri-State sediments was greatest for amphipod survival (25% of samples), midge biomass (20%), and mussel survival (14%). In southeast Missouri sediments, the frequency of highly toxic samples was greatest for mussel biomass (25%) and amphipod biomass (13%). Thresholds for metal toxicity to mussels, expressed as hazard quotients based on probable effect concentrations, were lower for southeast Missouri sediments than for Tri-State sediments. Southeast Missouri sites with toxic sediments had 2 or fewer live mussel taxa in a concurrent mussel population survey, compared with 7 to 26 taxa at reference sites. These results demonstrate that sediment toxicity tests with juvenile mussels can be conducted reliably by modifying existing standard methods; that the sensitivity of mussels to metals can be similar to or greater than standard test organisms; and that responses of mussels in laboratory toxicity tests are consistent with effects on wild mussel populations.

  20. Impact of a flood disaster on sediment toxicity in a major river system - the Elbe flood 2002 as a case study

    Energy Technology Data Exchange (ETDEWEB)

    Oetken, Matthias [Johann Wolfgang Goethe University Frankfurt am Main, Department of Ecology and Evolution, Siesmayerstrasse 70, D-60054 Frankfurt (Germany)]. E-mail: oetken@zoology.uni-frankfurt.de; Stachel, Burkhard [Wasserguetestelle Elbe der Arbeitsgemeinschaft fuer die Reinhaltung der Elbe, Nessdeich 120-121, D-21129 Hamburg (Germany); Pfenninger, Markus [Johann Wolfgang Goethe University Frankfurt am Main, Department of Ecology and Evolution, Siesmayerstrasse 70, D-60054 Frankfurt (Germany); Oehlmann, Joerg [Johann Wolfgang Goethe University Frankfurt am Main, Department of Ecology and Evolution, Siesmayerstrasse 70, D-60054 Frankfurt (Germany)

    2005-03-01

    The ecotoxicological implications of a flooding disaster were investigated with the exceptional Elbe flood in August 2002 as an example. Sediment samples were taken shortly after the flood at 37 sites. For toxicity assessment the midge Chironomus riparius (Insecta) and the mudsnail Potamopyrgus antipodarum (Gastropoda) were exposed to the sediment samples for 28 days. For a subset of 19 sampling sites, the contamination level and the biological response of both species were also recorded before the flood in 2000. The direct comparison of biological responses at identical sites revealed significant differences for samples taken before and immediately after the flood. After flood sediments of the river Elbe caused both higher emergence rates in the midge and higher numbers of embryos in the mudsnail. Contrary to expectations the toxicity of the sediments decreased after the flood, probably because of a dilution of toxic substances along the river Elbe and a reduction in bioavailability of pollutants as a result of increasing TOC values after the flood. - The extraordinary Elbe flood in August 2002 did not result in an overall increase of environmental contamination.

  1. ELISA detection of multixenobiotic resistance transporter induction in indigenous freshwater Chironomidae larvae (Diptera): A biomarker calibration step for in situ monitoring of xenobiotic exposure

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, X.; Saez, G.; Thiery, A. [Equipe ' Biomarqueurs and Bioindicateurs Environnementaux' , UMR-CNRS 6116 IMEP, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France); Clot-Faybesse, O.; Guiraudie-Capraz, G. [' Neurobiologie Integrative et Adaptative' -UMR 6149, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France); Bienboire-Frosini, C. [' Neurobiologie Integrative et Adaptative' -UMR 6149, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France); Pherosynthese, Le Rieu Neuf, 84490 St Saturnin d' Apt (France); Martin, C. [Equipe ' Biomarqueurs and Bioindicateurs Environnementaux' , UMR-CNRS 6116 IMEP, UAPV, 33 rue Louis Pasteur, 84000 Avignon (France); De Jong, L. [Equipe ' Biomarqueurs and Bioindicateurs Environnementaux' , UMR-CNRS 6116 IMEP, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France)], E-mail: laetitia.moreau@univ-provence.fr

    2008-06-15

    A new simple and sensitive method to distinguish chemically polluted from unpolluted situations in freshwater ecosystems is reported. For this purpose, Chironomus gr thumni larvae were collected from a polluted urban river downstream a sewage treatment plant. For the first time, ELISA assay was used to semi-quantify the multixenobiotic resistance transporters (MXR) in these small pertinent bioindicators. The use of samples immediately fixed in the field gives a delay to isolate larvae and allows multi-sampling along a longitudinal transect in a river at a given time. Results exhibit an induction of MXR proteins in larvae from the polluted river and a deinduction in larvae maintained 11 days in unpolluted water. They show new evidences to use midge larvae in biomonitoring environmental programs. They answer to first biomarker calibration steps for the ongoing development of MXR transporters as a detection tool of xenobiotic impacts on bioindicator invertebrates in their freshwater habitats. - Semi-quantification of midge larval MXR transporters by ELISA is a simple and sensitive method to detect chemically polluted situations in running freshwaters.

  2. Toxicity of silicon carbide nanowires to sediment-dwelling invertebrates in water or sediment exposures

    Science.gov (United States)

    Mwangi, Joseph N.; Wang, Ning; Ritts, Andrew; Kunz, James L.; Ingersoll, Christopher G.; Li, Hao; Deng, Baolin

    2011-01-01

    Silicon carbide nanowires (SiCNW) are insoluble in water. When released into an aquatic environment, SiCNW would likely accumulate in sediment. The objective of this study was to assess the toxicity of SiCNW to four freshwater sediment-dwelling organisms: amphipods (Hyalella azteca), midges (Chironomus dilutus), oligochaetes (Lumbriculus variegatus), and mussels (Lampsilis siliquoidea). Amphipods were exposed to either sonicated or nonsonicated SiCNW in water (1.0 g/L) for 48 h. Midges, mussels, and oligochaetes were exposed only to sonicated SiCNW in water for 96 h. In addition, amphipods were exposed to sonicated SiCNW in whole sediment for 10 d (44% SiCNW on dry wt basis). Mean 48-h survival of amphipods exposed to nonsonicated SiCNW in water was not significantly different from the control, whereas mean survival of amphipods exposed to sonicated SiCNW in two 48-h exposures (0 or 15% survival) was significantly different from the control (90 or 98% survival). In contrast, no effect of sonicated SiCNW was observed on survival of midges, mussels, or oligochaetes. Survival of amphipods was not significantly reduced in 10-d exposures to sonicated SiCNW either mixed in the sediment or layered on the sediment surface. However, significant reduction in amphipod biomass was observed with the SiCNW either mixed in sediment or layered on the sediment surface, and the reduction was more pronounced for SiCNW layered on the sediment. These results indicated that, under the experimental conditions, nonsonicated SiCNW in water were not acutely toxic to amphipods, sonicated SiCNW in water were acutely toxic to the amphipods, but not to other organisms tested, and sonicated SiCNW in sediment affected the growth but not the survival of amphipods.

  3. The range of attraction for light traps catching Culicoides biting midges (Diptera: Ceratopogonidae)

    DEFF Research Database (Denmark)

    Kirkeby, Carsten; Græsbøll, Kaare; Stockmarr, Anders

    2013-01-01

    Background Culicoides are vectors of e.g. bluetongue virus and Schmallenberg virus in northern Europe. Light trapping is an important tool for detecting the presence and quantifying the abundance of vectors in the field. Until now, few studies have investigated the range of attraction of light...... with greater light intensity, and in Model III Culicoides evaluate light sources in the field of view and fly towards the strongest. Model II and III incorporated the directionally dependent light field created around light traps with fluorescent light tubes. All three models were fitted to light trap...

  4. Non-essential viral proteins of orbiviruses are essential for vector-borne spread by midges

    Science.gov (United States)

    Members of the Reoviridae family are non-enveloped multi-layered viruses with a double stranded RNA genome consisting of 9-12 genome segments. The Orbivirus genus contains vector borne virus species with 10 genome segments such as bluetongue virus (BTV) with about 30 serotypes, and African horse sic...

  5. Effects of bioirrigation of non-biting midges (Diptera: Chironomidae) on lake sediment respiration

    Science.gov (United States)

    Baranov, Viktor; Lewandowski, Jörg; Romeijn, Paul; Singer, Gabriel; Krause, Stefan

    2016-06-01

    Bioirrigation or the transport of fluids into the sediment matrix due to the activities of organisms such as bloodworms (larvae of Diptera, Chironomidae), has substantial impacts on sediment respiration in lakes. However, previous quantifications of bioirrigation impacts of Chironomidae have been limited by technical challenges such as the difficulty to separate faunal and bacterial respiration. This paper describes a novel method based on the bioreactive tracer resazurin for measuring respiration in-situ in non-sealed systems with constant oxygen supply. Applying this new method in microcosm experiments revealed that bioirrigation enhanced sediment respiration by up to 2.5 times. The new method is yielding lower oxygen consumption than previously reported, as it is only sensitive to aerobic heterotrophous respiration and not to other processes causing oxygen decrease. Hence it decouples the quantification of respiration of animals and inorganic oxygen consumption from microbe respiration in sediment.

  6. Update on the Culicoides sonorensis transcriptome project: a peek into the molecular biology of the midge

    Science.gov (United States)

    Next Generation Sequencing is transforming the way scientists collect and measure an organism’s genetic background and gene dynamics, while bioinformatics and super-computing are merging to facilitate parallel sample computation and interpretation at unprecedented speeds. Analyzing the complete gene...

  7. Low species richness of non-biting midges (Diptera: Chironomidae) in Neotropical artificial urban water bodies

    DEFF Research Database (Denmark)

    Hamerlik, Ladislav; Jacobsen, Dean; Brodersen, Klaus Peter

    2011-01-01

    Chironomid assemblages of 22 artificial water bodies, mainly fountains, in two South American cities were surveyed. We found surprisingly low diversities, with a total of 11 taxa, averaging two taxa per site. The typical fountain assemblages mainly consisted of common species that have a wide...... distribution pattern and are tolerant to organic pollution. Also taxa independent of the natural aquatic sources, such as tap-water and semi-terrestrial species were represented. There was no significant difference between the taxa richness of the two S. American regions, however, the assemblage structures...

  8. Big data - modelling of midges in Europa using machine learning techniques and satellite imagery

    DEFF Research Database (Denmark)

    Cuellar, Ana Carolina; Kjær, Lene Jung; Skovgaard, Henrik

    2017-01-01

    -absence and monthly abundance data of Culicoides from 1005 sites across 9 countries (Spain, France, Denmark, Poland, Switzerland, Austria, Poland, Sweden, Norway) collected between the years 2007 and 2013. The dataset included information on the vector species abundance (number of specimens caught per night), GPS...

  9. Molecular Taxonomy of a Phantom Midge Species (Chaoborus flavicans in Korea

    Directory of Open Access Journals (Sweden)

    Haein An

    2012-01-01

    Full Text Available The larvae of Chaoborus are widely distributed in lakes, ponds, and reservoirs. These omnivorous Chaoborus larvae are crucial predators and play a role in structuring zooplankton communities, especially for small-sized prey. Larvae of Chaoborus are commonly known to produce predator-induced polyphenism in Daphnia sp. Nevertheless, their taxonomy and molecular phylogeny are very poorly understood. As a fundamental study for understanding the role of Chaoborus in predator-prey interactions in a freshwater ecosystem, the molecular identification and phylogenetic relationship of Chaoborus were analyzed in this study. A molecular comparison based on partial mitochondrial cytochrome oxidase I (COI between species in Chaoborus was carried out for the identification of Chaoborus larvae collected from 2 localities in Korea. According to the results, the Chaoborus species examined here was identified as C. flavicans, which is a lake-dwelling species. Furthermore, partial mitochondrial genome including COI, COII, ATP6, ATP8, COIII, and ND3 were also newly sequenced from the species and concatenated 5 gene sequences excluding ATP8 with another 9 dipteran species were compared to examine phylogenetic relationships of C. flavicans. The results suggested that Chaoborus was more related to the Ceratopogonidae than to the Culicidae. Further analysis based on complete mitochondrial DNA sequences and nuclear gene sequences will provide a more robust validation of the phylogenetic relationships of Chaoborus within dipteran lineages.

  10. Potential for Transovarial Transmission of Vesicular Stomatitis Virus in the biting midge, Culicoides sonorensis

    Science.gov (United States)

    Vesicular stomatitis virus (VSV) is an insect transmitted rhabdovirus which causes economically devastating disease in cattle and horses in the western U.S. Important insect vectors identified thus far include Lutzomyia shannoni sand flies, Simulium vittatum black flies, and Culicoides sonorensis bi...

  11. Additional notes on biting midges from the subtropical forest of northeastern Argentina (Diptera: Ceratopogonidae).

    Science.gov (United States)

    Ayala, Mahia M; Spinelli, Gustavo R; Funes, Amparo; Ronderos, María M

    2015-03-30

    Adult males and pupae of Culicoides guarani Ronderos & Spinelli and Parabezzia brasiliensis Spinelli & Grogan are fully described and illustrated with a modern criterium from material recently collected in the vicinities of the city of Posadas in Misiones province, Argentina. Both species are compared with their most similar congeners. Besides, Bezzia blantoni Spinelli & Wirth and B. brevicornis (Kieffer) are firstly recorded from Misiones province.

  12. Pyrosequencing reveals the predominance of Pseudomonadaceae in gut microbiome of a Gall Midge

    Science.gov (United States)

    Gut microbes are known to play various roles in insects such as digestion of inaccessible nutrients, synthesis of deficient amino acids, and interaction with ecological environments, including host plants. Here, we analyzed the gut microbiome in Hessian fly, a serious pest of wheat. A total of 3,654...

  13. A new species of predaceous midge of the genus Monohelea Kieffer from Mexico (Diptera: Ceratopogonidae).

    Science.gov (United States)

    Felippe-Bauer, M L; Huerta, H; Bernal, S I

    2000-01-01

    A description and illustrations of Monohelea maya, new species, based on male and female characteristics are provided. The specimens were collected in the special biosphere Reserves of Ria Lagartos and Ria Celestun, Yucatan State, Mexico.

  14. A new species of predaceous midge of the genus Monohelea Kieffer from Mexico (Diptera: Ceratopogonidae

    Directory of Open Access Journals (Sweden)

    Maria Luiza Felippe-Bauer

    2000-12-01

    Full Text Available A description and illustrations of Monohelea maya, new species, based on male and female characteristics are provided. The specimens were collected in the special biosphere Reserves of Ria Lagartos and Ria Celestun, Yucatan State, Mexico.

  15. Mosquitoes and Culicoides biting midges: vector range and the influence of climate change

    NARCIS (Netherlands)

    Elbers, A.R.W.; Koenraadt, C.J.M.; Meiswinkel, R.

    2015-01-01

    Vector-borne animal diseases pose a continuous and substantial threat to livestock economies around the globe. Increasing international travel, the globalisation of trade, and climate change are likely to play a progressively more important role in the introduction, establishment and spread of arthr

  16. Long-distance aerial dispersal modelling of Culicoides biting midges: case studies of incursions into Australia.

    Science.gov (United States)

    Eagles, Debbie; Melville, Lorna; Weir, Richard; Davis, Steven; Bellis, Glenn; Zalucki, Myron P; Walker, Peter J; Durr, Peter A

    2014-06-19

    Previous studies investigating long-distance, wind-borne dispersal of Culicoides have utilised outbreaks of clinical disease (passive surveillance) to assess the relationship between incursion and dispersal event. In this study, species of exotic Culicoides and isolates of novel bluetongue viruses, collected as part of an active arbovirus surveillance program, were used for the first time to assess dispersal into an endemic region. A plausible dispersal event was determined for five of the six cases examined. These include exotic Culicoides specimens for which a possible dispersal event was identified within the range of two days--three weeks prior to their collection and novel bluetongue viruses for which a dispersal event was identified between one week and two months prior to their detection in cattle. The source location varied, but ranged from Lombok, in eastern Indonesia, to Timor-Leste and southern Papua New Guinea. Where bluetongue virus is endemic, the concurrent use of an atmospheric dispersal model alongside existing arbovirus and Culicoides surveillance may help guide the strategic use of limited surveillance resources as well as contribute to continued model validation and refinement. Further, the value of active surveillance systems in evaluating models for long-distance dispersal is highlighted, particularly in endemic regions where knowledge of background virus and vector status is beneficial.

  17. Assessing the potential toxicity of resuspended sediment

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, C.; Babut, M.; Ferard, J.F.; Martel, L.; Garric, J.

    2000-05-01

    Two moderately contaminated freshwater sediments (Sorel Harbour, St. Lawrence River, Canada) were subjected to a suspension event. The objective was to assess the environmental impact of the disposal of dredged material in water, in particular, the short-term effects of dumping on the water column and the long-term effects of dredged sediment deposits. In a series of microcosms, the sediments were left to stand for 25 d under flow-through conditions. In a second series of microcosms, sediments were vigorously suspended for 15 min before being left to settle and were submitted to the same treatment as reference sediments during the following 25 d. Physicochemical and biological parameters (Daphnia magna and Hydra attenuata survival) were measured in overlying water throughout the experiment. Sediment toxicity was assessed with Chironomus tentans and Hyalella azteca exposed to sediments collected at both the beginning and end of the 25-d period. Pore-water toxicity was evaluated with D. magna. During the suspension process, in the Sorel Harbour mixed sediment overlying water, the authors observed effects on H. attenuata survival and ammonia and metals (chromium, copper, and zinc) releases. Meanwhile, in reference (nonmixed) and mixed sediments as well as in associated pore waters, there were no significant chemical modifications no biological effects after the 25-d experiments. The developed approach, which attempts to simulate a dumping process, aims at allowing the assessment of the short- and long-term hazards resulting from a resuspension process in overlying water and in resettled sediments using both chemical and biological measurements.

  18. Laboratory culture of the freshwater benthic gastropod Bellamya aeruginosa (Reeve) and its utility as a test species for sediment toxicity.

    Science.gov (United States)

    Ma, Taowu; Gong, Shuangjiao; Zhou, Ke; Zhu, Cheng; Deng, Kaidong; Luo, Qinghua; Wang, Zijian

    2010-01-01

    This study aimed to develop original laboratory culture and sediment toxicity testing protocols for the freshwater gastropod Bellamya aeruginosa (Reeve), a new potential species for sediment toxicity testing. B. aeruginosa was successfully cultured with an effective culture system under proposed laboratory conditions. Optimal ad libitum feeding levels for larvae, juveniles, and adults were 2.0, 6.0, and 16.0 mg fish food/(snail x day), respectively. Mean survival rates of juveniles were higher than 90%. The snails could be sexed at 9 weeks of age, and their generation time is approximately 4 months. Reproduction continued all year around; the mean fecundity was 0.55 newborn/(female x day). The utility of this species for bioassays was evaluated in both 10-day and 28-day case studies with artificial sediments. The 10-day LC50 of Cu for larvae was 480 gg/g dry weight (dw), and the lowest observed effects concentration of Cu for survival and growth of larvae was 195 microg/g dw. Survival and growth are reliable indicators of acute toxicity. Larvae accumulated more Cu than adults. B. aeruginosa exhibited a higher sensitivity to Cu exposure than standard test species (Hyalella azteca and Chironomus tentans). The 28-day test of sediment toxicity with adults showed that fecundity was a robust endpoint indicator of reproductive toxicity, and the biochemical endpoints of superoxide dismutase, catalase, and glutathione could be used as sensitive biomarkers for Cu-induced oxidative damage. B. aeruginosa can be therefore recommended as a candidate for the standardization of the freshwater sediment toxicity test protocol.

  19. The Influence of Test Conditions on the Performance of Chironomus dilutus and Hyalella azteca in Sediment Toxicity Tests

    Science.gov (United States)

    In most all sediment toxicity assessments, the performance of organisms in control sediments is a key parameter in defining sediment toxicity, whether through direct statistical comparison to control or by normalizing to control performance to compare results across sites or batc...

  20. Chronic toxicity and body residues of the nonpolar narcotic 1,2,3,4-tetrachrlorobenzene in Chironomus riparius

    NARCIS (Netherlands)

    Leslie, H.A.; Kraak, M.H.S.; Hermens, J.L.

    2004-01-01

    The use of internal concentrations as a dose parameter for baseline toxicity requires an understanding of the relationship between accumulation level and toxic effects, not only for acute but also for chronic exposure. In this study of chronic toxicity of the nonpolar narcotic 1,2,3,4-tetrachloroben

  1. The Influence of Test Conditions on the Performance of Chironomus dilutus and Hyalella azteca in Sediment Toxicity Tests

    Science.gov (United States)

    In most all sediment toxicity assessments, the performance of organisms in control sediments is a key parameter in defining sediment toxicity, whether through direct statistical comparison to control or by normalizing to control performance to compare results across sites or batc...

  2. Chronic toxicity and body residues of the nonpolar narcotic 1,2,3,4-tetrachrlorobenzene in Chironomus riparius

    NARCIS (Netherlands)

    Leslie, H.A.; Kraak, M.H.S.; Hermens, J.L.

    2004-01-01

    The use of internal concentrations as a dose parameter for baseline toxicity requires an understanding of the relationship between accumulation level and toxic effects, not only for acute but also for chronic exposure. In this study of chronic toxicity of the nonpolar narcotic

  3. Investigating a potential mechanism of Cd resistance in Chironomus riparius larvae using kinetic analysis of calcium and cadmium uptake

    Energy Technology Data Exchange (ETDEWEB)

    Gillis, Patricia L. [Department of Biology, McMaster University, Hamilton, ON, L8S-4K1 (Canada)], E-mail: patty.gillis@ec.gc.ca; Wood, Chris M. [Department of Biology, McMaster University, Hamilton, ON, L8S-4K1 (Canada)

    2008-09-17

    The uptake kinetics of waterborne Ca and Cd, both independently and in combination, were examined in C. riparius larvae, which are extremely Cd tolerant. Larvae exposed to Ca (100-2500 {mu}mol L{sup -1}), exhibited classic Michaelis-Menten saturation kinetics for Ca influx, measured using {sup 45}Ca as a radio-tracer. The maximum rate of Ca influx (J{sub max}{sup Ca}) was 0.39 {mu}mol g{sup -1} h{sup -1}, and the Ca concentration where the carrier reached half saturation (K{sub M}{sup Ca}) was 289 {mu}mol L{sup -1}. Cd influx was measured using {sup 109}Cd as a radio-tracer in larvae exposed to Cd (0-1400 {mu}mol L{sup -1}) while the Ca concentration was set to the K{sub M}{sup Ca}. This revealed a J{sub max}{sup Cd} (2.26 {mu}mol g{sup -1} h{sup -1}) which was nearly 6-fold higher that of Ca. This unusually high capacity for Cd uptake is in accordance with the huge tissue Cd burdens that chironomid larvae are able to accumulate during high level exposures. The apparent K{sub M}{sup Cd} (1133 {mu}mol Cd L{sup -1}), when recalculated to account for the background Ca level, was still high (567 {mu}mol Cd L{sup -1}), suggesting that this organism has a low affinity for Cd relative to most aquatic animals, indeed lower or comparable to its affinity for Ca. In consequence, even well above environmentally relevant Cd exposures, C. riparius does not accumulate Cd at the expense of Ca, thereby avoiding internal hypocalcaemia, in contrast to most other organisms which are much more sensitive to Cd. However, Ca influx was significantly reduced when 1200 {mu}mol Cd L{sup -1} was added to Ca exposures (96-2410 {mu}mol L{sup -1}). Michaelis-Menten analysis revealed a similar J{sub max}{sup Ca} in Cd-exposed and control larvae (i.e. exposed only to Ca), but that the apparent K{sub M}{sup Ca} was many-fold higher in larvae which were simultaneously exposed to Ca and Cd. Conversely, increasing Ca concentrations (96-2410 {mu}mol L{sup -1}) progressively inhibited Cd uptake from a Cd exposure concentration (1200 {mu}mol L{sup -1}), providing additional support for a common transport system. These results suggest that the interaction of Cd and Ca in C. riparius is one of simple competitive interaction, and that the unusual Cd transport kinetics (low affinity, high capacity) relative to fairly standard Ca transport kinetics help explain the unusual tolerance that this organism has to acute Cd exposure.

  4. Control of nitrous oxide emission from Chironomus plumosus larvae by nitrate and temperatur

    DEFF Research Database (Denmark)

    Stief, Peter; Polerecky, Lubos; Poulsen, Morten;

    2010-01-01

    Aquatic invertebrates that ingest large numbers of bacteria produce substantial amounts of the greenhouse gas N2O because of incomplete denitrification in their anoxic gut. We investigated the influence of two key environmental factors, temperature and NO3- availability, on N2O emission from larvae......, and N2O uptake was never observed. For both types of larvae, the rate of N2O emission was stimulated by temperature (when the NO3- concentration in the water column was higher than 25–50 µmol L-1) and by NO3- (when the temperature was higher than 4–10°C). Modeling based on experimentally determined...... ventilation parameters and sedimentary O2 and NO3- turnover rates predicted that NO3- concentrations inside the burrow and in the sediment surrounding the burrow fluctuated and were on average lower than those in the water column. In contrast, NO3- concentrations measured in the gut and hemolymph...

  5. Effects of cadmium and resource quality on freshwater detritus processing chains: a microcosm approach with two insect species.

    Science.gov (United States)

    Campos, Diana; Alves, Artur; Lemos, Marco F L; Correia, António; Soares, Amadeu M V M; Pestana, João L T

    2014-07-01

    Detritus processing is vital for freshwater ecosystems that depend on the leaf litter from riparian vegetation and is mediated by microorganisms and aquatic invertebrates. Shredder invertebrates transform coarse particulate organic matter into fine particulate organic matter used as food by collector species. Direct and indirect effects of contaminants can impair detritus processing and thus affect the functioning of these ecosystems. Here, we assessed the combined effects of a toxic metal (cadmium) and resource quality (leaf species) on detritus processing and shredder-collector interactions. We considered two types of leaves, alder and eucalyptus that were microbially conditioned under different Cd concentrations in the laboratory. The microbial communities present on leaves were analyzed by Denaturing Gradient Gel Electrophoresis (DGGE), and we also measured microbial respiration rates. Sericostoma vittatum (a caddisfly shredder) and Chironomus riparius (a midge collector) were also exposed to Cd and allowed to consume the corresponding alder or eucalyptus leaves. We evaluated C. riparius growth and leaf mass loss in multispecies microcosms. Cadmium exposure affected leaf conditioning and fungal diversity on both leaf species, as assessed by DGGE. Cadmium exposure also affected the mass loss of alder leaves by reductions in detritivore feeding, and impaired C. riparius growth. Chironomus riparius consumed alder leaf discs in the absence of shredders, but S. vittatum appear to promote C. riparius growth in treatments containing eucalyptus. These results show that indirect effects of contaminants along detritus-processing chains can occur through effects on shredder-collector interactions such as facilitation but they also depend on the nutritional quality of detritus and on sensitivity and feeding plasticity of detritivore species.

  6. Improving sediment-quality guidelines for nickel: development and application of predictive bioavailability models to assess chronic toxicity of nickel in freshwater sediments

    Science.gov (United States)

    Vangheluwe, Marnix L. U.; Verdonck, Frederik A. M.; Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.; Schlekat, Christan E.; Rogevich Garman, Emily

    2013-01-01

    Within the framework of European Union chemical legislations an extensive data set on the chronic toxicity of sediment nickel has been generated. In the initial phase of testing, tests were conducted with 8 taxa of benthic invertebrates in 2 nickel-spiked sediments, including 1 reasonable worst-case sediment with low concentrations of acid-volatile sulfide (AVS) and total organic carbon. The following species were tested: amphipods (Hyalella azteca, Gammarus pseudolimnaeus), mayflies (Hexagenia sp.), oligochaetes (Tubifex tubifex, Lumbriculus variegatus), mussels (Lampsilis siliquoidea), and midges (Chironomus dilutus, Chironomus riparius). In the second phase, tests were conducted with the most sensitive species in 6 additional spiked sediments, thus generating chronic toxicity data for a total of 8 nickel-spiked sediments. A species sensitivity distribution was elaborated based on 10% effective concentrations yielding a threshold value of 94 mg Ni/kg dry weight under reasonable worst-case conditions. Data from all sediments were used to model predictive bioavailability relationships between chronic toxicity thresholds (20% effective concentrations) and AVS and Fe, and these models were used to derive site-specific sediment-quality criteria. Normalization of toxicity values reduced the intersediment variability in toxicity values significantly for the amphipod species Hyalella azteca and G. pseudolimnaeus, but these relationships were less clearly defined for the mayfly Hexagenia sp. Application of the models to prevailing local conditions resulted in threshold values ranging from 126 mg to 281 mg Ni/kg dry weight, based on the AVS model, and 143 mg to 265 mg Ni/kg dry weight, based on the Fe model

  7. Development and application of freshwater sediment-toxicity benchmarks for currently used pesticides.

    Science.gov (United States)

    Nowell, Lisa H; Norman, Julia E; Ingersoll, Christopher G; Moran, Patrick W

    2016-04-15

    Sediment-toxicity benchmarks are needed to interpret the biological significance of currently used pesticides detected in whole sediments. Two types of freshwater sediment benchmarks for pesticides were developed using spiked-sediment bioassay (SSB) data from the literature. These benchmarks can be used to interpret sediment-toxicity data or to assess the potential toxicity of pesticides in whole sediment. The Likely Effect Benchmark (LEB) defines a pesticide concentration in whole sediment above which there is a high probability of adverse effects on benthic invertebrates, and the Threshold Effect Benchmark (TEB) defines a concentration below which adverse effects are unlikely. For compounds without available SSBs, benchmarks were estimated using equilibrium partitioning (EqP). When a sediment sample contains a pesticide mixture, benchmark quotients can be summed for all detected pesticides to produce an indicator of potential toxicity for that mixture. Benchmarks were developed for 48 pesticide compounds using SSB data and 81 compounds using the EqP approach. In an example application, data for pesticides measured in sediment from 197 streams across the United States were evaluated using these benchmarks, and compared to measured toxicity from whole-sediment toxicity tests conducted with the amphipod Hyalella azteca (28-d exposures) and the midge Chironomus dilutus (10-d exposures). Amphipod survival, weight, and biomass were significantly and inversely related to summed benchmark quotients, whereas midge survival, weight, and biomass showed no relationship to benchmarks. Samples with LEB exceedances were rare (n=3), but all were toxic to amphipods (i.e., significantly different from control). Significant toxicity to amphipods was observed for 72% of samples exceeding one or more TEBs, compared to 18% of samples below all TEBs. Factors affecting toxicity below TEBs may include the presence of contaminants other than pesticides, physical/chemical characteristics

  8. Persistence of aquatic insects across managed landscapes: effects of landscape permeability on re-colonization and population recovery.

    Directory of Open Access Journals (Sweden)

    Nika Galic

    Full Text Available Human practices in managed landscapes may often adversely affect aquatic biota, such as aquatic insects. Dispersal is often the limiting factor for successful re-colonization and recovery of stressed habitats. Therefore, in this study, we evaluated the effects of landscape permeability, assuming a combination of riparian vegetation (edge permeability and other vegetation (landscape matrix permeability, and distance between waterbodies on the colonization and recovery potential of weakly flying insects. For this purpose, we developed two models, a movement and a population model of the non-biting midge, Chironomus riparius, an aquatic insect with weak flying abilities. With the movement model we predicted the outcome of dispersal in a landscape with several linear water bodies (ditches under different assumptions regarding landscape-dependent movement. Output from the movement model constituted the probabilities of encountering another ditch and of staying in the natal ditch or perishing in the landscape matrix, and was used in the second model. With this individual-based model of midge populations, we assessed the implications for population persistence and for recovery potential after an extreme stress event. We showed that a combination of landscape attributes from the movement model determines the fate of dispersing individuals and, once extrapolated to the population level, has a big impact on the persistence and recovery of populations. Population persistence benefited from low edge permeability as it reduced the dispersal mortality which was the main factor determining population persistence and viability. However, population recovery benefited from higher edge permeability, but this was conditional on the low effective distance that ensured fewer losses in the landscape matrix. We discuss these findings with respect to possible landscape management scenarios.

  9. Acute and chronic toxicity of sodium sulfate to four freshwater organisms in water-only exposures.

    Science.gov (United States)

    Wang, Ning; Dorman, Rebecca A; Ingersoll, Christopher G; Hardesty, Doug K; Brumbaugh, William G; Hammer, Edward J; Bauer, Candice R; Mount, David R

    2016-01-01

    The acute and chronic toxicity of sulfate (tested as sodium sulfate) was determined in diluted well water (hardness of 100 mg/L and pH 8.2) with a cladoceran (Ceriodaphnia dubia; 2-d and 7-d exposures), a midge (Chironomus dilutus; 4-d and 41-d exposures), a unionid mussel (pink mucket, Lampsilis abrupta; 4-d and 28-d exposures), and a fish (fathead minnow, Pimephales promelas; 4-d and 34-d exposures). Among the 4 species, the cladoceran and mussel were acutely more sensitive to sulfate than the midge and fathead minnow, whereas the fathead minnow was chronically more sensitive than the other 3 species. Acute-to-chronic ratios ranged from 2.34 to 5.68 for the 3 invertebrates but were as high as 12.69 for the fish. The fathead minnow was highly sensitive to sulfate during the transitional period from embryo development to hatching in the diluted well water, and thus, additional short-term (7- to 14-d) sulfate toxicity tests were conducted starting with embryonic fathead minnow in test waters with different ionic compositions at a water hardness of 100 mg/L. Increasing chloride in test water from 10 mg Cl/L to 25 mg Cl/L did not influence sulfate toxicity to the fish, whereas increasing potassium in test water from 1 mg K/L to 3 mg K/L substantially reduced the toxicity of sulfate. The results indicate that both acute and chronic sulfate toxicity data, and the influence of potassium on sulfate toxicity to fish embryos, need to be considered when environmental guidance values for sulfate are developed or refined.

  10. Development and application of freshwater sediment-toxicity benchmarks for currently used pesticides

    Science.gov (United States)

    Nowell, Lisa H.; Norman, Julia E.; Ingersoll, Christopher G.; Moran, Patrick W.

    2016-01-01

    Sediment-toxicity benchmarks are needed to interpret the biological significance of currently used pesticides detected in whole sediments. Two types of freshwater sediment benchmarks for pesticides were developed using spiked-sediment bioassay (SSB) data from the literature. These benchmarks can be used to interpret sediment-toxicity data or to assess the potential toxicity of pesticides in whole sediment. The Likely Effect Benchmark (LEB) defines a pesticide concentration in whole sediment above which there is a high probability of adverse effects on benthic invertebrates, and the Threshold Effect Benchmark (TEB) defines a concentration below which adverse effects are unlikely. For compounds without available SSBs, benchmarks were estimated using equilibrium partitioning (EqP). When a sediment sample contains a pesticide mixture, benchmark quotients can be summed for all detected pesticides to produce an indicator of potential toxicity for that mixture. Benchmarks were developed for 48 pesticide compounds using SSB data and 81 compounds using the EqP approach. In an example application, data for pesticides measured in sediment from 197 streams across the United States were evaluated using these benchmarks, and compared to measured toxicity from whole-sediment toxicity tests conducted with the amphipod Hyalella azteca (28-d exposures) and the midge Chironomus dilutus (10-d exposures). Amphipod survival, weight, and biomass were significantly and inversely related to summed benchmark quotients, whereas midge survival, weight, and biomass showed no relationship to benchmarks. Samples with LEB exceedances were rare (n = 3), but all were toxic to amphipods (i.e., significantly different from control). Significant toxicity to amphipods was observed for 72% of samples exceeding one or more TEBs, compared to 18% of samples below all TEBs. Factors affecting toxicity below TEBs may include the presence of contaminants other than pesticides, physical

  11. Identification of anhydrobiosis-related genes from an expressed sequence tag database in the cryptobiotic midge Polypedilum vanderplanki (Diptera; Chironomidae).

    Science.gov (United States)

    Cornette, Richard; Kanamori, Yasushi; Watanabe, Masahiko; Nakahara, Yuichi; Gusev, Oleg; Mitsumasu, Kanako; Kadono-Okuda, Keiko; Shimomura, Michihiko; Mita, Kazuei; Kikawada, Takahiro; Okuda, Takashi

    2010-11-12

    Some organisms are able to survive the loss of almost all their body water content, entering a latent state known as anhydrobiosis. The sleeping chironomid (Polypedilum vanderplanki) lives in the semi-arid regions of Africa, and its larvae can survive desiccation in an anhydrobiotic form during the dry season. To unveil the molecular mechanisms of this resistance to desiccation, an anhydrobiosis-related Expressed Sequence Tag (EST) database was obtained from the sequences of three cDNA libraries constructed from P. vanderplanki larvae after 0, 12, and 36 h of desiccation. The database contained 15,056 ESTs distributed into 4,807 UniGene clusters. ESTs were classified according to gene ontology categories, and putative expression patterns were deduced for all clusters on the basis of the number of clones in each library; expression patterns were confirmed by real-time PCR for selected genes. Among up-regulated genes, antioxidants, late embryogenesis abundant (LEA) proteins, and heat shock proteins (Hsps) were identified as important groups for anhydrobiosis. Genes related to trehalose metabolism and various transporters were also strongly induced by desiccation. Those results suggest that the oxidative stress response plays a central role in successful anhydrobiosis. Similarly, protein denaturation and aggregation may be prevented by marked up-regulation of Hsps and the anhydrobiosis-specific LEA proteins. A third major feature is the predicted increase in trehalose synthesis and in the expression of various transporter proteins allowing the distribution of trehalose and other solutes to all tissues.

  12. Unbalanced activation of glutathione metabolic pathways suggests potential involvement in plant defense against the gall midge mayetiola destructor in wheat

    Science.gov (United States)

    Glutathione, a thiol tripeptide of '-glutamylcysteinylglycine, exists abundantly in nearly all organisms. Glutathione participates in various physiological processes involved in redox reactions by serving as an electron donor/acceptor. In this study, we found that the abundance of total glutathion...

  13. Two new species and new records of biting midges of the genus Culicoides from northwestern Argentina (Diptera: Ceratopogonidae)

    Science.gov (United States)

    Spinelli, Gustavo Ricardo; Aybar, Cecilia Veggiani; Juri, María Julia Dantur; de Grosso, Mercedes Lizarralde; Marino, Pablo Ignacio

    2013-01-01

    The following two new species of Culicoides from the Argentinean Yungas are described, illustrated and placed to subgenus or species group and compared with related congeners: Culicoides calchaqui Spinelli & Veggiani Aybar and Culicoides willinki Spinelli & Veggiani Aybar. Culicoides daedaloides Wirth & Blanton is recorded for the first time for Argentina and Culicoides pseudoheliconiae Felippe-Bauer is firstly mentioned from the northwestern region of the country. PMID:23903973

  14. Toxicity of sediments potentially contaminated by coal mining and natural gas extraction to unionid mussels and commonly tested benthic invertebrates.

    Science.gov (United States)

    Wang, Ning; Ingersoll, Christopher G; Kunz, James L; Brumbaugh, William G; Kane, Cindy M; Evans, R Brian; Alexander, Steven; Walker, Craig; Bakaletz, Steve

    2013-01-01

    Sediment toxicity tests were conducted to assess potential effects of contaminants associated with coal mining or natural gas extraction activities in the upper Tennessee River basin and eastern Cumberland River basin in the United States. Test species included two unionid mussels (rainbow mussel, Villosa iris, and wavy-rayed lampmussel, Lampsilis fasciola, 28-d exposures), and the commonly tested amphipod, Hyalella azteca (28-d exposure) and midge, Chironomus dilutus (10-d exposure). Sediments were collected from seven test sites with mussel communities classified as impacted and in proximity to coal mining or gas extraction activities, and from five reference sites with mussel communities classified as not impacted and no or limited coal mining or gas extraction activities. Additional samples were collected from six test sites potentially with high concentrations of polycyclic aromatic hydrocarbons (PAHs) and from a test site contaminated by a coal ash spill. Mean survival, length, or biomass of one or more test species was reduced in 10 of 14 test samples (71%) from impacted areas relative to the response of organisms in the five reference samples. A higher proportion of samples was classified as toxic to mussels (63% for rainbow mussels, 50% for wavy-rayed lampmussels) compared with amphipods (38%) or midge (38%). Concentrations of total recoverable metals and total PAHs in sediments did not exceed effects-based probable effect concentrations (PECs). However, the survival, length, or biomasses of the mussels were reduced significantly with increasing PEC quotients for metals and for total PAHs, or with increasing sum equilibrium-partitioning sediment benchmark toxic units for PAHs. The growth of the rainbow mussel also significantly decreased with increasing concentrations of a major anion (chloride) and major cations (calcium and magnesium) in sediment pore water. Results of the present study indicated that (1) the findings from laboratory tests were generally

  15. Toxicity of sediments potentially contaminated by coal mining and natural gas extraction to unionid mussels and commonly tested benthic invertebrates

    Science.gov (United States)

    Wang, Ning; Ingersoll, Christopher G.; Kunz, James L.; Brumbaugh, William G.; Kane, Cindy M.; Evans, R. Brian; Alexander, Steven; Walker, Craig; Bakaletz, Steve

    2013-01-01

    Sediment toxicity tests were conducted to assess potential effects of contaminants associated with coal mining or natural gas extraction activities in the upper Tennessee River basin and eastern Cumberland River basin in the United States. Test species included two unionid mussels (rainbow mussel, Villosa iris, and wavy-rayed lampmussel, Lampsilis fasciola, 28-d exposures), and the commonly tested amphipod, Hyalella azteca (28-d exposure) and midge, Chironomus dilutus (10-d exposure). Sediments were collected from seven test sites with mussel communities classified as impacted and in proximity to coal mining or gas extraction activities, and from five reference sites with mussel communities classified as not impacted and no or limited coal mining or gas extraction activities. Additional samples were collected from six test sites potentially with high concentrations of polycyclic aromatic hydrocarbons (PAHs) and from a test site contaminated by a coal ash spill. Mean survival, length, or biomass of one or more test species was reduced in 10 of 14 test samples (71%) from impacted areas relative to the response of organisms in the five reference samples. A higher proportion of samples was classified as toxic to mussels (63% for rainbow mussels, 50% for wavy-rayed lampmussels) compared with amphipods (38%) or midge (38%). Concentrations of total recoverable metals and total PAHs in sediments did not exceed effects-based probable effect concentrations (PECs). However, the survival, length, or biomasses of the mussels were reduced significantly with increasing PEC quotients for metals and for total PAHs, or with increasing sum equilibrium-partitioning sediment benchmark toxic units for PAHs. The growth of the rainbow mussel also significantly decreased with increasing concentrations of a major anion (chloride) and major cations (calcium and magnesium) in sediment pore water. Results of the present study indicated that (1) the findings from laboratory tests were generally

  16. Toxicity on aquatic organisms exposed to secondary effluent disinfected with chlorine, peracetic acid, ozone and UV radiation.

    Science.gov (United States)

    da Costa, Juliana Berninger; Rodgher, Suzelei; Daniel, Luiz Antonio; Espíndola, Evaldo Luiz Gaeta

    2014-11-01

    The toxic potential of four disinfectant agents (chlorine, ozone, peracetic acid and UV radiation), used in the disinfection of urban wastewater, was evaluated with respect to four aquatic organisms. Disinfection assays were carried out with wastewater from the city of Araraquara (São Paulo State, Brazil), and subsequently, toxicity bioassays were applied in order to verify possible adverse effects to the cladocerans (Ceriodaphnia silvestrii and Daphnia similis), midge larvae Chironomus xanthus and fish (Danio rerio). Under the experimental conditions tested, all the disinfectants were capable of producing harmful effects on the test organisms, except for C. xanthus. The toxicity of the effluent to C. silvestrii was observed to increase significantly as a result of disinfection using 2.5 mg L(-1) chlorine and 29.9 mg L(-1) ozone. Ozonation and chlorination significantly affected the survival of D. similis and D. rerio, causing mortality of 60 to 100 % in comparison to the non-disinfected effluent. In experiments with effluent treated with peracetic acid (PAA) and UV radiation, a statistically significant decrease in survival was only detected for D. rerio. This investigation suggested that the study of the ideal concentrations of disinfectants is a research need for ecologically safe options for the treatment of wastewater.

  17. Primary sources and toxicity of PAHs in Milwaukee-area streambed sediment

    Science.gov (United States)

    Baldwin, Austin K.; Corsi, Steven R.; Lutz, Michelle A.; Ingersoll, Christopher G.; Dorman, Rebecca A.; Magruder, Christopher; Magruder, Matthew

    2016-01-01

    High concentrations of polycyclic aromatic hydrocarbons (PAHs) in streams can be a significant stressor to aquatic organisms. To understand the likely sources and toxicity of PAHs in Milwaukee-area streams, streambed sediment samples from 40 sites and parking lot dust samples from 6 sites were analyzed for 38 parent PAHs and 25 alkylated PAHs. Diagnostic ratios, profile correlations, principal components analysis, source-receptor modeling, and mass fractions analysis were used to identify potential PAH sources to streambed sediment samples, and land-use analysis was used to relate streambed sediment PAH concentrations to different urban-related land uses. On the basis of this multiple lines-of-evidence approach, coal-tar pavement sealant was indicated as the primary source of PAHs in a majority of streambed sediment samples, contributing an estimated 77% of total PAHs to samples, on average. Comparison to the Probable Effect Concentrations and (or) the Equilibrium Partitioning Sediment Benchmark indicates that 78% of stream sediment samples are likely to cause adverse effects to benthic organisms. Laboratory toxicity tests on a 16-sample subset of the streambed sites using the amphipod Hyalella azteca (28-day) and the midge Chironomus dilutus (10-day) measured significant reductions in one or more biological endpoints, including survival, in 75% of samples, with H. azteca more responsive than C. dilutus.

  18. Ecotoxicological impact of Zequanox®, a novel biocide, on selected non-target Irish aquatic species.

    Science.gov (United States)

    Meehan, Sara; Shannon, Adam; Gruber, Bridget; Rackl, Sarahann M; Lucy, Frances E

    2014-09-01

    Effective, species-specific zebra mussel control is needed urgently for Ireland׳s freshwater bodies, which became infested with non-native zebra mussels in the 1990s. Zequanox®, a newly commercialized product for zebra and quagga mussel control, is composed of dead Pseudomonas fluorescens CL 145A cells. This paper describes ecotoxicology tests on three representative native Irish freshwater species: Anodonta (duck mussel), Chironomus plumosus (non-biting midge), and Austropotamobius pallipes (white-clawed crayfish). The species were exposed to Zequanox in a 72-h static renewal toxicity test at concentrations of 100-750mg active ingredient per liter (mga.i./L). Water quality parameters were measured every 12-24h before and after water and product renewal. After 72h, endpoints were reported as LC10, LC50, and LC100. The LC50 values derived were (1) Anodonta: ≥500mga.i./L (2) C. plumosus: 1075mga.i./L, and (3) A. pallipes: ≥750mga.i./L. These results demonstrate that Zequanox does not negatively affect these organisms at the concentration required for >80percent zebra mussel mortality (150mg a.i/L) and the maximum allowable treatment concentration in the United Sates (200mga.i./L). They also show the overall species-specificity of Zequanox, and support its use in commercial facilities and open waters. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Toxicity of carbon nanotubes to freshwater aquatic invertebrates

    Science.gov (United States)

    Mwangi, Joseph N.; Wang, Ning; Ingersoll, Christopher G.; Hardesty, Doug K.; Brunson, Eric L.; Li, Hao; Deng, Baolin

    2012-01-01

    Carbon nanotubes (CNTs) are hydrophobic in nature and thus tend to accumulate in sediments if released into aquatic environments. As part of our overall effort to examine the toxicity of carbon-based nanomaterials to sediment-dwelling invertebrates, we have evaluated the toxicity of different types of CNTs in 14-d water-only exposures to an amphipod (Hyalella azteca), a midge (Chironomus dilutus), an oligochaete (Lumbriculus variegatus), and a mussel (Villosa iris) in advance of conducting whole-sediment toxicity tests with CNTs. The results of these toxicity tests conducted with CNTs added to water showed that 1.00g/L (dry wt) of commercial sources of CNTs significantly reduced the survival or growth of the invertebrates. Toxicity was influenced by the type and source of the CNTs, by whether the materials were precleaned by acid, by whether sonication was used to disperse the materials, and by species of the test organisms. Light and electron microscope imaging of the surviving test organisms showed the presence of CNTs in the gut as well as on the outer surface of the test organisms, although no evidence was observed to show penetration of CNTs through cell membranes. The present study demonstrated that both the metals solubilized from CNTs such as nickel and the "metal-free" CNTs contributed to the toxicity.

  20. Deriving freshwater quality criteria for iron, lead, nickel, and zinc for protection of aquatic life in Malaysia.

    Science.gov (United States)

    Shuhaimi-Othman, M; Nadzifah, Y; Nur-Amalina, R; Umirah, N S

    2012-01-01

    Freshwater quality criteria for iron (Fe), lead (Pb), nickel (Ni), and zinc (Zn) were developed with particular reference to aquatic biota in Malaysia, and based on USEPA's guidelines. Acute toxicity tests were performed on eight different freshwater domestic species in Malaysia which were Macrobrachium lanchesteri (prawn), two fish: Poecilia reticulata and Rasbora sumatrana, Melanoides tuberculata (snail), Stenocypris major (ostracod), Chironomus javanus (midge larvae), Nais elinguis (annelid), and Duttaphrynus melanostictus (tadpole) to determine 96 h LC(50) values for Fe, Pb, Ni, and Zn. The final acute value (FAV) for Fe, Pb, Ni, and Zn were 74.5, 17.0, 165, and 304.9 μg L(-1), respectively. Using an estimated acute-to-chronic ratio (ACR) of 8.3, the value for final chronic value (FCV) was derived. Based on FAV and FCV, a criterion maximum concentration (CMC) and a criterion continuous concentration (CCC) for Fe, Pb, Ni, and Zn that are 37.2, 8.5, 82.5, and 152.4 μg L(-1) and 9.0, 2.0, 19.9, and 36.7 μg L(-1), respectively, were derived. The results of this study provide useful data for deriving national or local water quality criteria for Fe, Pb, Ni, and Zn based on aquatic biota in Malaysia. Based on LC(50) values, this study indicated that N. elinguis, M. lanchesteri, N. elinguis, and R. sumatrana were the most sensitive to Fe, Pb, Ni, and Zn, respectively.

  1. The role of a water bug, Sigara striata, in freshwater food webs

    Directory of Open Access Journals (Sweden)

    Jan Klecka

    2014-05-01

    Full Text Available Freshwater food webs are dominated by aquatic invertebrates whose trophic relationships are often poorly known. Here, I used laboratory experiments to study the role of a water bug, Sigara striata, as a potential predator and prey in food webs of stagnant waters. Multiple-choice predation experiment revealed that Sigara, which had been considered mostly herbivorous, also consumed larvae of Chironomus midges. Because they often occur in high densities and are among the most ubiquitous aquatic insects, Sigara water bugs may be important predators in fresh waters. A second experiment tested the role of Sigara as a potential prey for 13 common invertebrate predators. Mortality of Sigara inflicted by different predators varied widely, especially depending on body mass, foraging mode (ambush/searching and feeding mode (chewing/suctorial of the predators. Sigara was highly vulnerable to ambush predators, while searching predators caused on average 8.1 times lower mortality of Sigara. Additionally, suctorial predators consumed on average 6.6 times more Sigara individuals than chewing predators, which supports previous results hinting on potentially different predation pressures of these two types of predators on prey populations. The importance of these two foraging-related traits demonstrates the need to move from body mass based to multiple trait based descriptions of food web structure. Overall, the results suggests that detailed experimental studies of common but insufficiently known species can significantly enhance our understanding of food web structure.

  2. Laboratory and field studies on the effect of molinate, clomazone, and thiobencarb on nontarget aquatic invertebrates.

    Science.gov (United States)

    Burdett, A S; Stevens, M M; Macmillan, D L

    2001-10-01

    The midge Chironomus tepperi was used in laboratory experiments to assess the relative toxicity of formulated molinate, clomazone, and thiobencarb, three herbicides used in Australian rice crops. Static bioassays were initiated with first-instar larvae at herbicide concentrations between 0.0625 and 2 times the anticipated field concentrations (AFCs) expected from the registered application rates. Adult emergence success, development time, and wing length were used as indices of the effect of each herbicide. Clomazone had no effect on any parameters at concentrations up to 0.288 mg/L (p > 0.05). Molinate significantly increased development time at concentrations equivalent to the AFC (3.6 mg/L) and above (p < 0.05). Thiobencarb reduced emergence success of adult C. tepperi at 0.0625 times the AFC (0.1875 mg/L) as well as decreasing male adult size and increasing development time for males and females at 0.125 times the AFC (p < 0.05). Nontarget effects of the herbicides on aquatic invertebrate communities were assessed in shallow experimental ponds using commercial application rates. One week after treatment, only thiobencarb had a significant effect, suppressing populations of chironomids, calanoids, and cyclopoids (p < 0.05). Four weeks later, all populations had recovered, equaling or exceeding control densities.

  3. Evaluation of the effect of water type on the toxicity of nitrate to aquatic organisms.

    Science.gov (United States)

    Baker, Josh A; Gilron, Guy; Chalmers, Ben A; Elphick, James R

    2017-02-01

    A suite of acute and chronic toxicity tests were conducted to evaluate the sensitivity of freshwater organisms to nitrate (as sodium nitrate). Acute exposures with rainbow trout (Onchorhynchus mykiss) and amphipods (Hyalella azteca), as well as chronic exposures with H. azteca (14-d survival and growth), midges (Chironomus dilutus; 10-d survival and growth), daphnids (Ceriodaphnia dubia; 7-d survival and reproduction), and fathead minnows (Pimephales promelas; 7-d survival and growth) were used to determine sublethal and lethal effect concentrations. Modification of nitrate toxicity was investigated across a range of ionic strengths, created through the use of very soft water, and standard preparations of synthetic soft, moderately-hard and hard dilution waters. The most sensitive species tested were C. dubia and H. azteca, in soft water, with reproduction and growth IC25 values of 13.8 and 12.2 mg/L NO3-N, respectively. All of the organisms exposed to nitrate demonstrated significantly reduced effects with increasing ionic strength associated with changes in water type. Possible mechanisms responsible for the modifying effect of increasing major ion concentrations on nitrate toxicity are discussed.

  4. Toxicity of bed sediments from the Niagara River Area of Concern and tributaries, New York, to Chironomus dilutus and Hyalella azteca, 2014-15

    Science.gov (United States)

    George, Scott D.; Baldigo, Barry P.; Duffy, Brian T.

    2016-09-20

    The Niagara River was designated as an Area of Concern in 1987 on both the United States and Canadian sides of the international boundary line because past industrial discharges and hazardous waste sites had caused extensive degradation of aquatic habitats. The degradation of the “benthos”, or the benthic macroinvertebrate community, was identified as one of seven beneficial use impairments caused by contaminated bed sediments. The U.S. Geological Survey and the New York State Department of Environmental Conservation, in cooperation with the U.S. Environmental Protection Agency, conducted a study in 2014 and 2015 to gather more extensive data on (a) the toxicity of bed sediments and (b) the status of macroinvertebrate communities on the main stem and tributaries of the Niagara River. This report addresses the first component of that study (toxicity of bed sediments), and summarizes results from laboratory toxicity tests that compare the survival and growth of two macroinvertebrate species between bed sediments from study sites and laboratory controls. Sediment toxicity was negligible at most sites, however poor performance of one or both test species in bed sediments from several tributary sites suggests that the quality of sediments may be adversely affecting benthic macroinvertebrate communities in some tributaries to the Niagara River.

  5. Multi-scale approach to the environmental factors effects on spatio-temporal variability of Chironomus salinarius (Diptera: Chironomidae) in a French coastal lagoon

    Science.gov (United States)

    Cartier, V.; Claret, C.; Garnier, R.; Fayolle, S.; Franquet, E.

    2010-03-01

    The complexity of the relationships between environmental factors and organisms can be revealed by sampling designs which consider the contribution to variability of different temporal and spatial scales, compared to total variability. From a management perspective, a multi-scale approach can lead to time-saving. Identifying environmental patterns that help maintain patchy distribution is fundamental in studying coastal lagoons, transition zones between continental and marine waters characterised by great environmental variability on spatial and temporal scales. They often present organic enrichment inducing decreased species richness and increased densities of opportunist species like C hironomus salinarius, a common species that tends to swarm and thus constitutes a nuisance for human populations. This species is dominant in the Bolmon lagoon, a French Mediterranean coastal lagoon under eutrophication. Our objective was to quantify variability due to both spatial and temporal scales and identify the contribution of different environmental factors to this variability. The population of C. salinarius was sampled from June 2007 to June 2008 every two months at 12 sites located in two areas of the Bolmon lagoon, at two different depths, with three sites per area-depth combination. Environmental factors (temperature, dissolved oxygen both in sediment and under water surface, sediment organic matter content and grain size) and microbial activities (i.e. hydrolase activities) were also considered as explanatory factors of chironomid densities and distribution. ANOVA analysis reveals significant spatial differences regarding the distribution of chironomid larvae for the area and the depth scales and their interaction. The spatial effect is also revealed for dissolved oxygen (water), salinity and fine particles (area scale), and for water column depth. All factors but water column depth show a temporal effect. Spearman's correlations highlight the seasonal effect (temperature, dissolved oxygen in sediment and water) as well as the effect of microbial activities on chironomid larvae. Our results show that a multi-scale approach identifies patchy distribution, even when there is relative environmental homogeneity.

  6. High quality draft genome sequence of Brachymonas chironomi AIMA4(T) (DSM 19884(T)) isolated from a Chironomus sp. egg mass.

    Science.gov (United States)

    Laviad, Sivan; Lapidus, Alla; Han, James; Haynes, Matthew; Reddy, Tbk; Huntemann, Marcel; Pati, Amrita; Ivanova, Natalia N; Mavromatis, Konstantinos; Lang, Elke; Rohde, Manfred; Markowitz, Victor; Woyke, Tanja; Klenk, Hans-Peter; Kyrpides, Nikos C; Halpern, Malka

    2015-01-01

    Brachymonas chironomi strain AIMA4(T) (Halpern et al., 2009) is a Gram-negative, non-motile, aerobic, chemoorganotroph bacterium. B. chironomi is a member of the Comamonadaceae, a family within the class Betaproteobacteria. This species was isolated from a chironomid (Diptera; Chironomidae) egg mass, sampled from a waste stabilization pond in northern Israel. Phylogenetic analysis based on the 16S rRNA gene sequences placed strain AIMA4(T) in the genus Brachymonas. Here we describe the features of this organism, together with the complete genome sequence and annotation. The DNA GC content is 63.5%. The chromosome length is 2,509,395 bp. It encodes 2,382 proteins and 68 RNA genes. Brachymonas chironomi genome is part of the Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG) project.

  7. High quality draft genome sequence of Leucobacter chironomi strain MM2LB(T) (DSM 19883(T)) isolated from a Chironomus sp. egg mass.

    Science.gov (United States)

    Laviad, Sivan; Lapidus, Alla; Copeland, Alex; Reddy, Tbk; Huntemann, Marcel; Pati, Amrita; Ivanova, Natalia N; Markowitz, Victor M; Pukall, Rüdiger; Klenk, Hans-Peter; Woyke, Tanja; Kyrpides, Nikos C; Halpern, Malka

    2015-01-01

    Leucobacter chironomi strain MM2LB(T) (Halpern et al., Int J Syst Evol Microbiol 59:665-70 2009) is a Gram-positive, rod shaped, non-motile, aerobic, chemoorganotroph bacterium. L. chironomi belongs to the family Microbacteriaceae, a family within the class Actinobacteria. Strain MM2LB(T) was isolated from a chironomid (Diptera; Chironomidae) egg mass that was sampled from a waste stabilization pond in northern Israel. In a phylogenetic tree based on 16S rRNA gene sequences, strain MM2LB(T) formed a distinct branch within the radiation encompassing the genus Leucobacter. Here we describe the features of this organism, together with the complete genome sequence and annotation. The DNA GC content is 69.90%. The chromosome length is 2,964,712 bp. It encodes 2,690 proteins and 61 RNA genes. L. chironomi genome is part of the Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG) project.

  8. Ecotoxicological sediment survey of large German rivers; Oekotoxikologische Sedimentkartierung der grossen Fluesse Deutschlands

    Energy Technology Data Exchange (ETDEWEB)

    Duft, M.; Tillmann, M. [Internationales Hochschulinstitut Zittau (Germany); Oehlmann, J. [Frankfurt Univ. (Germany). Zoologisches Inst., Abt. Oekologie und Evolution

    2003-05-01

    In this project, a nation-wide, ecotoxicologically-based sediment survey was carried out. For this purpose, a total of about 200 sediment samples from 12 selected large German rivers (Danube, Elbe, Ems, Main, Mosel, Neckar, Neisse, Odra, Rhine, Ruhr, Saar and Weser) were analysed with regard to abiotic parameters (heavy metals, PAH, organic carbon content, particle size) and also by means of two biological test systems with benthic invertebrates (nematode test with the roundworm Caenorhabditis elegans and chironomid test with the non-biting midge Chironomus riparius). Subsequently, this comprehensive data set was analysed statistically. By means of an iterative method, a five-stage, statistically-derived assessment concept which is founded on the results of the biological tests, was developed following the EU water framework directive. In general, the classification with the nematode test turned out to be the more sensitive method. A principal component analysis and correlations showed that the parameters of both biotests provide different information which suggests a combined use of both tests. Correlations also indicate a connection of biotest results and abiotic parameters (organic carbon content, particle size and heavy metal contamination). (orig.) [German] Im Projekt wurde eine bundesweite oekotoxikologische Sedimentkartierung grosser Fliessgewaesser durchgefuehrt. Dazu wurden insgesamt etwa 200 Sedimentproben aus 12 ausgewaehlten grossen Fluessen Deutschlands (Donau, Elbe, Ems, Main, Mosel, Neckar, Neisse, Oder, Rhein, Ruhr, Saar und Weser) auf ihre abiotischen Parameter (Schwermetalle, PAK, organischer Kohlenstoffgehalt, Korngroesse) hin analysiert sowie mit zwei biologischen Testverfahren mit benthischen Invertebraten (Nematodentest mit dem Fadenwurm Caenorhabditis elegans und Chironomidentest mit der Zuckmuecke Chironomus riparius) untersucht. Dieses umfangreiche Datenmaterial wurde anschliessend statistisch ausgewertet und mit Hilfe eines iterativen

  9. Estimation of vanadium water quality benchmarks for the protection of aquatic life with relevance to the Athabasca Oil Sands region using species sensitivity distributions.

    Science.gov (United States)

    Schiffer, Stephanie; Liber, Karsten

    2017-06-21

    Elevated vanadium (V) concentrations in oil sands coke, which is produced and stored on site of some major Athabasca Oil Sands companies, could pose a risk to aquatic ecosystems in northern Alberta, Canada, depending on its future storage and utilization. In the present study, V toxicity was determined in reconstituted Athabasca River water to various freshwater organisms, including 2 midge species (Chironomus dilutus and Chironomus riparius; 4-d and 30-d to 40-d exposures) and 2 freshwater fish species (Oncorhynchus mykiss and Pimephales promelas; 4-d and 28-d exposures) to facilitate estimation of water quality benchmarks. The acute toxicity of V was 52.0 and 63.2 mg/L for C. dilutus and C. riparius, respectively, and 4.0 and 14.8 mg V/L for P. promelas and O. mykiss, respectively. Vanadium exposure significantly impaired adult emergence of C. dilutus and C. riparius at concentrations ≥16.7 (31.6% reduction) and 8.3 (18.0% reduction) mg/L, respectively. Chronic toxicity in fish presented as lethality, with chronic 28-d LC50s of 0.5 and 4.3 mg/L for P. promelas and O. mykiss, respectively. These data were combined with data from the peer-reviewed literature, and separate acute and chronic species sensitivity distributions (SSDs) were constructed. The acute and chronic hazardous concentrations endangering only 5% of species (HC5) were estimated as 0.64 and 0.05 mg V/L, respectively. These new data for V toxicity to aquatic organisms ensure that there are now adequate data available for regulatory agencies to develop appropriate water quality guidelines for use in the Athabasca Oil Sands region and elsewhere. Until then, the HC5 values presented in the present study could serve as interim benchmarks for the protection of aquatic life from exposure to hazardous levels of V in local aquatic environments. Environ Toxicol Chem 2017;9999:1-11. © 2017 SETAC. © 2017 SETAC.

  10. Development and application of freshwater sediment-toxicity benchmarks for currently used pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Nowell, Lisa H., E-mail: lhnowell@usgs.gov [U.S. Geological Survey, California Water Science Center, Placer Hall, 6000 J Street, Sacramento, CA 95819 (United States); Norman, Julia E., E-mail: jnorman@usgs.gov [U.S. Geological Survey, Oregon Water Science Center, 2130 SW 5" t" h Avenue, Portland, OR 97201 (United States); Ingersoll, Christopher G., E-mail: cingersoll@usgs.gov [U.S. Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, MO 65021 (United States); Moran, Patrick W., E-mail: pwmoran@usgs.gov [U.S. Geological Survey, Washington Water Science Center, 934 Broadway, Suite 300, Tacoma, WA 98402 (United States)

    2016-04-15

    Sediment-toxicity benchmarks are needed to interpret the biological significance of currently used pesticides detected in whole sediments. Two types of freshwater sediment benchmarks for pesticides were developed using spiked-sediment bioassay (SSB) data from the literature. These benchmarks can be used to interpret sediment-toxicity data or to assess the potential toxicity of pesticides in whole sediment. The Likely Effect Benchmark (LEB) defines a pesticide concentration in whole sediment above which there is a high probability of adverse effects on benthic invertebrates, and the Threshold Effect Benchmark (TEB) defines a concentration below which adverse effects are unlikely. For compounds without available SSBs, benchmarks were estimated using equilibrium partitioning (EqP). When a sediment sample contains a pesticide mixture, benchmark quotients can be summed for all detected pesticides to produce an indicator of potential toxicity for that mixture. Benchmarks were developed for 48 pesticide compounds using SSB data and 81 compounds using the EqP approach. In an example application, data for pesticides measured in sediment from 197 streams across the United States were evaluated using these benchmarks, and compared to measured toxicity from whole-sediment toxicity tests conducted with the amphipod Hyalella azteca (28-d exposures) and the midge Chironomus dilutus (10-d exposures). Amphipod survival, weight, and biomass were significantly and inversely related to summed benchmark quotients, whereas midge survival, weight, and biomass showed no relationship to benchmarks. Samples with LEB exceedances were rare (n = 3), but all were toxic to amphipods (i.e., significantly different from control). Significant toxicity to amphipods was observed for 72% of samples exceeding one or more TEBs, compared to 18% of samples below all TEBs. Factors affecting toxicity below TEBs may include the presence of contaminants other than pesticides, physical/chemical characteristics

  11. Biological and chemical characterization of metal bioavailability in sediments from Lake Roosevelt, Columbia River, Washington, USA

    Science.gov (United States)

    Besser, J.M.; Brumbaugh, W.G.; Ivey, C.D.; Ingersoll, C.G.; Moran, P.W.

    2008-01-01

    We studied the bioavailability and toxicity of copper, zinc, arsenic, cadmium, and lead in sediments from Lake Roosevelt (LR), a reservoir on the Columbia River in Washington, USA that receives inputs of metals from an upstream smelter facility. We characterized chronic sediment toxicity, metal bioaccumulation, and metal concentrations in sediment and pore water from eight study sites: one site upstream in the Columbia River, six sites in the reservoir, and a reference site in an uncontaminated tributary. Total recoverable metal concentrations in LR sediments generally decreased from upstream to downstream in the study area, but sediments from two sites in the reservoir had metal concentrations much lower than adjacent reservoir sites and similar to the reference site, apparently due to erosion of uncontaminated bank soils. Concentrations of acid-volatile sulfide in LR sediments were too low to provide strong controls on metal bioavailability, and selective sediment extractions indicated that metals in most LR sediments were primarily associated with iron and manganese oxides. Oligochaetes (Lumbriculus variegatus) accumulated greatest concentrations of copper from the river sediment, and greatest concentrations of arsenic, cadmium, and lead from reservoir sediments. Chronic toxic effects on amphipods (Hyalella azteca; reduced survival) and midge larvae (Chironomus dilutus; reduced growth) in whole-sediment exposures were generally consistent with predictions of metal toxicity based on empirical and equilibrium partitioning-based sediment quality guidelines. Elevated metal concentrations in pore waters of some LR sediments suggested that metals released from iron and manganese oxides under anoxic conditions contributed to metal bioaccumulation and toxicity. Results of both chemical and biological assays indicate that metals in sediments from both riverine and reservoir habitats of Lake Roosevelt are available to benthic invertebrates. These findings will be used as

  12. Fear and loathing in the benthos: Responses of aquatic insect larvae to the pesticide imidacloprid in the presence of chemical signals of predation risk.

    Science.gov (United States)

    Pestana, João L T; Loureiro, Susana; Baird, Donald J; Soares, Amadeu M V M

    2009-06-28

    The influence of interactions between pesticide exposure and perceived predation risk on the lethal and sub-lethal responses of two aquatic insects was investigated using the pesticide imidacloprid, and a combination of predator-release kairomones from trout and alarm substances from conspecifics. Laboratory experiments examined feeding and respiration rates of the caddisfly Sericostoma vittatum as well as the growth, emergence and respiration rates of the midge Chironomus riparius, exposed to sub-lethal concentrations of imidacloprid. The effects of the two stressors on burrowing behaviour of both species were also assessed. The results show significant effects of environmentally relevant concentrations of imidacloprid on all endpoints studied. Perceived predation risk also elicited sub-lethal effects in C. riparius and S. vittatum, the latter species being less responsive to predation cues. The effects of simultaneous exposure to both types of stressors were assessed using two different approaches: analysis of variance and conceptual models [concentration addition (CA) and independent action (IA)] normally used for the evaluation of contaminant mixture exposure. Both statistical approaches showed no significant interactions on responses in simultaneous exposures in the majority of parameters assessed with only a signification deviation from the reference CA and IA models being found for C. riparius respiration data contrary to the ANOVA results. Exposure to imidacloprid also compromised antipredator behavioural responses of both insect species, with potential negative consequences in terms of mortality from predation in the field. The results obtained demonstrate that natural and anthropogenic stressors can be treated within the same framework providing compatible data for modelling. For an improved interpretation of ecological effects it will be important to expand the mechanistic study of effects of combined exposure to pesticides and perceived predation risk

  13. Deriving Freshwater Quality Criteria for Iron, Lead, Nickel, and Zinc for Protection of Aquatic Life in Malaysia

    Directory of Open Access Journals (Sweden)

    M. Shuhaimi-Othman

    2012-01-01

    Full Text Available Freshwater quality criteria for iron (Fe, lead (Pb, nickel (Ni, and zinc (Zn were developed with particular reference to aquatic biota in Malaysia, and based on USEPA’s guidelines. Acute toxicity tests were performed on eight different freshwater domestic species in Malaysia which were Macrobrachium lanchesteri (prawn, two fish: Poecilia reticulata and Rasbora sumatrana, Melanoides tuberculata (snail, Stenocypris major (ostracod, Chironomus javanus (midge larvae, Nais elinguis (annelid, and Duttaphrynus melanostictus (tadpole to determine 96 h LC50 values for Fe, Pb, Ni, and Zn. The final acute value (FAV for Fe, Pb, Ni, and Zn were 74.5, 17.0, 165, and 304.9 μg L−1, respectively. Using an estimated acute-to-chronic ratio (ACR of 8.3, the value for final chronic value (FCV was derived. Based on FAV and FCV, a criterion maximum concentration (CMC and a criterion continuous concentration (CCC for Fe, Pb, Ni, and Zn that are 37.2, 8.5, 82.5, and 152.4 μg L−1 and 9.0, 2.0, 19.9, and 36.7 μg L−1, respectively, were derived. The results of this study provide useful data for deriving national or local water quality criteria for Fe, Pb, Ni, and Zn based on aquatic biota in Malaysia. Based on LC50 values, this study indicated that N. elinguis, M. lanchesteri, N. elinguis, and R. sumatrana were the most sensitive to Fe, Pb, Ni, and Zn, respectively.

  14. Molecular differentiation of Culicoides biting midges (Diptera: Ceratopogonidae) from the subgenus Culicoides Latreille in Denmark

    DEFF Research Database (Denmark)

    Lassen, S. B.; Nielsen, S. Achim; Skovgård, H.;

    2012-01-01

    complexes are hard to distinguish. We evaluated the use of the mitochondrial DNA cytochrome oxidase I gene (COI) barcode region in the identification of species within the subgenus Culicoides. COI barcode sequence divergence within species was ... impunctatus, and Culicoides grisescens. Additionally, this study confirms the existence of Culicoides halophilus as a valid taxon and presents the first Culicoides deltus barcode sequences. Three additional groups of specimens were identified: Culicoides dk1 with a COI barcode diverging by 14.3% to 17.2% from...... other subgenus Culicoides species and Culicoides Kalix and Culicoides dk3, which diverged by 5.9% from each other and showed 12.5% to 17.6% divergence in COI barcode to subgenus Culicoides specimens....

  15. Monitoring of biting midges (Diptera: Ceratopogonidae: Culicoides Latreille) on farms in Sweden during the emergence of the 2008 epidemic of bluetongue

    DEFF Research Database (Denmark)

    Nielsen, Søren Achim; Nielsen, Boy Overgaard; Chirico, Jan

    2010-01-01

    In light of the emergence of bluetongue in northern Europe, populations of Culicoides species were monitored in 2007-2008 by means of Onderstepoort blacklight suction traps operating at livestock farms in Sweden. The location of the 22 sampling sites ranged from about latitude 55°N to about 68°N....... A total of 61,669 male and female Culicoides were captured, of which, 52,319 were trapped outside the farms and 9,350 in byres or livestock sheds. Thirty-three Culicoides species were recorded, of which, 30 were new to Sweden. The species and their relative abundance and spatial distribution on sites...... are presented. Two species incriminated as vectors of bluetongue virus, viz. Culicoides obsoletus (about 38%) and Culicoides scoticus (about 36%), were predominant and common in the environment of livestock farms practically all over the Swedish mainland, penetrating far north to at least 65°N. The two species...

  16. Interactions among the predatory midge Aphidoletes aphidimyza (Diptera: Cecidomyiidae), the fungal pathogen Metarhizium brunneum (Ascomycota: Hypocreales), and maize-infesting aphids in greenhouse mesocosms

    DEFF Research Database (Denmark)

    Campos de Azevedo, Ana Gorete; Steinwender, Bernhardt Michael; Eilenberg, Jørgen

    2017-01-01

    agents. In a randomized complete block design, sweet corn (Zea mays var. saccharata) plants were grown in large pots filled with natural soil or natural soil inoculated with M. brunneum. At the third leaf stage, before being individually caged, plants were infested with Rhopalosiphum padi and A...

  17. Laboratory toxicity and benthic invertebrate field colonization of Upper Columbia River sediments: Finding adverse effects using multiple lines of evidence

    Science.gov (United States)

    Fairchild, J.F.; Kemble, N.E.; Allert, A.L.; Brumbaugh, W.G.; Ingersoll, C.G.; Dowling, B.; Gruenenfelder, C.; Roland, J.L.

    2012-01-01

    From 1930 to 1995, the Upper Columbia River (UCR) of northeast Washington State received approximately 12 million metric tons of smelter slag and associated effluents from a large smelter facility located in Trail, British Columbia, approximately 10 km north of the United States–Canadian border. Studies conducted during the past two decades have demonstrated the presence of toxic concentrations of heavy metals in slag-based sandy sediments, including cadmium, copper, zinc, and lead in the UCR area as well as the downstream reservoir portion of Lake Roosevelt. We conducted standardized whole-sediment toxicity tests with the amphipod Hyalella azteca (28-day) and the midge Chironomus dilutus (10-day) on 11 samples, including both UCR and study-specific reference sediments. Metal concentrations in sediments were modeled for potential toxicity using three approaches: (1) probable effects quotients (PEQs) based on total recoverable metals (TRMs) and simultaneously extracted metals (SEMs); (2) SEMs corrected for acid-volatile sulfides (AVS; i.e., ΣSEM - AVS); and (3) ΣSEM - AVS normalized to the fractional organic carbon (foc) (i.e., ΣSEM - AVS/foc). The most highly metal-contaminated sample (ΣPEQTRM = 132; ΣPEQSEM = 54; ΣSEM - AVS = 323; and ΣSEM - AVS/foc = 64,600 umol/g) from the UCR was dominated by weathered slag sediment particles and resulted in 80% mortality and 94% decrease in biomass of amphipods; in addition, this sample significantly decreased growth of midge by 10%. The traditional ΣAVS - SEM, uncorrected for organic carbon, was the most accurate approach for estimating the effects of metals in the UCR. Treatment of the toxic slag sediment with 20% Resinex SIR-300 metal-chelating resin significantly decreased the toxicity of the sample. Samples ΣSEM - AVS > 244 was not toxic to amphipods or midge in laboratory testing, indicating that this value may be an approximate threshold for effects in the UCR. In situ benthic invertebrate colonization

  18. The chronic toxicity of molybdate to freshwater organisms. I. Generating reliable effects data

    Energy Technology Data Exchange (ETDEWEB)

    De Schamphelaere, K.A.C., E-mail: karel.deschamphelaere@Ugent.be [Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University (Belgium); Stubblefield, W. [Oregon State University, Department of Environmental and Molecular Toxicology, 421 Weniger Hall, Corvallis, OR 97331 (United States); Rodriguez, P. [Centro de Investigacion Minera y Metalurgica (CIMM), Santiago (Chile); Vleminckx, K. [Department for Molecular Biomedical Research, Ghent University (Belgium); Janssen, C.R. [Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University (Belgium)

    2010-10-15

    The European Union regulation on Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH) (EC, 2006) requires the characterization of the chronic toxicity of many chemicals in the aquatic environment, including molybdate (MoO{sub 4}{sup 2-}). Our literature review on the ecotoxicity of molybdate revealed that a limited amount of reliable chronic no observed effect concentrations (NOECs) for the derivation of a predicted no-effect concentration (PNEC) existed. This paper presents the results of additional ecotoxicity experiments that were conducted in order to fulfill the requirements for the derivation of a PNEC by means of the scientifically most robust species sensitivity distribution (SSD) approach (also called the statistical extrapolation approach). Ten test species were chronically exposed to molybdate (added as sodium molybdate dihydrate, Na{sub 2}MoO{sub 4}.2H{sub 2}O) according to internationally accepted standard testing guidelines or equivalent. The 10% effective concentrations (EC10, expressed as measured dissolved molybdenum) for the most sensitive endpoint per species were 62.8-105.6 (mg Mo)/L for Daphnia magna (21 day-reproduction), 78.2 (mg Mo)/L for Ceriodaphnia dubia (7 day-reproduction), 61.2-366.2 (mg Mo)/L for the green alga Pseudokirchneriella subcapitata (72 h-growth rate), 193.6 (mg Mo)/L for the rotifer Brachionus calyciflorus (48 h-population growth rate), 121.4 (mg Mo)/L for the midge Chironomus riparius (14 day-growth), 211.3 (mg Mo)/L for the snail Lymnaea stagnalis (28 day-growth rate), 115.9 (mg Mo)/L for the frog Xenopus laevis (4 day-larval development), 241.5 (mg Mo)/L for the higher plant Lemna minor (7 day-growth rate), 39.3 (mg Mo)/L for the fathead minnow Pimephales promelas (34 day-dry weight/biomass), and 43.2 (mg Mo)/L for the rainbow trout Oncorhynchus mykiss (78 day-biomass). These effect concentrations are in line with the few reliable data currently available in the open literature. The data

  19. Weight-of-evidence approach in assessment of ecotoxicological risks of acid sulphate soils in the Baltic Sea river estuaries

    Energy Technology Data Exchange (ETDEWEB)

    Wallin, Jaana, E-mail: jaana.wallin@jyu.fi [Finnish Environment Institute SYKE, Survontie 9 A, FI-40500 Jyväskylä (Finland); Karjalainen, Anna K. [Finnish Environment Institute SYKE, Survontie 9 A, FI-40500 Jyväskylä (Finland); Schultz, Eija [Finnish Environment Institute SYKE, Hakuninmaantie 6, FI-00430 Helsinki (Finland); Järvistö, Johanna; Leppänen, Matti; Vuori, Kari-Matti [Finnish Environment Institute SYKE, Survontie 9 A, FI-40500 Jyväskylä (Finland)

    2015-03-01

    Acidity and leaching of metals from acid sulphate soils (ASSs) impair the water quality of receiving surface waters. The largest ASS areas in Europe are found in the coasts of the northern Baltic Sea. We used weight-of-evidence (WoE) approach to assess potential risks in 14 estuary sites affected by ASS in the Gulf of Finland, northern Baltic Sea. The assessment was based on exposure and effect profiles utilizing sediment and water metal concentrations and concurrent pH variation, sediment toxicity tests using the luminescent bacterium Vibrio fischeri and the midge Chironomus riparius, and the ecological status of benthic macroinvertebrate communities. Sediment metal concentrations were compared to national sediment quality criteria/guidelines, and water metal concentrations to environmental quality standards (EQSs). Hazard quotients (HQs) were established for maximum aluminium, cadmium and zinc concentrations at low pH based on applicable US EPA toxicity database. Sediment metal concentrations were clearly elevated in most of the studied estuaries. The EQS of cadmium (0.1 μg/l) was exceeded in 3 estuaries out of 14. The pH-minima were below the national threshold value (5.5) between good and satisfactory water quality in 10 estuaries. V. fischeri bioluminescence indicated toxicity of the sediments but toxic response was not observed in the C. riparius emergence test. Benthic invertebrate communities were deteriorated in 6 out of 14 sites based on the benthic invertebrate quality index. The overall ecotoxicological risk was assessed as low in five, moderate in three and high in five of the estuary sites. The risk assessment utilizing the WoE approach indicated that harmful effects of ASSs are likely to occur in the Baltic Sea river estuaries located at the ASS hotspot area. - Highlights: • Acid sulphate soils release high amounts of metals and acidity. • Metals and acidity are transported to estuary sites. • Acid sulphate soils impair the ecological status

  20. The chronic toxicity of molybdate to freshwater organisms. I. Generating reliable effects data.

    Science.gov (United States)

    De Schamphelaere, K A C; Stubblefield, W; Rodriguez, P; Vleminckx, K; Janssen, C R

    2010-10-15

    The European Union regulation on Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH) (EC, 2006) requires the characterization of the chronic toxicity of many chemicals in the aquatic environment, including molybdate (MoO(4)(2-)). Our literature review on the ecotoxicity of molybdate revealed that a limited amount of reliable chronic no observed effect concentrations (NOECs) for the derivation of a predicted no-effect concentration (PNEC) existed. This paper presents the results of additional ecotoxicity experiments that were conducted in order to fulfill the requirements for the derivation of a PNEC by means of the scientifically most robust species sensitivity distribution (SSD) approach (also called the statistical extrapolation approach). Ten test species were chronically exposed to molybdate (added as sodium molybdate dihydrate, Na(2)MoO(4)·2H(2)O) according to internationally accepted standard testing guidelines or equivalent. The 10% effective concentrations (EC10, expressed as measured dissolved molybdenum) for the most sensitive endpoint per species were 62.8-105.6 (mg Mo)/L for Daphnia magna (21day-reproduction), 78.2 (mg Mo)/L for Ceriodaphnia dubia (7day-reproduction), 61.2-366.2 (mg Mo)/L for the green alga Pseudokirchneriella subcapitata (72h-growth rate), 193.6 (mg Mo)/L for the rotifer Brachionus calyciflorus (48h-population growth rate), 121.4 (mg Mo)/L for the midge Chironomus riparius (14day-growth), 211.3 (mg Mo)/L for the snail Lymnaea stagnalis (28day-growth rate), 115.9 (mg Mo)/L for the frog Xenopus laevis (4day-larval development), 241.5 (mg Mo)/L for the higher plant Lemna minor (7day-growth rate), 39.3 (mg Mo)/L for the fathead minnow Pimephales promelas (34day-dry weight/biomass), and 43.2 (mg Mo)/L for the rainbow trout Oncorhynchus mykiss (78day-biomass). These effect concentrations are in line with the few reliable data currently available in the open literature. The data presented in this study can

  1. 中国蛙蠓科分类研究及两新种记述(双翅目:蛙蠓科)%The frog-biting midges from China with description of two new species (Diptera: Corethrellidae)

    Institute of Scientific and Technical Information of China (English)

    王飞鹏; 黄恩炯; 杨美琼; 虞以新; 欧阳明安; 关雄

    2015-01-01

    记述了采自福建省的蛙蠓科蛙蠓属的2个新种:德化蛙蠓Corethrella(Corethrella) dehuaiWang et Yu sp.nov.和铜色蛙蠓Corethrella(Corethrella)aereus Wang et Yu sp.nov.,并对飞鹏蛙蠓Corethrella(Corethrella)feipengi Yu,Huang and Zhang,2013触角嗅觉器的分布做了更正.至此我国已发现蛙蠓3种.模式标本保存于北京微生物流行病研究所医学昆虫标本馆.

  2. Gall midge attack intensity and host-plant response in a Neotropical coastal ecosystem Intensidade do parasitismo de inseto galhador e resposta da planta hospedeira em um ecossistema neotropical costeiro

    Directory of Open Access Journals (Sweden)

    Pedro de Araujo Lima Constantino

    2009-01-01

    Full Text Available The gall inducer Clusiamyia nitida Maia, 1996 (Diptera, Cecidomyiidae often infests the shrub Clusia lanceolata (Camb. (Clusiaceae in the Neotropical vegetation of restinga of Rio de Janeiro State, Brazil. Leaves of Clusia lanceolata host up to 20 spheroid galls and show variation in their shape. We aimed to evaluate the effect of gall's intensity on leaves of Clusia lanceolata, and the extension of gall's impact on adjacent non-galled leaves. We analyzed the effect of the number of galls on leaf area, biomass, specific area and leaf appearance from 509 leaves of 14 individual plants. The results showed that differences of individual plants, pairs of leaves, and gall presence were responsible for more then 90% of variation on infested leaves. Variation on parasitic intensity level created differences in leaf response. Under moderate gall attack characterized by scattered galls on a leaf, the increase of the number of galls caused an increase of leaf biomass and area, and a decrease of specific area. The specific area was smaller also under high attack intensity, characterized by coalescent galls on a leaf. In those cases of extremely high parasitic intensity, galled leaves became deformed and the surface area was severely reduced. Leaf deformation due to gall attack led to early leaf abscission, indicated by the 90% of deformed leaves found in the youngest leaf pair of the branch. There was insufficient evidence that the impact of galls on leaf morpho-physiological parameters extended beyond the attacked leaves, because ungalled leaves did not change significantly when their opposite leaf had been galled.O inseto galhador Clusiamyia nitida, 1996 (Diptera, Cecidomyiidae freqüentemente infesta o arbusto Clusia lanceolata (Camb. (Clusiaceae na vegetação Neotropical de restinga do Estado do Rio de Janeiro. As folhas de Clusia lanceolata hospedam até 20 galhas esferóides e apresentam variações em sua forma. Buscamos avaliar o efeito da intensidade de galhas nas folhas de Clusia lanceolata, e a extensão do impacto de galhas em folhas adjacentes não-galhadas. Analisamos o efeito do número de galhas sobre a área foliar, biomassa, área específica e aparência foliar de 509 folhas de 14 indivíduos. Os resultados indicaram que diferenças individuais entre plantas, nos pares de folhas e na presença de galhas, foram responsáveis por mais de 90% de variação entre folhas infestadas. A variação na intensidade de parasitismo criou diferenças de resposta foliar. Sob ataque moderado, caracterizado pela presença de galhas esparsas nas folhas, o aumento do número de galhas provocou o aumento de biomassa e área foliar e a diminuição da área específica. A área específica também foi menor sob ataque de alta intensidade, caracterizado por galhas unidas. Nos casos de parasitismo extremo, as folhas galhadas tornaram-se deformadas, apresentando a superfície foliar severamente reduzida. A deformação das folhas geradas pela presença de galhas provocou abscisão precoce, indicada pelos 90% de folhas deformadas encontradas apenas nos pares mais jovens de folhas. Não houve evidencias suficientes que indicassem o impacto das galhas em parâmetros morfo-fisiológicos além das folhas atacadas, já que folhas não galhadas não sofreram alterações quando opostas a folhas galhadas.

  3. Cationic Lipid-Formulated DNA Vaccine against Hepatitis B Virus : Immunogenicity of MIDGE-Th1 Vectors Encoding Small and Large Surface Antigen in Comparison to a Licensed Protein Vaccine

    NARCIS (Netherlands)

    Endmann, Anne; Klunder, Katharina; Kapp, Kerstin; Riede, Oliver; Oswald, Detlef; Talman, Eduard G.; Schroff, Matthias; Kleuss, Christiane; Ruiters, Marcel H. J.; Juhls, Christiane

    2014-01-01

    Currently marketed vaccines against hepatitis B virus (HBV) based on the small (S) hepatitis B surface antigen (HBsAg) fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible

  4. Studies on the Occurring Characteristics and Control Methods of Chestnut Gall Midge in Pinggu County%平谷县栗瘿蜂发生特点及防治方法探讨

    Institute of Scientific and Technical Information of China (English)

    郭永旺; 丁建云; 马淑英; 王永祥; 龚禹峰

    2001-01-01

    @@ 栗瘿蜂(Dryocosmus kuriphilus Yasumatus)又名栗瘤蜂,属膜翅目瘿蜂科,是板栗生产上的主要害虫之一.曾于20世纪70年代末80年代初在北京地区暴发成灾.1999~2000年平谷县又有约3 333 hm2板栗发生栗瘿蜂为害.1999年调查,6~10年生树被害株率达96%,10年生以上的树达100%,6年生以下的树受害较轻.为害严重的栗树几乎绝产,大部分栗树上果枝受害达70%以上,受害较轻的栗树达30%左右.并且随着树龄的增长,受害程度也越重.

  5. Attack behavior of junior midge school students of violent online games addictive disorder%暴力网络游戏成瘾初中生攻击行为的特征研究

    Institute of Scientific and Technical Information of China (English)

    孙月吉; 周世昱; 董颖; 林媛; 阎楠; 王娜; 徐福山; 郑亚; 徐国庆; 李娜

    2011-01-01

    Objective To discuss some characteristics of aggressive behavior of junior middle school students addicted to violence online game.Methods From Aug.to Dec.at 2009,6000 volunteers have been investigated with the self-made violence online game survey scale and the Chen's were screen out by CIAS,and in which 71 violence game addicts,and 66 entertainment game addicts.They were divided into two groups matched as age and sex(male 55 and female 11 in every group),average age was 14.36±0.81 years old.66 no-play game students served as control group.The mean value and standard deviation of aggressive behaviors in each group were compared with one way ANOVA with SPSS12.0 version.Results There were significant different inter groups in the behavioral scores expressed in physiological attack((21.59±4.36),(18.10±6.10,(14.92±5.61)),spoken language attack((21.04±3.98),(18.36±6.26),(15.66±5.23)),angry mood((21.37±4.43),(18.72±5.90),(16.56±5.70)),hostility cognition((21.69±5.77),(20.06±7.74),(16.39±6.85))and the total score((85.56±13.71),(75.28±22.36),(63.54±20.32))(F1-4=25.07,17.35,3.25,10.40,21.81);Moat severity attack behaviors were observed in the violence online game addictive group,but less done in other two groups(t1-4=3.48,2.68,2.65,10.27,P<0.01;t 1-5=6.66,5.37,4.48,5.30,22.01,P<0.01);and secondary was found in Entertainment online game addicts(t1-5:3.18,2.69,2.16,3.66,11.74,P<0.01).Conclusion Higher attack behavior scores are found in the violence online game in junior middle students,and entertainment online game also induce attack behavior,but is not so notable.%目的 探讨游戏成瘾初中生攻击行为特点.方法 2008年8~12月随机整群抽取大连市4区8所初中6000名学生为调查对象,采用自制网络游戏调查表和陈氏网络成瘾量表(CIAS)筛查出149名(2.5%)网络游戏成瘾初中生为研究对象,其中暴力游戏成瘾者71名,娱乐游戏成瘾者66名.匹配两组性别与年龄,最终两组入组学生都是66名,男性55名,女性11名,平均年龄(14.36±0.81)岁;非网络游戏成瘾组,按着性别和年龄匹配原则,随机抽出66名初中生.3组初中生都接受了攻击量表(AQ)评估.统计分析采用SPSS12.0版本软件包,对于3组游戏成瘾的攻击行为进行单因素方差分析(ANOVA).结果 在生理攻击[(21.59±4.36)分,(18.10±6.10)分,(14.92±5.61)分]、言语攻击[(21.04±3.98)分,(18.36±6.26)分,(15.66±5.23)分]、愤怒情绪[(21.37±4.43)分,(18.72±5.90)分,(16.56±5.70)分]、敌意认知[(21.69±5.77)分,(20.06±7.74)分,(16.39±6.85)分]和总分上[(85.56±13.71)分,(75.28±22.36)分,(63.54±20.32)分]上三组间差异显著(F1.4=25.07,17.35,3.25,10.40,21.81;P<0.01);暴力网络游戏成瘾与娱乐网络游戏成瘾组间,在生理攻击、言语攻击、愤怒情绪和总分上差异显著(t1-4=3.48,2.68,2.65,10.27,P<0.01).在4个因子和总分上,暴力网络游戏成瘾组明显高于非游戏组(t1-5=6.66,5.37,4.48,5.30,22.01,P<0.01),娱乐网络游戏成瘾组明显高于非游戏组(t1-5=3.18,2.69,2.16,3.66,11.74,P<0.01).结论 暴力网络游戏成瘾初中生攻击行为增加,娱乐网络游戏虽然也增加初中生攻击行为,但程度较轻.

  6. A new genus and species of gall midge (Diptera, Cecidomyiidae associated with Parkia pendula (Fabaceae, Mimosoideae Um novo gênero e espécie de mosquito galhador (Diptera: Cecidomyiidae associado com Parkia pendula (Fabaceae, Mimosoideae

    Directory of Open Access Journals (Sweden)

    Valéria Cid Maia

    2006-03-01

    Full Text Available Parkiamyia paraensis, a new genus and species of Cecidomyiidae that induces galls on Parkia pendula is described (larva, pupa, male,female and gall based on material from Pará (Brazil.Parkiamyia paraensis, um novo gênero e espécie de Cecidomyiidae é descrita (larva, pupa, macho e fêmea com base em material do Pará (Brasil.

  7. A simple trapping method to estimate abundances of blood-sucking flying insects in avian nests

    NARCIS (Netherlands)

    Tomás, G.; Merino, S.; Martínez-de la Puente, J.; Moreno, J.; Morales, J.; Lobato, E.

    2008-01-01

    [KEYWORDS: birds; biting midges; blackflies; blood parasite-insect vector-vertebrate host relationships; Ceratopogonidae; Culicoides; distance to water sources; insecticide treatment; sampling methods; Simuliidae

  8. ¿Alcoholismo en Galicia: un camiño sen esperanza?

    OpenAIRE

    Folgar de la Calle, José María; Martín Sánchez, Rita

    2012-01-01

    O alcoholismo en Galicia é un mal endémico, polo que os enfermos non son considerados marxi­ nados. Os dous filmes que comentamos tentan chamar a atención e concienciar á sociedade sobre o carácter atípico deste problema.

  9. Trait-based modelling of bioaccumulation by freshwater benthic invertebrates

    NARCIS (Netherlands)

    Sidney, L.A.; Diepens, N.J.; Guo, X.; Koelmans, A.A.

    2016-01-01

    Understanding the role of species traits in chemical exposure is crucial for bioaccumulation and toxicity assessment of chemicals. We measured and modelled bioaccumulation of polychlorinated biphenyls (PCBs) in Chironomus riparius, Hyalella azteca, Lumbriculus variegatus and Sphaerium corneum. We us

  10. Trait-based modelling of bioaccumulation by freshwater benthic invertebrates

    NARCIS (Netherlands)

    Sidney, L.A.; Diepens, N.J.; Guo, X.; Koelmans, A.A.

    2016-01-01

    Understanding the role of species traits in chemical exposure is crucial for bioaccumulation and toxicity assessment of chemicals. We measured and modelled bioaccumulation of polychlorinated biphenyls (PCBs) in Chironomus riparius, Hyalella azteca, Lumbriculus variegatus and Sphaerium corneum. We

  11. Evidence for Culicoides obsoletus group as vector for Schmallenberg virus in Denmark

    DEFF Research Database (Denmark)

    Rasmussen, Lasse Dam; Kristensen, Birgit; Kirkeby, Carsten

    the Bunyaviridae family and is closely related to Shamonda and Akabane viruses. These viruses are transmitted by insect vectors (including biting midges (Culicoides sp.) and mosquitoes). To determine whether these insects may act as vectors for SBV, biting midges (Culicoides spp.) caught in October 2011...

  12. Dasineura odoratae new to Denmark and new records of the rare Mayetiola hellwigi

    DEFF Research Database (Denmark)

    Bruun, Hans Henrik; Skuhravá, Marcela

    2011-01-01

    We report the first documented records of the gall midge Dasineura odoratae Stelter, based on adults reared from galls on the single host plant of the species, Viola odorata. We also report Aphanogmus abdominalis (Thomson) (Hymenoptera: Ceraphronidae) as a parasitoid of this gall midge. In addition...

  13. Rational Selection of Tailored Amendment Mixtures and Composites for In Situ Remediation of Contaminated Sediments

    Science.gov (United States)

    2008-12-01

    toxicity observed for Thiol-SAMMS was moderate at a dose of 5% by dry weight with a reduction in H. Azteca survival from 98% to 73%. Although Thiol...arenaceodentata, Chironomus dilutus, Hyalella Azteca and Leptocheirus plumulosus. Tests were conducted as described in existing chronic sediment toxicity test...illustrates the survival of three benthic organisms (Chironomus dilutus (a), Hyalella Azteca (b) and Leptocheirus plumulosus(c) in the amendment treated

  14. Possible over-wintering of bluetongue virus in Culicoides populations in the Onderstepoort area, Gauteng, South Africa

    Directory of Open Access Journals (Sweden)

    Jumari Steyn

    2016-02-01

    Full Text Available Several studies have demonstrated the ability of certain viruses to overwinter in arthropod vectors. The over-wintering mechanism of bluetongue virus (BTV is unknown. One hypothesis is over-wintering within adult Culicoides midges (Diptera; Ceratopogonidae that survive mild winters where temperatures seldom drop below 10 °C. The reduced activity of midges and the absence of outbreaks during winter may create the impression that the virus has disappeared from an area. Light traps were used in close association with horses to collect Culicoides midges from July 2010 to September 2011 in the Onderstepoort area, in Gauteng Province, South Africa. More than 500 000 Culicoides midges were collected from 88 collections and sorted to species level, revealing 26 different Culicoides species. Culicoides midges were present throughout the 15 month study. Nine Culicoides species potentially capable of transmitting BTV were present during the winter months. Midges were screened for the presence of BTV ribonucleic acid (RNA with the aid of a real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR assay. In total 91.2% of midge pools tested positive for BTV RNA. PCR results were compared with previous virus isolation results (VI that demonstrated the presence of viruses in summer and autumn months. The results indicate that BTV-infected Culicoides vectors are present throughout the year in the study area. Viral RNA-positive midges were also found throughout the year with VI positive midge pools only in summer and early autumn. Midges that survive mild winter temperatures could therefore harbour BTV but with a decreased vector capacity. When the population size, biting rate and viral replication decrease, it could stop BTV transmission. Over-wintering of BTV in the Onderstepoort region could therefore result in re-emergence because of increased vector activity rather than reintroduction from outside the region.

  15. Lake to land subsidies: experimental addition of aquatic insects increases terrestrial arthropod densities.

    Science.gov (United States)

    Hoekman, David; Dreyer, Jamin; Jackson, Randall D; Townsend, Philip A; Gratton, Claudio

    2011-11-01

    Aquatic insects are a common and important subsidy to terrestrial systems, yet little is known about how these inputs affect terrestrial food webs, especially around lakes. Mývatn, a lake in northern Iceland, has extraordinary midge (Chironomidae) emergences that result in large inputs of biomass and nutrients to terrestrial arthropod communities. We simulated this lake-to-land resource pulse by collecting midges from Mývatn and spreading their dried carcasses on 1-m2 plots at a nearby site that receives very little midge deposition. We hypothesized a positive bottom-up response of detritivores that would be transmitted to their predators and would persist into the following year. We sampled the arthropod community once per month for two consecutive summers. Midge addition resulted in significantly different arthropod communities and increased densities of some taxa in both years. Detritivores, specifically Diptera larvae, Collembola, and Acari increased in midge-addition plots, and so did some predators and parasitoids. Arthropod densities were still elevated a year after midge addition, and two years of midge addition further increased the density of higher-order consumers (e.g., Coleoptera and Hymenoptera). Midge addition increased arthropod biomass by 68% after one year and 108% after two years. By manipulating the nutrient pulse delivered by midges we were able to elucidate food web consequences of midge deposition and spatial and temporal dynamics that are difficult to determine based on comparative approaches alone. Resources cross ecosystem boundaries and are assimilated over time because of life-history strategies that connect aquatic and terrestrial food webs and these systems cannot be fully understood in isolation from each other.

  16. Dyes removal of textile wastewater onto surfactant modified zeolite from coal ash and evaluation of the toxic effects; Remocao de corantes de efluente textil por zeolita de cinzas de carvao modificada por surfactante e avaliacao dos efeitos toxicos

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Patricia Cunico

    2015-07-01

    Zeolites synthesized from fly and bottom ashes and modified with hexadecyltrimethylammonium (HDTMA) were used as adsorbent to remove dyes - Solophenyl Navy (SN) and Solophenyl Turquoise (ST) and their hydrolysed forms Solophenyl Navy Hydrolysed (SNH) and Solophenyl Turquoise Hydrolysed (STH), from simulated textile wastewater. The HDTMA-modified fly zeolite (ZMF) and HDTMA-modified bottom zeolite (ZMB) were characterized by different techniques, as X-ray fluorescence spectrometry, X-ray diffraction and scanning electron microscopy, etc. The ZMF and ZMB presented negative charge probably due to the formation of a partial bilayer of HDTMA on exchangeable active sites on the external surface of unmodified zeolite. Initial dye concentration, contact time and equilibrium adsorption were evaluated. The adsorption kinetic for SN, ST, SNH and STH onto the zeolites followed the pseudo second-order model. The equilibrium time was 20 min for SN and ST and 30 min for SNH and STH, respectively. Langmuir, Freundlich and Temkin models were applied to describe the adsorption isotherms. Adsorption of the dyes were best described by the Langmuir model, with exception to SN/ZPM, SNH/ZPM and SNH/ZLM systems that followed Freundlich model. The maximum adsorption capacities were 3,64; 3,57; 2,91 e 4,93 for SN, ST, SNH e STH by ZLM, respectively and 0,235; 0,492; 1,26 e 1,86 by ZPM, in this order. The best performance for hydrolyzed dyes has been attributed to reduction of the size of dyes molecules during the hydrolysis process. Acute toxicity of the dyes to a different organism were evaluated by different test-organisms. Waterflea, Ceriodaphnia dubia showed EC50 value of 1,25; 54,5; 0,78 and 2,56 mgL{sup -1} for SN, ST, SNH and STH, respectively. The plant Lemna minor showed EC50 values of 18,9; 69,4; 10,9 and 70,9 mgL{sup -1} for SN, ST, SNH and STH, respectively. Midges larvae of Chironomus tepperi showed EC50 values of 119 and 440 mgL{sup -1} for SN and ST, respectively. Regarding

  17. The effect of high frequency sound on Culicoides numbers collected with suction light traps

    Directory of Open Access Journals (Sweden)

    Gert J. Venter

    2012-04-01

    Full Text Available Culicoides midges (Diptera: Ceratopogonidae, are involved in the transmission of various pathogens that cause important diseases of livestock worldwide. The use of insect repellents to reduce the attack rate of these insects on livestock could play an important role as part of an integrated control programme against diseases transmitted by these midges. The objective of this study was to determine whether high frequency sound has any repellent effect on Culicoides midges. The number of midges collected with 220 V Onderstepoort white light traps fitted with electronic mosquito repellents (EMRs, emitting 5-20 KHz multi-frequency sound waves, was compared with that of two untreated traps. Treatments were rotated in two replicates of a 4 x 4 randomised Latin square design. Although fewer midges were collected in the two traps fitted with EMRs, the average number collected over eight consecutive nights was not significantly different. The EMRs also had no influence on any of the physiological groups of Culicoides imicola Kieffer or the species composition of the Culicoides population as determined with light traps. The results indicate that high frequency sound has no repellent effect on Culicoides midges. There is therefore no evidence to support their promotion or use in the protection of animals against pathogens transmitted by Culicoides midges.

  18. Ecosystem linkages revealed by experimental lake-derived isotope signal in heathland food webs.

    Science.gov (United States)

    Hoekman, David; Bartrons, Mireia; Gratton, Claudio

    2012-11-01

    Cross-ecosystem movement of nutrients and biomass can have important effects on recipient systems. Emerging aquatic insects are subsidies to terrestrial ecosystems and can influence foodweb interactions in riparian systems. In a 2-year field experiment, we simulated aquatic insect deposition by adding adult midge carcasses (150 g dry mass m(-2) year(-1)) to 1-m(2) heathland plots at a site with low natural midge deposition. We established four levels of midge-addition treatments and measured stable isotopes (δ(13)C and δ(15)N) in plants and arthropods within each treatment. We used a multiple-source isotope Bayesian mixing model to estimate the terrestrial versus aquatic contribution to the diets of arthropods. Aquatic resources were incorporated into plant, detritivore, and predator biomass. Detritivorous Collembola showed the greatest difference in isotope values (+3 ‰ δ(15)N and +4 ‰ δ(13)C) between midge-addition and reference treatments. Isotope values of small spiders followed the same trend of enrichment as Collembola while other arthropods (mites and large spiders) were only enriched after 2 years of midge addition. Although predator diets did not change, they became isotopically enriched via their likely prey (Collembola). Plants also had elevated δ(15)N (+1 ‰) in midge-addition treatments. The time required and amount of midge-derived C and N detected varied and depended on trophic position. Midge-derived nutrients were no longer present in arthropod biomass in the year following midge addition. Aquatic insect carcasses can be rapidly incorporated into terrestrial food webs in nearshore habitats, and repeated inputs can be detected at multiple trophic levels, thus highlighting the importance of the detrital pathway for aquatic to terrestrial cross-ecosystem subsidies.

  19. Galmyg i Odsherred – fem års systematisk lokal faunaundersøgelse

    DEFF Research Database (Denmark)

    Bruun, Hans Henrik

    2015-01-01

    -urban with summer cottages. One such cottage lot with natural vegetation has made up the geographical center of gravity of the investigation. During 114 days, a total of 114 species of gall midges have been found. Of these, 91 species were hitherto unknow to the faunistic district, including seven new......A systematic survey was undertaken of the fauna of phytophagous gall midges (Diptera: Cecidomyiidae: Cecidomyiinae) in a restricted area around Fårevejle in NW Zealand. Plant species occurring in the area were scrutinized for galling and non-galling gall midges based on knowledge of associated host...

  20. New Plasmid Tools for Genetic Analysis of Actinobacilus pleuropneumoniae and Other Pasteurellaceae

    National Research Council Canada - National Science Library

    Janine T Bossé; Andrew L Durham; Andrew N Rycroft; J Simon Kroll; Paul R Langford

    2009-01-01

      We have generated a set of plasmids, based on the mobilizable shuttle vector pMIDG100, which can be used as tools for genetic manipulation of Actinobacillus pleuropneumoniae and other members of the Pasteurellaceae...

  1. Molecular cloning and expression analysis of an ecdysone receptor (EcR) gene in the wheat midge, Sitodiplosis mosellana (Diptera: Cecidomyiidae)%麦红吸浆虫蜕皮激素受体(EcR)基因的克隆与表达分析

    Institute of Scientific and Technical Information of China (English)

    马康生; 李伯辽; 陈浩; 仵均祥

    2013-01-01

    In order to study the function of ecdysone receptor in the diapause of Sitodiplosis mosellana,the full-length cDNA sequence of an ecdysone receptor gene was amplified by using reverse transcriptionpolymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE),and the expression of the EcR gene was analyzed using real-time quantitative PCR (qPCR).The full-length cDNA sequence was named as SmEcR (GenBank accession number:KC491135).Its open reading frame (ORF) is 1 386 bp in length,encoding a 461-amino-acid protein,with a calculated molecular weight of 52.90 kD and the theoretical isoelectric point of 6.24.Multiple sequence alignment revealed that the deduced amino acid sequence of SmEcR has high identity with EcRs from other insect species,especially with that of Bradysia coprophila (92%).Real-time quantitative PCR showed that SmEcR transcripts were detected in all diapause and developmental stages.The expression of SmEcR was significantly different among different diapause stages,reaching the highest level in November and the lowest level in December.The larvae collected from wheat heads had a lower expression level of SmEcR while the adults had the highest SmEcR transcripts.This study lays the foundation for the further functional study of SmEcR in diapause regulation in S.mosellana.%为了研究蜕皮激素受体(EcR)在麦红吸浆虫Sitodiplosis mosellana (Géhin)滞育活动中的作用,利用RT-PCR和RACE技术克隆得到了麦红吸浆虫蜕皮激素受体基因cDNA全长,并通过Real-time quantitative PCR研究了其表达情况.该cDNA全长序列被命名为SmEcR(GenBank登录号:KC491135),其开放阅读框长1 386 bp,编码461个氨基酸残基.其蛋白预测分子量52.90 kD,理论等电点6.24.该蛋白与其他已报道的昆虫EcR蛋白具有很高的同源性,其中与迟眼蕈蚊Bradysia coprophila中相应蛋白的氨基酸序列一致性高达92%.SmEcR在麦红吸浆虫不同滞育时期和不同虫态中均有表达,且在不同滞育时期、不同虫态中的表达量差异很大.在滞育不同时期以11月表达量最高,12月表达量最低;在不同虫态以麦穗幼虫中的表达量较低,而成虫中的表达水平很高.本研究为进一步明确SmEcR在麦红吸浆虫滞育调控中的作用奠定了基础.

  2. Formation Flight Control for Aerial Refueling

    Science.gov (United States)

    2006-03-01

    Microbiotics , Inc. The IMU data were recorded on a flight of a Cessna 172, and a representative time slice was reproduced for all of the simulations...nothing about. The final position relative Data Source: Flight Test MIDG II IMU Cessna 172 Microbiotics , Inc. 48 to the boom will obviously...Embedded PC ATH-400 Athena Diamond Systems, Inc GPS Receiver Card JNS100 OEM Javad Navigation Systems MEMS IMU MIDG II INS/GPS Microbiotics , Inc UHF

  3. Les porcheries : réservoirs des Culicoides (Diptera : Ceratopogonidae), vecteurs des virus de la Maladie de la Langue bleue et de Schmallenberg ?

    OpenAIRE

    Zimmer, JY.; Saegerman, C.; Martinelle, L.; Losson, B.; Leroy, P; Haubruge, E.; Francis, F.

    2014-01-01

    Pig farms: reservoirs of vectors of Bluetongue and Schmallenberg viruses?. Bluetongue (BT) is a vector-borne disease that affects domestic and wild ruminants. Since its recent outbreak in northern Europe, this viral disease has caused considerable economic losses. The biological vectors of the bluetongue virus are biting midges belonging to the genus Culicoides (Diptera: Ceratopogonidae). Several light trapping campaigns targeting these adult midges have been previously conducted in Belgium w...

  4. LIFE CYCLE AND PRODUCTION OF CHIRONOMIDAE(DIPTERA) IN BIANDANTANG, A TYPICAL MACROPHYTIC LAKE (HUBEI, CHINA)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The life cycle and annual production of four dominant species of Chironomids (Chironomus plumosus, Chironomus sp., Clinotanypus sp., Tokunagayusurika akamusi) were studied with samples taken monthly in Biandantang Lake at eight stations from April, 1996 to March, 1997. Instar-frequency data showed C. plumosus was univoltine, while the other three were bivoltine. Production in wet weight (g/(m2.a)) calculated by the size-frequency method for each species were: C. plumosus, 2.663; Chironomus sp.,1.161 ;Clinotanypus sp., 0.270; T. akamusi, 1.476. Based on the mean standing stock, their P/B ratios were 3.2, 4.0, 6.2 and 4.4, respectively.

  5. The suitability of the Triple trap for the collection of South African livestock-associated Culicoides species

    Directory of Open Access Journals (Sweden)

    Gert J. Venter

    2013-02-01

    Full Text Available The relatively large number of Culicoides midges (Diptera: Ceratopogonidae that can be collected with a light trap makes it the most widely used tool for this purpose. However, the majority of these traps were originally designed for collecting mosquitoes. The evaluation and improvement of traps to increase their effectiveness in collecting Culicoides midges will unavoidably form part of research on these insects. In the present study the efficiency of the Triple trap for collecting livestock-associated Culicoides midges was compared with that of the Onderstepoort 220 V, the BG-sentinel and the mini-CDC traps. A unique feature of the Triple trap is that selected surfaces are coated with TiO2 (titanium dioxide which, in the presence of ultra violet light, acts as a photo-catalyser to produce CO2, which in turn may attract blood-feeding insects. Overall, the Onderstepoort trap collected significantly higher numbers of midges than the others. Relative efficiency varied between different occasions and under some conditions, for example periods with low midge abundance during the winter, the mean numbers collected with the Triple trap did not differ significantly from those of the Onderstepoort or BG-sentinel traps. By replacing the collection chamber of the Triple trap with a sock and beaker, similar to that of the Onderstepoort trap, it can effectively be used for the collection of Culicoides midges.

  6. An Asiatic Chironomid in Brazil: morphology, DNA barcode and bionomics

    Directory of Open Access Journals (Sweden)

    Gizelle Amora

    2015-07-01

    Full Text Available In most freshwater ecosystems, aquatic insects are dominant in terms of diversity; however, there is a disproportionately low number of records of alien species when compared to other freshwater organisms. The Chironomidae is one aquatic insect family that includes some examples of alien species around the world. During a study on aquatic insects in Amazonas state (Brazil, we collected specimens of Chironomidae that are similar, at the morphological level, to Chironomus kiiensis Tokunaga and Chironomus striatipennis Kieffer, both with distributions restricted to Asia. The objectives of this study were to provide morphological information on this Chironomus population, to investigate its identity using DNA barcoding and, to provide bionomic information about this species. Chironomus DNA barcode data were obtained from GenBank and Barcode of Life Data Systems (BOLD and, together with our data, were analyzed using the neighbor-joining method with 1000 bootstrap replicates and the genetic distances were estimated using the Kimura-2-parameter. At the morphological level, the Brazilian population cannot be distinguished either from C. striatipennis or C. kiiensis, configuring a species complex but, at the molecular level our studied population is placed in a clade together with C. striatipennis, from South Korea. Bionomic characteristics of the Brazilian Chironomus population differ from the ones of C. kiiensis from Japan, the only species in this species complex with bionomic information available. The Brazilian Chironomus population has a smaller size, the double of the number of eggs and inhabits oligotrophic water, in artificial container. In the molecular analysis, populations of C. striatipennis and C. kiiensis are placed in a clade, formed by two groups: Group A (which includes populations from both named species, from different Asiatic regions and our Brazilian population and Group B (with populations of C. kiiensis from Japan and South Korea

  7. Culicoides species abundance and potential over-wintering of African horse sickness virus in the Onderstepoort area, Gauteng, South Africa

    Directory of Open Access Journals (Sweden)

    Gert J. Venter

    2014-02-01

    Full Text Available In South Africa, outbreaks of African horse sickness (AHS occur in summer; no cases are reported in winter, from July to September. The AHS virus (AHSV is transmitted almost exclusively by Culicoides midges (Diptera: Ceratopogonidae, of which Culicoides imicola is considered to be the most important vector. The over-wintering mechanism of AHSV is unknown. In this study, more than 500 000 Culicoides midges belonging to at least 26 species were collected in 88 light traps at weekly intervals between July 2010 and September 2011 near horses in the Onderstepoort area of South Africa. The dominant species was C. imicola. Despite relatively low temperatures and frost, at least 17 species, including C. imicola, were collected throughout winter (June–August. Although the mean number of midges per night fell from > 50 000 (March to < 100 (July and August, no midge-free periods were found. This study, using virus isolation on cell cultures and a reverse transcriptase polymerase chain reaction (RT-PCR assay, confirmed low infection prevalence in field midges and that the detection of virus correlated to high numbers. Although no virus was detected during this winter period, continuous adult activity indicated that transmission can potentially occur. The absence of AHSV in the midges during winter can be ascribed to the relatively low numbers collected coupled to low infection prevalence, low virus replication rates and low virus titres in the potentially infected midges. Cases of AHS in susceptible animals are likely to start as soon as Culicoides populations reach a critical level.

  8. The effects of bioturbation on nutrient fluxes in lakes subjected to lake restoration

    DEFF Research Database (Denmark)

    Kristensen, Thomas Boll; Reitzel, Kasper; Andersen, Frede Østergaard;

    ) and cores from areas with and areas without an Al layer in Lake Nordborg with benthic macroinvertebrates in natural densities and "natural densities + 2800 Chironomus plumosus m-2" we are investigating the effects of benthic macroinvertebrates on nutrient fluxes and their influence on the effectiveness...

  9. Dicty_cDB: AFA166 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available salis histone H1-I gene, complete cds. 40 5.7 1 BZ436366...A Eimeria tenella cDNA 5' similar to TR:O89068 O89068 RIBOSOMAL PROTEIN S3 ;, mRNA sequence. 32 2.8 2 U21211 |U21211.1 Chironomus dor

  10. Page 1 Tropical Freshwater Biology, 12/13 (2003/2004) 25-33 25 ...

    African Journals Online (AJOL)

    Key Words: Aquatic insects, fish food, water quality, southern Nigeria. ... the larvae and nymphs of these invertebrates are herbivorous and carnivorous .... Culex sp. 6 (7.32) ap 6 (4.35). Chironomus fractilobus Kieffer 2 (3.57) 2 (1.45).

  11. Genetic characterization and molecular identification of the bloodmeal sources of the potential bluetongue vector Culicoides obsoletus in the Canary Islands, Spain

    Directory of Open Access Journals (Sweden)

    Martínez-de la Puente Josué

    2012-07-01

    Full Text Available Abstract Background Culicoides (Diptera: Ceratopogonidae biting midges are vectors for a diversity of pathogens including bluetongue virus (BTV that generate important economic losses. BTV has expanded its range in recent decades, probably due to the expansion of its main vector and the presence of other autochthonous competent vectors. Although the Canary Islands are still free of bluetongue disease (BTD, Spain and Europe have had to face up to a spread of bluetongue with disastrous consequences. Therefore, it is essential to identify the distribution of biting midges and understand their feeding patterns in areas susceptible to BTD. To that end, we captured biting midges on two farms in the Canary Islands (i to identify the midge species in question and characterize their COI barcoding region and (ii to ascertain the source of their bloodmeals using molecular tools. Methods Biting midges were captured using CDC traps baited with a 4-W blacklight (UV bulb on Gran Canaria and on Tenerife. Biting midges were quantified and identified according to their wing patterns. A 688 bp segment of the mitochondrial COI gene of 20 biting midges (11 from Gran Canaria and 9 from Tenerife were PCR amplified using the primers LCO1490 and HCO2198. Moreover, after selected all available females showing any rest of blood in their abdomen, a nested-PCR approach was used to amplify a fragment of the COI gene from vertebrate DNA contained in bloodmeals. The origin of bloodmeals was identified by comparison with the nucleotide-nucleotide basic alignment search tool (BLAST. Results The morphological identification of 491 female biting midges revealed the presence of a single morphospecies belonging to the Obsoletus group. When sequencing the barcoding region of the 20 females used to check genetic variability, we identified two haplotypes differing in a single base. Comparison analysis using the nucleotide-nucleotide basic alignment search tool (BLAST showed that both

  12. Inducing RNA interference in the arbovirus vector, Culicoides sonorensis.

    Science.gov (United States)

    Mills, M K; Nayduch, D; Michel, K

    2015-02-01

    Biting midges in the genus Culicoides are important vectors of arboviral diseases, including epizootic haemorrhagic disease, bluetongue and most likely Schmallenberg, which cause significant economic burdens worldwide. Research on these vectors has been hindered by the lack of a sequenced genome, the difficulty of consistent culturing of certain species and the absence of molecular techniques such as RNA interference (RNAi). Here, we report the establishment of RNAi as a research tool for the adult midge, Culicoides sonorensis. Based on previous research and transcriptome analysis, which revealed putative small interfering RNA pathway member orthologues, we hypothesized that adult C. sonorensis midges have the molecular machinery needed to perform RNA silencing. Injection of control double-stranded RNA targeting green fluorescent protein (dsGFP), into the haemocoel of 2-3-day-old adult female midges resulted in survival curves that support virus transmission. dsRNA injection targeting the newly identified C. sonorensis inhibitor of apoptosis protein 1 (CsIAP1) orthologue resulted in a 40% decrease of transcript levels and 73% shorter median survivals as compared with dsGFP-injected controls. These results reveal the conserved function of IAP1. Importantly, they also demonstrate the feasibility of RNAi by dsRNA injection in adult midges, which will greatly facilitate studies of the underlying mechanisms of vector competence in C. sonorensis.

  13. Light and noise pollution interact to disrupt interspecific interactions.

    Science.gov (United States)

    McMahon, Taegan A; Rohr, Jason R; Bernal, Ximena E

    2017-05-01

    Studies on the consequences of urbanization often examine the effects of light, noise, and heat pollution independently on isolated species providing a limited understanding of how these combined stressors affect species interactions. Here, we investigate how these factors interact to affect parasitic frog-biting midges (Corethrella spp.) and their túngara frog (Engystomops pustulosus) hosts. A survey of túngara frog calling sites revealed that frog abundance was not significantly correlated with urbanization, light, noise, or temperature. In contrast, frog-biting midges were sensitive to light pollution and noise pollution. Increased light intensity significantly reduced midge abundance at low noise levels. At high noise intensity, there were no midges regardless of light level. Two field experiments controlling light and noise levels to examine attraction of the midges to their host and their feeding behavior confirmed the causality of these field patterns. These findings demonstrate that both light and noise pollution disrupt this host-parasite interaction and highlight the importance of considering interactions among species and types of pollutants to accurately assess the impacts of urbanization on ecological communities. © 2017 by the Ecological Society of America.

  14. Assessment of the repellent effect of citronella and lemon eucalyptus oil against South African Culicoides species.

    Science.gov (United States)

    Venter, Gert J; Labuschagne, Karien; Boikanyo, Solomon N B; Morey, Liesl

    2014-08-08

    The use of insect repellents to reduce the attack rate of Culicoides species (Diptera:Ceratopogonidae) should form part of an integrated control programme to combat African horse sickness and other diseases transmitted by these blood-feeding midges. In the present study the repellent effects of a commercially available mosquito repellent, a combination of citronella and lemon eucalyptus oils, on Culicoides midges was determined. The number of midges collected with two 220 V Onderstepoort traps fitted with 8 W 23 cm white light tubes and baited with peel-stick patches, each containing 40 mg of active ingredient, was compared with that of two unbaited traps. Two trials were conducted and in each trial the four traps were rotated in two replicates of a 4 x 4 randomised Latin square design. Although more midges were collected in the baited traps, the mean number in the baited and unbaited traps was not significantly different. This mosquito repellent did not influence either the species composition or the physiological groups of Culicoides imicola Kieffer. The higher mean numbers in the baited traps, although not statistically significant, may indicate that this mosquito repellent might even attract Culicoides midges under certain conditions.

  15. Assessment of the repellent effect of citronella and lemon eucalyptus oil against South African Culicoides species

    Directory of Open Access Journals (Sweden)

    Gert J. Venter

    2014-02-01

    Full Text Available The use of insect repellents to reduce the attack rate of Culicoides species (Diptera:Ceratopogonidae should form part of an integrated control programme to combat Africanhorse sickness and other diseases transmitted by these blood-feeding midges. In the presentstudy the repellent effects of a commercially available mosquito repellent, a combinationof citronella and lemon eucalyptus oils, on Culicoides midges was determined. The numberof midges collected with two 220 V Onderstepoort traps fitted with 8 W 23 cm white lighttubes and baited with peel-stick patches, each containing 40 mg of active ingredient, wascompared with that of two unbaited traps. Two trials were conducted and in each trial thefour traps were rotated in two replicates of a 4 x 4 randomised Latin square design. Althoughmore midges were collected in the baited traps, the mean number in the baited and unbaitedtraps was not significantly different. This mosquito repellent did not influence either thespecies composition or the physiological groups of Culicoides imicola Kieffer. The highermean numbers in the baited traps, although not statistically significant, may indicate that thismosquito repellent might even attract Culicoides midges under certain conditions.

  16. Culicoides monitoring in Belgium in 2011: analysis of spatiotemporal abundance, species diversity and Schmallenberg virus detection.

    Science.gov (United States)

    DE Regge, N; DE Deken, R; Fassotte, C; Losson, B; Deblauwe, I; Madder, M; Vantieghem, P; Tomme, M; Smeets, F; Cay, A B

    2015-09-01

    In 2011, Culicoides (Diptera: Ceratopogonidae) were collected at 16 locations covering four regions of Belgium with Onderstepoort Veterinary Institute (OVI) traps and at two locations with Rothamsted suction traps (RSTs). Quantification of the collections and morphological identification showed important variations in abundance and species diversity between individual collection sites, even for sites located in the same region. However, consistently higher numbers of Culicoides midges were collected at some sites compared with others. When species abundance and diversity were analysed at regional level, between-site variation disappeared. Overall, species belonging to the subgenus Avaritia together with Culicoides pulicaris (subgenus Culicoides) were the most abundant, accounting for 80% and 96% of all midges collected with RSTs and OVI traps, respectively. Culicoides were present during most of the year, with Culicoides obsoletus complex midges found from 9 February until 27 December. Real-time reverse-transcription polymerase chain reaction screening for Schmallenberg virus in the heads of collected midges resulted in the first detection of the virus in August 2011 and identified C. obsoletus complex, Culicoides chiopterus and Culicoides dewulfi midges as putative vector species. At Libramont in the south of Belgium, no positive pools were identified.

  17. Optimal vaccination strategies against vector-borne diseases

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Enøe, Claes; Bødker, Rene

    2014-01-01

    Using a process oriented semi-agent based model, we simulated the spread of Bluetongue virus by Culicoides, biting midges, between cattle in Denmark. We evaluated the minimum vaccination cover and minimum cost for eight different preventive vaccination strategies in Denmark. The simulation model...... replicates both a passive and active flight of midges between cattle distributed on pastures and cattle farms in Denmark. A seasonal abundance of midges and temperature dependence of biological processes were included in the model. The eight vaccination strategies were investigated under four different...... grazing conditions. Furthermore, scenarios were tested with three different index locations stratified for cattle density. The cheapest way to vaccinate cattle with a medium risk profile (less than 1000 total affected cattle) was to vaccinate cattle on pasture. Regional vaccination displayed better...

  18. Aquatic assessment of the Pike Hill Copper Mine Superfund site, Corinth, Vermont

    Science.gov (United States)

    Piatak, Nadine M.; Argue, Denise M.; Seal, Robert R.; Kiah, Richard G.; Besser, John M.; Coles, James F.; Hammarstrom, Jane M.; Levitan, Denise M.; Deacon, Jeffrey R.; Ingersoll, Christopher G.

    2013-01-01

    -based criteria are commonly lower values than the hardness-based criteria and thus suggest a greater degree or magnitude of impairment at the sampling locations. The riffle-habitat benthic invertebrate richness and abundance data correlate strongly with the extent of impact based on water quality for both brooks. Similarly, the fish community assessments document degraded conditions throughout most of Pike Hill Brook, whereas the data for the tributary to Cookville Brook suggest less degradation to this brook. The sediment environment shows similar extents of impairment to the surface-water environment, with most sampling locations in Pike Hill Brook, including the wetland areas, and the tributary to Cookville Brook affected. Sediment impairment is caused by elevated copper concentrations, although localized degradation due to elevated cadmium and zinc concentrations was documented on the basis of exceedances of probable effects concentrations (PECs). In contrast to impairment determined by exceedances of PECs, equilibrium-partitioning sediment benchmarks (based on simultaneously extracted metals, acid volatile sulfides, and total organic carbon) predict no toxic effects in sediments at the background locations and uncertain toxic effects throughout Pike Hill Brook and the tributary to Cookville Brook, with the exception of the most downstream Cookville Brook location, which indicated no toxic effects. Acute laboratory toxicity testing using the amphipod Hyalella azteca and the midge Chironomus dilutus on pore waters extracted from sediment in situ indicate impairment (based on tests with H. azteca) at only one location in Pike Hill Brook and no impairment in the tributary to Cookville Brook. Chronic laboratory sediment toxicity testing using H. azteca and C. dilutus indicated toxicity in Pike Hill Brook at several locations in the lower reach and two locations in the tributary to Cookville Brook. Toxicity was not indicated for either species in sediment from the most acidic

  19. Forcipomyia (Pterobosca) paludis (Macfie, 1936) (Diptera, Ceratopogonidae) on adult dragonflies (Odonata) in Sardinia, Italy.

    Science.gov (United States)

    Dell'Anna, L; Utzeri, C; Sabatini, A; Coluzzi, M

    1995-04-01

    Ceratopogonid midges, referred to Forcipomyia paludis, were recorded from five dragonfly species in Sardinia, Italy. All ceratopogonids were females and almost all were in the last phase of the gonotrophic cycle (gravid females). Although a parasitic association cannot be excluded, no evidence was obtained of the midge biting activity, neither by direct observation nor indirectly, by detecting the expected lesions on the host cuticle. The attachment to dragonflies of F. paludis (perhaps an autogenous species) might fit well with the hypothesis of a phoretic association which would favour the long range dispersal of the gravid females.

  20. The Parthenogenetic Cosmopolitan Chironomid, Paratanytarsus grimmii, as a New Standard Test Species for Ecotoxicology: Culturing Methodology and Sensitivity to Aqueous Pollutants.

    Science.gov (United States)

    Gagliardi, Bryant S; Long, Sara M; Pettigrove, Vincent J; Hoffmann, Ary A

    2015-09-01

    Chironomids from the genus Chironomus are widely used in laboratory ecotoxicology, but are prone to inbreeding depression, which can compromise test results. The standard Chironomus test species (C. riparius, C. dilutus and C. yoshimatsui) are also not cosmopolitan, making it difficult to compare results between geographic regions. In contrast, the chironomid Paratanytarsus grimmii is cosmopolitan, and not susceptible to inbreeding depression because it reproduces asexually by apomictic parthenogenesis. However, there is no standardised culturing methodology for P. grimmii, and a lack of acute toxicity data for common pollutants (metals and pesticides). In this study, we developed a reliable culturing methodology for P. grimmii. We also determined 24-h first instar LC50s for the metals Cu, Pb, Zn, Cd and the insecticide imidacloprid. By developing this culturing methodology and generating the first acute metal and imidacloprid LC50s for P. grimmii, we provide a basis for using P. grimmii in routine ecotoxicological testing.

  1. Enhanced Image-Aided Navigation Algorithm with Automatic Calibration and Affine Distortion Prediction

    Science.gov (United States)

    2012-03-01

    algorithm. . . . . . . . . . . . . . . 57 3.2 MIDG II MEMS -grade INS model. . . . . . . . . . . . . . . . . 58 3.3 Kalman filter state definitions...40 bb Gyroscope bias vector. . . . . . . . . . . . . . . . . . . . . 40 tnm Location of landmark m in the navigation frame. . . . . . 40...15 INS Inertial Navigation System . . . . . . . . . . . . . . . . . . 16 MEMS Micro Eletro-mechanical Systems

  2. Environmental statistical modelling of mosquito vectors at different geographical scales

    NARCIS (Netherlands)

    Cianci, D.

    2015-01-01

    Vector-borne diseases are infections transmitted by the bite of infected arthropod vectors, such as mosquitoes, ticks, fleas, midges and flies. Vector-borne diseases pose an increasingly wider threat to global public health, both in terms of people affected and their geographical spread. Mosquitoes

  3. Bluetongue, Schmallenberg - what is next? : Culicoides-borne viral diseases in the 21st Century

    NARCIS (Netherlands)

    Koenraadt, Constantianus Jm; Balenghien, Thomas; Carpenter, Simon; Ducheyne, Els; Elbers, Armin Rw; Fife, Mark; Garros, Claire; Ibáñez-Justicia, Adolfo; Kampen, Helge; Kormelink, Richard Jm; Losson, Bertrand; van der Poel, Wim Hm; De Regge, Nick; van Rijn, Piet A; Sanders, Christopher; Schaffner, Francis; Sloet van Oldruitenborgh-Oosterbaan, Marianne M|info:eu-repo/dai/nl/075234394; Takken, Willem; Werner, Doreen; Seelig, Frederik

    2014-01-01

    In the past decade, two pathogens transmitted by Culicoides biting midges (Diptera: Ceratopogonidae), bluetongue virus and Schmallenberg virus, have caused serious economic losses to the European livestock industry, most notably affecting sheep and cattle. These outbreaks of arboviral disease have h

  4. Non-structural protein NS3/NS3a is required for propagation of bluetongue virus in Culicoides sonorensis

    NARCIS (Netherlands)

    Feenstra, Femke; Drolet, B.S.; Boonstra, Jan; Rijn, Van P.A.

    2015-01-01

    Background: Bluetongue virus (BTV) causes non-contagious haemorrhagic disease in ruminants and is transmitted by Culicoides spp. biting midges. BTV encodes four non-structural proteins of which NS3/NS3a is functional in virus release. NS3/NS3a is not essential for in vitro virus replication. Howe

  5. Turnover rate of NS3 proteins modulates bluetongue virus replication kinetics in a host-specific manner

    NARCIS (Netherlands)

    Ftaich, Najate; Ciancia, Claire; Viarouge, Cyril; Barry, Gerald; Ratinier, Maxime; Rijn, van P.A.; Breard, Emmanuel; Vitour, Damien; Zientara, Stephan; Palmarini, Massimo; Terzian, Christophe; Arnaud, Frédérick

    2015-01-01

    Bluetongue virus (BTV) is an arbovirus transmitted to livestock by midges of the Culicoides family and is the etiological agent of a hemorrhagic disease in sheep and other ruminants. In mammalian cells, BTV particles are released primarily by virus-induced cell lysis, while in insect cells they b

  6. First description of the male and additional data on the female morphology of Aprostocetus rubi Graham (Hymenoptera: Chalcidoidea: Eulophidae).

    Science.gov (United States)

    Jałoszyński, Paweł

    2016-07-01

    The previously unknown male of Aprostocetus rubi Graham (Eulophidae: Tetrastichinae) was reared, together with females, from galls of the raspberry gall midge Lasioptera rubi (Schrank) (Diptera: Cecidomyiidae) collected in Central Poland. The male is described and illustrated for the first time, and additional information provided on the morphology of the female.

  7. VP2-serotyped live-attenuated bluetongue virus without NS3/NS3a expression provided serotype-specific protection and enables DIVA.

    NARCIS (Netherlands)

    Feenstra, F.; Maris-Veldhuis, M.A.; Daus, F.J.; Tacken, M.G.J.; Moormann, R.J.M.; Gennip, van H.G.P.; Rijn, van P.A.

    2014-01-01

    Bluetongue virus (BTV) causes Bluetongue in ruminants and is transmitted by Culicoides biting midges. Vaccination is the most effective measure to control vector borne diseases; however, there are 26 known BTV serotypes showing little cross protection. The BTV serotype is mainly determined by genome

  8. Disease: H01061 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available c with no distinct and specific clinical picture, but may cause transient upper a...bdominal pain, subcutaneous swellings, eosinophilia, and skin rashes. Infectious disease Mansonella perstans... Culicoides (biting midges) ICD-10: B74.4 MeSH: D008368 PMID:20152790 Simonsen PE

  9. Repellence of the red bud borer (Resseliella oculiperda) to grafted apple trees by impregnation of budding tape with essential oils

    NARCIS (Netherlands)

    Tol, van R.W.H.M.; Linden, van der A.; Swarts, H.J.; Visser, J.H.

    2007-01-01

    The red bud borer Resseliella oculiperda (Rübs.) is a pest insect of apple trees when rootstocks are grafted with scion buds by shield budding. The female midges are attracted to the wounds of the grafted buds where they lay their eggs. The larvae feed on the cambium and destroy the buds completely

  10. European bluetongue serotype 8

    NARCIS (Netherlands)

    Drolet, Barbara S.; Reister-Hendricks, Lindsey M.; Podell, Brendan K.; Breitenbach, Jonathan E.; Mcvey, D.S.; Rijn, van Piet A.; Bowen, Richard A.

    2016-01-01

    Bluetongue virus (BTV) is an orbivirus transmitted by biting midges (Culicoides spp.) that can result in moderate to high morbidity and mortality primarily in sheep and white-tailed deer. Although only 5 serotypes of BTV are considered endemic to the United States, as many as 11 incursive serotyp

  11. Larvae of North American Eukiefferiella and Tvetenia (Diptera: Chironomidae). Bulletin No. 452.

    Science.gov (United States)

    Bode, Robert W.

    "Eukiefferiella" and "Tvetenia" are closely related genera belonging to the subfamily Orthocladiinae within the Chironomidae, a family of non-biting midges. All known larvae in these genera are aquatic, being found predominantly in running water. Most species prefer cold, swift-flowing, well-oxygenated streams. Although larvae…

  12. Human mesenchymal stromal cells could deliver erythropoietin and migrate to the basal layer of hair shaft when subcutaneously implanted in a murine model.

    Science.gov (United States)

    Mok, P L; Cheong, S K; Leong, C F; Chua, K H; Ainoon, O

    2012-08-01

    Mesenchymal stromal cells (MSC) are an attractive cell-targeting vehicle for gene delivery. MIDGE (an acronym for Minimalistic, Immunologically Defined Gene Expression) construct is relatively safer than the viral or plasmid expression system as the detrimental eukaryotic and prokaryotic gene and sequences have been eliminated. The objective of this study was to test the ability of the human MSC (hMSC) to deliver the erythropoietin (EPO) gene in a nude mice model following nucleofection using a MIDGE construct. hMSC nucleofected with MIDGE encoding the EPO gene was injected subcutaneously in Matrigel at the dorsal flank of nude mice. Subcutaneous implantation of nucleofected hMSC resulted in increased hemoglobin level with presence of human EPO in the peripheral blood of the injected nude mice in the first two weeks post-implantation compared with the control groups. The basal layer of the hair shaft in the dermal layer was found to be significantly positive for immunohistochemical staining of a human EPO antibody. However, only a few basal layers of the hair shaft were found to be positively stained for CD105. In conclusion, hMSC harboring MIDGE-EPO could deliver and transiently express the EPO gene in the nude mice model. These cells could be localized to the hair follicle and secreted EPO protein might have possible role in hair regeneration.

  13. Feasibility Study of Shoreline Protection and Lake Level Regulation for Lake Ontario. Reconnaissance Report. Volume II. Appendices.

    Science.gov (United States)

    1981-11-01

    midges) Isopoda, (aquatic sow bug ), Hirudinea (leeches), and Gastropoda (snails) (IJC 1969; Casy, Fisher, Kleveno, 1973). A-2-79 A 0 , 1-a vC C V, a C...also a nondocumented sighting of orange- milkweed (Asclepias tuberosa) (Corps 1975) in this area. It is probable that other protected plants may be

  14. Environmental statistical modelling of mosquito vectors at different geographical scales

    NARCIS (Netherlands)

    Cianci, D.|info:eu-repo/dai/nl/370432134

    2015-01-01

    Vector-borne diseases are infections transmitted by the bite of infected arthropod vectors, such as mosquitoes, ticks, fleas, midges and flies. Vector-borne diseases pose an increasingly wider threat to global public health, both in terms of people affected and their geographical spread. Mosquitoes

  15. Equine insect bite hypersensitivity : Pathogenesis, diagnosis and immunomodulation

    NARCIS (Netherlands)

    Meulenbroeks, C.

    2016-01-01

    Insect bite hypersensitivity (IBH) is a seasonal allergic dermatitis primarily caused by Culicoides midges like C. obsoletus. The welfare of IBH-affected horses is compromised due to severe itch with secondary dermatitis and skin infections. Similar to most allergies, IBH can only be controlled rath

  16. A Comparison of Elementary, Middle, and High School Teachers' Orientations toward Motivating Students

    Science.gov (United States)

    Hansen, Mark David

    2010-01-01

    Developmental psychologists have long known that students are less interested in school and academic tasks with each additional year in school (Eccles & Midgely, 1989). In addition, they know that the most effective predictor of motivation at any age is self-efficacy, a student's perception of his/her academic ability in a specific domain. Factors…

  17. Delineation of Culicoides species by morphology and barcode exemplified by three new species of the subgenus Culicoides (Diptera: Ceratopogonidae) from Scandinavia

    DEFF Research Database (Denmark)

    Nielsen, Søren Achim; Kristensen, Michael

    2015-01-01

    Background Culicoides biting midges (Diptera: Ceratopogonidae) cause biting nuisance to livestock and humans and are vectors of a range of pathogens of medical and veterinary importance. Despite their economic significance, the delineation and identification of species where only morphology is co...

  18. Nest ectoparasites increase physiological stress in breeding birds: an experiment

    Science.gov (United States)

    Martínez-de La Puente, Josué; Merino, Santiago; Tomás, Gustavo; Moreno, Juan; Morales, Judith; Lobato, Elisa; Martínez, Javier

    2011-02-01

    Parasites are undoubtedly a biotic factor that produces stress. Heat shock proteins (HSPs) are important molecules buffering cellular damage under adverse conditions. During the breeding season, blue tit Cyanistes caeruleus (L.) adults are affected by blood parasites, nest-dwelling parasites and biting flies, potentially affecting their HSP-mediated responses. Here, we treated females with primaquine to reduce blood parasites and fumigated nests with permethrin to reduce nest-dwelling parasites to test whether these treatments affect HSP60 level during the breeding season. Medicated females, but not controls, had a significant reduction of the intensity of infection by Haemoproteus spp. blood parasites. However, final intensity of infection did not differ significantly between groups, and we did not find an effect of medication on change in HSP60 level. Fumigation reduced the abundance of nest-dwelling parasites (mites, fleas and blowfly larvae) and engorged biting midges in nests. Females breeding in non-fumigated nests increased HSP60 levels during the season more than those breeding in fumigated nests. Furthermore, the change in HSP60 level was positively correlated with the abundance of biting midges. These results show how infections by nest ectoparasites during the breeding period can increase the level of HSPs and suggest that biting midges impose physiological costs on breeding female blue tits. Although plausible, the alternative that biting midges prefer to feed on more stressed birds is poorly supported by previous studies.

  19. Establishment, population increase, spread, and ecological host range of Lophodiplosis trifida (Diptera: Cecidomyiidae), a biological control agent of the invasive tree Melaleuca quinquenervia (Myrtales:Myrtaceae).

    Science.gov (United States)

    The Australian tree Melaleuca quinquenervia (Cav.) Blake is an invasive weed in wetland systems of Florida, USA. A biological control program targeting M. quinquenervia has culminated in the release of the gall forming midge Lophodiplosis trifida Gagné (Cecidomyiidae). Populations of the introduced ...

  20. Blood Feeding Behavior of Vesicular Stomatitis Virus Infected Culicoides Sonorensis (Diptera: Ceratopogonidae)

    Science.gov (United States)

    To determine whether vesicular stomatitis virus (VSV) infection of Culicoides sonorensis affects subsequent blood feeding behavior, midges injected with either virus-infected or virus-free cell lysates were allowed to blood feed for short (10 min) or long (60 min) periods of time on days 2, 3, and 4...

  1. Dicty_cDB: Contig-U04769-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 27-01-01-1... 42 7e-04 2 ( FC469241 ) CAXH4857.fwd CAXH Mnemiopsis leidyi whole animal ... 56 8e-04 2 ( EJ59...21 ) SmSal1238 Orange wheat blossom midge salivary gla... 56 0.003 1 ( FC469240 ) CAXH4857.rev CAXH Mnemiopsis leidyi

  2. Determinants of abundance and effects of blood-sucking flying insects in the nest of a hole-nesting bird

    NARCIS (Netherlands)

    Tomás, G.; Merino, S.; Martínez-de la Puente, J.; Moreno, J.; Morales, J.; Lobato, E.

    2008-01-01

    Compared to non-flying nest-dwelling ectoparasites, the biology of most species of flying ectoparasites and its potential impact on avian hosts is poorly known and rarely, if ever, reported. In this study we explore for the first time the factors that may affect biting midge (Diptera:

  3. North Fork Snoqualmie River Basin Wildlife Study.

    Science.gov (United States)

    1981-03-01

    sample of total Arthropoda Insecta Trichoptera Psychoglypha sp. 1 43.1 0.5 1.8 Diptera Chironomidae 35 1506.9 17.5 64.9 Odonata 1 43.1 0.5 1.8 Annelida...Odentoceridae --- unid. Hydropsychidae --- Psychoglypha sp. dragonflies and damselflies Odonata flies Diptera, midges Chironomidae crane flies

  4. Quantitative analysis of the probability of introducing equine encephalosis virus (EEV) into The Netherlands

    NARCIS (Netherlands)

    Fischer, E.A.J.|info:eu-repo/dai/nl/298675331; Martínez López, Evelyn Pamela; De Vos, Clazien; Faverjon, Céline

    2016-01-01

    Equine encephalosis is a midge-borne viral disease of equines caused by equine encephalosis virus (EEV, Orbivirus, Reoviridae), and closely related to African horse sickness virus (AHSV). EEV and AHSV share common vectors and show similar transmission patterns. Until now EEV has caused outbreaks in

  5. Quantitative analysis of the probability of introducing equine encephalosis virus (EEV) into The Netherlands

    NARCIS (Netherlands)

    Fischer, Egil Andreas Joor; Martínez López, Evelyn Pamela; Vos-de Jong, de Clazien; Faverjon, Céline

    2016-01-01

    Equine encephalosis is a midge-borne viral disease of equines caused by equine encephalosis virus (EEV, Orbivirus, Reoviridae), and closely related to African horse sickness virus (AHSV). EEV and AHSV share common vectors and show similar transmission patterns. Until now EEV has caused outbreaks

  6. Potential role of ticks as vectors of bluetongue virus

    NARCIS (Netherlands)

    Bouwknegt, C.; Rijn, van P.A.; Schipper, J.M.J.; Holzel, D.R.; Boonstra, J.; Nijhof, A.; Rooij, van E.M.A.; Jongejan, F.

    2010-01-01

    When the first outbreak of bluetongue virus serotype 8 (BTV8) was recorded in North-West Europe in August 2006 and renewed outbreaks occurred in the summer of 2007 and again in 2008, the question was raised how the virus survived the winter. Since most adult Culicoides vector midges are assumed not

  7. Inducing RNA interference in the arbovirus vector, Culicoides sonorensis

    Science.gov (United States)

    Biting midges in the genus Culicoides are important vectors of arboviral diseases, including Epizootic Hemorrhagic Disease, Bluetongue, and likely Schmallenberg, which cause significant economic burden worldwide. Research on these vectors has been hindered by the lack of a sequenced genome, the diff...

  8. Advancing vector biology research

    NARCIS (Netherlands)

    Kohl, Alain; Pondeville, Emilie; Schnettler, Esther; Crisanti, Andrea; Supparo, Clelia; Christophides, George K.; Kersey, Paul J.; Maslen, Gareth L.; Takken, Willem; Koenraadt, Constantianus J.M.; Oliva, Clelia F.; Busquets, Núria; Abad, F.X.; Failloux, Anna Bella; Levashina, Elena A.; Wilson, Anthony J.; Veronesi, Eva; Pichard, Maëlle; Arnaud Marsh, Sarah; Simard, Frédéric; Vernick, Kenneth D.

    2016-01-01

    Vector-borne pathogens impact public health, animal production, and animal welfare. Research on arthropod vectors such as mosquitoes, ticks, sandflies, and midges which transmit pathogens to humans and economically important animals is crucial for development of new control measures that target t

  9. World catalog of extant and fossil Corethrellidae (Diptera).

    Science.gov (United States)

    Borkent, Art

    2014-05-20

    A world catalog of extant and fossil frog-biting midges (Diptera: Corethrellidae) provides full type information, known life stages, and distribution of each species. There are 105 extant and seven fossil species of Corethrellidae but unnamed species are known from Costa Rica, Colombia and Madagascar. New information on types and other important specimens are provided.

  10. Counting circadian cycles to determine the period of a circasemilunar rhythm in a marine insect.

    Science.gov (United States)

    Soong, Keryea; Chang, Yin-Hao

    2012-12-01

    Semilunar and lunar rhythms are often controlled endogenously, but the mechanisms of their respective free-run periods, when external factors are absent, are mostly unclear. In this investigation, the authors studied the mechanism controlling the period of the circasemilunar emergence rhythm of a marine midge, Pontomyia oceana, in southern Taiwan. Experimental approaches were adopted with various artificial light-dark (LD) periods, or T, from 22 to 28 h per cycle in the first experiment, and 18 to 30 h per cycle in the second experiment, as treatments on the same cohorts of midge larvae. The responses in emergence days were directly proportional to the magnitude of the treatments, just as that predicted by the frequency demultiplication hypothesis. A counting mechanism is thus the only hypothesis supported by this finding. To further test whether it is endogenous oscillations that are counted, submultiples as well as multiples of 24 h, i.e., 6, 12, 24, and 48 h per cycle, were used as T. The midges under all these treatments emerged at similar days. This result supports the hypothesis that endogenous circadian oscillations, not external LD cycles, are counted in this circasemilunar emergence rhythm of the marine midge. This paper reports a first case supporting the frequency demultiplication hypothesis in a circasemilunar rhythm that is based on counting the cycles of endogenous circadian rhythms.

  11. Evaluation of Propane Combustion Traps for the Collection of Phlebotomus papatasi (Scopoli) in Southern Israel

    Science.gov (United States)

    2011-03-01

    Ceratopogonidae) biting midges (Cilek and Hallmon 2005, Cilek et al. 2003) in the U.S.; some Lutzomyia have been collaterally collected. To our...Ashbel 1951). Average daily temperature is 20° C from the end of September to Report Documentation Page Form ApprovedOMB No. 0704-0188 Public

  12. Quantitative analysis of the probability of introducing equine encephalosis virus (EEV) into The Netherlands

    NARCIS (Netherlands)

    Fischer, Egil Andreas Joor; Martínez López, Evelyn Pamela; Vos-de Jong, de Clazien; Faverjon, Céline

    2016-01-01

    Equine encephalosis is a midge-borne viral disease of equines caused by equine encephalosis virus (EEV, Orbivirus, Reoviridae), and closely related to African horse sickness virus (AHSV). EEV and AHSV share common vectors and show similar transmission patterns. Until now EEV has caused outbreaks

  13. Quantitative analysis of the probability of introducing equine encephalosis virus (EEV) into The Netherlands

    NARCIS (Netherlands)

    Fischer, E.A.J.; Martínez López, Evelyn Pamela; De Vos, Clazien; Faverjon, Céline

    2016-01-01

    Equine encephalosis is a midge-borne viral disease of equines caused by equine encephalosis virus (EEV, Orbivirus, Reoviridae), and closely related to African horse sickness virus (AHSV). EEV and AHSV share common vectors and show similar transmission patterns. Until now EEV has caused outbreaks in

  14. An Asiatic Chironomid in Brazil: morphology, DNA barcode and bionomics.

    Science.gov (United States)

    Amora, Gizelle; Hamada, Neusa; Fusari, Lívia Maria; Andrade-Souza, Vanderly

    2015-01-01

    In most freshwater ecosystems, aquatic insects are dominant in terms of diversity; however, there is a disproportionately low number of records of alien species when compared to other freshwater organisms. The Chironomidae is one aquatic insect family that includes some examples of alien species around the world. During a study on aquatic insects in Amazonas state (Brazil), we collected specimens of Chironomidae that are similar, at the morphological level, to Chironomuskiiensis Tokunaga and Chironomusstriatipennis Kieffer, both with distributions restricted to Asia. The objectives of this study were to provide morphological information on this Chironomus population, to investigate its identity using DNA barcoding and, to provide bionomic information about this species. Chironomus DNA barcode data were obtained from GenBank and Barcode of Life Data Systems (BOLD) and, together with our data, were analyzed using the neighbor-joining method with 1000 bootstrap replicates and the genetic distances were estimated using the Kimura-2-parameter. At the morphological level, the Brazilian population cannot be distinguished either from Chironomusstriatipennis or Chironomuskiiensis, configuring a species complex but, at the molecular level our studied population is placed in a clade together with Chironomusstriatipennis, from South Korea. Bionomic characteristics of the Brazilian Chironomus population differ from the ones of Chironomuskiiensis from Japan, the only species in this species complex with bionomic information available. The Brazilian Chironomus population has a smaller size, the double of the number of eggs and inhabits oligotrophic water, in artificial container. In the molecular analysis, populations of Chironomusstriatipennis and Chironomuskiiensis are placed in a clade, formed by two groups: Group A (which includes populations from both named species, from different Asiatic regions and our Brazilian population) and Group B (with populations of

  15. A spatial simulation model for the dispersal of the bluetongue vector Culicoides brevitarsis in Australia.

    Directory of Open Access Journals (Sweden)

    Joel K Kelso

    Full Text Available The spread of Bluetongue virus (BTV among ruminants is caused by movement of infected host animals or by movement of infected Culicoides midges, the vector of BTV. Biologically plausible models of Culicoides dispersal are necessary for predicting the spread of BTV and are important for planning control and eradication strategies.A spatially-explicit simulation model which captures the two underlying population mechanisms, population dynamics and movement, was developed using extensive data from a trapping program for C. brevitarsis on the east coast of Australia. A realistic midge flight sub-model was developed and the annual incursion and population establishment of C. brevitarsis was simulated. Data from the literature was used to parameterise the model.The model was shown to reproduce the spread of C. brevitarsis southwards along the east Australian coastline in spring, from an endemic population to the north. Such incursions were shown to be reliant on wind-dispersal; Culicoides midge active flight on its own was not capable of achieving known rates of southern spread, nor was re-emergence of southern populations due to overwintering larvae. Data from midge trapping programmes were used to qualitatively validate the resulting simulation model.The model described in this paper is intended to form the vector component of an extended model that will also include BTV transmission. A model of midge movement and population dynamics has been developed in sufficient detail such that the extended model may be used to evaluate the timing and extent of BTV outbreaks. This extended model could then be used as a platform for addressing the effectiveness of spatially targeted vaccination strategies or animal movement bans as BTV spread mitigation measures, or the impact of climate change on the risk and extent of outbreaks. These questions involving incursive Culicoides spread cannot be simply addressed with non-spatial models.

  16. Evaluation of Metarhizium anisopliae for the control of Culicoides brevitarsis Kieffer (Diptera: Ceratopogonidae), the principal vector of bluetongue virus in Australia.

    Science.gov (United States)

    Nicholas, A H; McCorkell, B

    2014-06-01

    Four isolates of the entomopathogenic fungus Metarhizium anisopliae were tested for their potential to control the biting midge Culicoides brevitarsis, the principal vector of bluetongue virus in Australia. Adult C. brevitarsis died three to eight days after walking on paper substrate treated with 0.7 g/m(2) conidia of any of the isolates, indicating that M. anisopliae has potential as a surface treatment or topical application control strategy. Incorporation of the fungus into freshly excreted cattle dung at rates of between 0.25 and 1 g conidia/kg reduced the emergence of adult midges by up to 98.5% compared to untreated dung indicating that M. anisopliae has the potential to control C. brevitarsis larvae in cattle dung. Three of the isolates produced similar mortality rates on adult and immature C. brevitarsis while the fourth isolate produced lower, but still significant, mortality rates on adult and immature stages.

  17. Sirovena Bouček (Pteromalidae: Pireninae), a new member of the fig wasp community associated with Ficus microcarpa (Moraceae).

    Science.gov (United States)

    Li, Zi; Xiao, Hui; Huang, Da-Wei

    2013-01-01

    Sirovena Bouček (Chalcidoidea: Pteromalidae, Pireninae) was known only from females of its type species, S. stigma Bouček, 1988. Males and host associations were both unknown. Both sexes of a second species of Sirovena, S. costallifera sp. nov., reared from Ficus microcarpa L. (Moraceae) in Yunnan, China, are described based on morphological characters and mitochondrial COI sequences. The males of S. costallifera show sexual dimorphism in body coloration, structure of the antennae and notauli, and body sculpture. Reliable host records of Pireninae are Cecidomyiidae (Diptera). Because midges also parasitize some figs, we speculate that S. costallifera is a parasitoid of some cecidomyiid midge that attacks fig syconia. A key to differentiate the two species is provided.

  18. Saltbush-associated Asphondylia species (Diptera: Cecidomyiidae) in the Mediterranean Basin and their chalcidoid parasitoids (Hymenoptera: Chalcidoidea).

    Science.gov (United States)

    Dorchin, Netta; Mifsud, David; Askew, Richard

    2014-10-02

    Numerous species of gall midges (Diptera: Cecidomyiidae) have been recorded from saltbush (Chenopodiaceae: Atriplex) around the world but only 11 of them belong to the large cecidomyiid genus Asphondylia. Of these, two species were described in the late 19th century from complex bud galls on Atriplex halimus in the Mediterranean Basin. In the present study Asphondylia punica is redescribed, A. conglomerata is synonymized with it, and Asphondylia scopuli is described from Atriplex lanfrancoi, an endemic plant to the Maltese Islands. Descriptions are accompanied by information about the galls and life history of the gall midges, and a review of the parasitic Hymenoptera associated with A. scopuli is provided. Four species of parasitoids were found and attributed to the families Eurytomidae, Pteromalidae, Eupelmidae and Eulophidae, of which the pteromalid Mesopolobus melitensis is described as new.

  19. Gene regulatory networks reused to build novel traits: co-option of an eye-related gene regulatory network in eye-like organs and red wing patches on insect wings is suggested by optix expression.

    Science.gov (United States)

    Monteiro, Antónia

    2012-03-01

    Co-option of the eye developmental gene regulatory network may have led to the appearance of novel functional traits on the wings of flies and butterflies. The first trait is a recently described wing organ in a species of extinct midge resembling the outer layers of the midge's own compound eye. The second trait is red pigment patches on Heliconius butterfly wings connected to the expression of an eye selector gene, optix. These examples, as well as others, are discussed regarding the type of empirical evidence and burden of proof that have been used to infer gene network co-option underlying the origin of novel traits. A conceptual framework describing increasing confidence in inference of network co-option is proposed. Novel research directions to facilitate inference of network co-option are also highlighted, especially in cases where the pre-existent and novel traits do not resemble each other.

  20. Long-range Acoustic Interactions in Insect Swarms: An Adaptive Gravity Model

    CERN Document Server

    Gorbonos, Dan; Puckett, James G; Ni, Rui; Ouellette, Nicholas T; Gov, Nir S

    2015-01-01

    The collective motion of groups of animals emerges from the net effect of the interactions between individual members of the group. In many cases, such as birds, fish, or ungulates, these interactions are mediated by sensory stimuli that predominantly arise from nearby neighbors. But not all stimuli in animal groups are short range. Here, we consider mating swarms of midges, which interact primarily via long-range acoustic stimuli. We exploit the similarity in form between the decay of acoustic and gravitational sources to build a model for swarm behavior. By accounting for the adaptive nature of the midges' acoustic sensing, we show that our "adaptive gravity" model makes mean-field predictions that agree well with experimental observations of laboratory swarms. Our results highlight the role of sensory mechanisms and interaction range in collective animal behavior. The adaptive interactions that we present here open a new class of equations of motion, which may appear in other biological contexts.

  1. Fluctuating Asymmetry in Flies, What Does It Mean?

    Directory of Open Access Journals (Sweden)

    Athol J. McLachlan

    2010-06-01

    Full Text Available The degree of departure from perfect symmetry in organisms, fluctuating asymmetry (FA, is seen in most populations of animals. It has particular impact on choice of mate which lies within the world of sexual selection. Here I consider a relatively little studied aspect of sexual selection, i.e. the effect of FA on contests between males for mates, based not on display ornament but rather on agility seen in the mating systems of many insects. The model organism considered is the ubiquitous chironomid midge. In these flies, mating takes place in the air, so symmetry in the length of wings bears directly on a male’s aerobatic ability on which successful mating depends. The role of parasites and predators in creating and responding to FA in the host/prey midge is considered.

  2. Rediscovery and identity of Pumilomyia protrahenda De Stefani (Diptera, Cecidomyiidae) in Sicily with redescription and reassessment of its taxonomic position.

    Science.gov (United States)

    Skuhravá, Marcela; Massa, Bruno; Cerasa, Giuliano

    2016-01-01

    A population of the gall midge Pumilomyia protrahenda De Stefani, 1919 causing galls on Artemisia arborescens (Asteraceae) was discovered near Palermo (Sicily) in 2008. This species had not been found since 1918. Detailed study of morphological characters of adults, larvae and pupae revealed that Pumilomyia protrahenda belongs to the genus Rhopalomyia Rübsaamen, 1892, tribe Rhopalomyiini. The monotypic genus Pumilomyia De Stefani, 1919 is therefore synonymized under Rhopalomyia Rübsaamen, 1892. Rhopalomyia protrahenda comb. n. is redescribed, with important morphological characters illustrated. Adults have one-segmented palpi, antennae with 12-13 short flagellomeres and long legs with simple tarsal claws. A neotype is designated in the present paper because the type of this species is lost. The host plant has a circum-Mediterranean distribution but the gall midge is currently known only from Sicily, where it completes several generations between January and May.

  3. Rediscovery and identity of Pumilomyia protrahenda De Stefani (Diptera, Cecidomyiidae in Sicily with redescription and reassessment of its taxonomic position

    Directory of Open Access Journals (Sweden)

    Marcela Skuhravá

    2016-09-01

    Full Text Available A population of the gall midge Pumilomyia protrahenda De Stefani, 1919 causing galls on Artemisia arborescens (Asteraceae was discovered near Palermo (Sicily in 2008. This species had not been found since 1918. Detailed study of morphological characters of adults, larvae and pupae revealed that P. protrahenda belongs to the genus Rhopalomyia Rübsaamen, 1892, tribe Rhopalomyiini. The monotypic genus Pumilomyia De Stefani, 1919 is therefore synonymized under Rhopalomyia Rübsaamen, 1892. Rhopalomyia protrahenda comb. n. is redescribed, with important morphological characters illustrated. Adults have one-segmented palpi, antennae with 12–13 short flagellomeres and long legs with simple tarsal claws. A neotype is designated in the present paper because the type of this species is lost. The host plant has a circum-Mediterranean distribution but the gall midge is currently known only from Sicily, where it completes several generations between January and May.

  4. Behavioral and catastrophic drift of invertebrates in two streams in northeastern Wyoming

    Science.gov (United States)

    Wangsness, David J.; Peterson, David A.

    1980-01-01

    Invertebrate drift samples were collected in August 1977 from two streams in the Powder River structural basin in northeastern Wyoming. The streams are Clear Creek, a mountain stream, and the Little Powder River, a plains stream. Two major patterns of drift were recognized. Clear Creek was sampled during a period of normal seasonal conditions. High drift rates occurred during the night indicating a behavioral drift pattern that is related to the benthic invertebrate density and carrying capacity of the stream substrates. The mayfly genes Baetis, a common drift organism, dominated the peak periods of drift in Clear Creek. The Little Powder River has a high discharge during the study period. Midge larvae of the families Chironomidae and Ceratopogonidae, ususally not common in drift, dominated the drift community. The dominance of midge larvae, the presence of several other organisms not common in drift, and the high discharge during the study period caused a catastrophic drift pattern. (USGS)

  5. Summer eczema in exported Icelandic horses: influence of environmental and genetic factors

    Directory of Open Access Journals (Sweden)

    Broström Hans

    2006-05-01

    Full Text Available Abstract A cross sectional study was designed to estimate the prevalence of summer eczema (a chronic, recurrent seasonal dermatitis in exported Icelandic horses and the influence of environmental and genetic factors on the development of the disease. Among 330 horses, which had been exported to Germany, Denmark and Sweden, 114 (34.5% were found to have clinical signs of summer eczema. The prevalence was highest 2 years after export and the exposure to the biting midges Culicoides spp., was found to be the main risk factor for developing the disease. Genetic influence on the sensitivity for the disease was not established. It was concluded that exported Icelandic horses are predisposed for summer dermatitis and the fact that they are not introduced to the antigens of the biting midges early in live, due to it's absence in Iceland, is likely to explain the high prevalence of the disease after export.

  6. Fungal biological control agents for integrated management of Culicoides spp. (Diptera: Ceratopogonidae of livestock

    Directory of Open Access Journals (Sweden)

    B. W. Narladkar

    2015-02-01

    Full Text Available Aim: Entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana had wide host range against insects and hence these are being exploited as fungal bio-pesticide on a large scale. Both fungi are proved pesticides against many crop pests and farmers are well acquainted with their use on the field. Thus, research was aimed to explore the potency of these fungal spores against larval and adult Culicoides midges, a pest of livestock. Materials and Methods: In-vitro testing of both fungal biological control agents was undertaken in Petri dishes against field collected Culicoides larvae, while in plastic beakers against field collected blood-engorged female Culicoides midges. In-vivo testing was undertaken by spraying requisite concentration of fungal spores on the drainage channel against larvae and resting sites of adult Culicoides midges in the cattle shed. Lethal concentration 50 (LC50 values and regression equations were drawn by following probit analysis using SPSS statistical computerized program. Results: The results of this study revealed LC50 values of 2692 mg and 3837 mg (108 cfu/g for B. bassiana and M. anisopliae, respectively, against Culicoides spp. larvae. Death of Culicoides larvae due to B. bassiana showed greenish coloration in the middle of the body with head and tail showed intense blackish changes, while infection of M. anisopliae resulted in death of Culicoides larvae with greenish and blackish coloration of body along with total destruction, followed by desquamation of intestinal channel. The death of adult Culicoides midges were caused by both the fungi and after death growth of fungus were very well observed on the dead cadavers proving the efficacy of the fungus. Conclusion: Preliminary trials with both funguses (M. anisopliae, B. bassiana showed encouraging results against larvae and adults of Culicoides spp. Hence, it was ascertained that, these two fungal molecules can form a part of biological control and

  7. Sobre uma nova espécie do gênero Aedokritus Roback, 1958 (Diptera: Chironomidae On a new species of the genus Aedokritus Roback, 1958 (Diptera: Chironomidae

    Directory of Open Access Journals (Sweden)

    Sebastião José de Oliveira

    1989-01-01

    Full Text Available In this paper we describe a new species of a non-biting midge of the genus Aedokritus Roback, 1958 (Chironominae, Chironomidae from Brazil and Bolívia. That is the fifth species of this genus. The other species of the genus are: A. penicilligerus (Edwards, 1931, from Argentina and Peru; A. pruinescens (Edwards, 1931, from Argentina; A. platycnemis (Edwards, 1931, from Argentina; and A. sartis Roback, 1960, from Brazil.

  8. Combining dispersion modelling with synoptic patterns to understand the wind-borne transport into the UK of the bluetongue disease vector

    Science.gov (United States)

    Burgin, Laura; Ekström, Marie; Dessai, Suraje

    2017-07-01

    Bluetongue, an economically important animal disease, can be spread over long distances by carriage of insect vectors ( Culicoides biting midges) on the wind. The weather conditions which influence the midge's flight are controlled by synoptic scale atmospheric circulations. A method is proposed that links wind-borne dispersion of the insects to synoptic circulation through the use of a dispersion model in combination with principal component analysis (PCA) and cluster analysis. We illustrate how to identify the main synoptic situations present during times of midge incursions into the UK from the European continent. A PCA was conducted on high-pass-filtered mean sea-level pressure data for a domain centred over north-west Europe from 2005 to 2007. A clustering algorithm applied to the PCA scores indicated the data should be divided into five classes for which averages were calculated, providing a classification of the main synoptic types present. Midge incursion events were found to mainly occur in two synoptic categories; 64.8% were associated with a pattern displaying a pressure gradient over the North Atlantic leading to moderate south-westerly flow over the UK and 17.9% of the events occurred when high pressure dominated the region leading to south-easterly or easterly winds. The winds indicated by the pressure maps generally compared well against observations from a surface station and analysis charts. This technique could be used to assess frequency and timings of incursions of virus into new areas on seasonal and decadal timescales, currently not possible with other dispersion or biological modelling methods.

  9. Social Research On Renaissance Period

    Institute of Scientific and Technical Information of China (English)

    张蕾蕾

    2009-01-01

    The historical period known as the Renaissance spans the fifteenth and siXteenth centuries. ‘Renaissance'means‘re-birth'in French and during this time Europe left behind the mindset of the Midge Ages and created the beginnings of the modern world.This thesis mainly rotates on the background,the main features and significance of Renaissance,especially focuses on the discovery of man and the humanism and the detailed unfolding of the society on several aspect in Renaissance.

  10. Description, host range and distribution of a new Macrodiplosis species (Diptera: Cecidomyiidae) that induces leaf-margin fold galls on deciduous Quercus (Fagaceae) with comparative notes on Palaearctic congeners.

    Science.gov (United States)

    Kim, Wanggyu; Yukawa, Junichi; Harris, Keith M; Minami, Tsuneo; Matsuo, Kazunori; Skrzypczyńska, Małgorzata

    2014-06-20

    A gall midge that induces upwardly folded leaf-margin galls on Quercus serrata, Q. mongolica and Q. dentata (Fagaceae) in Japan and South Korea is described as Macrodiplosis selenis sp. n. (Diptera: Cecidomyiidae). M. selenis is distinguished from Palaearctic congeners by a combination of morphological characters. Genetic differences supported the result of morphological comparison and indicated that M. selenis is closely related to the European M. roboris, whose gall is similar to that of M. selenis.

  11. Combined production of broilers and fruits

    OpenAIRE

    Lindhard Pedersen, H.; Olsen, A.; Pedersen, B; Korsgaard, M.; Horsted, K

    2004-01-01

    Combined production of broilers and fruit trees is a subject often discussed in organic fruit production in Denmark. Very little research has been carried out on this type of production system. In organic production in Denmark, nearly no pesticides are allowed, so the need for alternative pest control is large. Apple sawfly (Hoplocampa testudinea) and pear midge (Contarinia pyrivora) cause big crop losses in apples and pears respectively, in unsprayed organic fruit production. ...

  12. New species of Lopesia (Diptera, Cecidomyiidae associated with Eichhornia azurea (Pontederiaceae from Brazil

    Directory of Open Access Journals (Sweden)

    Maria V. Urso-Guimarães

    2014-12-01

    Full Text Available A new species of gall midge, Lopesia eichhorniae sp. nov. (Cecidomyiidae, Diptera, associated with rhizomes of Eichhornia azurea (Sw. Kunth (Pontederiaceae is described. This is the first record of Lopesia galls in this species of macrophyte, quite common in natural and artificial lakes in Southeast Brazil. Illustrations of the adults (male and female, pupa, larva, and gall of the new species are presented.

  13. Selenium Concentrations in Irrigation Drain Inflows to the Salton Sea, California, October 2006 and January 2007

    Science.gov (United States)

    May, Thomas W.; Walther, Mike W.; Brumbaugh, William G.

    2007-01-01

    This report presents raw data on selenium concentrations in samples of water, sediment, detritus, and selected food-chain matrices collected from selected agricultural drains in the southern portion of the Salton Sea during October 2006 and January 2007. Total selenium and selenium species were determined in water samples, whereas total selenium was determined in sediment, detritus, algae, plankton, midge larvae (Family Chironomidae), and two fish species (western mosquitofish, Gambusia affinis, and sailfin molly, Poecilia latipinna).

  14. Combining dispersion modelling with synoptic patterns to understand the wind-borne transport into the UK of the bluetongue disease vector

    Science.gov (United States)

    Burgin, Laura; Ekström, Marie; Dessai, Suraje

    2017-01-01

    Bluetongue, an economically important animal disease, can be spread over long distances by carriage of insect vectors (Culicoides biting midges) on the wind. The weather conditions which influence the midge's flight are controlled by synoptic scale atmospheric circulations. A method is proposed that links wind-borne dispersion of the insects to synoptic circulation through the use of a dispersion model in combination with principal component analysis (PCA) and cluster analysis. We illustrate how to identify the main synoptic situations present during times of midge incursions into the UK from the European continent. A PCA was conducted on high-pass-filtered mean sea-level pressure data for a domain centred over north-west Europe from 2005 to 2007. A clustering algorithm applied to the PCA scores indicated the data should be divided into five classes for which averages were calculated, providing a classification of the main synoptic types present. Midge incursion events were found to mainly occur in two synoptic categories; 64.8% were associated with a pattern displaying a pressure gradient over the North Atlantic leading to moderate south-westerly flow over the UK and 17.9% of the events occurred when high pressure dominated the region leading to south-easterly or easterly winds. The winds indicated by the pressure maps generally compared well against observations from a surface station and analysis charts. This technique could be used to assess frequency and timings of incursions of virus into new areas on seasonal and decadal timescales, currently not possible with other dispersion or biological modelling methods.

  15. Arthropod Surveillance Programs: Basic Components, Strategies, and Analysis

    Science.gov (United States)

    2012-01-01

    Amblyomma americanum (Acari: Ix- odidae) in beef cattle forage areas. J. Med. Entomol. 28: 557Ð564. Barrera, R. 2009. SimpliÞed pupal surveys of Aedes...to assess reproduction rates in an area; however, ovitrapsmay be too simplistic formimicking aquatic habitats and do not compete adequately with the... cattle was associated with an in- crease in the biting rate of the primary midge vector Culicoides sonorensis Wirth and Jones. Similarly, an increase in

  16. Detection of Schmallenberg virus in different Culicoides spp. by real-time RT-PCR.

    Science.gov (United States)

    De Regge, N; Deblauwe, I; De Deken, R; Vantieghem, P; Madder, M; Geysen, D; Smeets, F; Losson, B; van den Berg, T; Cay, A B

    2012-12-01

    To identify possible vectors of Schmallenberg virus (SBV), we tested pools containing heads of biting midges (Culicoides) that were caught during the summer and early autumn of 2011 at several places in Belgium by real-time RT-PCR. Pools of heads originating from following species: C. obsoletus complex, C. dewulfi and C. chiopterus were found positive, strongly indicating that these species are relevant vectors for SBV.

  17. Nest-climatic factors affect the abundance of biting flies and their effects on nestling condition

    Science.gov (United States)

    Martínez-de la Puente, Josué; Merino, Santiago; Lobato, Elisa; Aguilar, Juan Rivero-de; del Cerro, Sara; Ruiz-de-Castañeda, Rafael; Moreno, Juan

    2010-11-01

    The first step in the establishment of a host-biting fly relationship is host location. While a number of studies highlight the role of host emitted products as important cues affecting host location by biting flies, the role of host temperature is far from clear. We investigated the role of different nest microclimatic variables affecting the interaction between pied flycatchers and two biting flies: black flies and biting midges. Biting midge abundances increased with temperature inside the nest, supporting the potential importance of nest temperature as a cue used by insects to localize their hosts. The possibility that biting fly infestations were associated to ecological conditions in the vicinity of the nests is also discussed. Furthermore, we found a negative association between nestling weight (including tarsus length as a covariate in the analyses) and the interaction between the abundance of biting midges and the presence/absence of black flies in nests. The potential negative effect of these ectoparasites on nestling weight (condition index) and potential differences in the bird phenotypic/genetic quality associated with nest site choice and parasite infestations are considered.

  18. Food and growth parameters of juvenile chinook in the central Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.D.

    1994-10-01

    Juvenile chinook, salmon (Oncorhynchus tshawytscha) in the Hanford area of the free-flowing central Columbia River, Washington consume almost entirely adult and larval stages of aquatic insects. The diet is dominated by midges (Diptera: Chironomidae). By numbers, adult midges provided 64 and 58% of the diet and larval midges 17 and 18% of the diet, in 1968 and 1969, respectively. The families Hydropsychidae (Trichoptera), Notonectidae (Hemiptera) and Hypogastruridae (Collembola) are of minor numerical importance with a combined utilization of 7% in 1968 and 15% in 1969. Distinctive features of food and feeding activity of juvenile chinook at Hanford are fourfold: (1) the fish utilize relatively few insect groups, predominantly Chironomidae; (2) they depend largely upon autochthonous river organisms; (3) they visually select living prey drifting, floating or swimming in the water; and (4) they are apparently habitat opportunists to a large extent. Analyses were made of variations in diet and numbers of insects consumed between six sampling stations distributed along a 38 km section of the river. Data are provided on feeding intensity, fish lengths, length-weight relationships, and coefficients of condition. Seasonal changes in river temperature and discharge, as well as variations in regulated flow levels are environmental features influencing feeding, growth, and emigration of fish in the Hanford environs.

  19. Repellence of the red bud borer Resseliella oculiperda from grafted apple trees by impregnation of rubber budding strips with essential oils.

    Science.gov (United States)

    van Tol, Rob W H M; Swarts, Henk J; van der Linden, Anton; Visser, J H

    2007-05-01

    The red bud borer Resseliella oculiperda (Rübs.) is a pest insect of apple trees when rootstocks are grafted with scion buds by 'shield budding'. The female midges are attracted to the wounds of the grafted buds where they lay their eggs. The larvae feed on the cambium and destroy the buds completely or partially, leading to bad union of the buds with the rootstocks. Budding strips are used very often by growers to bind scion buds to rootstocks. These strips cannot prevent midges from reaching the damaged tissue. Chemical treatments applied to the grafts and other types of strip do not provide better protection against the pest and may cause other risks for growers. In orchard experiments in 2000 and 2001, the authors evaluated the repellent action provided by three essential oils and five compounds of plant origin against the midges by impregnating budding strips with them. The essential oils of lavender, Lavandula angustifolia (P. Mill.), and alpha-terpineol decreased the infestation of buds by more than 95 and 80% respectively. The other potential repellents tested [the essential oil of Juniperus virginiana (L.), citronellal, the essential oil of Cinnamomum camphora (L.) J. Presl, R-carvone, linalool and R-fenchone] decreased infestation by 67, 66, 51, 45, 37 and 25% respectively. The formulation and commercial development of budding strips impregnated with lavender oil is discussed.

  20. DEET (N,N-diethyl-meta-toluamide)/PMD (para-menthane-3,8-diol) repellent-treated mesh increases Culicoides catches in light traps.

    Science.gov (United States)

    Murchie, A K; Clawson, S; Rea, I; Forsythe, I W N; Gordon, A W; Jess, S

    2016-09-01

    Biting midges (Culicoides spp.) are vectors of bluetongue and Schmallenberg viruses. Treatment of mesh barriers is a common method for preventing insect-vectored diseases and has been proposed as a means of limiting Culicoides ingression into buildings or livestock transporters. Assessments using animals are costly, logistically difficult and subject to ethical approval. Therefore, initial screening of test repellents/insecticides was made by applying treatments to mesh (2 mm) cages surrounding Onderstepoort light traps. Five commercial treatments were applied to cages as per manufacturers' application rates: control (water), bendiocarb, DEET/p-menthane-3,8-diol (PMD) repellent, Flygo (a terpenoid based repellent) and lambda-cyhalothrin. The experimental design was a 5 × 5 Latin square, replicated in time and repeated twice. Incongruously, the traps surrounded by DEET/PMD repellent-treated mesh caught three to four times more Obsoletus group Culicoides (the commonest midge group) than the other treatments. A proposed hypothesis is that Obsoletus group Culicoides are showing a dose response to DEET/PMD, being attracted at low concentrations and repelled at higher concentrations but that the strong light attraction from the Onderstepoort trap was sufficient to overcome close-range repellence. This study does not imply that DEET/PMD is an ineffective repellent for Culicoides midges in the presence of an animal but rather that caution should be applied to the interpretation of light trap bioassays.

  1. Blood meal analysis of culicoides (Diptera: ceratopogonidae) in central Tunisia.

    Science.gov (United States)

    Slama, Darine; Haouas, Najoua; Mezhoud, Habib; Babba, Hamouda; Chaker, Emna

    2015-01-01

    To evaluate the host preferences of Culicoides species (Diptera: Ceratopogonidae) in Central Tunisia, we identified the source of blood meals of field collected specimens by sequencing of the cytochrome b (cyt b) mitochondrial locus and Prepronociceptine single copy nuclear gene. The study includes the most common and abundant livestock associated species of biting midges in Tunisia: C. imicola, C. jumineri, C. newsteadi, C. paolae, C. cataneii, C. circumscriptus, C. kingi, C. pseudojumineri, C. submaritimus, C. langeroni, C. jumineri var and some unidentified C. species. Analysis of cyt b PCR products from 182 field collected blood-engorged females' midges revealed that 92% of them fed solely on mammalian species, 1.6% on birds, 2.4% on insects and 0.8% on reptiles. The blast results identified the blood origin of biting midges to the species level with exact or nearly exact matches (≥98%). The results confirm the presence of several Culicoides species, including proven vectors in Central Tunisia. Blood meal analyses show that these species will indeed feed on bigger mammals, thereby highlighting the risk that these viruses will be able to spread in Tunisia.

  2. An appraisal of current and new techniques intended to protect bulls against Culicoides and other haematophagous nematocera: the case of Schmergow, Brandenburg, Germany.

    Science.gov (United States)

    Bauer, Burkhard; Jandowsky, Anabell; Schein, Eberhard; Mehlitz, Dieter; Clausen, Peter-Henning

    2009-08-01

    The outbreak of bluetongue (BTV-8) in many parts of north-western Europe led to efforts to curb the spread of the disease, particularly in farms with valuable livestock, as on a stud bull farm in Schmergow, Brandenburg, Germany. In the abundance of the putative BT vectors, Palaearctic Culicoides species, several vector control methods were applied in the hope for a reduction of the target insect populations. Insecticide-impregnated ear tags and regular treatments at 6-week intervals of all bulls with deltamethrin pour on were expected to achieve the desired control of the biting midges. Additionally, insecticide-treated mosquito fences circumventing much of the pens were tried for the first time against Culicoides. Two suction black-light traps (BioGents(R) sentinel traps) helped to monitor the densities of Culicoides and other haematophagous nematocera during the trial period from July to December 2007. Despite all efforts, the densities of Culicoides were not distinctly reduced. Several thousand midges were repeatedly recorded during one-night catches. Examinations of midges and other haematophagous nematocera (Aedes and Anopheles species) revealed high percentages of successful feedings between 10% and 35% for Culicoides and more than 50% for Aedes and Anopheles species. Since all insects were caught inside the pens, the concept of endophily vs exophily or endophagy vs exophagy for some Culicoides species needs to be revised accordingly. Also, stabling of valuable livestock does not reduce the host-vector interface and, hence, the risk of transmission of BT.

  3. Deceit pollination and the effect of deforestation on reproduction in dioecious Schisandra sphenanthera (Schisandraceae) in central China

    Institute of Scientific and Technical Information of China (English)

    Wei DU; Lan-Jie HUANG; Xiao-Fan WANG

    2012-01-01

    The fruits of Schisandra sphenanthera (dioecious) are used to produce ‘Nan-Wuweizi',an important Chinese medicine.However,long-term exploitation and habitat destruction have threatened these plants in nature.Knowledge of the reproductive biology ofS.sphenanthera is essential to help formulate a conservation strategy for these plants.Field studies were conducted at Jigong Mountain (JGM) and Jinji Valley (JJV) in Henan and Hubei Provinces,China.The reproductive biology of S.sphenanthera was analyzed at these sites,including population structure,pollination,floral morphology,and natural fruit set.The 11 populations at two sites were male biased.The primary floral visitors were gall midges (Resseliella sp.,Cecidomyiidae; Diptera) and thrips (Thripsflavidulus;Thysanoptera).Floral visitor exclusion experiments and pollen load analysis indicate that gall midges are the primary pollinators.Pollen was the only floral reward for the gall midges.Female flowers attracted pollinators using deceit.The natural fruit set ratio in the cut forest site (JJV) was significantly lower than that at the JGM site,where habitats of S.sphenanthera were well preserved.This indicates that the life cycles of S.sphenanthera and the pollinating insects are vulnerable in disturbed (or cut) habitats.

  4. Seroepidemiology of bluetongue in South Bengal

    Directory of Open Access Journals (Sweden)

    Arkendu Halder

    2016-01-01

    Full Text Available Aim: With the aim of revealing the epidemiological intricacies of bluetongue (BT in the southern part of West Bengal state, the present study was undertaken to assess seroprevalence of BT along with identification of the vector of the disease, i.e., Culicoides midges available in the region in their breeding season with conducive environmental factors, if any. Materials and Methods: A total of 1509 (sheep-504, goat-1005 samples were collected from three different agroclimatic zones of South Bengal viz. new alluvial, red laterite and coastal saline. To detect anti-BT antibodies in the collected serum samples, indirect-enzyme-linked immunosorbent assay (i-ELISA was performed. Culicoides midges were collected from those agro-climatic zones of South Bengal for species identification. The meteorological parameters, viz. temperature (maximum and minimum, rainfall and relative humidity of three agro-climatic zones of South Bengal were analyzed for the months of July to December during 2010-2013. Results: The overall seropositivity was 33.13% and 30.24% in sheep and goat, respectively as assessed by i-ELISA. In South Bengal, the predominant species of Culicoides found were Culicoides schultzei, Culicoides palpifer and Culicoides definitus. Conclusion: Since virus transmitting species of Culicoides midges could be detected in South Bengal, besides high seropositivity in ruminants, the possibility of circulating BT virus in South Bengal is quite imminent.

  5. Damage Patterns, Monitoring, and Management of Procontarinia mangiferae (Diptera: Cecidomyiidae) in Pakistan.

    Science.gov (United States)

    Rehman, Hafiz M; Mahmood, Riaz; Razaq, Muhammad; Reddy, Gadi V P

    2016-09-11

    Since 2005, mango has been damaged by a group of new pests, the gall midges, in all mango-growing areas of Pakistan. Little is known about these pests in Pakistan. In this report, we present information on the occurrence, damage patterns, methods for monitoring, and management of Procontarinia mangiferae (Felt), a mango gall midge found in the country. At the study site (Rahim Yar Khan, a district of the province Punjab, Pakistan), the pest was active from January/February to April as eggs, larvae, and adults on mango inflorescence buds, branches (axillaries), and immature fruits. Females of P. mangiferae oviposited in inflorescence tissues, and larvae, after feeding on plant tissues, dropped to the soil under the mango trees for pupation from February to April. Mango trees in commercial orchards were more heavily damaged by P. mangiferae than were isolated trees in farmer fields (66.7%). The adults of P. mangiferae were captured on sticky traps of all tested colors, and were in flight from January to May. Captures per trap were highest on yellow traps, followed by green, blue, and clear traps. Control of mango gall midge was effectively provided by the synthetic insecticide bifenthrin (Talstar 10 EC) and also by application of neem seed kernel extract on the tree canopy if integrated with raking the soil under the mango tree canopy.

  6. Les porcheries : réservoirs des Culicoides (Diptera : Ceratopogonidae, vecteurs des virus de la Maladie de la Langue bleue et de Schmallenberg ?

    Directory of Open Access Journals (Sweden)

    Zimmer, JY.

    2014-01-01

    Full Text Available Pig farms: reservoirs of vectors of Bluetongue and Schmallenberg viruses?. Bluetongue (BT is a vector-borne disease that affects domestic and wild ruminants. Since its recent outbreak in northern Europe, this viral disease has caused considerable economic losses. The biological vectors of the bluetongue virus are biting midges belonging to the genus Culicoides (Diptera: Ceratopogonidae. Several light trapping campaigns targeting these adult midges have been previously conducted in Belgium within cattle and sheep farms, but none have been performed inside pig farms. This study therefore aims to assess, using light traps, the levels of Culicoides populations that may have been present inside two Belgian pig farms during the fall and winter of 2008. The presence of (potential Culicoides vector species was demonstrated inside the pig buildings during the fall: 8 and 749 specimens belonging to 2 and 7 species were respectively trapped inside the pigsties, with the majority being Obsoletus complex females. The opening up of the buildings seemed to strongly influence their presence. Observation of the females' nutritional status suggests that these midges were likely to have fed or to have laid eggs inside the pig farms, despite the fact that pig's blood could not be identified in the abdomen of engorged females and that pig manure did not reveal the presence of larvae. Pigs could thus be involved in the maintenance of potential vector species populations of the BT virus, or of the new Schmallenberg virus.

  7. Bioaccumulation of metals in aquatic insects of streams located in areas with sugar cane cultivation

    Directory of Open Access Journals (Sweden)

    Juliano José Corbi

    2010-01-01

    Full Text Available Streams located in areas of sugar cane cultivation receive elevated concentrations of metal ions from soils of adjacent areas. The accumulation of metals in the sediments results in environmental problems and leads to bioaccumulation of metal ions by the aquatic organisms. In the present study, bioaccumulation of the metals ions Al, Cd, Cr, Cu, Fe, Mg, Mn and Zn in aquatic insects in streams impacted by the sugar cane was evaluated. The results pointed out that the insects were contaminated by the sediment and that the collector organisms as Chironomus species accumulated higher concentration of metals than the predator organisms.

  8. Nitrous Oxide Emission by Aquatic Macrofauna

    DEFF Research Database (Denmark)

    Stief, Peter; Nielsen, Lars Peter; Schramm, Andreas

    -term metabolic induction of gut denitrification is the preferential production of nitrous oxide rather than dinitrogen. These observations were made in detailed studies on the larvae of the freshwater insects Chironomus plumosus and Ephemera danica which both can be very abundant in lake and stream sediments......Many macrofauna species co-ingest large quantities of microorganisms some of which survive the gut passage. Denitrifying bacteria, in particular, become metabolically induced by anoxic conditions, nitrate, and labile organic compounds in the gut of invertebrates. A striking consequence of the short...

  9. Taxonomic notes on Chironomidae (Diptera from Okinawa Island, Japan, with the description of three new species

    Directory of Open Access Journals (Sweden)

    Masaru Yamamoto

    2015-07-01

    Full Text Available Three new species: Ionthosmittia cuneipenne sp. nov., Orthocladius (Euorthocladius okinawanus sp. nov. and Parakiefferiella semiovata sp. nov., are described from Okinawa Island, Ryukyus, Japan. In addition to these species, twelve species are newly recorded from this island. Diagnostic characters of Tokyobrillia tamamegaseta (Kobayashi et Sasa are emended. Pentapedilum yakuabeum Sasa et Suzuki syn. nov. and Polypedilum yakucedeum Sasa et Suizuki syn. nov. are junior synonyms of Ainuyusurika tuberculatum (Tokunaga. Einfeldia kanazawai (Yamamoto is transferred to the genus Chironomus Meigen and its systematic position is discussed.

  10. SELECTIVIDAD DEL INSECTICIDA CARTAP EMPLEANDO BIOENSAYOS CON ORGANISMOS NO DESTINATARIOS

    OpenAIRE

    Iannacone, José; Universidad Nacional Federico Villarreal (Perú).; Alvariño, Lorena; Universidad Nacional Federico Villarreal (Perú).

    2016-01-01

    El objetivo de la presente investigación fue evaluar la ecotoxicidad del cartap (Bala® 50 PS) sobre ocho organismos animales no destinatarios: 1) Melanoides tuberculata (Müller, 1774) (Mollusca), 2) Emerita analoga (Stimpson, 1857) (Crustácea), 3) Chironomus calligraphus Goeldi, 1805 (Diptera), 4) Cyprinus carpio (Linné, 1758) (Osteichyties), 5) Eisenia foetida (Savigny, 1826) (Annelida), 6) Podisus nigrispinus (Dallas, 1851) (Hemiptera), 7) Trichogramma fuentesi Torre, 1980 (Hymenoptera) y 8...

  11. Comportamento de variedades de sorgo em relação a Contarinia sorghicola e Rhopalosiphum maidis em diferentes épocas de plantio Behaviour of sorghum varieties in relation to Contarinia sorghicola and Rhopalosiphum maidis in different planting seasons

    Directory of Open Access Journals (Sweden)

    C. J. Rossbtto

    1976-07-01

    Full Text Available A interação entre variedades de sorgo com diferentes graus de resistência à mosca (Contarinia sorghicola (Coquillet e ao pulgão (Rhopalosiphum maidis (Fitch, com épocas de plantio, foi estudada em Campinas, em 1967-1968. Essa interação foi significativa. Algumas variedades como sumac e b. leoti, quando plantadas mais cedo, praticamente não sofreram dano de mosca, mas em plantio tardio foram completamente danificadas. Ambas são precoces e moderadamente resistentes à mosca. A variedade AF 117 teve comportamento uniforme, não sofrendo o efeito de épocas: é tardia e resistente à mosca. Em média, a infestação de mosca aumentou nos plantios tardios e a do pulgão, ao contrário, caiu. As variedades de panícula aberta foram mais resistentes ao pulgão que as de panícula compacta. A variedade AF-28 foi mais resistente ao pulgão e à mosca; a M 35-1 foi mais suscetível ao pulgão e à mosca; e a AF-37 mostrou-se bem resistente ao pulgão e suscetível à mosca. As variedades sumac e b. leoti, de resistência moderada à mosca, são suscetíveis ao pulgão. Os resultados demonstram uma independência entre a resistência à mosca e ao pulgão.The sorghum midge Contarinia sorghicola (Coquillet (Diptera Cecidomyiidae is a severe sorghum pest in the State of São Paulo, Brazil, and the aphid Rhopa-losiphum maidis (Fitch (Hemiptera Aphididae is commonly found in the crop. The interaction among varieties of different cycles and resistance, planted in successive dates in relation to the damage done by sorghum midge and the size of the aphid population were studied in 1967-1968. The planting season for sorghum in the State of São Paulo goes from October to January. The plantings were made on XI-3-1967, XI-23-1967, XII-13-1967, and I-2-1968. The different responses of the varieties in relation to the sorghum midge damage were evident. Varieties AF-28 and AF-117 were resistant and Sumac and B. Leoti were moderately resistant. These last two

  12. Taxonomic and numeric structure of Chironomidae (Diptera in different habitats of a Neotropical floodplain

    Directory of Open Access Journals (Sweden)

    Cristina Márcia de Menezes Butakka

    2014-09-01

    Full Text Available We characterized the local benthic Chironomidae by analyzing the numerical density, biomass, diversity index of Shannon-Wiener and dominance of larvae in the main channel of the Ivinhema River, in a secondary channel, in five lakes connected to the main channel and in five lakes without connection. Of the 68 taxa identified, Aedokritus sp., Tanytarsus sp., Chironomus strenzkei Fittkau, 1968 and Procladius sp.1 were found in all sampling sites and were considered morphospecies with greater of greatest ecological plasticity. Chironomus strenzkei Fittkau, 1968, contributed with the greatest biomass in the central region of lakes without connection, whereas Aedokritus sp. dominated in the littoral of lakes. The greater values of diversity indices in the littoral region of channels were due to the greater water flow and to the higher food availability in these areas. The dominance indices, by contrast, were greater on the central region of these environments. The littoral region has exclusive characteristics, representing habitats that could play important controlling in the numerical density and index diversity on the ecosystem, whereas that the biomass of benthic invertebrates in the central region in some biotopes would have different spatial probably according organisms drift.

  13. Productivity of chironomid larvae exposed to oil sands process water : in situ vs. lab bioassay results

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, K.; Ciborowski, J. [Windsor Univ., ON (Canada)

    2010-07-01

    Oil sands process water (OSPW) contains toxic concentrations of salts and napthenic acids that may compromise wetland reclamation efforts. The productivity of wetland biota is one of the criteria used by the Alberta government to determine if land leased to oil sands mining companies is restored. This study determined how chironomid productivity is influenced by the water from oil sands process material (OSPM) affected wetland. In this study, 26 10-day in situ and laboratory bioassays from water of three oil sands process material (OSPM) were compared with water from 3 reference wetlands to determine the influence of water from OSPM affected wetlands on chironomid productivity. Parallel studies were conducted with Chironomus riparius lab-cultured larvae and Chironomus sp larvae cultured from egg masses collected from an OSPW-affected wetland. In situ, chironomids were housed in small cylinders with fine-mesh netting to allow water exchange and contact with the sediment. Preliminary estimates of chironomids emerging from study wetlands indicated that native and lab cultured chironomids are not uniformly responsive to OSPW.

  14. Feeding bionomics of juvenile chinook salmon relative to thermal discharges in the central Columbia River

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.D.

    1994-10-01

    Juvenile chinook salmon (Oncorhynchus tshawytscha) in the Hanford environs of the central Columbia River, Washington consumed almost entirely adult and larval stages of aquatic insects. The food organisms were dominated by midges (Diptera: Tendipedidae); by numbers, adult midges provided 64 and 58% of the diet and larval midges 17 and 18% of the diet, in 1968 and 1969, respectively. The families Hydropsychidae (Trichoptera), Notonectidae (Hemiptera) and Hypogastruridae (Collembola) were of secondary importance. Small fry fed almost exclusively on the small tendipedids. Over 95% of all food organisms originated within the river ecosystem. The distinctive features of food and feeding activity were fourfold: first, relatively few insect groups were utilized; second, the fish depended on drifting, floating, or swimming organisms; third, they visually selected living prey moving in or on the water; and fourth, they were habitat opportunists to a high degree. The 1969 data, were studied to reveal possible thermal effects of heated discharges from plutonium production reactors at Hanford on food and growth parameters. All data were characterized by considerable variation between and within stations. No discernable effects between coldwater and warmwater stations were revealed by analyses of: (1) groups of food organisms utilized, (2) food and feeding activity, (3) numbers of insects consumed, (4) seasonal increases in fish length, (5) fish length-weight relationships, (6) fish coefficients of condition, and (7) stomach biomass. The lack of detectable thermal effects was apparently due to the fact that the main effluent plumes discharge in midstream and the effluents are well mixed before reaching inshore feeding areas. The transient nature of fish groups at each station, influenced by changes in regulated river flows, and the availability of food organisms in the river drift were ecological factors affecting critical thermal evaluation in situ.

  15. RNA interference targets arbovirus replication in Culicoides cells.

    Science.gov (United States)

    Schnettler, Esther; Ratinier, Maxime; Watson, Mick; Shaw, Andrew E; McFarlane, Melanie; Varela, Mariana; Elliott, Richard M; Palmarini, Massimo; Kohl, Alain

    2013-03-01

    Arboviruses are transmitted to vertebrate hosts by biting arthropod vectors such as mosquitoes, ticks, and midges. These viruses replicate in both arthropods and vertebrates and are thus exposed to different antiviral responses in these organisms. RNA interference (RNAi) is a sequence-specific RNA degradation mechanism that has been shown to play a major role in the antiviral response against arboviruses in mosquitoes. Culicoides midges are important vectors of arboviruses, known to transmit pathogens of humans and livestock such as bluetongue virus (BTV) (Reoviridae), Oropouche virus (Bunyaviridae), and likely the recently discovered Schmallenberg virus (Bunyaviridae). In this study, we investigated whether Culicoides cells possess an antiviral RNAi response and whether this is effective against arboviruses, including those with double-stranded RNA (dsRNA) genomes, such as BTV. Using reporter gene-based assays, we established the presence of a functional RNAi response in Culicoides sonorensis-derived KC cells which is effective in inhibiting BTV infection. Sequencing of small RNAs from KC and Aedes aegypti-derived Aag2 cells infected with BTV or the unrelated Schmallenberg virus resulted in the production of virus-derived small interfering RNAs (viRNAs) of 21 nucleotides, similar to the viRNAs produced during arbovirus infections of mosquitoes. In addition, viRNA profiles strongly suggest that the BTV dsRNA genome is accessible to a Dicer-type nuclease. Thus, we show for the first time that midge cells target arbovirus replication by mounting an antiviral RNAi response mainly resembling that of other insect vectors of arboviruses.

  16. Chemical control of Haplodiplosis marginata von Roser (Diptera: Cecidomyiidae).

    Science.gov (United States)

    Censier, F; Chavalle, S; Wittouck, D; De Proft, M; Bodson, B

    2012-01-01

    The saddle gall midge, Haplodiplosis marginata (von Roser), has been detected in Belgium since 2010, after several decades without any reporting. It had indeed caused serious damages between 1965 and 1970. This insect is a European cereal pest whose larvae feed on stems and engender saddle-shaped depressions, resulting in yield losses. Face with the resurgence of this pest, it was decided to study its spatial distribution and, because serious damages were observed in some regions, to develop effective curative control. To date, chemical protection seems to be the only immediate solution in case of heavy emergences. Experimentation was conducted in a highly infested field (Meetkerke, Belgian Polders), according to a randomized complete blocks arrangement with four replications. Foremost, a lambdacyhalothrin-based insecticide was used to evaluate efficiency of several protection schemes, ranging between one and four spray(s). The large spread of flights observed during the 2011 spring allowed to highlight the effect of treatment date on the attack intensity and also on the galls distribution along the stem, on the different internodes: the lower internodes were protected by the early sprayings, while last sprayings induced reduction of galls number on the upper internodes. Moreover, several insecticides already registrated in cereals against aphids were compared for their efficacy against saddle gall midge. Studied pyrethroids have shown a very good efficacy, ranging between 75% and 87%, when applied twice with a 2 weeks interval. To be efficient, insecticide applications must thus be synchronized with the flights and egg-laying periods. Monitoring the phenology of flights is thus essential as part of integrated pest management against saddle gall midge.

  17. Bluetongue virus detection by real-time RT-PCR in Culicoides captured during the 2006 epizootic in Belgium and development of an internal control.

    Science.gov (United States)

    Vanbinst, T; Vandenbussche, F; Vandemeulebroucke, E; De Leeuw, I; Deblauwe, I; De Deken, G; Madder, M; Haubruge, E; Losson, B; De Clercq, K

    2009-06-01

    After the emergence of bluetongue (BT) in Belgium in 2006, two types of entomological surveys were initiated, the one to identify the local vector species, and the other to study their population dynamics. In the vector study, Culicoides were captured near farms with recently infected cattle or sheep; in the population study Culicoides were captured in two meadows situated in the BT-affected region. A total of 130 pools of parous, non-blood engorged female midges (with a mean of 7.5 midges per pool) were analysed with real-time reverse transcription PCR (RT-qPCR) targeting bluetongue virus (BTV) segment 5. To ensure the RNA integrity of the samples, all pools were also tested in a second RT-qPCR targeting Culicoides 18S rRNA, which served as an internal control. Seventeen pools with negative results for both 18S and BTV were excluded, most of which originated from the population survey. In the vector survey near outbreak sites, female midges of the obsoletus complex, including C. obsoletus, C. scoticus, C. dewulfi and C. chiopterus, dominated the black-light trap collections with 19 of 89 pools being BTV-positive. Moreover, all the collections from the vector survey included at least one positive pool of the obsoletus complex compared with only 20% collections (C. obsoletus/C. scoticus) in the population survey. The current study also revealed the presence of BTV RNA in one of five pools of C. pulicaris females captured near recent BT outbreaks, suggesting that this species might have played a role in transmission. Finally, the use of RT-qPCR for the recognition of new potential BTV vector species and the impact of an appropriate monitoring method and internal control are discussed.

  18. Digging for Fossils in the Hertzsprung Gap

    Science.gov (United States)

    Ayres, Thomas R.

    1999-01-01

    Objective was to conduct deep (approx. 250 ks) pointings on two EUV sources, the early-F giant beta Cas and the mid-G giant mu Velorum; to obtain spectra in the range 70-300 A and to record Deep Survey light curves over the extensive duration of each observation. We have analyzed the DS lightcurve and the SW spectrum, breaking the latter lip into time slices corresponding to key phases of the observation: pre-flare, flare rise, and two segments of the flare decay.

  19. Spatio-temporal abundance and dispersal of Culicoides

    DEFF Research Database (Denmark)

    Kirkeby, Carsten

    , and especially infected sheep and cattle are constitute a problem for farmers. The symptoms of BTV include fever, cyanotic tongue, oedemas and decreased milk production. The last symptom affects the economy and animal welfare in the farming industry. In 2011 and 2012, outbreaks of SBV were also recorded......This PhD project comprises studies of biting midges (Culicoides) in Denmark with regards to vector-borne diseases such as bluetongue virus (BTV) and Schmallenberg virus (SBV). Both diseases are new in northern Europe. In Denmark there was an outbreak of BTV in 2007 and 2008. BTV infects ruminants...

  20. Mansonelliasis, a neglected parasitic disease in Haiti.

    Science.gov (United States)

    Raccurt, Christian Pierre; Brasseur, Philippe; Boncy, Jacques

    2014-09-01

    Reported in Haiti as early as 1923, Mansonella ozzardi is still a neglected disease ignored by the health authorities of the country. This review is an update on the geographic distribution of the coastal foci of mansonelliasis in Haiti, the epidemiological profile and prevalence rates of microfilariae in people living in endemic areas, the clinical impact of the parasite on health and the efficiency of the transmission of the parasite among three Culicoides biting-midge species identified as vectors in Haiti. Additionally, interest in establishing a treatment programme to combat this parasite using a single dose of ivermectin is emphasised.

  1. The Toxicity of Nitroguanidine and Photolyzed Nitroguandine to Freshwater Aquatic Organisms

    Science.gov (United States)

    1985-03-01

    teema R0.t) - 33ICY WORDfl1’CAtttewe amee~A ejolft~l ofc.. "**eef andatIA"b 5 Welt ftwaeo)•ute tox city • mannel cattish1,H allela azteca • ’Midge...of well water for transfer to the test chambers. One amphipod used ii testing was _Hyalella azteca , which was collected from Hunt’s Pvnd nedr Norwich...NY. H. azteca was keyed to species using Pennak. 12 The other amphipod tested was Gammarus minus, which was obtained from a spring in the Frederick M

  2. Leaf litter as a possible food source for chironomids (Diptera in Brazilian and Portuguese headwater streams Detritos foliares como possível fonte de alimento para Chironomidae (Diptera em riachos de cabeceira brasileiros e portugueses

    Directory of Open Access Journals (Sweden)

    Marcos Callisto

    2007-06-01

    Full Text Available Our objective was to evaluate the potential use of leaf detritus by chironomid larvae. Field and laboratory experiments were performed using leaves and chironomid species collected in Portugal and Brazil. Laboratory experiments under controlled conditions were done using microbial conditioned senescent leaves of Alnus glutinosa (L. Gaertn, Neriumoleander L., Protium heptaphilum (Aubl. March, Protium brasiliense (Spreng Engl., Myrcia guyanensis(Aubl. DC and Miconia chartacea Triana. Laboratory experiments were performed using specimens collected from leaf litter in local streams. Whenever possible, after the experiments, chironomids were allowed to emerge as adults and identified. In Portugal the following taxa were identified: Micropsectra apposita (Walker, 1856, Polypedilum albicorne (Meigen, 1838,Eukiefferiella claripennis Lundbeck (1898, Rheocricotopus (Psilocricotopus atripes Rempel (1937 and Ablabesmyia Johannsen (1905 (Diptera, Chironomidae. Consumption rates ranged from 0.15 ± 0.10 mg (AFDM of leaf animal-1 day-1 (Micropsectra apposita feeding on Alnus glutinosa up to 0.85 ± 0.33 mg (AFDM of leaf animal-1 day-1 (Polypedilum albicorne feeding on Miconia chartacea. In Brazil, the following taxa were identified from leaves: Phaenopsectra sp., Chironomus spp. and Polypedilum sp. and maximum consumption rates reached 0.47 ± 0.28 (AFDM of leaf mg.animal-1.day-1 (Chironomus Meigen (1803 feeding on Protium heptaphilum. Feeding experiments with laboratory cultured specimens, revealed that some chironomids were unable to feed on decomposing leaves (e.g., C. xanthus Rempel (1939 on P.brasiliensis and M.guyanensis. Our results suggest that some stream chironomids (not typical shredders can use leaf litter of riparian vegetation as a complementary food source.O objetivo foi avaliar o potencial uso de detritos foliares por larvas de Chironomidae. Foram realizados experimentos em campo e em laboratório utilizando folhas e larvas de Chironomidae

  3. THE CHIRONOMIDAE ASSEMBLAGES IN SOMESUL MIC RIVER (ROMANIA DURING 1996 AND 1997

    Directory of Open Access Journals (Sweden)

    Maria-Monica Tudorancea

    2001-01-01

    Full Text Available The communities of Chironomidae larvae in the Gilau – Gherla sector of the Somesul Mic River (Transylvania, Romania were studied during 1996 and 1997 in order to compare their species composition and to see if their component species could be good indicators for water quality deterioration. A total of 102 species were recorded, out of which 12 are new records for the Romanian fauna. Four of these species are known only from East Asia and from the North America. Some species such as Chironomus thumi, Microcricotopus bicolor, Dicrotendipes nervosus and Dicrotendipes notatus occurred in organically enriched waters. Other species, such as Cricotopus algarum, Cricotopus bicinctus, Cricotopus tremulus and Cricotopus trifasciatus occurred in both clean and organically polluted water which indicate they are not good bioindicators for water quality deterioration.

  4. [Molecular phylogeny and the time of divergence of minges (Chironomidae, Nematocera, Diptera) inferred from a partial nucleotide sequence of the cytochrome oxidase I gene (COI)].

    Science.gov (United States)

    Demin, A G; Polukonova, N V; Miuge, N S

    2011-10-01

    This is the first study to infer the phylogenetic structure of minges of the subfamily Chironominae from the amino acid sequence of cytochrome oxidase I (COI). The subdivision of Chironominae into two tribes, Chironomini and Tanytarsini, has been confirmed. The segregation of the genera Pseudochironomus and Riethia into a separate tribe has not been confirmed. Stenochironomus gibbus forms a branch considerably deviating from the subfamily Chironominae. The genus Micropsectra is formed by a large polyphyletic cluster that also includes the genera Virgotanytharsus, Reotanytharsus, Kenopsectra, and Parapsectra. Tanytarsus is the basal genus of the tribe Tanytarsini. The times of divergence of the main taxa of Chironominae have been estimated. The calculated time of divergence of the genus Chironomus disproves the assumption that it is phylogenetically old.

  5. Invasive alien species water hyacinth Eichhornia crassipes as abode for macroinvertebrates in hypertrophic Ramsar Site, Lake Xochimilco, Mexico.

    Science.gov (United States)

    Rocha-Ramirez, A; Robles-Valderrama, E; Ramirez-Flores, E

    2014-11-01

    This paper presents information on the density, diversity and functional feeding groups of macroinvertebrate assemblages associated with water hyacinth in Antiguo Canal Cuemanco, part of Lake Xochimilco in Mexico City. Rare (low frequency and density) and dominant (high frequency and density) taxa prevailed in the assemblages, with the most predominant being Hyalella azteca, Chironomus plumosus and Ischnura denticollis. Nonmetric Multidimensional Scaling confirmed two climatic seasons: warm-rainy and cold-dry; the former with the highest diversity and density of taxa. Canonical Correspondence Analysis showed that conductivity, nitrates and turbidity explained the density variations of taxa. Antiguo Canal Cuemanco waters are spatially homogeneous with the characteristics of hypertrophic shallow lakes, inhabited by scrapers and gathering-collectors. The species found were tolerant to organic pollution.

  6. Feeding habits of Solea senegalensis in earthen ponds in Sado estuary

    Science.gov (United States)

    Castelo Branco, Maria Ana; Arruda, Marco A.; Gamito, Sofia

    2010-11-01

    The senegale sole, Solea senegalensis Kaup, 1858, is a commercially valuable fish and it is beginning to be cultured in a semi-intensive way in fish farms in southern European countries. The present study was initiated to investigate the diet of S. senegalensis under semi-extensive conditions. The feeding habits of sole were studied in two earthen ponds of a fish farm in the Sado estuary. In one earthen pond, artificial fish ration was given. S. senegalensis feeds on few prey items, its diet is mainly composed of insect larvae ( Chironomus salinarus) and polychaeta ( Hediste diversicolor). The diet composition of this species suggests feeding specialization, by consuming mainly annelids and insect larvae and by avoiding other items, extremely abundant in the environment, such as gastropods. In the water reservoir where ration was given, some fish consumed simultaneously benthic organism together with ration. However, benthic organisms seem to be the most important component of S. senegalensis diet.

  7. Toxicity of fluoride to aquatic species and evaluation of toxicity modifying factors.

    Science.gov (United States)

    Pearcy, Krysta; Elphick, James; Burnett-Seidel, Charlene

    2015-07-01

    The present study was performed to investigate the toxicity of fluoride to a variety of freshwater aquatic organisms and to establish whether water quality variables contribute substantively to modifying its toxicity. Water hardness, chloride, and alkalinity were tested as possible toxicity modifying factors for fluoride using acute toxicity tests with Hyalella azteca and Oncorhynchus mykiss. Chloride appeared to be the major toxicity modifying factor for fluoride in these acute toxicity tests. The chronic toxicity of fluoride was evaluated with a variety of species, including 3 fish (Pimephales promelas, O. mykiss, and Salvelinus namaycush), 3 invertebrates (Ceriodaphnia dubia, H. azteca, and Chironomus dilutus), 1 plant (Lemna minor), and 1 alga (Pseudokirchneriella subcapitata). Hyalella azteca was the most sensitive species overall, and O. mykiss was the most sensitive species of fish. The role of chloride as a toxicity modifying factor was inconsistent between species in the chronic toxicity tests.

  8. Nitrous Oxide Production by Abundant Benthic Macrofauna

    DEFF Research Database (Denmark)

    Stief, Peter; Schramm, Andreas

    Detritivorous macrofauna species co-ingest large quantities of microorganisms some of which survive the gut passage. Denitrifying bacteria, in particular, become metabolically induced by anoxic conditions, nitrate, and labile organic compounds in the gut of invertebrates. A striking consequence...... of the short-term metabolic induction of gut denitrification is the preferential production of nitrous oxide rather than dinitrogen. On a large scale, gut denitrification in, for instance, Chironomus plumosus larvae can increase the overall nitrous oxide emission of lake sediment by a factor of eight. We...... that do not ingest large quantities of microorganisms produced insignificant amounts of nitrous oxide. Ephemera danica, a very abundant mayfly larva, was monitored monthly in a nitrate-polluted stream. Nitrous oxide production by this filter-feeder was highly dependent on nitrate availability...

  9. Parachironomus Lenz from China and Japan (Diptera, Chironomidae

    Directory of Open Access Journals (Sweden)

    Chuncai Yan

    2015-04-01

    Full Text Available Members of the genus Parachironomus Lenz known from China and Japan are revised, and a key to their male adults is given. Parachironomus poyangensis sp. n. is described in this life stage. Parachironomus frequens (Johannsen and P. monochromus (van der Wulp are recorded from China for the first time, thus are redescribed from Chinese specimens. Parachironomus kamaabeus Sasa & Tanaka and P. toneabeus Sasa & Tanaka are new junior synonyms of P. frequens. Three Chinese or Japanese species formerly placed in Parachironomus are transferred to other genera, resulting in the new combinations Cryptochironomus inafegeus (Sasa, Kitami & Suzuki, Demicryptochironomus (Irmakia lobus (Yan, Sæther, Jin & Wang, and Microchironomus lacteipennis (Kieffer. Chironomus sauteri Kieffer, Parachironomus kisobilobalis Sasa & Kondo and P. kuramaexpandus Sasa are removed from Parachironomus; the last of these three denotes a valid species of uncertain generic placement, the first two are nomina dubia.

  10. Sesquiterpenes of the geosmin-producing cyanobacterium Calothrix PCC 7507 and their toxicity to invertebrates.

    Science.gov (United States)

    Höckelmann, Claudia; Becher, Paul G; von Reuss, Stephan H; Jüttner, Friedrich

    2009-01-01

    The occurrence of sesquiterpenes was investigated with the geosmin-producing cyanobacterium Calothrix PCC 7507. The essential oil obtained by vacuum destillation was studied in more detail by GC-MS methods and superposition with authentic compounds. Geosmin was the dominating compound while the other sesquiterpenes were minor components. Sesquiterpenes that have not been described before in cyanobacteria were isodihydroagarofuran, eremophilone and 6,11-epoxyisodaucane. Closed-loop stripping analysis revealed that most of the sesquiterpenes were found in the biomass of Calothrix, while eremophilone was mainly observed in the medium of the axenic culture. Eremophilone showed acute toxicity (LC50) against Chironomus riparius (insecta) at 29 microM and against Thamnocephalus platyurus (crustacea) at 22 microM. The compound was not toxic for Plectus cirratus (nematoda). 6,11-Epoxyisodaucane and isodihydroagarofuran exhibited no toxicity to invertebrates when applied in concentrations up to 100 microM.

  11. The exosome associates cotranscriptionally with the nascent pre-mRNP through interactions with heterogeneous nuclear ribonucleoproteins

    DEFF Research Database (Denmark)

    Hessle, Viktoria; Björk, Petra; Sokolowski, Marcus

    2009-01-01

    Eukaryotic cells have evolved quality control mechanisms to degrade aberrant mRNA molecules and prevent the synthesis of defective proteins that could be deleterious for the cell. The exosome, a protein complex with ribonuclease activity, is a key player in quality control. An early quality...... checkpoint takes place cotranscriptionally but little is known about the molecular mechanisms by which the exosome is recruited to the transcribed genes. Here we study the core exosome subunit Rrp4 in two insect model systems, Chironomus and Drosophila. We show that a significant fraction of Rrp4...... is associated with the nascent pre-mRNPs and that a specific mRNA-binding protein, Hrp59/hnRNP M, interacts in vivo with multiple exosome subunits. Depletion of Hrp59 by RNA interference reduces the levels of Rrp4 at transcription sites, which suggests that Hrp59 is needed for the exosome to stably interact...

  12. Microalgae associated with Leptoconops breeding sites in selected sandy beaches of Malaysia.

    Science.gov (United States)

    Rohani, A; Khadri, M S; Lee, H L

    2006-12-01

    A study was carried out to investigate correlation between presence of specific microalgal species and Leptoconops biting midge larvae in its breeding habitats. Sand samples containing microalgae were collected from the beach where the midges were most commonly biting and from sand beaches which are potential as breeding habitats of Leptoconops. The survey covered sand beaches from 12 seperate islands. At all sites, the Bacillariophyta constituted the largest representatives of the microalgae community with the majority from the Naviculaceae family. A total of 24 microalgal species were identified from the sand samples collected from the study sites. Sand samples from Kentot Kecil Island had the highest number of algal species (11.0) and the highest algae species diversity ( Shanon-Weiner Diversity Index, H' = 0.884). Besar Island (Johor) had the lowest number of algal species (2.0) whereas Tengol A Island had the lowest algae species diversity (H'=0.234). Highest similarity index was recorded between sand samples collected from Tengol A Island and Tengol B Island (75.0%) followed by Besar Island (Melaka) and Tengol B Island (62.0 %). The variation between other islands were relatively high. Virtually many kinds of algae were found where Leptoconops were breeding but Fragilaria intermedia, Mastigloia minuta and Navicula advena were particularly common.

  13. Diversity and distribution of Chironomidae (Insecta: Diptera of protected areas in North Tunisia

    Directory of Open Access Journals (Sweden)

    Boulaaba S.

    2014-01-01

    Full Text Available In North Africa seasonal streams called wadi are an unique habitats with serve hydrological and thermal regime. Non-biting midges take an important part of freshwater biodiversity in North Africa. We present new data on the distribution and diversity of Chironomidae in North Tunisia. Larvae, pupal exuviae and adult males of chironomids were collected from a various freshwater ecosystems from May 2005 till April 2006. The aim of this study was to recognize the pattern of midge diversity in North Tunisia to estimate ecological value of running waters in the region. In total, 79 taxa were identified. Nearly all of the taxa were typical representatives of the Palaearctic and Mediterranean complexes. The majority of the investigated sites belonged to the protected areas in North Tunisia, such as the Ichkeul National Park, the Kroumerie Mountains and the El Feija National Park, part of the Intercontinental Reserve of the Mediterranean Biosphere. Altitudinal zonation of the communities composition was found in the lowland (250 m a.s.l. with maximum of 760 m. Whereas among the data 39 species are recorded from Tunisia for the first time, the species richness of Chironomidae is higher than previously estimated.

  14. A new species of Stenodiplosis (Diptera: Cecidomyiidae) on Spartina grasses (Poaceae) with notes on its biology and its parasitoid Tetrastichus bromi (Hymenoptera: Eulophidae).

    Science.gov (United States)

    López, J Manuel Perilla; Johnson, Paul J; Gagné, Raymond J; Boe, Arvid

    2015-12-09

    Stenodiplosis spartinae Gagné new species (Diptera: Cecidomyiidae) is described from eastern South Dakota and coastal North Carolina, and compared with other American congeners. The known host plants are Spartina alterniflora and S. pectinata. The larva is a seed predator of the ovule and immature caryopsis of the host plant. Adult activity is from the early emergence of the host inflorescence through anthesis. Oviposition occurs in the floret with eggs laid under the edges of the palea and lemma. The larva apparently overwinters in dehisced spikelets in the soil among rhizomes of S. pectinata, with pupation in late spring. Laboratory emergence and field activity of the adults suggest a potentialsecond or third generation developing on late emerging inflorescences. Larval feeding does not induce external color or shape changes in the spikelet. Apparently all three instars are ectoparasitized by Tetrastichus bromi Kostyukov (Hymenoptera: Eulophidae) that was probably introduced to North America in the late 1800's and is inculcated into parasitoid guilds of several Stenodiplosis species. Resource partitioning appears to occur between the gall midge and early instars of Aethes spartinana Barnes and McDunnough (Lepidoptera: Tortricidae) that feed on maturing caryopses. The feeding of this gall midge and the moth probably account for most of the reduced seed production in both natural and agronomic populations of S. pectinata.

  15. Molecular differentiation of the Old World Culicoides imicola species complex (Diptera, Ceratopogonidae), inferred using random amplified polymorphic DNA markers.

    Science.gov (United States)

    Sebastiani, F; Meiswinkel, R; Gomulski, L M; Guglielmino, C R; Mellor, P S; Malacrida, A R; Gasperi, G

    2001-07-01

    Samples of seven of the 10 morphological species of midges of the Culicoides imicola complex were considered. The importance of this species complex is connected to its vectorial capacity for African horse sickness virus (AHSV) and bluetongue virus (BTV). Consequently, the risk of transmission may vary dramatically, depending upon the particular cryptic species present in a given area. The species complex is confined to the Old World and our samples were collected in Southern Africa, Madagascar and the Ivory Coast. Genomic DNA of 350 randomly sampled individual midges from 19 populations was amplified using four 20-mer primers by the random amplified polymorphic DNA (RAPD) technique. One hundred and ninety-six interpretable polymorphic bands were obtained. Species-specific RAPD profiles were defined and for five species diagnostic RAPD fragments were identified. A high degree of polymorphism was detected in the species complex, most of which was observed within populations (from 64 to 76%). Principal coordinate analysis (PCO) and cluster analysis provided an estimate of the degree of variation between and within populations and species. There was substantial concordance between the taxonomies derived from morphological and molecular data. The amount and the different distributions of genetic (RAPD) variation among the taxa can be associated to their life histories, i.e. the abundance and distribution of the larval breeding sites and their seasonality.

  16. Total Selenium and Selenium Species in Irrigation Drain Inflows to the Salton Sea, California, April and July 2008

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2009-01-01

    This report presents the results for two sampling periods (April 2008 and July 2008) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (dissolved selenite, selenate, organoselenium), and total suspended solids were determined in water samples and total selenium was determined in water column particulates and in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species - western mosquitofish (Gambusia affinis) and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 1.93 to 44.2 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 0.75 to 3.39; plankton, 0.88 to 4.03; midges, 2.52 to 44.3; fish, 3.37 to 18.9; detritus, 1.11 to 13.6; sediment, 0.11 to 8.93.

  17. Total Selenium and Selenium Species in Irrigation Drain Inflows to the Salton Sea, California, October 2008 and January 2009

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2009-01-01

    This report presents the results for two sampling periods (October 2008 and January 2009) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (dissolved selenite, selenate, organoselenium), and total suspended solids were determined in water samples. Total selenium also was determined in water column particulates and in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species (western mosquitofish, Gambusia affinis, and sailfin molly, Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 1.00 to 33.6 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 1.52 to 8.26; plankton, 0.79 to 3.66; midges, 2.68 to 50.6; fish, 3.09 to 30.4; detritus, 1.78 to 58.0; and sediment, 0.42 to 10.0.

  18. Total Selenium and Selenium Species in Irrigation Drain Inflows to the Salton Sea, California, October 2007 and January 2008

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2008-01-01

    This report presents the results for two sampling periods (October 2007 and January 2008) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (selenite, selenate, organoselenium), and total suspended solids were determined in water samples, and total selenium was determined in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species?western mosquitofish (Gambusia affinis) and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 0.97 to 64.5 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 0.95 to 5.99; plankton, 0.15 to 19.3; midges, 1.39 to 15.4; fish, 3.71 to 25.1; detritus, 0.85 to 21.7; sediment, 0.32 to 7.28.

  19. Obolodiplosis robiniae (Haldeman (Diptera: Cecidomyiidae: A new invasive insect pest on black locust in Serbia

    Directory of Open Access Journals (Sweden)

    Mihajlović Ljubodrag

    2008-01-01

    Full Text Available Locust gall midge Obolodiplosis robiniae (Haldeman originates from Pennsylvania, USA. It was introduced to Europe in 2003, to Italy, Veneto. Its spreading was very fast and in the following year it was identified from the Check Republic and Slovenia. In 2005, it was recorded from South Tyrol and in 2006 from Hungary, south Slovakia, Germany, Croatia, Ukraine and Serbia. During 2007 it was identified from Albania, Austria, Belgium, Bosnia & Herzegovina, France, Montenegro, the Netherlands, Poland, Switzerland, Russia and UK. The expansion of locust gall midge was also recorded in Japan, South Korea, where it was identified for the first time in 2002, and in 2005 it was identified from China. The first finding from Serbia was recorded in the autumn 2006 in the surroundings of Šabac. During 2007, it was identified from Belgrade, and in the same year and the following year (2008 it was found at numerous sites in Serbia, the Republic of Srpska and Montenegro. This study presents O. robiniae biology, method of distribution, natural enemies and the ecological significance.

  20. Two cell cycle blocks caused by iron chelation of neuroblastoma cells: separating cell cycle events associated with each block.

    Science.gov (United States)

    Siriwardana, Gamini; Seligman, Paul A

    2013-12-01

    Studies have presented evidence that besides the well described S phase block, treatment of cancer cell lines with the iron chelator deferrioxamine (DFO) also results in an earlier block in G1 phase. In this article, measurements of cell cycle regulatory proteins define this block at a very specific point in G1. DFO treatment results in markedly decreased cyclin A protein levels. Cyclin E levels that accumulate in early to mid-G1 are increased in cells treated with DFO as compared to the resting cells. The DFO S phase block is shown after cells are arrested at G1/S by (aphidicolin) then released into DFO. The same S phase block occurs with DFO treatment of a neuroblastoma cell line relatively resistant to the G1 DFO block. These experiments clearly differentiate the S phase DFO block from the earlier block pinpointed to a point in mid-G1, before G1/S when cyclin E protein increases but before increased cyclin A synthesis. Apoptosis was observed in cells inhibited by DFO at both cell cycle arrest points.

  1. Chironomids as indicators of natural and human impacts in a 700-yr record from the northern Patagonian Andes

    Science.gov (United States)

    Williams, Natalia; Rieradevall, Maria; Añón Suárez, Diego; Rizzo, Andrea; Daga, Romina; Ribeiro Guevara, Sergio; Arribére, María Angélica

    2016-09-01

    Chironomid communities were studied in a sediment core collected from Lake Moreno Oeste, located in Nahuel Huapi National Park. A major change in midge assemblages occurred at ∼AD 1760, which was characterized by a decrease of "cold taxa" including Polypedilum sp.2 and Dicrotendipes, and an increase of "warm taxa" including Apsectrotanypus and Polypedilum sp.1. These taxa are likely related to climatic conditions concurrent with the end of a cold period at ∼AD 1500-1700 and the beginning of a drying climate at ∼AD 1740-1900 in northern Patagonia. Coarse tephra layers had low midge diversity; however they did not disrupt the climatic trend as the community recovered rapidly after the event. Since AD 1910, after the increase in suburban housing, fish introduction, and the construction of a road, there was an increase in the relative abundances of taxa typically associated with the littoral zone, such as Parapsectrocladius, Riethia, Apsectrotanypus, and some Tanytarsini morphotypes. The main change in the chironomid community appears to be associated with long-term climate change. At the beginning of the 20th century, other site-specific environmental factors (catchment change and fish introduction) altered the chironomid assemblages, making it more difficult to understand the relative importance of each driver of assemblage change.

  2. SuperFly: a comparative database for quantified spatio-temporal gene expression patterns in early dipteran embryos.

    Science.gov (United States)

    Cicin-Sain, Damjan; Pulido, Antonio Hermoso; Crombach, Anton; Wotton, Karl R; Jiménez-Guri, Eva; Taly, Jean-François; Roma, Guglielmo; Jaeger, Johannes

    2015-01-01

    We present SuperFly (http://superfly.crg.eu), a relational database for quantified spatio-temporal expression data of segmentation genes during early development in different species of dipteran insects (flies, midges and mosquitoes). SuperFly has a special focus on emerging non-drosophilid model systems. The database currently includes data of high spatio-temporal resolution for three species: the vinegar fly Drosophila melanogaster, the scuttle fly Megaselia abdita and the moth midge Clogmia albipunctata. At this point, SuperFly covers up to 9 genes and 16 time points per species, with a total of 1823 individual embryos. It provides an intuitive web interface, enabling the user to query and access original embryo images, quantified expression profiles, extracted positions of expression boundaries and integrated datasets, plus metadata and intermediate processing steps. SuperFly is a valuable new resource for the quantitative comparative study of gene expression patterns across dipteran species. Moreover, it provides an interesting test set for systems biologists interested in fitting mathematical gene network models to data. Both of these aspects are essential ingredients for progress toward a more quantitative and mechanistic understanding of developmental evolution.

  3. Hessian fly-associated bacteria: transmission, essentiality, and composition.

    Directory of Open Access Journals (Sweden)

    Raman Bansal

    Full Text Available Plant-feeding insects have been recently found to use microbes to manipulate host plant physiology and morphology. Gall midges are one of the largest groups of insects that manipulate host plants extensively. Hessian fly (HF, Mayetiola destructor is an important pest of wheat and a model system for studying gall midges. To examine the role of bacteria in parasitism, a systematic analysis of bacteria associated with HF was performed for the first time. Diverse bacteria were found in different developmental HF stages. Fluorescent in situ hybridization detected a bacteriocyte-like structure in developing eggs. Bacterial DNA was also detected in eggs by PCR using primers targeted to different bacterial groups. These results indicated that HF hosted different types of bacteria that were maternally transmitted to the next generation. Eliminating bacteria from the insect with antibiotics resulted in high mortality of HF larvae, indicating that symbiotic bacteria are essential for the insect to survive on wheat seedlings. A preliminary survey identified various types of bacteria associated with different HF stages, including the genera Enterobacter, Pantoea, Stenotrophomonas, Pseudomonas, Bacillus, Ochrobactrum, Acinetobacter, Alcaligenes, Nitrosomonas, Arcanobacterium, Microbacterium, Paenibacillus, and Klebsiella. Similar bacteria were also found specifically in HF-infested susceptible wheat, suggesting that HF larvae had either transmitted bacteria into plant tissue or brought secondary infection of bacteria to the wheat host. The bacteria associated with wheat seedlings may play an essential role in the wheat-HF interaction.

  4. Is the chronic Tier-1 effect assessment approach for insecticides protective for aquatic ecosystems?

    Science.gov (United States)

    Brock, Theo Cm; Bhatta, Ranjana; van Wijngaarden, René Pa; Rico, Andreu

    2016-10-01

    We investigated the appropriateness of several methods, including those recommended in the Aquatic Guidance Document of the European Food Safety Authority (EFSA), for the derivation of chronic Tier-1 regulatory acceptable concentrations (RACs) for insecticides and aquatic organisms. The insecticides represented different chemical classes (organophosphates, pyrethroids, benzoylureas, insect growth regulators, biopesticides, carbamates, neonicotinoids, and miscellaneous). Chronic Tier-1 RACs derived using toxicity data for the standard species Daphnia magna, Chironomus spp., and/or Americamysis bahia, were compared with Tier-3 RACs derived from micro- and mesocosm studies on basis of the ecological threshold option (ETO-RACs). ETO-RACs could be derived for 31 insecticides applied to micro- and mesocosms in single or multiple applications, yielding a total number of 36 cases for comparison. The chronic Tier-1 RACs calculated according to the EFSA approach resulted in a sufficient protection level, except for 1 neonicotinoid (slightly underprotective) and for several pyrethroids if toxicity data for A. bahia were not included. This latter observation can be explained by 1) the fact that A. bahia is the most sensitive standard test species for pyrethroids, 2) the hydrophobic properties of pyrethroids, and 3) the fact that long-term effects observed in (epi) benthic arthropods may be better explained by exposure via the sediment than via overlying water. Besides including toxicity data for A. bahia, the protection level for pyrethroids can be improved by selecting both D. magna and Chironomus spp. as standard test species for chronic Tier-1 derivation. Although protective in the majority of cases, the conservativeness of the recommended chronic Tier-1 RACs appears to be less than an order of magnitude for a relatively large proportion of insecticides when compared with their Tier-3 ETO-RACs. This may leave limited options for refinement of the chronic effect assessment

  5. Distribution of chironomidae (Insecta: Diptera) in polluted rivers of the Juru River Basin, Penang, Malaysia.

    Science.gov (United States)

    Al-Shami, Salman A; Rawi, Che Salmah Md; HassanAhmad, Abu; Nor, Siti Azizah Mohd

    2010-01-01

    The influence of physical and chemical parameters on the abundance and diversity of chironomids was studied in six rivers with moderate to highly polluted water in the Juru River Basin. The rivers: Ceruk Tok Kun (CTKR) as reference site, and polluted rivers of Pasir (PR), Juru (JR), Permatang Rawa (PRR), Ara (AR) and Kilang Ubi (KUR) were sampled over a period of five months (November 2007-March 2008). Nine chirnomid species: Chironimus kiiensis, C. javanus, Polypedilum trigonus, Microchironomus sp., Dicrotendipes sp., Tanytarsus formosanus, Clinotanypus sp., Tanypus punctipennis and Fittkauimyia sp. were identified. Assessment of their relationships with several environmental parameters was performed using the canonical correspondence analysis (CCA). Tanytarsus formosanus was the most dominant in the relatively clean CTKR and moderately polluted JR with mean densities of 19.66 and 25.32 m(-2), respectively while C. kiiensis was abundant in more polluted rivers. Tanytarsus formosanus, Dicrotendipes sp. and Microchironomus sp. were grouped under moderate to high water temperature, total organic matter (TOM), total suspended solids (TSS), velocity, pH, phosphates and sulphates. However, Tanypus punctipennis, Fittkauimyia sp., and Clinotanypus sp. were associated with high contents of river sediment such as TOM, Zn and Mn and water ammonium-N and nitrate-N and they were associated with higher dissolved oxygen (DO) content in the water. Chironomus kiiensis, C. javanus and P. trigonus showed positive relationships with TOM, ammonium-N and nitrate-N as well as trace metals of Zn, Cu and Mn. These three species could be considered as tolerant species since they have the ability to survive in extreme environmental conditions with low DO and high concentrations of pollutants. Based on the water parameter scores in all rivers, the highest diversity of chironomid larvae was reported in CTKR. With higher concentrations of organic and/or inorganic pollutants as reported in PPR

  6. Chronic toxicity of nickel-spiked freshwater sediments: variation in toxicity among eight invertebrate taxa and eight sediments

    Science.gov (United States)

    Besser, John M.; Brumbaugh, William G.; Ingersoll, Christopher G.; Ivey, Chris D.; Kunz, James L.; Kemble, Nile E.; Schlekat, Christian E.; Garman, Emily R.

    2013-01-01

    This study evaluated the chronic toxicity of Ni-spiked freshwater sediments to benthic invertebrates. A 2-step spiking procedure (spiking and sediment dilution) and a 2-stage equilibration period (10 wk anaerobic and 1 wk aerobic) were used to spike 8 freshwater sediments with wide ranges of acid-volatile sulfide (AVS; 0.94–38 µmol/g) and total organic carbon (TOC; 0.42–10%). Chronic sediment toxicity tests were conducted with 8 invertebrates (Hyalella azteca, Gammarus pseudolimnaeus, Chironomus riparius, Chironomus dilutus, Hexagenia sp., Lumbriculus variegatus, Tubifex tubifex, and Lampsilis siliquoidea) in 2 spiked sediments. Nickel toxicity thresholds estimated from species-sensitivity distributions were 97 µg/g and 752 µg/g (total recoverable Ni; dry wt basis) for sediments with low and high concentrations of AVS and TOC, respectively. Sensitive species were tested with 6 additional sediments. The 20% effect concentrations (EC20s) for Hyalella and Gammarus, but not Hexagenia, were consistent with US Environmental Protection Agency benchmarks based on Ni in porewater and in simultaneously extracted metals (SEM) normalized to AVS and TOC. For Hexagenia, sediment EC20s increased at less than an equimolar basis with increased AVS, and toxicity occurred in several sediments with Ni concentrations in SEM less than AVS. The authors hypothesize that circulation of oxygenated water by Hexagenia led to oxidation of AVS in burrows, creating microenvironments with high Ni exposure. Despite these unexpected results, a strong relationship between Hexagenia EC20s and AVS could provide a basis for conservative site-specific sediment quality guidelines for Ni.

  7. Polytene chromosomes of Chironomidae (Diptera as a bioassay of trace-metal-induced genome instability

    Directory of Open Access Journals (Sweden)

    Paraskeva Vladimirova Michailova

    2012-10-01

    Full Text Available Chironomids are a ubiquitous group of aquatic insects that are very sensitive to environmental stress. Due to the presence of polytene (‘giant’ salivary gland chromosomes, it is possible to define the genome response of several Chironomid species to various stress agents. The aim of this study was to assess the genotoxic changes in populations of widely distributed chironomid species from aquatic basins in Bulgaria, Italy, Russia, U.K. and Poland, which were exposed to high concentrations of trace metals. We analyzed the structural and functional alterations of polytene chromosomes of the salivary glands of larvae belonging to three different cytocomplexes of the genus Chironomus (“thummi”, “lacunarius”, “pseudothummi”, and genera Glyptotendipes and Kiefferulus. Somatic structural chromosome rearrangements (para- and pericentric heterozygous inversions, deletions, deficiencies and amplifications were used to estimate a Somatic index (S for each population. The highest S indexes were detected in Chironomus riparius populations from locations with high concentrations of trace metals in the sediment. Each species showed specific genome responses to stress agents which we discussed in the light of the specific DNA structures and cytogenetic characteristics of the species. In larvae from polluted sediments two key structures of the salivary gland chromosomes (Balbiani Rings and Nucleolar Organizer sharply reduced their activity to levels below those observed under non-polluted conditions. It is concluded that polytene chromosomes can be used as tools for evaluating the genotoxicity of the aquatic environment. Structural and functional chromosome alterations provide cost-effective early-warning signals of genotoxic concentrations of environmental pollutants.doi: 10.5324/fn.v31i0.1355.Published online: 17 October 2012.

  8. Polychlorinated biphenyls in aquatic invertebrates and fish and observations about nitrogen and carbon isotope composition in relation to trophic structure and bioaccumulation patterns, Lake Worth and Meandering Road Creek, Fort Worth, Texas, 2007-08

    Science.gov (United States)

    Moring, J. Bruce

    2010-01-01

    During 2007-08 the U.S. Geological Survey, in cooperation with the U.S. Air Force, evaluated the concentration of polychlorinated biphenyls (PCBs) in aquatic invertebrates and fish from one site in the main body of Lake Worth, two sites in a small inlet in Lake Worth (upper and lower Woods Inlet), and one site in Meandering Road Creek in Fort Worth, Texas. The four sites sampled during 2007-08 were located at or near sites where surficial bed-sediment samples had been collected and analyzed for PCBs during previous U.S. Geological Survey studies so that PCB concentrations in aquatic invertebrates and fish and PCB concentrations in surficial bed-sediment samples could be compared. Stable nitrogen and carbon isotopes were used to help assess differences in the amount of these isotopes by species and sampling location. The sum of 15 PCB-congener concentrations was highest for aquatic invertebrates and fish from the upper Woods Inlet site and lowest for the same aquatic invertebrates and fish from Lake Worth site, where PCBs historically had not been detected in lake bed sediment. An increase in the ratio of the heavier nitrogen-15 (15N) isotope to the lighter nitrogen-14 (14N) isotope, referred to as enrichment of 15N, was highest in largemouth bass (representing the highest trophic level sampled) at all sites and lowest for true midge larvae inhabiting surficial bed sediment in the lake (representing the lowest trophic level sampled). Enrichment of 15N was less variable in largemouth bass and other fish from the highest trophic level compared with shorter lived, primary consumer invertebrates from lower trophic levels, such as true midge larvae, mayfly nymphs, and zooplankton. The delta carbon-13 (delta13C) values measured in true midge larvae collected at the Lake Worth and upper and lower Woods Inlet sites were more negative compared with the delta13C values measured for all other taxa, indicating true midge larvae were more depleted of carbon-13 (13C) compared

  9. Weather, host and vector--their interplay in the spread of insect-borne animal virus diseases.

    Science.gov (United States)

    Sellers, R F

    1980-08-01

    , B and C correspond to endemic and zones D and E to epidemic conditions.Similar zones can be recognized for African horse sickness, bluetongue, Ibaraki disease and bovine ephemeral fever - examples of diseases transmitted in a midge-mammal cycle. In zones A and B viruses are transported by infected midges carried on the wind in association with the movement of ITCZ and undergo cycles in young animals. In these zones and in zone C there is a continual movement of midges on the warm wind between one area and another, colonizing new sites or reinforcing populations of midges already present. Virus is introduced at times into fringe areas (zones D and E) and, as there is little resistance in the host, gives rise to clinical signs of disease. In some areas there is persistence during adverse conditions; in others, the virus is carried back to the endemic zones by infected midges or vectors.Examples of viruses maintained in a mosquito/biting fly-mammal cycle are Venezuelan equine encephalitis and vesicular stomatitis. These viruses enter a migratory cycle from a local cycle and the vectors in the migratory cycle are carried over long distances on the wind. Further examples of virus spread by movement of vectors include West Nile, Rift Valley fever, yellow fever, epizootic haemorrhagic disease of deer and Akabane viruses.In devising means of control it is essential to decide the relationship of host, vector and virus and the nature of the zone in which the area to be controlled lies. Because of the continual risk of reintroduction of infected vectors, it is preferable to protect the host by dipping, spraying or by vaccination rather than attempting to eliminate the local population of insects.

  10. Larval development sites of the main Culicoides species (Diptera: Ceratopogonidae) in northern Europe and distribution of coprophilic species larvae in Belgian pastures.

    Science.gov (United States)

    Zimmer, Jean-Yves; Brostaux, Yves; Haubruge, Eric; Francis, Frédéric

    2014-10-15

    Some Culicoides species of biting midges (Diptera: Ceratopogonidae) are biological virus vectors worldwide and have indeed been associated with outbreaks of important epizoonoses in recent years, such as bluetongue and Schmallenberg disease in northern Europe. These diseases, which affect domestic and wild ruminants, have caused considerable economic losses. Knowledge of substrates suitable for Culicoides larval development is important, particularly for the main vector temperate species. This study, realized during two years, aimed to highlight the larval development sites of these biting midge species in the immediate surroundings of ten Belgian cattle farms. Moreover, spatial distribution of the coprophilic Culicoides larvae (C. chiopterus and C. dewulfi) within pastures was studied with increasing distance from farms along linear transects (farm-pasture-woodland). A total of 4347 adult specimens belonging to 13 Culicoides species were obtained by incubation of 2131 soil samples belonging to 102 different substrates; 18 of these substrates were suitable for larval development. The Obsoletus complex (formed by two species) was observed in a wide range of substrates, including silage residues, components of a chicken coop, dung adhering to walls inside stables, leftover feed along the feed bunk, a compost pile of sugar beet residues, soil of a livestock trampling area, and decaying wood, while the following served as substrates for the other specimens: C. chiopterus, mainly cow dung; C. dewulfi, cow dung and molehill soil; C. circumscriptus, algae; C. festivipennis, algae and soil in stagnant water; C. nubeculosus, algae and silt specifically from the edge of a pond; C. punctatus, mainly wet soil between silage reserves; C. salinarius, algae; and C. stigma, algae and wet soil between silage reserves. We also recorded significantly higher densities of coprophilic larvae within pastures in cow dung located near forests, which is likely due to the localization of

  11. Serosurveillance of Schmallenberg virus in Switzerland using bulk tank milk samples.

    Science.gov (United States)

    Balmer, Sandra; Vögtlin, Andrea; Thür, Barbara; Büchi, Martina; Abril, Carlos; Houmard, Matthias; Danuser, Jürg; Schwermer, Heinzpeter

    2014-10-15

    Infections with Schmallenberg virus (SBV), a novel Orthobunyavirus transmitted by biting midges, can cause abortions and malformations of newborns and severe symptoms in adults of domestic and wild ruminants. Understanding the temporal and spatial distribution of the virus in a certain territory is important for the control and prevention of the disease. In this study, seroprevalence of antibodies against SBV and the spatial spread of the virus was investigated in Swiss dairy cattle applying a milk serology technique on bulk milk samples. The seroprevalence in cattle herds was significantly higher in December 2012 (99.5%) compared to July 2012 (19.7%). This high between-herd seroprevalence in cattle herds was observed shortly after the first detection of viral infections. Milk samples originating from farms with seropositive animals taken in December 2012 (n=209; mean 160%) revealed significantly higher S/P% ratios than samples collected in July 2012 (n=48; mean 103.6%). This finding suggests a high within-herd seroprevalence in infected herds which makes testing of bulk tank milk samples for the identification farms with past exposures to SBV a sensitive method. It suggests also that within-herd transmission followed by seroconversion still occurred between July and December. In July 2012, positive bulk tank milk samples were mainly restricted to the western part of Switzerland whereas in December 2012, all samples except one were positive. A spatial analysis revealed a separation of regions with and without positive farms in July 2012 and no spatial clustering within the regions with positive farms. In contrast to the spatial dispersion of bluetongue virus, a virus that is also transmitted by Culicoides midges, in 2008 in Switzerland, the spread of SBV occurred from the western to the eastern part of the country. The dispersed incursion of SBV took place in the western part of Switzerland and the virus spread rapidly to the remaining territory. This spatial

  12. Optimal vaccination scenarios against vector-borne diseases

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Enøe, Claes; Bødker, Rene

    Using a process oriented semi-agent based model we simulated the spread of Bluetongue virus in Denmark. We evaluated the efficiency and minimum vaccination cover for eight different preventive vaccination strategies in Denmark. The simulation model replicates both passive and active flight...... of Culicoides between hosts on pasture and stables in Denmark. Seasonal abundance of midges and temperature dependence on biological processes were included in the model. The eight vaccination scenarios comprised of: All holdings vaccinated to a given percentage, random holdings selected for vaccination, two...... scenarios based on the size of holdings, mosaic vaccination of nearest neighbor farms, vaccination of hosts on pasture, regional vaccination, and trench vaccination from the border to Germany. These eight scenarios were investigated under normal grazing conditions and under a forced housing scenario...

  13. Predator-prey interactions and community structure: chironomids, mosquitoes and copepods in Heliconia imbricata (Musaceae).

    Science.gov (United States)

    Naeem, Shahid

    1988-11-01

    Evidence from both field observations and experimental work indicates that predation by larvae of a midge, Pentaneura n. sp. (Chironomidae), causes the low densities of mosquito larvae (Culicidae) found in the water filled bracts of Heliconia imbricata (Musaceae), microhabitats typically colonized by mosquitoes. This predation affects 2 species of mosquitoes, Wyeomyia pseudopecten, a resident species, and Trichoprosopon digitatum, a non-resident species. Predation keeps resident mosquito densities low while completely excluding the nonresident mosquito from the habitat. Both these effects of predation depend on the presence of an abundant alternative prey, an undescribed species of harpacticoid copepod found in the bracts. These copepod prey sustain chironomids when resident mosquito densities are low, permiting predator densities to remain high enough to exclude the non-resident mosquito. I discuss the evolutionary and ecological implications of predation structuring communities.

  14. Spatial abundance and clustering of Culicoides (Diptera: Ceratopogonidae) on a local scale

    DEFF Research Database (Denmark)

    Kirkeby, Carsten; Bødker, Rene; Stockmarr, Anders;

    2013-01-01

    Background Biting midges, Culicoides, of the Obsoletus group and the Pulicaris group have been involved in recent outbreaks of bluetongue virus and the former was also involved in the Schmallenberg virus outbreak in northern Europe. Methods For the first time, here we investigate the local...... abundance pattern of these two species groups in the field by intensive sampling with a grid of light traps on 16 catch nights. Neighboring trap catches can be spatially dependent on each other, hence we developed a conditional autoregressive (CAR) model framework to test a number of spatial and non......, and cluster locations shifted between catch nights. No significant temporal autocorrelation was detected. CAR models for both species groups identified a significant positive impact of humidity and significant negative impacts of precipitation and wind turbulence. Temperature was also found to be significant...

  15. Phylogenetic relationships of the Culicomorpha inferred from 18S and 5.8S ribosomal DNA sequences. (Diptera:Nematocera).

    Science.gov (United States)

    Miller, B R; Crabtree, M B; Savage, H M

    1997-05-01

    We investigated the evolutionary origins of the mosquito family Culicidae by examination of 18S and 5.8S ribosomal gene sequence divergence. Phylogenetic analyses demonstrated that within the infraorder Culicomorpha, taxa in the families Corethrellidae, Chaoboridae and Culicidae formed a monophyletic group; there was support for a sister relationship between this lineage and a representative of the Chironomidae. A chaoborid midge was the closest relative of the mosquitoes. Taxa from four genera of mosquitoes formed a monophyletic group; lack of a spacer in the 5.8S gene was unique to members of the Culicidae. A member of the genus Anopheles formed the most basal lineage among the mosquitoes analysed. Phylogenetic relationships were unresolved for representatives in the families Dixidae, Simuliidae and Ceratopogonidae.

  16. Mitochondrial genome sequences of Nematocera (lower Diptera): evidence of rearrangement following a complete genome duplication in a winter crane fly.

    Science.gov (United States)

    Beckenbach, Andrew T

    2012-01-01

    The complete mitochondrial DNA sequences of eight representatives of lower Diptera, suborder Nematocera, along with nearly complete sequences from two other species, are presented. These taxa represent eight families not previously represented by complete mitochondrial DNA sequences. Most of the sequences retain the ancestral dipteran mitochondrial gene arrangement, while one sequence, that of the midge Arachnocampa flava (family Keroplatidae), has an inversion of the trnE gene. The most unusual result is the extensive rearrangement of the mitochondrial genome of a winter crane fly, Paracladura trichoptera (family Trichocera). The pattern of rearrangement indicates that the mechanism of rearrangement involved a tandem duplication of the entire mitochondrial genome, followed by random and nonrandom loss of one copy of each gene. Another winter crane fly retains the ancestral diperan gene arrangement. A preliminary mitochondrial phylogeny of the Diptera is also presented.

  17. Triacylglycerol-rich lipophorins are found in the dipteran infraorder Culicomorpha, not just in mosquitoes

    Directory of Open Access Journals (Sweden)

    James E. Pennington

    2002-08-01

    Full Text Available Lipophorin is the major hemolymph protein responsible for lipid transport between tissues of insects. Lipophorins from several insect species in order Diptera (the fruit fly Drosophila melanogaster from the suborder Brachycera, the mosquito Aedes aegypti; the phantom midges Chaoborus maximus and minimus; the black fly Simulium vittatum; the crane fly Nephrotoma abbreviata, all from the suborder Nematocera were isolated and characterized. All lipophorins consisted of two protein subunits of approximately 240 and 75 kDa each. The density of each lipophorin was in the high-density lipoprotein range (1.112 to 1.128 g/ml. The predominant neutral lipid carried by lipophorin from insects belonging to the infraorder Culicomorpha was triacylglycerol. Lipophorin from the crane fly Nephrotoma abbreviata, which belongs to the infraorder Tipulomorpha, carried approximately equivalent amounts of diacylglycerol and triacylglycerol. Lipophorin from D. melanogaster was found to carry diacylglycerol as the predominant neutral lipid.

  18. The complete mitochondrial genome of Dixella aestivalis (Diptera: Nematocera: Dixidae).

    Science.gov (United States)

    Briscoe, Andrew G; Sivell, Duncan; Harbach, Ralph E

    2017-01-01

    Dixidae, meniscus midges, belong to the suborder Nematocera of the order Diptera. The family includes 197 known species classified in nine genera. The complete mitochondrial genome of the Dixella aestivalis (Meigen) from the United Kingdom is reported here, along with its annotation and comparison with the genome of an unidentified species of Dixella from China. The circular genome consists of 16 465 bp and has a gene content consisting of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes and a non-coding, A + T-rich, control region. The mitochondrial genome of D. aestivalis can be used to identify genetic markers for species identification, and will be valuable for resolving phylogenetic relationships within the genus, family Dixidae and suborder Nematocera.

  19. Climatic change and indigenous and non-indigenous ravagers : a new reality?; Changements climatiques et les ravageurs indigenes et exotiques : une nouvelle realite?

    Energy Technology Data Exchange (ETDEWEB)

    Regniere, J.; Cooke, B.; Logan, J.A.; Carroll, A.; Safranyik, L. [Natural Resources Canada, Ottawa, ON (Canada). Canadian Forest Service

    2005-07-01

    The impact that climate change may have on ecological diversity was discussed with particular reference to the movement of indigenous and non-indigenous insects that are harmful to trees. Insects in particular, are more likely to evolve rapidly and adapt to ecological change. Those with a high rate of reproduction and which can move long distances will colonize new habitats and survive a wide range of bio-physical conditions. This PowerPoint presentation included a series of graphs, tables and charts to illustrate the increased presence of various harmful insects in northern forests, including the balsam twig aphid, balsam gall midge, gypsy moth, hemlock looper, western spruce budworm, and forest tent caterpillar. It was shown that large changes in ecosystems are expected to occur at northern latitudes and higher altitudes. tabs., figs.

  20. Diet of canvasbacks during breeding

    Science.gov (United States)

    Austin, J.E.; Serie, J.R.; Noyes, J.H.

    1990-01-01

    We examined diets of canvasbacks (Aythya valisineria) breeding in southwestern Manitoba during 1977-81. Percent volume of animal foods consumed did not differ between males and females nor among prenesting, rapid follicle growth, laying, incubation, and renesting periods in females (mean = 50.1%). Tubers and shoots of fennelleaf pondweed (Potamogeton pectinatus) and midge larvae (Chironomidae) were the predominant foods, comprising on average 45% and 23% of the diet volume, respectively. Continued importance of plant foods to canvasbacks throughout reproduction contrasts with the mostly invertebrate diets of other prairie-breeding ducks, and does not fit current theories of nutritional ecology of breeding anatids (i.e., females meet the protein requirements of reproduction by consuming a high proportion of animal foods).

  1. Range expansion of the Bluetongue vector, Culicoides imicola, in continental France likely due to rare wind-transport events

    Science.gov (United States)

    Jacquet, Stéphanie; Huber, Karine; Pagès, Nonito; Talavera, Sandra; Burgin, Laura E.; Carpenter, Simon; Sanders, Christopher; Dicko, Ahmadou H.; Djerbal, Mouloud; Goffredo, Maria; Lhor, Youssef; Lucientes, Javier; Miranda-Chueca, Miguel A.; Pereira Da Fonseca, Isabel; Ramilo, David W.; Setier-Rio, Marie-Laure; Bouyer, Jérémy; Chevillon, Christine; Balenghien, Thomas; Guis, Hélène; Garros, Claire

    2016-01-01

    The role of the northward expansion of Culicoides imicola Kieffer in recent and unprecedented outbreaks of Culicoides-borne arboviruses in southern Europe has been a significant point of contention. We combined entomological surveys, movement simulations of air-borne particles, and population genetics to reconstruct the chain of events that led to a newly colonized French area nestled at the northern foot of the Pyrenees. Simulating the movement of air-borne particles evidenced frequent wind-transport events allowing, within at most 36 hours, the immigration of midges from north-eastern Spain and Balearic Islands, and, as rare events, their immigration from Corsica. Completing the puzzle, population genetic analyses discriminated Corsica as the origin of the new population and identified two successive colonization events within west-Mediterranean basin. Our findings are of considerable importance when trying to understand the invasion of new territories by expanding species. PMID:27263862

  2. Comparative toxicity of methanol and N,N-dimethylformamide to freshwater fish and invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, S.H.; Knuth, M.L.; Anderson-Buchou, C.D.; Brooke, L.T.; Lima, A.R.; Shubat, P.J.

    1986-10-01

    The organic solvents methanol and N,N-dimethylformamide (DMF) are used widely as industrial solvents. Although some toxicity data appear in the literature for methanol and DMF, there have been few studies which have been flow-through tests for a standard 48- or 96-h exposure period with measured toxicant concentrations. In this study, 96-h flow-through acute toxicity tests with methanol and DMF were conducted with three species of freshwater fish - rainbow trout (Salmo gairdneri), bluegill (Lepomis macrochirus) and fathead minnow (Pimephales promelas). Static acute toxicity tests (48 h) were conducted with DMF and two species of freshwater invertebrates - a midge (Paratanytarsus parthenogeneticus) and a daphnid (Daphnia magna). Median lethal (LC50) and median effect (EC50) concentrations for 96-h exposures were determined for fish and 48-h EC50's were determined for invertebrates.

  3. Canadair CL-227 Remotely Piloted Vehicle

    Science.gov (United States)

    Clark, Andrew S.

    1983-08-01

    The Canadair CL-227 is a rotary winged Remotely Piloted Vehicle (RPV) intended initially as the air-vehicle for a medium range battlefield surveillance and target acquisition system. The concept on which this vehicle is based brings together in-house expertise as a designer and manufacturer of surveillance drones (AN-USD-50l -MIDGE-) with experience in rigid rotor technology from the CL-84 tilt wing VTOL program. The vehicle is essentially modular in design with a power module containing the engine, fuel and related systems, a rotor module containing the two counter-rotating rotors and control actuators, and a control module containing the autopilot, data link and sensor system. The vehicle is a true RPV (as opposed to a drone) as it is flown in real time by an operator on the ground and requires relatively little skill to pilot.

  4. Arboviruses pathogenic for domestic and wild animals.

    Science.gov (United States)

    Hubálek, Zdenek; Rudolf, Ivo; Nowotny, Norbert

    2014-01-01

    The objective of this chapter is to provide an updated and concise systematic review on taxonomy, history, arthropod vectors, vertebrate hosts, animal disease, and geographic distribution of all arboviruses known to date to cause disease in homeotherm (endotherm) vertebrates, except those affecting exclusively man. Fifty arboviruses pathogenic for animals have been documented worldwide, belonging to seven families: Togaviridae (mosquito-borne Eastern, Western, and Venezuelan equine encephalilitis viruses; Sindbis, Middelburg, Getah, and Semliki Forest viruses), Flaviviridae (mosquito-borne yellow fever, Japanese encephalitis, Murray Valley encephalitis, West Nile, Usutu, Israel turkey meningoencephalitis, Tembusu and Wesselsbron viruses; tick-borne encephalitis, louping ill, Omsk hemorrhagic fever, Kyasanur Forest disease, and Tyuleniy viruses), Bunyaviridae (tick-borne Nairobi sheep disease, Soldado, and Bhanja viruses; mosquito-borne Rift Valley fever, La Crosse, Snowshoe hare, and Cache Valley viruses; biting midges-borne Main Drain, Akabane, Aino, Shuni, and Schmallenberg viruses), Reoviridae (biting midges-borne African horse sickness, Kasba, bluetongue, epizootic hemorrhagic disease of deer, Ibaraki, equine encephalosis, Peruvian horse sickness, and Yunnan viruses), Rhabdoviridae (sandfly/mosquito-borne bovine ephemeral fever, vesicular stomatitis-Indiana, vesicular stomatitis-New Jersey, vesicular stomatitis-Alagoas, and Coccal viruses), Orthomyxoviridae (tick-borne Thogoto virus), and Asfarviridae (tick-borne African swine fever virus). They are transmitted to animals by five groups of hematophagous arthropods of the subphyllum Chelicerata (order Acarina, families Ixodidae and Argasidae-ticks) or members of the class Insecta: mosquitoes (family Culicidae); biting midges (family Ceratopogonidae); sandflies (subfamily Phlebotominae); and cimicid bugs (family Cimicidae). Arboviral diseases in endotherm animals may therefore be classified as: tick

  5. An annotated checklist of scale insects (Hemiptera: Coccoidea) of Saint Lucia, Lesser Antilles .

    Science.gov (United States)

    Malumphy, Chris

    2014-07-31

    An annotated list of 83 scale insect species (Hemiptera: Sterorrhyncha: Coccoidea) recorded from Saint Lucia is presented, based on data gathered from UK quarantine interceptions, samples collected in an urban coastal habitat in the North West of the Island in 2013, and published records. Thirty-three species (40%) are recorded for the first time for the country, including Dysmicoccus joannesiae (Costa Lima), a South American mealybug, and Poliaspoides formosana (Takahashi), an Asian armoured scale insect pest of bamboo, which are new for the Caribbean region. The economic, environmental and social impacts caused by introduced exotic species of scale insect are discussed. Two predatory midges Diadiplosis ?coccidivora (Felt) and Diadiplosis multifila (Felt) (Diptera: Cecidomyiidae) are recorded for the first time from Saint Lucia. The latter species was observed causing 90% mortality of a large infestation of passion vine mealybug Planococcus minor (Maskell) on soursop fruit. 

  6. Macrophyte decomposition in a surface-flow ammonia-dominated constructed wetland: Rates associated with environmental and biotic variables

    Science.gov (United States)

    Thullen, J.S.; Nelson, S.M.; Cade, B.S.; Sartoris, J.J.

    2008-01-01

    Decomposition of senesced culm material of two bulrush species was studied in a surface-flow ammonia-dominated treatment wetland in southern California. Decomposition of the submerged culm material during summer months was relatively rapid (k = 0.037 day-1), but slowed under extended submergence (up to 245 days) and during fall and spring sampling periods (k = 0.009-0.014 day-1). Stepwise regression of seasonal data indicated that final water temperature and abundance of the culm-mining midge, Glyptotendipes, were significantly associated with culm decomposition. Glyptotendipes abundance, in turn, was correlated with water quality parameters such as conductivity and dissolved oxygen and ammonia concentrations. No differences were detected in decomposition rates between the bulrush species, Schoenoplectus californicus and Schoenoplectus acutus.

  7. Herança da resistência da variedade de sorgo AF-28 a Contarinia sorghicola Coquillet Inheritance of resistance to Contarinia sorghicola Coquillet in the AF-28 sorghum variety

    Directory of Open Access Journals (Sweden)

    Carlos Jorge Rossetto

    1983-01-01

    Full Text Available Foram feitos cruzamentos recíprocos entre as variedades AF-28, resistente à mosquinha-do-sorgo, e Sart, suscetível. A geração F1 derivada desse cruzamento foi quase tão danificada - nota de dano: 8,5 - quanto o pai suscetível Sart - nota de dano: 9,2. O pai resistente teve nota 1,2. Isso mostra que a suscetibilidade à mosca é dominante ou parcialmente dominante. O comportamento de famílias derivadas de plantas F2 e cultivadas na geração F3 sugere que, no mínimo, dois pares de genes recessivos são responsáveis pela herança da resistência à mosquinha. A variedade resistente AF-28 apresenta diversas características indesejáveis: colmo seco; muito tardia; não-ereta; panícula muito aberta e muito alta. Sua resistência à mosquinha, todavia, pode ser transferida facilmente e recombinada com características agronômicas desejáveis. Obtiveram-se linhas resistentes, mais baixas, precoces, eretas, com. colmo sucoso e panículas mais fechadas.Reciprocal crosses were made between the sorghum varieties AF-28 resistant to the sorghum midge, and Sart susceptible. In 1975 under field conditions at Campinas, State of São Paulo, Brazil, the average damage of the Fl of these crosses was 8.5, the average damage of Sart was 9.2 and of AF-28 was 1.2 showing that susceptibility to sorghum midge is dominant or incompletely dominant. Inflorescences of F2 plants were bagged at random and F2 derived families in the generation F3 (S1 lines were studied under field conditions in 1977. Fourteen families out of a total of 216 from the cross Sart x AF-28, did not differ significantly at the 5% level from the resistant parent AF-28. The chi-square between the observed ratio of 14:202 and the expected ratio of 14:210 was not significant. This result fits into the hypothesis of a minimum of two genes governing the resistance to sorghum midge in the variety AF-28. Three families out of a total of 109 from the cross AF-28 x Sart did not differ

  8. Insects as vectors: systematics and biology.

    Science.gov (United States)

    Rodhain, F

    2015-04-01

    Among the many complex relationships between insects and microorganisms such as viruses, bacteria and parasites, some have resulted in the establishment of biological systems within which the insects act as a biological vector for infectious agents. It is therefore advisable to understand the identity and biology of these vectors in depth, in order to define procedures for epidemiological surveillance and anti-vector control. The following are successively reviewed in this article: Anoplura (lice), Siphonaptera (fleas), Heteroptera (bugs: Cimicidae, Triatoma, Belostomatidae), Psychodidae (sandflies), Simuliidae (black flies), Ceratopogonidae (biting midges), Culicidae (mosquitoes), Tabanidae (horseflies) and Muscidae (tsetse flies, stable flies and pupipara). The authors provide a rapid overview of the morphology, systematics, development cycle and bio-ecology of each of these groups of vectors. Finally, their medical and veterinary importance is briefly reviewed.

  9. Pulmonary localization of Mansonella perstans in a 16 months-old male patient in a tertiary care hospital in Bukavu, Democratic Republic of Congo.

    Science.gov (United States)

    Kabego, Landry; Kasengi, Joe Bwija; Mirindi, Patrick; Ruhanya, Vurayai; Lupande, David; Bulabula, André; Ngoma, Patrick

    2016-12-01

    Mansonella perstans is a human filarial parasite transmitted by biting midges (Diptera: Ceratopogonidae) belonging to the genus Culicoides and it is widely spread in sub-Saharan Africa. While most cases are asymptomatic, mansonelliasis can be associated with angioedema, arthralgia, swellings, pain in the scrotum or in serous cavities such as the pleura, the peritoneum, the pericardium, etc. Mansonelliasis can be really hard to treat, but it has been shown that an intensive treatment using albendazole can clear the parasite. Here we describe a case of a 16 months-old malnourished child with pneumonia due to M. perstans in the east of the Democratic Republic of Congo. Although our investigations confirmed M. perstans infection, this case shows that it is very difficult to come to a conclusive diagnosis.

  10. Schmallenberg virus infection of ruminants: challenges and opportunities for veterinarians

    Directory of Open Access Journals (Sweden)

    Claine F

    2015-06-01

    Full Text Available François Claine, Damien Coupeau, Laetitia Wiggers, Benoît Muylkens, Nathalie Kirschvink Veterinary Department, Faculty of Sciences, Namur Research Institute for Life Sciences (NARILIS, University of Namur (UNamur, Namur, Belgium Abstract: In 2011, European ruminant flocks were infected by Schmallenberg virus (SBV leading to transient disease in adult cattle but abortions and congenital deformities in calves, lambs, and goat kids. SBV belonging to the Simbu serogroup (family Bunyaviridae and genus Orthobunyavirus was first discovered in the same region where bluetongue virus serotype 8 (BTV-8 emerged 5 years before. Both viruses are transmitted by biting midges (Culicoides spp. and share several similarities. This paper describes the current knowledge of temporal and geographical spread, molecular virology, transmission and susceptible species, clinical signs, diagnosis, prevention and control, impact on ruminant health, and productivity of SBV infection in Europe, and compares SBV infection with BTV-8 infection in ruminants. Keywords: Schmallenberg virus, Europe, ruminants, review

  11. Vector monitoring at Belgian outbreak sites during the bluetongue epidemic of 2006.

    Science.gov (United States)

    De Deken, G; Madder, M; Deblauwe, I; De Clercq, K; Fassotte, C; Losson, B; Haubruge, E; De Deken, R

    2008-10-15

    In response to the first bluetongue outbreak in Belgium a monitoring programme was started at the end of August 2006 to identify possible vectors transmitting the disease. Black light traps were deployed at 36 outbreak sites and captured 1959 Culicoides specimens belonging to 16 different species. Eighty four percent of the biting midges captured belonged to the C. obsoletus complex, among them C. obsoletus s.s., C. dewulfi and C. scoticus, three suspected bluetongue vectors. The Veterinary and Agrochemical Research Centre detected viral RNA in pools of individuals belonging to this complex. Culicoides pulicaris, a potential bluetongue vector in Italy, should yet not be excluded as a possible vector in Belgium as this species was frequently found around outbreak sites, notwithstanding this species is not easily captured with the trapping techniques used during this survey.

  12. Seasonal prevalence of different species of Culicoides in Bangalore rural and urban districts of South India

    Directory of Open Access Journals (Sweden)

    M. Archana

    2014-07-01

    Full Text Available Aim: The study was undertaken to know the seasonal prevalence of different species of Culicoides in Bangalore rural and urban districts of South India. Materials and Methods: The flies were collected with UV-light traps (Onderstepoort Veterinary Institute. ARC. LNR ?? during rainy season (south west monsoon: June, July, August and September: North West monsoon: October, November and December, winter season (January, February and summer season (March, April and May in eleven different farms of cattle, buffalo, sheep and goats in Bangalore rural and urban districts. Results: From a total of 83, 629 number of Culicoides midges collected, 77906 (93.16% were female and 5723 (6.84% were males. In rainy season a total of 48,318 (57.77%, winter season 18,592 (22.23% and summer season 16719 (19.99% were reported. Conclusion: In rainy season, highest numbers of Culicoides were found whereas least in summer.

  13. Convergence between a mosquito-eating predator's natural diet and its prey-choice behaviour

    Science.gov (United States)

    Jackson, Robert R.; Deng, Chan

    2016-01-01

    On the basis of 1115 records of Evarcha culicivora feeding in the field, we can characterize this East African jumping spider (Salticidae) as being distinctively stenophagic. We can also, on the basis of laboratory prey-choice experiments, characterize E. culicivora as having a specialized prey-classification system and a hierarchy of innate preferences for various categories of mosquitoes and other arthropods. Prey from the field belonged to 10 arthropod orders, but 94.5% of the prey records were dipterans. Mosquitoes were the dominant prey (80.2% of the records), with the majority (82.9%) of the mosquitoes being females, and thereafter midges were the most common prey (9.2% of the records). Preference profiles that were determined from experiments showed strong convergence with natural diet in some, but not all, instances. In experiments, E. culicivora adults appeared to distinguish between six prey categories and juveniles between seven, with blood-carrying anopheline female mosquitoes being ranked highest in preference. For adults, this was followed by blood-carrying culicine female mosquitoes and then anopheline female mosquitoes not carrying blood, but these two preferences were reversed for juveniles. Moreover, for juveniles, but not for adults, anopheline male mosquitoes seem to be a distinct prey category ranked in preference after blood-carrying culicine females and, for both adults and juveniles, preference for midges is evident when the alternatives are not mosquitoes. These findings illustrate the importance of going beyond simply specifying preferred prey categories when characterizing predators as ‘specialized’ and a need to make clear conceptual distinctions between a predator's natural diet, the prey categories that are relevant to the predator, and the predator's prey-choicebehaviour. PMID:28083103

  14. Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California.

    Science.gov (United States)

    Saiki, Michael K; Martin, Barbara A; May, Thomas W

    2012-09-01

    Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 μg/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98-58.0 μg Se/g; midge larvae, 12.7-50.6 μg Se/g; mosquitofish, 13.2-20.2 μg Se/g; and mollies, 12.8-30.4 μg Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish.

  15. Evidence for transmission of bluetongue virus serotype 26 through direct contact.

    Directory of Open Access Journals (Sweden)

    Carrie Batten

    Full Text Available The aim of this study was to assess the mechanisms of transmission of bluetongue virus serotype 26 (BTV-26 in goats. A previous study, which investigated the pathogenicity and infection kinetics of BTV-26 in goats, unexpectedly revealed that one control goat may have been infected through a direct contact transmission route. To investigate the transmission mechanisms of BTV-26 in more detail an experimental infection study was carried out in which three goats were infected with BTV-26, three goats were kept uninfected, but were housed in direct contact with the infected goats, and an additional four goats were kept in indirect contact separated from infected goats by metal gates. This barrier allowed the goats to have occasional face-to-face contact in the same airspace, but feeding, watering, sampling and environmental cleaning was carried out separately. The three experimentally infected goats did not show clinical signs of BTV, however high levels of viral RNA were detected and virus was isolated from their blood. At 21 dpi viral RNA was detected in, and virus was isolated from the blood of the three direct contact goats, which also seroconverted. The four indirect barrier contact goats remained uninfected throughout the duration of the experiment. In order to assess replication in a laboratory model species of Culicoides biting midge, more than 300 Culicoides sonorensis were fed a BTV-26 spiked blood meal and incubated for 7 days. The dissemination of BTV-26 in individual C. sonorensis was inferred from the quantity of virus RNA and indicated that none of the insects processed at day 7 possessed transmissible infections. This study shows that BTV-26 is easily transmitted through direct contact transmission between goats, and the strain does not seem to replicate in C. sonorensis midges using standard incubation conditions.

  16. Interacting effects of aromatic plants and female age on nest-dwelling ectoparasites and blood-sucking flies in avian nests.

    Science.gov (United States)

    Tomás, G; Merino, S; Martínez-de la Puente, J; Moreno, J; Morales, J; Lobato, E; Rivero-de Aguilar, J; Del Cerro, S

    2012-06-01

    Some avian species incorporate aromatic plants to their nests. The "nest protection hypothesis", which posits that volatile secondary compounds contained in these plants may have antiparasite properties, has not received full support. All previous tests of this hypothesis have only considered effects on nest-dwelling ectoparasites, but not on blood-sucking flies. The "drug hypothesis" posits that aromatic plants may stimulate nestling immune system, development, or condition. We tested these hypotheses experimentally in wild blue tits, Cyanistes caeruleus, a species that adds aromatic plants to their nests. We supplemented aromatic plants to half of a sample of nests, while adding grass to the other half of nests. We quantified abundance of two groups of blood-sucking flies (blackflies and biting midges) at two different stages of the reproductive period, and abundance of three nest-dwelling ectoparasites (fleas, mites, and blowflies). Experimental supplementation of aromatic plants reduced abundance of fleas only in nests of yearling females and not in nests of older females. Blackflies and biting midges were both more numerous in nests of yearling females than in nests of older females. Mass of aromatic plants added by females was negatively related with abundance of fleas in control nests but not in experimental nests supplied with aromatic plants. Mass of plants added by females was also positively related with abundance of blackflies during the nestling stage. Finally, aromatic plants did not affect nestling growth or immune responses. We conclude that several factors such as female experience and their ability to add plants to the nest interact to explain effects of aromatic plants on different parasites.

  17. Ionotropic glutamate receptors mediate inducible defense in the water flea Daphnia pulex.

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    Hitoshi Miyakawa

    Full Text Available Phenotypic plasticity is the ability held in many organisms to produce different phenotypes with a given genome in response to environmental stimuli, such as temperature, nutrition and various biological interactions. It seems likely that environmental signals induce a variety of mechanistic responses that influence ontogenetic processes. Inducible defenses, in which prey animals alter their morphology, behavior and/or other traits to help protect against direct or latent predation threats, are among the most striking examples of phenotypic plasticity. The freshwater microcrustacean Daphnia pulex forms tooth-like defensive structures, "neckteeth," in response to chemical cues or signals, referred to as "kairomones," in this case released from phantom midge larvae, a predator of D. pulex. To identify factors involved in the reception and/or transmission of a kairomone, we used microarray analysis to identify genes up-regulated following a short period of exposure to the midge kairomone. In addition to identifying differentially expressed genes of unknown function, we also found significant up-regulation of genes encoding ionotropic glutamate receptors, which are known to be involved in neurotransmission in many animal species. Specific antagonists of these receptors strongly inhibit the formation of neckteeth in D. pulex, although agonists did not induce neckteeth by themselves, indicating that ionotropic glutamate receptors are necessary but not sufficient for early steps of neckteeth formation in D. pulex. Moreover, using co-exposure of D. pulex to antagonists and juvenile hormone (JH, which physiologically mediates neckteeth formation, we found evidence suggesting that the inhibitory effect of antagonists is not due to direct inhibition of JH synthesis/secretion. Our findings not only provide a candidate molecule required for the inducible defense response in D. pulex, but also will contribute to the understanding of complex mechanisms

  18. Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California

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    Saiki, Michael K.; Martin, Barbara A.; May, Thomas W.

    2012-01-01

    Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 μg/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98–58.0 μg Se/g; midge larvae, 12.7–50.6 μg Se/g; mosquitofish, 13.2–20.2 μg Se/g; and mollies, 12.8–30.4 μg Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish.

  19. Ionotropic glutamate receptors mediate inducible defense in the water flea Daphnia pulex.

    Science.gov (United States)

    Miyakawa, Hitoshi; Sato, Masanao; Colbourne, John K; Iguchi, Taisen

    2015-01-01

    Phenotypic plasticity is the ability held in many organisms to produce different phenotypes with a given genome in response to environmental stimuli, such as temperature, nutrition and various biological interactions. It seems likely that environmental signals induce a variety of mechanistic responses that influence ontogenetic processes. Inducible defenses, in which prey animals alter their morphology, behavior and/or other traits to help protect against direct or latent predation threats, are among the most striking examples of phenotypic plasticity. The freshwater microcrustacean Daphnia pulex forms tooth-like defensive structures, "neckteeth," in response to chemical cues or signals, referred to as "kairomones," in this case released from phantom midge larvae, a predator of D. pulex. To identify factors involved in the reception and/or transmission of a kairomone, we used microarray analysis to identify genes up-regulated following a short period of exposure to the midge kairomone. In addition to identifying differentially expressed genes of unknown function, we also found significant up-regulation of genes encoding ionotropic glutamate receptors, which are known to be involved in neurotransmission in many animal species. Specific antagonists of these receptors strongly inhibit the formation of neckteeth in D. pulex, although agonists did not induce neckteeth by themselves, indicating that ionotropic glutamate receptors are necessary but not sufficient for early steps of neckteeth formation in D. pulex. Moreover, using co-exposure of D. pulex to antagonists and juvenile hormone (JH), which physiologically mediates neckteeth formation, we found evidence suggesting that the inhibitory effect of antagonists is not due to direct inhibition of JH synthesis/secretion. Our findings not only provide a candidate molecule required for the inducible defense response in D. pulex, but also will contribute to the understanding of complex mechanisms underlying the recognition

  20. Bluetongue virus serotype 1 outbreak in the Basque Country (Northern Spain 2007-2008. Data support a primary vector windborne transport.

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    Rodrigo García-Lastra

    Full Text Available BACKGROUND: Bluetongue (BT is a vector-borne disease of ruminants that has expanded its traditional global distribution in the last decade. Recently, BTV-1 emerged in Southern Spain and caused several outbreaks in livestock reaching the north of the country. The aim of this paper was to review the emergence of BTV-1 in the Basque Country (Northern Spain during 2007 and 2008 analyzing the possibility that infected Culicoides were introduced into Basque Country by winds from the infected areas of Southern Spain. METHODOLOGY/PRINCIPAL FINDINGS: We use a complex HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory model to draw wind roses and backward wind trajectories. The analysis of winds showed September 28 to October 2 as the only period for the introduction of infected midges in the Basque Country. These wind trajectories crossed through the areas affected by serotype 1 on those dates in the South of the Iberian Peninsula. Additionally meteorological data, including wind speed and humidity, and altitude along the trajectories showed suitable conditions for Culicoides survival and dispersion. CONCLUSIONS/SIGNIFICANCE: An active infection in medium-long distance regions, wind with suitable speed, altitude and trajectory, and appropriate weather can lead to outbreaks of BTV-1 by transport of Culicoides imicola, not only over the sea (as reported previously but also over the land. This shows that an additional factor has to be taken into account for the control of the disease which is currently essentially based on the assumption that midges will only spread the virus in a series of short hops. Moreover, the epidemiological and serological data cannot rule out the involvement of other Culicoides species in the spread of the infection, especially at a local level.