WorldWideScience

Sample records for leptinotarsa decemlineata larvae

  1. A complex of genes involved in adaptation of Leptinotarsa decemlineata larvae to induced potato defence

    NARCIS (Netherlands)

    Petek, M.; Turnšek, N.; Gašparic, M.B.; Novak, M.P.; Gruden, K.; Slapar, N.; Popovic, T.; Štrukelj, B.; Jongsma, M.A.

    2012-01-01

    The Colorado potato beetle (Leptinotarsa decemlineata) is the most important pest of potato in many areas of the world. One of the main reasons for its success lies in the ability of its larvae to counteract plant defense compounds. Larvae adapt to protease inhibitors (PIs) produced in potato leaves

  2. Some factors relating to the larval growth of the Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), on artificial diets

    NARCIS (Netherlands)

    Wardojo, S.

    1969-01-01

    A brief account of the history of the development of artificial diets for phytophagous insects is given. Some conceptions with regard to terminology are discussed (chapter 3).

    Artificial diets for the larvae of the Colorado potato beetle, Leptinotarsa decemlineata Say, were developed

  3. A peptide from the male accessory gland in Leptinotarsa decemlineata: Purification, characterization and molecular cloning.

    NARCIS (Netherlands)

    Smid, H.M.; Koopmanschap, A.B.; Kort, de C.A.D.; Schooneveld, H.

    1997-01-01

    Our interest in the male accessory glands (MAGs) of Leptinotarsa decemlineata was raised recently by our finding that certain cells produce a secretory substance that is recognized by one of our monoclonal antibodies (MAC-18), developed for the immunohistochemical demonstration of peptidergic

  4. A model species for agricultural pest genomics: the genome of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

    Science.gov (United States)

    The Colorado potato beetle, Leptinotarsa decemlineata Say, is one of the most challenging agricultural pests to manage and has shown a spectacular ability to rapidly adapt to a broad range of solanaceaeous (nightshade/potato) plants, variable climate during its global invasion, and, most notably, an...

  5. Spatial and Temporal Potato Intensification Drives Insecticide Resistance in the Specialist Herbivore, Leptinotarsa decemlineata.

    Directory of Open Access Journals (Sweden)

    Anders S Huseth

    Full Text Available Landscape-scale intensification of individual crops and pesticide use that is associated with this intensification is an emerging, environmental problem that is expected to have unequal effects on pests with different lifecycles, host ranges, and dispersal abilities. We investigate if intensification of a single crop in an agroecosystem has a direct effect on insecticide resistance in a specialist insect herbivore. Using a major potato pest, Leptinotarsa decemlineata, we measured imidacloprid (neonicotinoid resistance in populations across a spatiotemporal crop production gradient where potato production has increased in Michigan and Wisconsin, USA. We found that concurrent estimates of area and temporal frequency of potato production better described patterns of imidacloprid resistance among L. decemlineata populations than general measures of agricultural production (% cropland, landscape diversity. This study defines the effects individual crop rotation patterns can have on specialist herbivore insecticide resistance in an agroecosystem context, and how impacts of intensive production can be estimated with general estimates of insecticide use. Our results provide empirical evidence that variation in the intensity of neonicotinoid-treated potato in an agricultural landscape can have unequal impacts on L. decemlineata insecticide insensitivity, a process that can lead to resistance and locally intensive insecticide use. Our study provides a novel approach applicable in other agricultural systems to estimate impacts of crop rotation, increased pesticide dependence, insecticide resistance, and external costs of pest management practices on ecosystem health.

  6. Biochemical characterisation of α-glucosidase and β-glucosidase in the alimentary canal of larval Leptinotarsa decemlineata SAY, 1824 (Coleoptera: Chrysomelidae

    Directory of Open Access Journals (Sweden)

    Kazzazi Majid

    2014-12-01

    Full Text Available Host plant resistance is an environmentally safe method used for reducing a pest population. Basically, when developing resistant cultivars one needs to study the biochemical characteristics of the digestive enzymes in the insect’s midgut. In this study, the activities of α- and β-glucosidase were determined from Leptinotarsa decemlineata midgut using p-nitrophenyl-α-Dglucopyranoside and p-nitrophenyl-β-D-glucopyranoside as substrates respectively. The results showed that the specific activity of α- and β-glucosidase from 4th instar larvae midguts of L. decemlineata were 5.14 and 5.48 Umg-1 protein respectively. The activity of α-glucosidase was optimal at pH 4, whereas the maximum activity of β-glucosidase in the midgut of L. decemlineata occurred at pH 4-5.5. Both enzymes were stable at pH 3-8 over an incubation time of 8 hours. The respective activities of α- and β-glucosidase were at their highest at 45 °C and 50 °C, but they were not stable at 50 °C during an incubation time of 8 days. Furthermore, our data showed that MgCl2, Tris and urea have a moderate but SDS a severe inhibitory effect on enzyme activity. Biochemical characterisation revealed one and three bands of α- and β-glucosidase activities in the midgut of L. decemlineata respectively.

  7. RNA interference ofchitin synthasegenes inhibits chitin biosynthesis and affects larval performance inLeptinotarsa decemlineata(Say).

    Science.gov (United States)

    Shi, Ji-Feng; Mu, Li-Li; Chen, Xu; Guo, Wen-Chao; Li, Guo-Qing

    2016-01-01

    Dietary introduction of bacterially expressed double-stranded RNA (dsRNA) has great potential for management of Leptinotarsa decemlineata . Identification of the most attractive candidate genes for RNA interference (RNAi) is the first step. In the present paper, three complete chitin synthase cDNA sequences ( LdChSAa , LdChSAb and LdChSB ) were cloned. LdChSAa and LdChSAb , two splicing variants of LdChSA gene, were highly expressed in ectodermally-derived epidermal cells forming epidermis, trachea, foregut and hindgut, whereas LdChSB was mainly transcribed in midgut cells. Feeding bacterially expressed ds ChSA (derived from a common fragment of LdChSAa and LdChSAb ), ds ChSAa , ds ChSAb and ds ChSB in the second- and fourth-instar larvae specifically knocked down their target mRNAs. RNAi of LdChSAa + LdChSAb and LdChSAa lowered chitin contents in whole body and integument samples, and thinned tracheal taenidia. The resulting larvae failed to ecdyse, pupate, or emerge as adults. Comparably, knockdown of LdChSAb mainly affected pupal-adult molting. The LdChSAb RNAi pupae did not completely shed the old larval exuviae, which caused failure of adult emergence. In contrast, silencing of LdChSB significantly reduced foliage consumption, decreased chitin content in midgut sample, damaged midgut peritrophic matrix, and retarded larval growth. As a result, the development of the LdChSB RNAi hypomorphs was arrested. Our data reveal that these LdChS s are among the effective candidate genes for an RNAi-based control strategy against L. decemlineata .

  8. The broadly insecticidal Photorhabdus luminescens toxin complex a (Tca): Activity against the Colorado potato beetle, Leptinotarsa decemlineata, and sweet potato whitefly, Bemisia tabaci

    OpenAIRE

    Blackburn, Michael B.; Domek, John M.; Gelman, Dale B.; Hu, Jing S.

    2005-01-01

    Toxin complex a (Tca), a high molecular weight insecticidal protein complex produced by the entomopathogenic bacterium Photorhabdus luminescens, has been found to be orally toxic to both the Colorado potato beetle, Leptinotarsa decemlineata, and the sweet potato whitefly, Bemisia tabaci biotype B. The 48 hour LC50 for Tca against neonate L. decemlineata was found to be 2.7 ppm, and the growth of 2nd instar L. decemlineata exposed to Tca for 72 hours was almost entirely inhibited at concentrat...

  9. Identification of Differentially Expressed miRNAs in Colorado Potato Beetles (Leptinotarsa decemlineata (Say Exposed to Imidacloprid

    Directory of Open Access Journals (Sweden)

    Mathieu D. Morin

    2017-12-01

    Full Text Available The Colorado potato beetle (Leptinotarsa decemlineata (Say is a significant pest of potato plants that has been controlled for more than two decades by neonicotinoid imidacloprid. L. decemlineata can develop resistance to this agent even though the molecular mechanisms underlying this resistance are not well characterized. MicroRNAs (miRNAs are short ribonucleic acids that have been linked to response to various insecticides in several insect models. Unfortunately, the information is lacking regarding differentially expressed miRNAs following imidacloprid treatment in L. decemlineata. In this study, next-generation sequencing and quantitative real-time polymerase chain reaction (qRT-PCR were used to identify modulated miRNAs in imidacloprid-treated versus untreated L. decemlineata. This approach identified 33 differentially expressed miRNAs between the two experimental conditions. Of interest, miR-282 and miR-989, miRNAs previously shown to be modulated by imidacloprid in other insects, and miR-100, a miRNA associated with regulation of cytochrome P450 expression, were significantly modulated in imidacloprid-treated beetles. Overall, this work presents the first report of a miRNA signature associated with imidacloprid exposure in L. decemlineata using a high-throughput approach. It also reveals interesting miRNA candidates that potentially underly imidacloprid response in this insect pest.

  10. Amplification and quantification of cold-associated microRNAs in the Colorado potato beetle (Leptinotarsa decemlineata) agricultural pest.

    Science.gov (United States)

    Morin, M D; Frigault, J J; Lyons, P J; Crapoulet, N; Boquel, S; Storey, K B; Morin, P Jr

    2017-10-01

    The Colorado potato beetle [Leptinotarsa decemlineata (Say)] is an important insect pest that can inflict considerable damage to potato plants. This insect can survive extended periods of cold exposure, and yet the molecular switches underlying this phenomenon have not been fully elucidated. A better characterization of this process would highlight novel vulnerabilities associated with L. decemlineata that could serve as targets for the management of this devastating pest. Using high-throughput sequencing, the current work reveals a cold-associated signature group of microRNAs (miRNAs) in control (15 °C) and -5 °C-exposed L. decemlineata. The results show 42 differentially expressed miRNAs following cold exposure including miR-9a-3p, miR-210-3p, miR-276-5p and miR-277-3p. Functional analysis of predicted targets associated with these cold-responsive miRNAs notably linked these changes with vital metabolic and cellular processes. Overall, this study highlights the miRNAs probably responsible for facilitating cold adaptation in L. decemlineata and implicates miRNAs as a key molecular target to consider in the development of novel pest management strategies against these insects. © 2017 The Royal Entomological Society.

  11. Suppression of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera:Chrysomelidae), on solanaceous crops with a copper-based fungicide

    Energy Technology Data Exchange (ETDEWEB)

    Hare, J.D.

    1984-08-01

    Field experiments were carried out to determine if a copper-based fungicide known to deter feeding by the Colorado potato beetle, Leptinotarsa decemlineata (Say), in the laboratory, could suppress the growth of L. decemlineata populations in the field when used regularly for plant disease protection on tomatoes, potatoes, and eggplants. Larval densities on plants treated with a fungicide formulated with copper hydroxide (Cu(OH)/sub 2/) were between 44 and 100% lower than on untreated control plants or plants treated with a more commonly used fungicide, mancozeb. The greatest reductions occurred on tomatoes, the least suitable host of the three for L. decemlineata growth and survival.

  12. EFFECTS OF SOME BIOINSECTICIDES AND ENTOMOPATHOGENIC FUNGI ON COLORADO POTATO BEETLE (LEPTINOTARSA DECEMLINEATA L.).

    Science.gov (United States)

    Öztürk, H E; Güven, Ö; Karaca, I

    2015-01-01

    In this study, biological activity of entomopathogenic fungi (4 strains) isolated from the Colorado potato beetle and the commercial biopesticides containing entomopathogenic fungi; Priority® (Paecilomyces fumosoroseus), Nibortem® (Verticillium lecanii), Nostalgist® (Beauveria bassiana), Bio-Magic* (Metarhizium anisopliae), Bio-Nematon* (Paeciliomyces sp.) and plant extracts; Nimbedicine EC* (Azadiractin) were determined against Leptinotarsa decemlineata under laboratory conditions. An Imidacloprid active ingredient commercial insecticide was also used to compare the insecticidal activity and distilled water was used as control. The biological control agents were applied to 2nd-3rd larval instars, 4th larval instars and adults with spray and leaf dipping methods. Single concentration (10⁸ conidia/mL⁻¹) of entomopathogenic fungi and recommended dose of bioinsecticides were prepared for application. The number of dead insects were determined at 3, 5, and 7 days after applications. Experiments were conducted at 25 ±1° C and 60% ± 5 relative humidity with 16:8 h light: dark conditions. Entomopathogenic fungi and bioinsecticides were found to be more effective on larval stage than 4th larval instars and adults. In spray methods, Bio-Magic®, Nibortem®, and Nostalgist® caused 96.4%, 92.9% and 82.1% mortality on 2nd larval instars and 20%, 36.7% and 33.3% mortality on adults, respectively. All local fungal isolates (B. bassiana) applied on 2nd and 4th larval instars caused 100% mortality. Adults showed 58.6-86.2% mortality.

  13. Population dependent effects of photoperiod on diapause related physiological traits in an invasive beetle (Leptinotarsa decemlineata).

    Science.gov (United States)

    Lehmann, Philipp; Lyytinen, Anne; Sinisalo, Tuula; Lindström, Leena

    2012-08-01

    Organisms undergoing latitudinal range expansion face a change in the photoperiod which can lead to a mismatch between the timing of seasonal changes in physiological and life history traits with seasonal environmental changes. This mismatch can lead to lowered survival, for example, due to unsynchronized diapause timing. Successful range expansion even in recent introductions requires that organisms which use the photoperiod for seasonal predictions should show interpopulational differences in photoperiodic responses at different latitudes, as the photoperiod is a function of latitude. We investigated among population differences in photoperiodic responses of life history and physiological traits linked to diapause in the invasive beetle Leptinotarsa decemlineata. Beetles from a northern marginal and a southern European population were reared under short day (12:12L:D) and long day (18:6L:D) photoperiods. Both populations reacted similarly to the short day photoperiod. Their abdominal total lipid content increased and water content decreased which suggests that the beetles prepared for diapause. This was also indicated by low mortality during diapause. In the long day photoperiod large interpopulational differences were found, the southern population ceased lipid accumulation after 5 days, while the northern population continued lipid accumulation as beetles in the short day photoperiod. This indicates that the northern population has a longer critical photoperiod than the southern one. Abdominal total lipid stores in 10 day old beetles were shown to be predominantly composed of neutral lipids (85%), most likely representing storage triacylglycerols. Fatty acid profiles of both the neutral lipids and the phospholipids showed large shifts during the first 10 day of adult life, predominantly in the fractions of 18:0, 18:1ω9, 18:2ω6 and 18:3ω3. Although the degree of unsaturation increased with age, it was not higher in diapausing than non-diapausing beetles. This

  14. A model species for agricultural pest genomics: the genome of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Schoville, Sean D; Chen, Yolanda H; Andersson, Martin N; Benoit, Joshua B; Bhandari, Anita; Bowsher, Julia H; Brevik, Kristian; Cappelle, Kaat; Chen, Mei-Ju M; Childers, Anna K; Childers, Christopher; Christiaens, Olivier; Clements, Justin; Didion, Elise M; Elpidina, Elena N; Engsontia, Patamarerk; Friedrich, Markus; García-Robles, Inmaculada; Gibbs, Richard A; Goswami, Chandan; Grapputo, Alessandro; Gruden, Kristina; Grynberg, Marcin; Henrissat, Bernard; Jennings, Emily C; Jones, Jeffery W; Kalsi, Megha; Khan, Sher A; Kumar, Abhishek; Li, Fei; Lombard, Vincent; Ma, Xingzhou; Martynov, Alexander; Miller, Nicholas J; Mitchell, Robert F; Munoz-Torres, Monica; Muszewska, Anna; Oppert, Brenda; Palli, Subba Reddy; Panfilio, Kristen A; Pauchet, Yannick; Perkin, Lindsey C; Petek, Marko; Poelchau, Monica F; Record, Éric; Rinehart, Joseph P; Robertson, Hugh M; Rosendale, Andrew J; Ruiz-Arroyo, Victor M; Smagghe, Guy; Szendrei, Zsofia; Thomas, Gregg W C; Torson, Alex S; Vargas Jentzsch, Iris M; Weirauch, Matthew T; Yates, Ashley D; Yocum, George D; Yoon, June-Sun; Richards, Stephen

    2018-01-31

    The Colorado potato beetle is one of the most challenging agricultural pests to manage. It has shown a spectacular ability to adapt to a variety of solanaceaeous plants and variable climates during its global invasion, and, notably, to rapidly evolve insecticide resistance. To examine evidence of rapid evolutionary change, and to understand the genetic basis of herbivory and insecticide resistance, we tested for structural and functional genomic changes relative to other arthropod species using genome sequencing, transcriptomics, and community annotation. Two factors that might facilitate rapid evolutionary change include transposable elements, which comprise at least 17% of the genome and are rapidly evolving compared to other Coleoptera, and high levels of nucleotide diversity in rapidly growing pest populations. Adaptations to plant feeding are evident in gene expansions and differential expression of digestive enzymes in gut tissues, as well as expansions of gustatory receptors for bitter tasting. Surprisingly, the suite of genes involved in insecticide resistance is similar to other beetles. Finally, duplications in the RNAi pathway might explain why Leptinotarsa decemlineata has high sensitivity to dsRNA. The L. decemlineata genome provides opportunities to investigate a broad range of phenotypes and to develop sustainable methods to control this widely successful pest.

  15. The change of the potential occurence of Colorado Potato Beetle (Leptinotarsa decemlineata, Say 1824 in the Czech Republic till 2050

    Directory of Open Access Journals (Sweden)

    Eva Kocmánková

    2008-01-01

    Full Text Available This present study is focused on the modeling of the most important potato pest i.e Colorado potato beetle (Leptinotarsa decemlineata, Say 1824 development in relation to the climate conditions over the area of the Czech Republic. The aim was to develop a model allowing the assessment of the CPB possible spread under the climate change. For the estimation of the CPB occurrence in expected climate conditions we used a dynamic model CLIMEX that enables to determine the suitability of a given location climate for the pests survival and infestation capability based on known pests requirements to the climate conditions. Following the validation and calibration of the model outputs, the meteorological data were altered according to three Global Circulation Models (ECHAM4, HadCM3, NCARPCM that were driven by two SRES emission scenarios (A2, B1 with two assumed levels of climate system sensitivity for period 2025 and 2050. Model output, for current and expected climate conditions, were visualized by GIS using a digital landscape model. Under all climate change scenarios we noted a widening of CPB distribution area and change in the infestation pressure of the pest.

  16. Bacillus thuringiensis var. tenebrionis’in Leptinotarsa decemlineata (Say.) (Coleoptera:Chrysomelidae) larvalarının ortabarsağina etik sürecinin histolojik yöntemlerle belirlenmesi

    Czech Academy of Sciences Publication Activity Database

    Turanli, F.; Cabuk, M.; Kismali, S.; Gelbič, Ivan

    2006-01-01

    Roč. 30, č. 2 (2006), s. 137-150 ISSN 1010-6960 Institutional research plan: CEZ:AV0Z50070508 Keywords : Bacillus thuringiensis var. tenebrionis * Leptinotarsa decemlineata * mode of action Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection

  17. Northward range expansion requires synchronization of both overwintering behaviour and physiology with photoperiod in the invasive Colorado potato beetle (Leptinotarsa decemlineata).

    Science.gov (United States)

    Lehmann, Philipp; Lyytinen, Anne; Piiroinen, Saija; Lindström, Leena

    2014-09-01

    Photoperiodic phenological adaptations are prevalent in many organisms living in seasonal environments. As both photoperiod and growth season length change with latitude, species undergoing latitudinal range expansion often need to synchronize their life cycle with a changing photoperiod and growth season length. Since adaptive synchronization often involves a large number of time-consuming genetic changes, behavioural plasticity might be a faster way to adjust to novel conditions. We compared behavioural and physiological traits in overwintering (diapause) preparation in three latitudinally different European Colorado potato beetle (Leptinotarsa decemlineata) populations reared under two photoperiods. Our aim was to study whether behavioural plasticity could play a role in rapid range expansion into seasonal environments. Our results show that while burrowing into the soil occurred in the southernmost studied population also under a non-diapause-inducing long photoperiod, the storage lipid content of these beetles was very low compared to the northern populations. However, similar behavioural plasticity was not found in the northern populations. Furthermore, the strongest suppression of energy metabolism was seen in pre-diapause beetles from the northernmost population. These results could indicate accelerated diapause preparation and possibly energetic adjustments due to temporal constraints imposed by a shorter, northern, growth season. Our results indicate that behavioural plasticity in burrowing may have facilitated initial range expansion of L. decemlineata in Europe. However, long-term persistence at high latitudes has required synchronization of burrowing behaviour with physiological traits. The results underline that eco-physiological life-history traits of insects, such as diapause, should be included in studies on range expansion.

  18. Target site insensitivity mutations in the AChE enzyme confer resistance to organophosphorous insecticides in Leptinotarsa decemlineata (Say).

    Science.gov (United States)

    Malekmohammadi, M; Galehdari, H

    2016-01-01

    In the present study, we demonstrated the use and optimization of the tetra-primer ARMS-PCR procedure to detect and analyze the frequency of the R30K and I392T mutations in resistant field populations of CPB. The R30K mutation was detected in 72%, 84%, 52% and 64% of Bahar, Dehpiaz, Aliabad and Yengijeh populations, respectively. Overall frequencies of the I392T mutation were 12%, 8% and 16% of Bahar, Aliabad and Yengijeh populations, respectively. No I392T point mutation was found among samples from Dehpiaz field population. Moreover, only 31% and 2% of samples from the resistant field populations were homozygous for R30K and I392T mutations, respectively. No individual simultaneously had both I392T and S291G/R30K point mutations. The incidence of individuals with both S291G and R30K point mutations in the samples from Bahar, Dehpiaz, Aliabad, and Yengijeh populations were 31.5%, 44.7%, 41.6%, and 27.3% respectively. Genotypes determined by the tetra-primer ARMS-PCR method were consistent with those determined by PCR sequencing. There was no significant correlation between the mutation frequencies and resistance levels in the resistant populations, indicating that other mutations may contribute to this variation. Polymorphism in the partial L. decemlineata cDNA AChE gene Ldace2 of four field populations was identified by direct sequencing of PCR-amplified fragments. Among 45 novel mutations detected in this study, T29P mutation was found across all four field populations that likely contribute to the AChE insensitivity. Site-directed mutagenesis and protein expression experiments are needed for a more complete evaluation. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Independent action between DvSnf7 RNA and Cry3Bb1 protein in southern corn rootworm, Diabrotica undecimpunctata howardi and Colorado potato beetle, Leptinotarsa decemlineata.

    Directory of Open Access Journals (Sweden)

    Steven L Levine

    Full Text Available In recent years, corn rootworm (CRW-resistant maize events producing two or more CRW-active Bt proteins have been commercialized to enhance efficacy against the target pest(s by providing multiple modes of action (MoA. The maize hybrid MON 87411 has been developed that produces the CRW-active Cry3Bb1 Bt protein (hereafter Cry3Bb1 and expresses a RNAi-mediated MoA that also targets CRW. As part of an environmental risk assessment for MON 87411, the potential for an interaction between the CRW-active DvSnf7 RNA (hereafter DvSnf7 and Cry3Bb1 was assessed in 12-day diet incorporation bioassays with the southern corn rootworm (SCR, Diabrotica undecimpunctata howardi. The potential for an interaction between DvSnf7 and Cry3Bb1 was evaluated with two established experimental approaches. The first approach evaluated each substance alone and in combination over three different response levels. For all three response levels, observed responses were shown to be additive and not significantly different from predicted responses under the assumption of independent action. The second approach evaluated the potential for a fixed sub-lethal concentration of Cry3Bb1 to decrease the median lethal concentration (LC50 of DvSnf7 and vice-versa. With this approach, the LC50 value of DvSnf7 was not altered by a sub-lethal concentration of Cry3Bb1 and vice-versa. In addition, the potential for an interaction between the Cry3Bb1 and DvSnf7 was tested with Colorado potato beetle (CPB, Leptinotarsa decemlineata, which is sensitive to Cry3Bb1 but not DvSnf7. CPB assays also demonstrated that DvSnf7 does not alter the activity of Cry3Bb1. The results from this study provide multiple lines of evidence that DvSnf7 and Cry3Bb1 produced in MON 87411 have independent action.

  20. The Effects of Extracts Obtained by Supercritical Fluid Extraction and Traditional Extraction Techniques on Larvae Leptinotarsa decemlineata SAY

    Czech Academy of Sciences Publication Activity Database

    Pavela, R.; Sajfrtová, Marie; Sovová, Helena; Karban, Jindřich; Bárnet, M.

    2009-01-01

    Roč. 21, č. 4 (2009), s. 367-373 ISSN 1041-2905 R&D Projects: GA MŠk 2B06049 Institutional research plan: CEZ:AV0Z40720504 Keywords : satureja hortensis * thymus vulgaris * botanical insecticides Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.498, year: 2009

  1. Effectiveness of entomopathogenic nematode Steinernema feltiae in agar gel formulations against larvae of the Colorado potato beetle, Leptinotarsa decemlineata (Say.) (Coleoptera: Chrysomelidae)

    Czech Academy of Sciences Publication Activity Database

    Hussein, Hany; Adel, M. M.; Gelbič, Ivan

    2012-01-01

    Roč. 7, č. 1 (2012), s. 77-82 ISSN 1895-104X Institutional research plan: CEZ:AV0Z50070508 Keywords : anti-desiccant * foliar application * drought Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 0.818, year: 2012

  2. Screening Test for Detection of Leptinotarsa decemlineata (Say Sensitivity to Insecticides

    Directory of Open Access Journals (Sweden)

    Dušanka Inđić

    2012-01-01

    Full Text Available In 2009, the sensitivity of 15 field populations of Colorado potato beetle (Leptinotarsadecemlineata Say. - CPB was assessed to chlorpyrifos, cypermethrin, thiamethoxam and fipronil,four insecticides which are mostly used for its control in Serbia. Screening test that allows rapidassessment of sensitivity of overwintered adults to insecticides was performed. Insecticideswere applied at label rates, and two, five and 10 fold higher rates by soaking method (5 sec.Mortality was assessed after 72h. From 15 monitored populations of CPB, two were sensitiveto label rate of chlorpyrifos, one was slightly resistant, 11 were resistant and one populationwas highly resistant. Concerning cypermethrin, two populations were sensitive, two slightlyresistant, five were resistant and six highly resistant. Highly sensitive to thiamethoxam labelrate were 12 populations, while three were sensitive. In the case of fipronil applied at label rate,two populations were highly sensitive, six sensitive, one slightly resistant and six were resistant.The application of insecticides at higher rates (2, 5 and 10 fold, that is justified only in bioassays,provided a rapid insight into sensitivity of field populations of CPB to insecticides.

  3. Stage-specific distribution of oxidative radicals and antioxidant enzymes in the midgut of Leptinotarsa decemlineata.

    Science.gov (United States)

    Krishnan, Natraj; Kodrík, Dalibor; Turanli, Ferit; Sehnal, Frantisek

    2007-01-01

    The titers of reactive oxygen species (ROS) represented by superoxide anion and general peroxides, and the activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), are regulated in the midgut of the Colorado potato beetle (CPB) relative to the gut compartment, developmental stage, and food intake. ROS concentration is low in the potato leaves but it is very high in their digest in insect's anterior midgut. It is proposed that intensive ROS production in this gut region is linked to the processing of allelochemicals. SOD and CAT activities, low oxygen tension, and unidentified redox systems that maintain a slightly reducing milieu in the midgut lumen (pe+pH=6.95 declining to 5.36), obviously contribute to the decrease of ROS concentration along the gut length to a minimum in the wall of posterior midgut region. SOD and CAT activities are higher in the potato leaves than in the midgut tissues but the role of plant enzymes in ROS elimination within the gut lumen remains to be shown. A lower level of ROS and a higher antioxidant potential in the adult than in the larval midgut indicate stage specificity in the management of oxidative stress. The antioxidant defense is high in the diapausing adults that contain no detectable superoxide and about ten times less peroxides than the reproducing adults.

  4. Stage specific distribution of oxidative radicals and antioxidant enzymes in the midgut of Leptinotarsa decemlineata

    Czech Academy of Sciences Publication Activity Database

    Krishnan, Natraj; Kodrík, Dalibor; Turanli, F.; Sehnal, František

    2007-01-01

    Roč. 53, č. 1, (2007), s. 67-74 ISSN 0022-1910 R&D Projects: GA ČR(CZ) GA522/06/1591; GA ČR GA522/05/0151 Institutional research plan: CEZ:AV0Z50070508 Keywords : catalase * insect digestion * peroxides Subject RIV: ED - Physiology Impact factor: 2.294, year: 2007

  5. Immunological mechanisms of synergy between fungus Metarhizium robertsii and bacteria Bacillus thuringiensis ssp. morrisoni on Colorado potato beetle larvae.

    Science.gov (United States)

    Yaroslavtseva, Olga N; Dubovskiy, Ivan M; Khodyrev, Viktor P; Duisembekov, Bahytzhan A; Kryukov, Vadim Yu; Glupov, Viktor V

    2017-01-01

    The synergistic effect between the entomopathogenic fungus Metarhizium robertsii and a sublethal dose of the bacterium Bacillus thuringiensis ssp. morrisoni var. tenebrionis was studied in terms of immune defense reactions and detoxification system activity of the Colorado potato beetle, Leptinotarsa decemlineata, fourth instar larvae. Bacterial infection led to more rapid germination of fungal conidia on integuments. We found a significant decrease of cellular immunity parameters, including total hemocyte count and encapsulation response, under the influence of bacteria. Phenoloxidase activity in integuments was increased under bacteriosis, mycosis and combined infection compared to controls. However, phenoloxidase activity in the hemolymph was enhanced under bacteriosis alone, and it was decreased under combined infection. Activation of both nonspecific esterases and glutathione-S-transferases in the hemolymph was shown at the first day of mycosis and third day of bacteriosis. However, inhibition of detoxification enzymes was detected under combined infection. The suppression of cellular immunity and detoxification reactions in Colorado potato beetle larvae with a sublethal dose of bacteria is discussed as a reason for synergy between B. thuringiensis and M. robertsii. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Chemical Ecology of the Colorado Potato Beetle, Leptinotarsa decemlineata (Say (Coleoptera: Chrysomelidae, and Potential for Alternative Control Methods

    Directory of Open Access Journals (Sweden)

    François J. Verheggen

    2012-12-01

    Full Text Available The Colorado potato beetle (CPB has been a major insect pest to potato farming for over 150 years and various control methods have been established to reduce its impact on potato fields. Crop rotation and pesticide use are currently the most widely used approaches, although alternative methods are being developed. Here we review the role of various volatile and nonvolatile chemicals involved in behavior changes of CPB that may have potential for their control. First, we describe all volatile and nonvolatile chemicals involved in host plant localization and acceptance by CPB beetles, including glycoalcaloids and host plant volatiles used as kairomones. In the second section, we present the chemical signals used by CPB in intraspecific communication, including sex and aggregation pheromones. Some of these chemicals are used by natural enemies of CPBs to locate their prey and are presented in the third section. The last section of this review is devoted a discussion of the potential of some natural chemicals in biological control of CPB and to approaches that already reached efficient field applications.

  7. Digestive proteolysis in the Colorado potato beetle, Leptinotarsa decemlineata: Activity-based profiling and imaging of a multipeptidase network

    Czech Academy of Sciences Publication Activity Database

    Srp, Jaroslav; Nussbaumerová, Martina; Horn, Martin; Mareš, Michael

    2016-01-01

    Roč. 78, Nov (2016), s. 1-11 ISSN 0965-1748 R&D Projects: GA MŠk LO1302; GA ČR GA15-18929S Institutional support: RVO:61388963 Keywords : Colorado potato beetle * peptidase * cathepsin * activity-based probe * digestive system * multienzyme network Subject RIV: CE - Biochemistry Impact factor: 3.756, year: 2016

  8. Effects of photoperiod and temperature on the rate of larval development, food conversion efficiency, and imaginal diapause in Leptinotarsa decemlineata

    Czech Academy of Sciences Publication Activity Database

    Doležal, Petr; Habuštová, Oxana; Sehnal, František

    2007-01-01

    Roč. 53, - (2007), s. 849-857 ISSN 0022-1910 R&D Projects: GA ČR GA522/05/0151; GA ČR(CZ) GA522/06/1591 Institutional research plan: CEZ:AV0Z50070508 Keywords : colorado potato beetle * food conversion * insect development Subject RIV: ED - Physiology Impact factor: 2.294, year: 2007

  9. Is the titer of adipokinetic peptides in Leptinotarsa decemlineata fed on genetically modified potatoes increased by oxidative stress?

    Czech Academy of Sciences Publication Activity Database

    Kodrík, Dalibor; Krishnan, Natraj; Habuštová, Oxana

    2007-01-01

    Roč. 28, č. 5, (2007), s. 974-980 ISSN 0196-9781 R&D Projects: GA ČR GA522/05/0151; GA ČR(CZ) GA522/06/1591 Institutional research plan: CEZ:AV0Z50070508 Keywords : adipokinetic hormone * oxidative stress * GMO Subject RIV: ED - Physiology Impact factor: 2.368, year: 2007

  10. Sexual dimorphism of Colorado beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae in the west and northwest of Iran by geometric morphometric method

    Directory of Open Access Journals (Sweden)

    Rahim Abdolahi Mesbah

    2014-12-01

    Full Text Available The males and females of Colorado beetles do not reveal clear dimorphism and therefore they have high resemblance so that recognition of the sexes by simple eye is too difficult. In order to study sexual dimorphism in Colorado beetle, three geographical populations were collected from potato fields in Ardabil, Bahar and Hamedan regions by manual method and direct observation in the summer of 2012. Fore and hind wings were separated and 7 and 8 landmarks were orderly selected for the fore and hind wings at the end and angle of veins. Geometric coordinate of landmarks were converted to shape and size variables as comparison factors between the sexes. Wings relative variations were determined separately in male and female and it revealed variations of wing shape in evolutionary process. Multivariate analysis based on the results of regression of shape variables showed fore wing had allometry and hind wing had not allometry. Two way MANOVA analysis was conducted for observation of shape differences (base on average of shape variables and size differences. The analysis showed that there were significant differences in shape of fore wing between the sexes.

  11. Larvae for layers

    DEFF Research Database (Denmark)

    Bjerrum, Lotte; Fischer, Christian Holst; Nordentoft, Steen

    2013-01-01

    Companies and researchers are in close collaboration developing a container- based system for cultivating fly larvae at organic poultry farms. In a one week process, manure will be converted to compost and the live larvae will be harvested and used for feeding laying hens. The larvae are expected...

  12. High insecticidal activity of Leclercia adecarboxylata isolated from ...

    African Journals Online (AJOL)

    Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is an important pest on solanaceous crops worldwide. CPB has developed resistance to insecticides used for its control. In this study, in order to find a more effective and safer biological control agent against L. decemlineata, we studied the bacterial flora of ...

  13. Effect of water extracts from Artemisia absinthium L. on feeding of selected pests and their response to the odor of this plant

    Directory of Open Access Journals (Sweden)

    Milena RUSIN

    2016-02-01

    Full Text Available The aim of this study was to determine the effect of water extracts from fresh and dry matter of Artemisia absinthium L. on the feeding of selected pests. Moreover their reactions on the smell of this plant by using the olfactometer were examined. Beetles feeding intensity assessment was carried out by measuring the surface of feeds caused by Sitona lineatus L. In the case of Acyrthosiphon pisum Harris contact poisoning on mortality of adults and larvae were tested. In determining the effect of extracts of A. absinthium L. on Leptinotarsa decemlineata Say. food weight eaten by adult beetles and larvae and changes in larvae body weight were established. In studies on the olfactory reaction of above mentioned insects, for S. lineatus and L. decemlineata glass olfactometer Y-tube was used and for winged A. pisum females - 4-armed arena olfactometer. The results of the experiment showed that extract from dry matter of A. absinthium L. at concentration of 10% greatly reduced feeding of Sitona lineatus L. The highest mortality of A. pisum Harris was observed in objects in which extracts from dry and fresh matter of the highest concentrations (10% and 30% respectivelly were applied. Extract from fresh matter in concentration of 30% made the greatest contribution to reduce feeding of L. decemlineata Say, while extract made from the dry matter at concentration of 10% significantly contributed to reduce the weight of food eaten by the larvae of this pest. Studies using the olfactometer showed a strong deterring reaction of odors derived from A. absinthium L. in relation to S. lineatus (both males and females and males of L. decemlineata Say.

  14. Key to marine arthropod larvae

    Directory of Open Access Journals (Sweden)

    John A. Fornshell

    2012-03-01

    Full Text Available The scope of this key is restricted to the larvae of marine arthropods. The key is based solely on their morphology, patterns of body segmentation, numbers of appendages, and mode of locomotion. An effort has been made to treat all traditionally named larval forms, both planktonic and benthic. It is intended that this key be useful for a researcher working with archived museum specimens and therefore, does not include habitat information as a identifying trait, even though this information is usually available in the archived records. Within the phylum Arthropoda there are two sub-phyla and eleven classes having larval stages in the marineenvironment. Where feasible the original names of the various larval types have been used. Because this nomenclature is less commonly used today compared to the past, the more recent taxonomic affinities are included in parentheses after the original larval name. The key includes the following thirty-four larvae: Branchhiopoda nauplii; Cephalocarida nauplii; Mystacocarida nauplii; trilobite larva; protonymphon; hexapod larvae; Remipedia nauplii; nauplius - Y larvae; Cirripedia nauplii; Ascothoracida nauplii; Ostracoda nauplii; Euphausiacea nauplii; Penaeidea nauplii; Cyclopoida nauplii; Calanoida nauplii; Harpacticoida nauplii;Polyarthra nauplii; cypris larva; eryonecius larva; cypris-Y larva; elapthocaris larvae; mysis larvae; lucifer zoea; acetes zoea; acanthosoma larva; phyllosoma; antizoea larva; anomuran zoea; brachyuran zoea; calyptopis larvae; furcilia larva; crytopia larva; puerulus larva; alima larva.

  15. Baylisascaris Larva Migrans

    Science.gov (United States)

    Kazacos, Kevin R.; Abbott, Rachel C.; van Riper, Charles

    2016-05-26

    SummaryBaylisascaris procyonis, the common raccoon roundworm, is the most commonly recognized cause of clinical larva migrans (LM) in animals, a condition in which an immature parasitic worm or larva migrates in a host animal’s tissues, causing obvious disease. Infection with B. procyonis is best known as a cause of fatal or severe neurologic disease that results when the larvae invade the brain, the spinal cord, or both; this condition is known as neural larva migrans (NLM). Baylisascariasis is a zoonotic disease, that is, one that is transmissible from animals to humans. In humans, B. procyonis can cause damaging visceral (VLM), ocular (OLM), and neural larva migrans. Due to the ubiquity of infected raccoons around humans, there is considerable human exposure and risk of infection with this parasite. The remarkable disease-producing capability of B. procyonis in animals and humans is one of the most significant aspects of the biology of ascarids (large roundworms) to come to light in recent years. Infection with B. procyonis has important health implications for a wide variety of free-ranging and captive wildlife, zoo animals, domestic animals, as well as human beings, on both an individual and population level. This report, eighth in the series of U.S. Geological Survey Circulars on zoonotic diseases, will help us to better understand the routes of Baylisascaris procyonis infections and how best to adequately monitor this zoonotic disease.

  16. Berbagai Cara Pengendalian Larva Nyamuk

    Directory of Open Access Journals (Sweden)

    Nungki Hapsari Suryaningtyas

    2017-02-01

    Full Text Available Tindakan pencegahan dengan memberantas sarang nyamuk dan membunuh larva serta nyamuk dewasa terus digalakkan. Stadium pradewasa atau larva dapat dikontrol secara biologi maupun kimiawi.1 Berikut adalah beberapa cara pengendalian larva nyamuk.Pengendalian secara biologi Beberapa organisme yang efektif untuk mengendalikan larva secara biologi diantaranya adalah Ikan (larvavivorous fish,Aplocheilus panchax (ikan kepala timah, Ctenops vittatus (ikan cupang,Oreochromis (Tilapia mossambicus (ikan nila dan Cyprinus carpio (ikan tombro, larva nyamuk dari genus Toxorhynchites, Capung (Dragonflies/Labellula . Kelompok Udang (Cyclopoid copepods Jenis Copepoda yang tersebar sebagai plankton dan bentos ini bersifat predator yang efektif untuk mengendalikan stadium pradewasa nyamuk instar satu dan instar dua. Pada suatu penelitian di Polynesia Perancis terbukti bahwa M. aspericornis pengaruhnya tidak konsisten terhadap larva Ae. aegypti yang ditemukan berada di tangki air, drum dan sumur yang tertutup. Keadaan tersebut tampaknya bergantung pada tersedianya mikrofauna di tempat perkembangbiakannya yang dibutuhkan untuk pertumbuhan Copepoda tersebut

  17. Overview: Pyraloidea larvae (Insecta: Lepidoptera)

    Science.gov (United States)

    The larvae of pyraloid or snout moths are pests to many crops and stored products and rank as among the most destructive pests to graminaceous crops such as corn, sugarcane, and rice. On the other hand, some larvae have been investigated and used for the biological control of noxious terrestrial a...

  18. Cutaneous larva migrans

    Directory of Open Access Journals (Sweden)

    Aleksandra Wieczorek

    2016-09-01

    Full Text Available Introduction . Cutaneous larva migrans (CLM is a tropical zoonosis, caused by parasites, usually Ancylostoma braziliense. Humans are an accidental host. Polish patients with CLM are usually tourists visiting tropical and subtropical countries. The first symptoms do not always appear as creeping eruptions, which complicates the diagnosis. Objective. To present the case of a man with CLM after returning from Thailand to Poland and associated diagnostic difficulties. Case report. We present a case of a 28-year-old man who returned to Poland from Thailand. The first symptoms appeared as disseminated pruritic papules. No improvement after treatment with corticosteroids and antihistamines was observed. The diagnosis was established after the appearance of serpentine erythemas and improvement after albendazole therapy. Conclusions. In the case of returnees from exotic countries suffering from raised, pruritic rashes, and no improvement after treatment with corticosteroids and antihistamines, parasitic etiology should be considered.

  19. Culturing larvae of marine invertebrates.

    Science.gov (United States)

    Strathmann, Richard R

    2014-01-01

    Larvae of marine invertebrates cultured in the laboratory experience conditions that they do not encounter in nature, but development and survival to metamorphic competence can be obtained in such cultures. This protocol emphasizes simple methods suitable for a wide variety of larvae. Culturing larvae requires seawater of adequate quality and temperature within the tolerated range. Beyond that, feeding larvae require appropriate food, but a few kinds of algae and animals are sufficient as food for diverse larvae. Nontoxic materials include glass, many plastics, hot-melt glue, and some solvents, once evaporated. Cleaners that do not leave toxic residues after rinsing include dilute hydrochloric or acetic acid, sodium hypochlorite (commercial bleach), and ethanol. Materials that can leave toxic residues, such as formaldehyde, glutaraldehyde, detergents, and hand lotions, should be avoided, especially with batch cultures that lack continuously renewed water. Reverse filtration can be used to change water gently at varying frequencies, depending on temperature and the kinds of food that are provided. Bacterial growth can be limited by antibiotics, but antibiotics are often unnecessary. Survival and growth are increased by low concentrations of larvae and stirring of large or dense cultures. One method of stirring large numbers of containers is a rack of motor-driven paddles. Most of the methods and materials are inexpensive and portable. If necessary, a room within a few hours of the sea could be temporarily equipped for larval culture.

  20. Desiccation resistance of Chironomid larvae

    Directory of Open Access Journals (Sweden)

    Jan Frouz

    2015-07-01

    Full Text Available Resistance to desiccation in larvae of eight species of aquatic, semiaquatic and terrestrial chironomids (Pseudodiamesa branickii, Macropelopia sp., Prodiamesa olivacea, Micropsectra sp., Chironomus riparius, Chironomus dorsalis, Metriocnemus martini and Camptocladius stercorarius was studied. The larvae were desiccated in exicator at constant conditions (15 °C, 80% RH and changes in moisture and body water content was recorded. The LD-50 for loss of body water was calculated. The lowest resistance to loss of body water was found in larvae from subfamilies Tanypodinae and Diamesinae Macropelopia sp. and P. branickii. They survived loss of 49.7 and 56.6% of original water content (presented values are LD-50. On the other hand the highest resistance to water loss was found in C. dorsalis. M. martini and C. stercorarius. The larvae of these species may survive loss of 67.4, 76.6 and 84.2% of original water content. Nevertheless the survival time under experimental conditions depends more closely on larval size than on lethal level of water loss. The smaller larvae desiccated faster and perished sooner than large ones despite they tolerate higher loss of body water.

  1. [Biotechnological aspects in "loco" larvae].

    Science.gov (United States)

    Inestrosa, N C; Labarca, R; Perelman, A; Campos, E O; Araneda, R; González, M; Brandan, E; Sánchez, J P; González-Plaza, R

    1990-10-01

    The biology of planktotrophic larvae of Concholepas concholepas is the main bottleneck towards developing biotechnologies to rear this muricid. Data concerning planktonic larvae development, diets and environmental signals triggering larval settlement and recruitment is scarce. We have begun the study of the molecular and cell biology of embryos, larvae and recruits having as a final goal, the development of appropriate biotechnologies to rear this gastropod. First, an inverse ratio between BuChE and AChE enzyme activities was established. This ratio may be a precise developmental marker for this species. Second, for the first time a phosphoinositide related regulatory pathway is reported in a muricid, opening a new approach to the biotechnological management of larvae. Third, the relation between sulfate in sea water and larval motility was studied. Concentrations below 125 microM sulfate decreases larval motility. The sulfate is incorporated in proteoglycans which participate in different developmental phenomena. Lastly, a genomic Concholepas concholepas DNA sequence, similar to that of a human growth hormone probe was detected. This is very interesting since growth factors are key molecules during development, growth and are involved in food conversion rates in fish and also, in a variety of marine invertebrates.

  2. Positive selection of digestive Cys proteases in herbivorous Coleoptera.

    Science.gov (United States)

    Vorster, Juan; Rasoolizadeh, Asieh; Goulet, Marie-Claire; Cloutier, Conrad; Sainsbury, Frank; Michaud, Dominique

    2015-10-01

    Positive selection is thought to contribute to the functional diversification of insect-inducible protease inhibitors in plants in response to selective pressures exerted by the digestive proteases of their herbivorous enemies. Here we assessed whether a reciprocal evolutionary process takes place on the insect side, and whether ingestion of a positively selected plant inhibitor may translate into a measurable rebalancing of midgut proteases in vivo. Midgut Cys proteases of herbivorous Coleoptera, including the major pest Colorado potato beetle (Leptinotarsa decemlineata), were first compared using a codon-based evolutionary model to look for the occurrence of hypervariable, positively selected amino acid sites among the tested sequences. Hypervariable sites were found, distributed within -or close to- amino acid regions interacting with Cys-type inhibitors of the plant cystatin protein family. A close examination of L. decemlineata sequences indicated a link between their assignment to protease functional families and amino acid identity at positively selected sites. A function-diversifying role for positive selection was further suggested empirically by in vitro protease assays and a shotgun proteomic analysis of L. decemlineata Cys proteases showing a differential rebalancing of protease functional family complements in larvae fed single variants of a model cystatin mutated at positively selected amino acid sites. These data confirm overall the occurrence of hypervariable, positively selected amino acid sites in herbivorous Coleoptera digestive Cys proteases. They also support the idea of an adaptive role for positive selection, useful to generate functionally diverse proteases in insect herbivores ingesting functionally diverse, rapidly evolving dietary cystatins. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. A simple method for the detection of imaginal diapause in beetles

    Czech Academy of Sciences Publication Activity Database

    Doležal, Petr; Sehnal, František

    2007-01-01

    Roč. 131, č. 3 (2007), s. 221-223 ISSN 0931-2048 R&D Projects: GA MŠk 1M06030 Institutional research plan: CEZ:AV0Z50070508 Keywords : Ips typographus * Leptinotarsa decemlineata * flight muscles Subject RIV: ED - Physiology Impact factor: 1.030, year: 2007

  4. Regulation of the juvenile hormone titre in the Colorado potato beetle

    NARCIS (Netherlands)

    Kramer, S.J.

    1978-01-01

    Three main topics were investigated in regulation of the titre of juvenile hormone in haemolymph of the Colorado potato beetle ( Leptinotarsa decemlineata Say): enzymic breakdown of the hormone; binding and protection of the hormone by carrier proteins; the synthetic capacity of

  5. Potato expressing beetle-specific Bacillus thuringiensis Cry3Aa toxin reduces performance of a moth

    Czech Academy of Sciences Publication Activity Database

    Hussein, H. M.; Habuštová, Oxana; Turanli, Ferit; Sehnal, František

    2006-01-01

    Roč. 32, č. 1 (2006), s. 1-13 ISSN 0098-0331 R&D Projects: GA ČR(CZ) GA522/02/1507 Institutional research plan: CEZ:AV0Z50070508 Keywords : Bacillus thuringiensis * Spodoptera littoralis * Leptinotarsa decemlineata Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 1.896, year: 2006

  6. Comparative ecophysiology of cold-tolerance-related traits: Assessing range expansion potential for an invasive insect at high latitude

    Czech Academy of Sciences Publication Activity Database

    Lehmann, P.; Kaunisto, S.; Košťál, Vladimír; Margus, A.; Zahradníčková, Helena; Lindström, L.

    2015-01-01

    Roč. 88, č. 3 (2015), s. 254-265 ISSN 1522-2152 R&D Projects: GA MŠk LH12103 Grant - others:Academy of Finland(FI) 118456; Academy of Finland(FI) 128888 Institutional support: RVO:60077344 Keywords : Leptinotarsa decemlineata Subject RIV: ED - Physiology Impact factor: 2.007, year: 2015

  7. Transgenic resistance of eggplants to the Colorado potato beetle

    NARCIS (Netherlands)

    Arpaia, S.

    1999-01-01

    The subject of this thesis is the use of transgenic plant resistance as a method to control the Colorado potato beetle, Leptinotarsa decemlineata Say in eggplant. The gene conferring resistance is coding for a Cry3B toxin and it is a synthetic version of a wild-type

  8. Cloning and sequence analysis of cDNA encoding a putative juvenile hormone esterase from the Colorado potato beetle.

    NARCIS (Netherlands)

    Vermunt, A.M.W.; Koopmanschap, A.B.; Vlak, J.M.; Kort, de C.A.D.

    1998-01-01

    In the Colorado potato beetle, Leptinotarsa decemlineata, reproduction and diapause are mediated by the juvenile hormone (JH) titer in the hemolymph. This titer is controlled by JH synthesis in the corpora allata and by JH degradation. The main pathway of JH degradation is by JH esterase in the

  9. A peptide from the male accessory glands of the Colorado potato beetle

    NARCIS (Netherlands)

    Smid, H.M.

    1998-01-01

    This thesis describes a study of the male accessory glands of the Colorado potato beetle, Leptinotarsa decemlineata (Say). These glands add various substances to the ejaculate. On mating, the ejaculate is transferred to the female, together with the substances from the

  10. Aspects of host-plant relationship of the Colorado beetle

    NARCIS (Netherlands)

    Bongers, W.

    1970-01-01

    Host plant choice, suitability of and conditioning to the host in Leptinotarsa decemlineata SAY were studied under controlled conditions.

    The literature on historical and geographical distribution of the Colorado beetle has been reviewed and an extensive survey is given of the

  11. Location and function of serotonin in the central and peripheral nervous system of the Colorado potato beetle

    NARCIS (Netherlands)

    Haeften, van T.

    1993-01-01

    In this thesis we have localized serotoninergic neurons in the central and peripheral nervous system of the Colorado potato beetle, Leptinotarsa decemlineata by means of immunohistochemistry with a specific antiserurn to serotonin and assessed the possible role of these

  12. Isolamento de esporos de Paenibacillus larvae subsp. larvae no Brasil Detectionof Paenibacillus larvae subsp. larvae spores in Brazil

    Directory of Open Access Journals (Sweden)

    Dulce Maria Tocchetto Schuch

    2003-03-01

    Full Text Available Este trabalho objetivou detectar presença de esporos de Paenibacillus larvae subsp. larvae em produtos de um entreposto do interior do Estado do Rio Grande do Sul, a identificação de possíveis fontes de contaminação e a avaliação da possibilidade da transferência de esporos para colméias de apiários adjacentes a partir de produtos importados contaminados. Foram analisados mel e pólen importados disponíveis no entreposto, favo do ninho (crias, pólen e mel colhido de uma colméia sadia, mel estocado em um dos apiários e abelhas adultas. Os resultados foram positivosem relação ao mel e pólen importados, a três grupos de abelhas adultas e ao mel do favo.The objective of this work was to detect the presence of Paenibacillus larvae subsp. larvae spores in products from a warehouse located in Rio Grande do Sul State, Brazil, the identification of possible contamination sources, and the assessment of spores transference possibility from contaminated imported products from the warehouse to apiaries located in the surrounding area. Samples of imported pollen and bulk honey stocked in the warehouse, and honeycomb (brood, honey and pollen from a healthy hive, honey from one apiary and adult bees were analyzed. Imported honey and pollen, and three groups of adult bees and the honey collected from the honeycomb resulted positive.

  13. THE EFFECT OF WATER EXTRACT FROM WILD THYME ON COLORADO POTATO BEETLE FEEDING

    Directory of Open Access Journals (Sweden)

    Milena Rusin

    2016-09-01

    Full Text Available The aim of this study was to determine the effect of water extracts prepared from fresh and dry matter of wild thyme (Thymus serpyllum L. on feeding adults and larvae of Colorado potato beetle (Leptinotarsa decemlineata Say.. The experiment was conducted in the laboratory, in six replicates. Dry extracts were prepared at concentration of 2%, 5% and 10%, while the fresh plant at concentration of 10%, 20% and 30%. Feeding intensity assessment was conducted by dipping leaves of potato in respective solutions of the extracts and determining the mass of food consumed by adults and larvae, and changes of larvae body weight once daily. In addition, absolute deterrence index and palatability index were calculated. The results of the experiment showed that for an efficient limitation of the feeding adult Colorado potato beetles, an extract from dry matter of wild thyme with a concentration of at least 10% should be used. L4 larvae appear to be considerably more susceptible to the effect of T. serpyllum extract. In their case, an efficient limitation of the feeding, as well as body weight gain can be obtained using extracts from both dry and fresh matter, at concentrations of over 5% for dry matter and over 20% for fresh matter. With the increase of extract concentration, the value of the calculated palatability index decreases, and the deterrence index value increases.

  14. Radiosensitivity of spores of Paenibacillus larvae ssp. larvae in honey

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Wanderley Mendes de [Ministerio da Agricultura, Pecuaria e Abastecimento, Rio de Janeiro, RJ (Brazil). Servico de Inspecao de Produtos de Origem Animal]. E-mail: sipa-rj@agricultura.gov.br; Vital, Helio de Carvalho [Centro Tecnologico do Exercito CTEx, Rio de Janeiro, RJ (Brazil). Div. de Defesa Quimica, Biologica e Nuclear]. E-mail: vital@ctex.eb.br; Schuch, Dulce Maria Tocchetto [Ministerio da Agricultura, Pecuaria e Abastecimento, Porto Alegre, RS (Brazil)]. E-mail: micro-lara-rs@agricultura.gov.br

    2007-07-01

    Irradiation, usually used in combination with other conventional methods of conservation, has been proven to be an efficient tool to ensure the safety of many types of foods by destroying pathogenic microorganisms and extending their shelf-lives. This work has investigated the efficacy of gamma irradiation to inactivate spores of the bacterium Paenibacillus larvae that causes the 'American foulbrood', a highly contagious disease still exotic in Brazil that kills bees and contaminates honey, preventing its commercialization and causing great economical losses. In this study, 60 g samples of two types of honey inoculated with 3.5x10{sup 3} spores/mL of that bacterium were irradiated with doses of 0, 5, 7.5, 10, 12.5 and 15 kGy and counted. The analyses indicated a mean reduction of 97.5{+-}0.7% in the number of viable spores exposed to 5 kGy. The application of doses of 7.5 kGy or higher yielded no viable spores above the detection threshold (10/mL). In addition the value of D{sub 10} (3.1{+-}0.3 kGy) was estimated and the logarithm of the population of viable spores of Paenibacillus larvae subsp. larvae was determined as linear and quadratic polynomial functions of the radiation dose. The results indicated that the dose of 10 kGy could be insufficient to assure complete sterilization of honey in some cases while suggesting that 25 kGy would perform such task adequately. (author)

  15. Extreme morphologies of mantis shrimp larvae

    DEFF Research Database (Denmark)

    Haug, Carolin; Ahyong, Shane T.; Wiethase, Joris H.

    2016-01-01

    diversity of stomatopod larvae, which is largely unstudied. We describe here four previously unknown larval types with extreme morphologies. All specimens were found in the collections of the Zoological Museum, University of Copenhagen and were collected during the Danish Dana Expedition round the world...... was possible. Further investigations of these larvae are crucial to understand their life habits and ecological impact, especially as stomatopod and other crustacean larvae might have a much more important position in the marine ecosystems than their corresponding adults....

  16. Coral larvae move toward reef sounds

    NARCIS (Netherlands)

    Vermeij, M.J.A.; Marhaver, K.L.; Huijbers, C.M.; Nagelkerken, I.; Simpson, S.D.

    2010-01-01

    Free-swimming larvae of tropical corals go through a critical life-phase when they return from the open ocean to select a suitable settlement substrate. During the planktonic phase of their life cycle, the behaviours of small coral larvae (<1 mm) that influence settlement success are difficult to

  17. The wheat multidomain cystatin TaMDC1 displays antifungal, antibacterial, and insecticidal activities in planta.

    Science.gov (United States)

    Christova, P K; Christov, N K; Mladenov, P V; Imai, R

    2018-03-12

    Expression of the TaMDC1 in transgenic tomato plants confer resistance to bacterial and fungal pathogens, as well as an insect pest and thus prove in planta function of the wheat cystatin. Cystatins are the polypeptides with cysteine proteinase inhibitory activities. Plant cystatins or phytocystatins are known to contribute to plant resistance against insect pests. Recently, increasing data proved that some of the phytocystatins also have antifungal activities in vitro. Here, we functionally characterized a wheat multidomain cystatin, TaMDC1, using in planta assays. Expression of TaMDC1 in wheat seedlings is up-regulated in response to methyl jasmonate and salicylic acid, indicating that TaMDC1 is involved in biotic stress responses mediated by these plant hormones. The TaMDC1 cDNA was integrated in tomato genome and expressed under cauliflower mosaic virus 35S promoter. Four transgenic plants that show high level of the transgene expression were selected by RNA gel blot and immunoblot analysis and utilized to assess biotic stress resistance against the bacterial pathogen Pseudomonas syringae, the fungal pathogens Botrytis cinerea and Alternaria alternata, and the insect pest Colorado potato beetle (CPB, Leptinotarsa decemlineata). Detached leaf inoculation assays revealed that the tomato plants expressing TaMDC1 showed high levels of resistance against P. syringae and A. alternata, and elevated tolerance against B. cinerea. Sustenance of L. decemlineata larvae to the transgenic plants demonstrated inhibition of CPB larvae growth. Inhibitory activity of TaMDC1 against selected pathogens was also demonstrated by in vitro assays with total protein extracted from transgenic tomato plants. Taken together, the presented data suggest that TaMDC1 is involved in a broad spectrum biotic stress resistance in planta.

  18. Image-based automatic recognition of larvae

    Science.gov (United States)

    Sang, Ru; Yu, Guiying; Fan, Weijun; Guo, Tiantai

    2010-08-01

    As the main objects, imagoes have been researched in quarantine pest recognition in these days. However, pests in their larval stage are latent, and the larvae spread abroad much easily with the circulation of agricultural and forest products. It is presented in this paper that, as the new research objects, larvae are recognized by means of machine vision, image processing and pattern recognition. More visional information is reserved and the recognition rate is improved as color image segmentation is applied to images of larvae. Along with the characteristics of affine invariance, perspective invariance and brightness invariance, scale invariant feature transform (SIFT) is adopted for the feature extraction. The neural network algorithm is utilized for pattern recognition, and the automatic identification of larvae images is successfully achieved with satisfactory results.

  19. Activity of R(+ limonene against Anisakis larvae

    Directory of Open Access Journals (Sweden)

    Filippo Giarratana

    2015-12-01

    Full Text Available The aim of this work is to evaluate the activity of R(+ limonene of against Anisakidae larvae. Its effectiveness was tested in vitro. The results obtained showing a significant activity of the compound against Anisakis larvae, suggesting further investigation on its potential use in the industrial marinating process. In this regard, the use of R(+ limonene in seafood products could be interesting, also due the sensory attributes resulting from its use and its relatively safe status.

  20. Activity of R(+) Limonene Against Anisakis Larvae

    Science.gov (United States)

    Muscolino, Daniele; Panebianco, Felice; Patania, Andrea; Benianti, Chiara; Ziino, Graziella; Giuffrida, Alessandro

    2015-01-01

    The aim of this work is to evaluate the activity of R(+) limonene of against Anisakidae larvae. Its effectiveness was tested in vitro. The results obtained showed a significant activity of the compound against Anisakis larvae, suggesting further investigation on its potential use in the industrial marinating process. In this regard, the use of R(+) limonene in seafood products could be interesting, also due the sensory attributes resulting from its use and its relatively safe status. PMID:27800423

  1. Activity of R(+) limonene against Anisakis larvae

    OpenAIRE

    Filippo Giarratana; Daniele Muscolino; Felice Panebianco; Andrea Patania; Chiara Benianti; Graziella Ziino; Alessandro Giuffrida

    2015-01-01

    The aim of this work is to evaluate the activity of R(+) limonene of against Anisakidae larvae. Its effectiveness was tested in vitro. The results obtained showing a significant activity of the compound against Anisakis larvae, suggesting further investigation on its potential use in the industrial marinating process. In this regard, the use of R(+) limonene in seafood products could be interesting, also due the sensory attributes resulting from its use and its relatively safe status.

  2. Coral larvae move toward reef sounds.

    Directory of Open Access Journals (Sweden)

    Mark J A Vermeij

    Full Text Available Free-swimming larvae of tropical corals go through a critical life-phase when they return from the open ocean to select a suitable settlement substrate. During the planktonic phase of their life cycle, the behaviours of small coral larvae (<1 mm that influence settlement success are difficult to observe in situ and are therefore largely unknown. Here, we show that coral larvae respond to acoustic cues that may facilitate detection of habitat from large distances and from upcurrent of preferred settlement locations. Using in situ choice chambers, we found that settling coral larvae were attracted to reef sounds, produced mainly by fish and crustaceans, which we broadcast underwater using loudspeakers. Our discovery that coral larvae can detect and respond to sound is the first description of an auditory response in the invertebrate phylum Cnidaria, which includes jellyfish, anemones, and hydroids as well as corals. If, like settlement-stage reef fish and crustaceans, coral larvae use reef noise as a cue for orientation, the alleviation of noise pollution in the marine environment may gain further urgency.

  3. Predatory activity of Rhantus sikkimensis and larvae of Toxorhynchites splendens on mosquito larvae in Darjeeling, India.

    Science.gov (United States)

    Aditya, Gautam; Ash, Anirban; Saha, Goutam K

    2006-06-01

    Predation potential of the dytiscid beetle, Rhantus sikkimensis Regimbart 1899 and the larvae of Toxorhynchites splendens Wiedemann 1819 occurring along with the larval stages of the mosquitoes in the annual lentic water bodies of Darjeeling was evaluated using the larvae of Culex quinquefasciatus Say 1823 as preys, in the laboratory under simulated natural conditions. Field collected R. sikkimensis and larvae of Tx. splendens were offered IV instar larvae of Cx. quinquefasciatus to observe the rate of predation, at varying prey and predator densities. Based on the data obtained on the predation for a period of three consecutive days, two indices of predation, predatory impact (PI) and clearance rate (CR) values were estimated, and compared between the predator species. The rate of predation of IV instar Cx. quinquefasciatus larvae by R. sikkimensis ranged between 21.56 and 86.89 larvae per day, depending on the prey and predator densities. The PI value remained between 18.67 and 35.33 larvae/day depending on prey densities, while the CR ranged between 2.21 and 2.23 larvae litres/day/predator. Compared to these, the Tx. splendens larvae consumed the prey larvae at the rate of 0.67 to 34.22 larvae per day, depending on the prey and predator densities. The PI value ranged between 7.67 and 11.33 larvae/day, and the CR value ranged between 1.41 and 1.76 larvae litres/day/predator. The rate of predation, CR values and PI values of R. sikkimensis and Tx. splendens varied significantly. Both the predators R. sikkimensis and larvae of Tx. splendens can consume a good number of mosquito larvae, though the rate of consumption between the two predators vary owing to the difference in the life history traits and features. It can be assumed that these predators play an important role in larval population regulation of mosquitoes and thereby impart an effect on species composition and interactions in the aquatic insect communities of Darjeeling Hills, India.

  4. PEMELIHARAAN LARVA KEPITING BAKAU, Scylla olivacea DENGAN PENAMBAHAN BIOFLOK

    Directory of Open Access Journals (Sweden)

    Gunarto Gunarto

    2014-06-01

    Full Text Available Abstrak lengkap dapat dilihat pada Full PDF   Tujuan penelitian ini adalah untuk mengetahui efek penambahan bioflok pada pemeliharaan larva kepiting bakau Scylla olivacea terutaman pada sintasan dan perkembangan larva hingga mencapai stadia krablet.

  5. Nutritional condition and vertical distribution of Baltic cod larvae

    DEFF Research Database (Denmark)

    Grønkjær, P.; Clemmesen, C.; St. John, Michael

    1997-01-01

    Newly hatched Baltic cod Gadus morhua larvae are typically found at depths >60 m. This is a region of low light and prey availability, hence generating the hypothesis that larvae have to migrate from hatching depth to the surface layer to avoid starvation and improve their nutritional condition....... To lest this hypothesis, Baltic cod larvae were sampled during the spawning seasons of 1994 and 1995 with depth-resolving multiple opening/closing nets. Each larva was aged by otolith readings and its RNA/DNA ratio was determined as a measure of nutritional condition. The RNA/DNA ratios of these larvae...... caught larvae had RNA/DNA ratios between the mean values found for starving and fed laboratory larvae. Only larvae aged 8-11 days had higher mean RNA/DNA ratios above 45 m than below (t-test, P...

  6. CalCOFI Larvae Counts, Scientific Names HB to HI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  7. CalCOFI Larvae Counts, Scientific Names CP to DE

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  8. CalCOFI Larvae Counts, Scientific Names OM to OX

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  9. CalCOFI Larvae Counts, Scientific Names SB to SC

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  10. Decapod larvae from the nearshore waters of Karwar

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, V.R.; Paulinose, V.T.

    Abundance of decapod larvae at three stations in Binge Bay, Karwar has been reported based on surface collections taken during the period October 1975 to September 1976. The larvae were very common in the Bay and the postmonsoon months sustained...

  11. CalCOFI Larvae Counts, Scientific Names DH to EC

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fish larvae counts and standardized counts for larvae captured in CalCOFI icthyoplankton nets (primarily vertical [Calvet or Pairovet], oblique [bongo or ring nets],...

  12. Suppressing bullfrog larvae with carbon dioxide

    Science.gov (United States)

    Gross, Jackson A.; Ray, Andrew; Sepulveda, Adam J.; Watten, Barnaby J.; Densmore, Christine L.; Layhee, Megan J.; Mark Abbey-Lambert,; ,

    2014-01-01

    Current management strategies for the control and suppression of the American Bullfrog (Lithobates catesbeianus = Rana catesbeiana Shaw) and other invasive amphibians have had minimal effect on their abundance and distribution. This study evaluates the effects of carbon dioxide (CO2) on pre- and prometamorphic Bullfrog larvae. Bullfrogs are a model organism for evaluating potential suppression agents because they are a successful invader worldwide. From experimental trials we estimated that the 24-h 50% and 99% lethal concentration (LC50 and LC99) values for Bullfrog larvae were 371 and 549 mg CO2/L, respectively. Overall, larvae that succumbed to experimental conditions had a lower body condition index than those that survived. We also documented sublethal changes in blood chemistry during prolonged exposure to elevated CO2. Specifically, blood pH decreased by more than 0.5 pH units after 9 h of exposure and both blood partial pressure of CO2 (pCO2) and blood glucose increased. These findings suggest that CO2 treatments can be lethal to Bullfrog larvae under controlled laboratory conditions. We believe this work represents the necessary foundation for further consideration of CO2 as a potential suppression agent for one of the most harmful invaders to freshwater ecosystems.

  13. Low salinity tolerance 0/ eggs and larvae.

    African Journals Online (AJOL)

    the larvae permitting C. krauss; to spread into areas where it is unable to breed successfully. ACKNOWLEDGEMENTS. The author acknowledges the financial assistance of the Department of Nature Conserva- tion of the Cape Province of South Africa, and the South African National Committee for. Oceanographic Research ...

  14. Evolution of foraging behavior in Drosophilid larvae

    Science.gov (United States)

    Rivera-Alba, Marta; Kabra, Mayank; Branson, Kristin; Mirth, Christen

    2015-03-01

    Drosophilids, like other insects, go through a larval phase before metamorphosing into adults. Larvae increase their body weight by several orders of magnitude in a few days. We therefore hypothesized that foraging behavior is under strong evolutionary pressure to best fit the larval environment. To test our hypothesis we used a multidisciplinary approach to analyze foraging behavior across species and larval stages. First, we recorded several videos of larvae foraging for each of 47 Drosophilid species. Then, using a supervised machine learning approach, we automatically annotated the video collection for the foraging sub-behaviors, including crawling, turning, head casting or burrowing. We also computed over 100 features to describe the posture and dynamics of each animal in each video frame. From these data, we fit models to the behavior of each species. The models each had the same parametric form, but differed in the exact parameters. By simulating larva behavior in virtual arenas we can infer which properties of the environments are better for each species. Comparisons between these inferred environments and the actual environments where these animals live will give us a deeper understanding about the evolution of foraging behavior in Drosophilid larvae.

  15. ISOLASI BACILLUS THURINGIENSIS DARI LARVA DAN PENGUJIAN PATOGENISITASNYA TERHADAP LARVA NYAMUK VEKTOR

    Directory of Open Access Journals (Sweden)

    Blondine Ch. P.

    2012-09-01

    Full Text Available A study to evaluate pathogenic organisms as cause of mosquito larvae death was conducted at Wonokerto and Pabelan villages, Salatiga Luar Kota subdistrict, Semarang regency in Central Java from May 1991 through December 1991. Bacterial isolation from dead larvae showed that 31 B. thuringicnsis isolates were obtained from 31 larvae samples collected from 2 location e.g Wonokerto village (3 samples, Pabelan village (28 samples. Nineteen isolates (61,3% showed a pathogenicity of more than 50% to third toward instar larvae of Aedes aegypti and Culex quinquefasciatus respectively 24 hours after exposure. This study shows the possible use of B. thuringiensis for biologic control of mosquitoes which can act as vectors for human diseases.

  16. Lagrangian Observations and Modeling of Marine Larvae

    Science.gov (United States)

    Paris, Claire B.; Irisson, Jean-Olivier

    2017-04-01

    Just within the past two decades, studies on the early-life history stages of marine organisms have led to new paradigms in population dynamics. Unlike passive plant seeds that are transported by the wind or by animals, marine larvae have motor and sensory capabilities. As a result, marine larvae have a tremendous capacity to actively influence their dispersal. This is continuously revealed as we develop new techniques to observe larvae in their natural environment and begin to understand their ability to detect cues throughout ontogeny, process the information, and use it to ride ocean currents and navigate their way back home, or to a place like home. We present innovative in situ and numerical modeling approaches developed to understand the underlying mechanisms of larval transport in the ocean. We describe a novel concept of a Lagrangian platform, the Drifting In Situ Chamber (DISC), designed to observe and quantify complex larval behaviors and their interactions with the pelagic environment. We give a brief history of larval ecology research with the DISC, showing that swimming is directional in most species, guided by cues as diverse as the position of the sun or the underwater soundscape, and even that (unlike humans!) larvae orient better and swim faster when moving as a group. The observed Lagrangian behavior of individual larvae are directly implemented in the Connectivity Modeling System (CMS), an open source Lagrangian tracking application. Simulations help demonstrate the impact that larval behavior has compared to passive Lagrangian trajectories. These methodologies are already the base of exciting findings and are promising tools for documenting and simulating the behavior of other small pelagic organisms, forecasting their migration in a changing ocean.

  17. Feeding frequency and caste differentiation in Bombus terrestris larvae

    NARCIS (Netherlands)

    Ribeiro, M.F.; Velthuis, H.H.W.; Duchateau, Marie José; Tweel, I. van der

    1998-01-01

    The frequency with which bumble bee larvae are fed during their development was studied using video-recordings. The behaviour of the workers while feeding worker, male and queen larvae of Bombus terrestris was recorded. At the beginning of development, female larvae of both castes were fed at a

  18. Odour avoidance learning in the larva of Drosophila melanogaster

    Indian Academy of Sciences (India)

    Prakash

    with electric shock in normal and mutant larvae and Tully et al. reported the passage of olfactory ... Drosophila larvae can be trained to avoid odours associated with electric shock. We describe here, an improved method of ..... Pairing odour with shock drives the larvae to the opposite zone. Preference learning index PLI.

  19. Lethal infection thresholds of Paenibacillus larvae for honeybee drone and worker larvae (Apis mellifera).

    Science.gov (United States)

    Behrens, Dieter; Forsgren, Eva; Fries, Ingemar; Moritz, Robin F A

    2010-10-01

    We compared the mortality of honeybee (Apis mellifera) drone and worker larvae from a single queen under controlled in vitro conditions following infection with Paenibacillus larvae, a bacterium causing the brood disease American Foulbrood (AFB). We also determined absolute P. larvae cell numbers and lethal titres in deceased individuals of both sexes up to 8 days post infection using quantitative real-time PCR (qPCR). Our results show that in drones the onset of infection induced mortality is delayed by 1 day, the cumulative mortality is reduced by 10% and P. larvae cell numbers are higher than in worker larvae. Since differences in bacterial cell titres between sexes can be explained by differences in body size, larval size appears to be a key parameter for a lethal threshold in AFB tolerance. Both means and variances for lethal thresholds are similar for drone and worker larvae suggesting that drone resistance phenotypes resemble those of related workers. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  20. Larva of Palaemnema brasiliensis Machado (Odonata: Platystictidae), from Amazonas, Brazil.

    Science.gov (United States)

    Neiss, Ulisses Gaspar; Hamada, Neusa

    2016-02-09

    The larva of Palaemnema brasiliensis Machado, 2009 is described and illustrated based on last-instar larvae and exuviae of reared larvae collected in a blackwater stream in Barcelos and Presidente Figueiredo municipalities, Amazonas state, Brazil. The larva of P. brasiliensis can be distinguished from the two South American species of the genus with described larvae (P. clementia Selys and P. mutans Calvert), mainly by presence of a single obtuse cusp on the labial palp, the presence and configuration of setae in the caudal lamellae, and the proportional length of terminal filaments of the caudal lamellae. The family is recorded here for the first time in Brazilian state of Amazonas.

  1. Analysis of feeding behavior of Drosophila larvae on liquid food.

    Science.gov (United States)

    Shen, Ping

    2012-05-01

    The food responses of Drosophila larvae offer an excellent opportunity to study the genetic and neural regulation of feeding behavior. Compared with fed larvae, hungry larvae are more likely to display aggressive foraging, rapid food intake, compensatory feeding, and stress-resistant food procurement. Behavioral assays have been developed to quantitatively assess particular aspects of the hunger-driven food response. In combination, these assays help define the specific role of signaling molecules or neurons in the regulation of feeding behavior in foraging larvae. This protocol describes the analysis of larvae feeding on liquid food. The test is designed for quantitative assessment of the food ingestion rate of individual larvae under different energy states. It provides a simple and reliable way to measure the graded modification of the baseline feeding rate of larvae as food deprivation is prolonged. The test is applicable to routine functional testing and larger-scale screening of genetic mutations and biologics that might affect food consumption.

  2. The active evolutionary lives of echinoderm larvae.

    Science.gov (United States)

    Raff, R A; Byrne, M

    2006-09-01

    Echinoderms represent a researchable subset of a dynamic larval evolutionary cosmos. Evolution of echinoderm larvae has taken place over widely varying time scales from the origins of larvae of living classes in the early Palaeozoic, approximately 500 million years ago, to recent, rapid and large-scale changes that have occurred within living genera within a span of less than a million years to a few million years. It is these recent evolutionary events that offer a window into processes of larval evolution operating at a micro-evolutionary level of evolution of discrete developmental mechanisms. We review the evolution of the diverse larval forms of living echinoderms to outline the origins of echinoderm larval forms, their diversity among living echinoderms, molecular clocks and rates of larval evolution, and finally current studies on the roles of developmental regulatory mechanisms in the rapid and radical evolutionary changes observed between closely related congeneric species.

  3. Sporulation and Germination of Paenibacillus larvae Cells.

    Science.gov (United States)

    Mahdi, Osama S; Fisher, Nathan A

    2018-02-22

    Endospores are metabolically dormant cells formed by a variety of Gram-positive bacteria within the phylum Firmicutes in response to nutrient limiting or otherwise unfavorable growth conditions. American foulbrood disease (AFB) is a serious disease of honeybees that is caused by the introduction of Paenibacillus larvae endospores into a honeybee colony. Progression to fulminant disease and eventual collapse of the colony requires multiple rounds of endospore germination, vegetative replication, endospore formation, and subsequent spread within the colony. This unit includes protocols for the in vitro sporulation and germination of P. larvae to assist investigators in the study of these processes. © 2018 by John Wiley & Sons, Inc. Copyright © 2018 John Wiley & Sons, Inc.

  4. Immunity through early development of coral larvae.

    Science.gov (United States)

    Palmer, C V; Graham, E; Baird, A H

    2012-10-01

    As a determinant of survival, immunity is likely to be significant in enabling coral larvae to disperse and successfully recruit, however, whether reef-building coral larvae have immune defenses is unknown. We investigated the potential presence and variation in immunity in the lecithotrophic larvae of Acropora tenuis through larval development. Enzymes indicative of tyrosinase and laccase-type melanin-synthesis were quantified, and the concentration of three coral fluorescent proteins was measured over six developmental stages; egg, embryo, motile planula, planula post-exposure to crustose coralline algae (CCA; settlement cue), settled, settled post-exposure to Symbiodinium (endosymbiont). Both types of melanin-synthesis pathways and the three fluorescent proteins were present in A. tenuis throughout development. Laccase-type activity and red fluorescence increased following exposure of planula to CCA, whereas tyrosinase-type activity and cyan fluorescence increased following settlement. No change was detected in the measured parameters following exposure to Symbiodinium. This study is the first to document coral larval immune responses and suggests the melanin-synthesis pathways have disparate roles-the laccase-type potentially non-immunological and the tyrosinase-type in cytotoxic defense. Our results indicate that corals have the potential to resist infection from the earliest life history phase. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Transgenic potato plants expressing cry3A gene confer resistance to Colorado potato beetle.

    Science.gov (United States)

    Mi, Xiaoxiao; Ji, Xiangzhuo; Yang, Jiangwei; Liang, Lina; Si, Huaijun; Wu, Jiahe; Zhang, Ning; Wang, Di

    2015-07-01

    The Colorado potato beetle (Leptinotarsa decemlineata Say, CPB) is a fatal pest, which is a quarantine pest in China. The CPB has now invaded the Xinjiang Uygur Autonomous Region and is constantly spreading eastward in China. In this study, we developed transgenic potato plants expressing cry3A gene. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that the cry3A gene expressed in leaves, stems and roots of the transgenic plants under the control of CaMV 35S promoter, while they expressed only in leaves and stems under the control of potato leaf and stem-specific promoter ST-LS1. The mortality of the larvae was higher (28% and 36%) on the transgenic plant line 35S1 on the 3rd and 4th days, and on ST3 (48%) on the 5th day after inoculation with instar larvae. Insect biomass accumulation on the foliage of the transgenic plant lines 35S1, 35S2 and ST3 was significantly lower (0.42%, 0.43% and 0.42%). Foliage consumption was lowest on transgenic lines 35S8 and ST2 among all plant foliage (7.47 mg/larvae/day and 12.46 mg/larvae/day). The different transgenic plant foliages had varied inhibition to larval growth. The survivors on the transgenic lines obviously were smaller than their original size and extremely weak. The transgenic potato plants with CPB resistance could be used to develop germplasms or varieties for controlling CPB damage and halting its spread in China. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  6. From trochophore to pilidium and back again - a larva's journey.

    Science.gov (United States)

    Maslakova, Svetlana A; Hiebert, Terra C

    2014-01-01

    Nemerteans, a phylum of marine lophotrochozoan worms, have a biphasic life history with benthic adults and planktonic larvae. Nemertean larval development is traditionally categorized into direct and indirect. Indirect development via a long-lived planktotrophic pilidium larva is thought to have evolved in one clade of nemerteans, the Pilidiophora, from an ancestor with a uniformly ciliated planuliform larva. Planuliform larvae in a member of a basal nemertean group, the Palaeonemertea, have been previously shown to possess a vestigial prototroch, homologous to the primary larval ciliated band in the trochophores of other spiralian phyla, such as annelids and mollusks. We review literature on nemertean larval development, and include our own unpublished observations. We highlight recent discoveries of numerous pilidiophoran species with lecithotrophic larvae. Some of these larvae superficially resemble uniformly ciliated planuliform larvae of other nemerteans. Others possess one or two transverse ciliary bands, which superficially resemble the prototroch and telotroch of some spiralian trochophores. We also summarize accumulating evidence for planktotrophic feeding by larvae of the order Hoplonemertea, which until now were considered to be lecithotrophic. We suggest that 1) non-feeding pilidiophoran larval forms are derived from a feeding pilidium; 2) such forms have likely evolved many times independently within the Pilidiophora; 3) any resemblance of such larvae to the trochophores of other spiralians is a result of convergence and that 4) the possibility of planktotrophy in hoplonemertean larvae may influence estimates of pelagic larval duration, dispersal, and population connectivity in this group.

  7. The Identification of Congeners and Aliens by Drosophila Larvae.

    Directory of Open Access Journals (Sweden)

    Francisco Del Pino

    Full Text Available We investigated the role of Drosophila larva olfactory system in identification of congeners and aliens. We discuss the importance of these activities in larva navigation across substrates, and the implications for allocation of space and food among species of similar ecologies. Wild type larvae of cosmopolitan D. melanogaster and endemic D. pavani, which cohabit the same breeding sites, used species-specific volatiles to identify conspecifics and aliens moving toward larvae of their species. D. gaucha larvae, a sibling species of D. pavani that is ecologically isolated from D. melanogaster, did not respond to melanogaster odor cues. Similar to D. pavani larvae, the navigation of pavani female x gaucha male hybrids was influenced by conspecific and alien odors, whereas gaucha female x pavani male hybrid larvae exhibited behavior similar to the D. gaucha parent. The two sibling species exhibited substantial evolutionary divergence in processing the odor inputs necessary to identify conspecifics. Orco (Or83b mutant larvae of D. melanogaster, which exhibit a loss of sense of smell, did not distinguish conspecific from alien larvae, instead moving across the substrate. Syn97CS and rut larvae of D. melanogaster, which are unable to learn but can smell, moved across the substrate as well. The Orco (Or83b, Syn97CS and rut loci are necessary to orient navigation by D. melanogaster larvae. Individuals of the Trana strain of D. melanogaster did not respond to conspecific and alien larval volatiles and therefore navigated randomly across the substrate. By contrast, larvae of the Til-Til strain used larval volatiles to orient their movement. Natural populations of D. melanogaster may exhibit differences in identification of conspecific and alien larvae. Larval locomotion was not affected by the volatiles.

  8. SEBARAN LARVA IKAN DAN KAITANNYA DENGAN KONDISI OSEANOGRAFI LAUT SULAWESI

    Directory of Open Access Journals (Sweden)

    Khairul Amri

    2015-06-01

    Full Text Available Laut Sulawesi diketahui sebagai daerah penangkapan ikan yang potensial sekaligus diduga sebagai lokasi pemijahan. Berbagai jenis larva ikan pelagis maupun demersal ditemukan di perairan ini. Kelimpahan dan sebaran larva ikan di suatu perairan sangat dipengaruhi oleh kondisi oseanografi seperti temperatur, salinitas dan sejumlah parameter lainnya termasuk ketersediaan pakan. Untuk mengetahui pengaruh parameter oseanografi terhadap kelimpahan dan sebaran spasial larva ikan di Laut Sulawesi, telah dilakukan penelitian menggunakan kapal riset KR Baruna Jaya VII pada Oktober 2012. Parameter oseanografi yaitu temperatur dan salinitas diukur menggunakan iCTD dan sampling larva menggunakan bonggo net pada 18 stasiun pengukuran. Analisa hubungan kondisi oseanografi dengan sebaran larva dilakukan secara deskriptif dan pemetaan sebarannya dilakukan secara spasial. Hasil menunjukan keterkaitan sejumlah parameter oseanografi dengan kelimpahan dan sebaran spasial larva ikan. Sebaran larva famili Scombroidae dominan berada pada perairan bersalinitas tinggi karena merupakan jenis ikan oseanik. Larva ikan demersal banyak ditemukan di perairan sekitar Kep.Sangihe Talaud. Kelimpahan larva tertinggi ditemukan di perairan bagian utara dan barat lokasi penelitian dimana kelimpahan plankton tinggi ditemukan.   Celebes Sea is known as a potential fishing and spawning grounds for several pelagic fish species. Abundance and distribution of fish larvae are allegedly linked to oceanographic conditions such as temperature, salinity and others oceanographic parameters including food availablity. To see the effect of oceanographic on the abundance and spatial distribution of fish larvae in the Celebes Sea, has conducted a research in October 2012using the research vessel KR Baruna Jaya VII. The measurement of oceanographic parameters including temperature and salinity and larval sampling were done respectively by using iCTD and Bonggo net at 18 measuring stations. The

  9. Analysis of feeding behavior of Drosophila larvae on solid food.

    Science.gov (United States)

    Shen, Ping

    2012-05-01

    The food responses of Drosophila larvae offer an excellent opportunity to study the genetic and neural regulation of feeding behavior. Compared with fed larvae, hungry larvae are more likely to display aggressive foraging, rapid food intake, compensatory feeding, and stress-resistant food procurement. Behavioral assays have been developed to quantitatively assess particular aspects of the hunger-driven food response. In combination, these assays help define the specific role of signaling molecules or neurons in the regulation of feeding behavior in foraging larvae. This protocol is designed for quantitative assessment of the willingness of individual larvae to procure solid food under different energy states. It provides a simple and reliable way to measure the graded modification of the baseline feeding rate of larvae as the period of food deprivation is increased. The test is applicable to routine functional testing and larger-scale screening of genetic mutations and biologics that might affect food consumption.

  10. Modeling peripheral olfactory coding in Drosophila larvae.

    Directory of Open Access Journals (Sweden)

    Derek J Hoare

    Full Text Available The Drosophila larva possesses just 21 unique and identifiable pairs of olfactory sensory neurons (OSNs, enabling investigation of the contribution of individual OSN classes to the peripheral olfactory code. We combined electrophysiological and computational modeling to explore the nature of the peripheral olfactory code in situ. We recorded firing responses of 19/21 OSNs to a panel of 19 odors. This was achieved by creating larvae expressing just one functioning class of odorant receptor, and hence OSN. Odor response profiles of each OSN class were highly specific and unique. However many OSN-odor pairs yielded variable responses, some of which were statistically indistinguishable from background activity. We used these electrophysiological data, incorporating both responses and spontaneous firing activity, to develop a bayesian decoding model of olfactory processing. The model was able to accurately predict odor identity from raw OSN responses; prediction accuracy ranged from 12%-77% (mean for all odors 45.2% but was always significantly above chance (5.6%. However, there was no correlation between prediction accuracy for a given odor and the strength of responses of wild-type larvae to the same odor in a behavioral assay. We also used the model to predict the ability of the code to discriminate between pairs of odors. Some of these predictions were supported in a behavioral discrimination (masking assay but others were not. We conclude that our model of the peripheral code represents basic features of odor detection and discrimination, yielding insights into the information available to higher processing structures in the brain.

  11. Learning and memory in zebrafish larvae

    Science.gov (United States)

    Roberts, Adam C.; Bill, Brent R.; Glanzman, David L.

    2013-01-01

    Larval zebrafish possess several experimental advantages for investigating the molecular and neural bases of learning and memory. Despite this, neuroscientists have only recently begun to use these animals to study memory. However, in a relatively short period of time a number of forms of learning have been described in zebrafish larvae, and significant progress has been made toward their understanding. Here we provide a comprehensive review of this progress; we also describe several promising new experimental technologies currently being used in larval zebrafish that are likely to contribute major insights into the processes that underlie learning and memory. PMID:23935566

  12. Biofilms and Marine Invertebrate Larvae: What Bacteria Produce That Larvae Use to Choose Settlement Sites

    Science.gov (United States)

    Hadfield, Michael G.

    2011-01-01

    Communities of microorganisms form thin coats across solid surfaces in the sea. Larvae of many marine invertebrates use biofilm components as cues to appropriate settlement sites. Research on the tube-dwelling polychaete worm Hydroides elegans, a globally common member of biofouling communities, is described to exemplify approaches to understanding biofilm bacteria as a source of settlement cues and larvae as bearers of receptors for bacterial cues. The association of species of the bacterial genus Pseudoalteromonas with larval settlement in many phyla is described, and the question of whether cues are soluble or surface-bound is reviewed, concluding that most evidence points to surface-bound cues. Seemingly contradictory data for stimulation of barnacle settlement are discussed; possibly both explanations are true. Paleontological evidence reveals a relationship between metazoans and biofilms very early in metazoan evolution, and thus the receptors for bacterial cues of invertebrate larvae are very old and possibly unique. Finally, despite more than 60 years of intense investigation, we still know very little about either the bacterial ligands that stimulate larval settlement or the cellular basis of their detection by larvae.

  13. Effect of gut bacterial isolates from Apis mellifera jemenitica on Paenibacillus larvae infected bee larvae

    Directory of Open Access Journals (Sweden)

    Ahmad Al-Ghamdi

    2018-02-01

    Full Text Available The probiotic effects of seven newly isolated gut bacteria, from the indegenous honey bees of Saudi Arabia were investigated. In vivo bioassays were used to investigate the effects of each gut bacterium namely, Fructobacillus fructosus (T1, Proteus mirabilis (T2, Bacillus licheniformis (T3, Lactobacillus kunkeei (T4, Bacillus subtilis (T5, Enterobacter kobei (T6, and Morganella morganii (T7 on mortality percentage of honey bee larvae infected with P. larvae spores along with negative control (normal diet and positive control (normal diet spiked with P. larvae spores. Addition of gut bacteria to the normal diet significantly reduced the mortality percentage of the treated groups. Mortality percentage in all treated groups ranged from 56.67% up to 86.67%. T6 treated group exhibited the highest mortality (86.67%, whereas T4 group showed the lowest mortality (56.67%. Among the seven gut bacterial treatments, T4 and T3 decreased the mortality 56.67% and 66.67%, respectively, whereas, for T2, T6, and T7 the mortality percentage was equal to that of the positive control (86.67%. Mortality percentages in infected larval groups treated with T1, and T5 were 78.33% and 73.33% respectively. Most of the mortality occurred in the treated larvae during days 2 and 3. Treatments T3 and T4 treatments showed positive effects and reduced mortality.

  14. Toxicity of phenol on Macrobrachium rosenbergii (de Man) eggs, larvae, and post-larvae

    Energy Technology Data Exchange (ETDEWEB)

    Law, A.T.; Yeo, M.E. [Universiti Kolej Terengganu (UPM), Darul Iman (Malaysia)

    1997-03-01

    Literature on the toxicities of phenol on aquatic organisms is very limited. USEPA reported that the acute and chronic toxicities of phenol to freshwater aquatic life occur at concentrations as low as 10.2 mg/L and 2.56 mg/L, respectively. While for the saltwater aquatic life the acute toxicity occurs at concentrations as low as 5.8 mg/L. No data are available for the chronic toxicity of phenol to saltwater aquatic life. Sublethal concentrations of phenol have significant effects on the physiological and histological processes of the aquatic organisms: such as gill necrosis; destruction of erythrocyte cells; inhibition of sexual activities; suppression on growth and reduction of resistance to diseases. Macrobrachium rosenbergii(de Man) is the sole freshwater prawn cultured in Malaysia. Occasionally, the hatcheries are unable to produce the post-larvae because of undefined pollutants present in the water supplies. It has been observed that the use of cracked fiberglass tanks for larvae rearing is correlated with high mortality. This high mortality is probably due to the toxicity of the phenolic compounds which are leached out from the fiber glass tank into the water. This study was undertaken to evaluate the toxicity of phenol on eggs, larvae and post-larvae of M. rosenbergii and to set the water quality criteria of phenol for the said species. 16 refs., 3 tabs.

  15. A Madurella mycetomatis Grain Model in Galleria mellonella Larvae.

    Directory of Open Access Journals (Sweden)

    Wendy Kloezen

    Full Text Available Eumycetoma is a chronic granulomatous subcutaneous infectious disease, endemic in tropical and subtropical regions and most commonly caused by the fungus Madurella mycetomatis. Interestingly, although grain formation is key in mycetoma, its formation process and its susceptibility towards antifungal agents are not well understood. This is because grain formation cannot be induced in vitro; a mammalian host is necessary to induce its formation. Until now, invertebrate hosts were never used to study grain formation in M. mycetomatis. In this study we determined if larvae of the greater wax moth Galleria mellonella could be used to induce grain formation when infected with M. mycetomatis. Three different M. mycetomatis strains were selected and three different inocula for each strain were used to infect G. mellonella larvae, ranging from 0.04 mg/larvae to 4 mg/larvae. Larvae were monitored for 10 days. It appeared that most larvae survived the lowest inoculum, but at the highest inoculum all larvae died within the 10 day observation period. At all inocula tested, grains were formed within 4 hours after infection. The grains produced in the larvae resembled those formed in human and in mammalian hosts. In conclusion, the M. mycetomatis grain model in G. mellonella larvae described here could serve as a useful model to study the grain formation and therapeutic responses towards antifungal agents in the future.

  16. Fate of pharmaceuticals and pesticides in fly larvae composting

    Energy Technology Data Exchange (ETDEWEB)

    Lalander, C., E-mail: cecilia.lalander@slu.se [Department of Energy and Technology, Swedish University of Agricultural Sciences (Sweden); Senecal, J.; Gros Calvo, M. [Department of Energy and Technology, Swedish University of Agricultural Sciences (Sweden); Ahrens, L.; Josefsson, S.; Wiberg, K. [Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences (Sweden); Vinnerås, B. [Department of Energy and Technology, Swedish University of Agricultural Sciences (Sweden)

    2016-09-15

    A novel and efficient organic waste management strategy currently gaining great attention is fly larvae composting. High resource recovery efficiency can be achieved in this closed-looped system, but pharmaceuticals and pesticides in waste could potentially accumulate in every loop of the treatment system and spread to the environment. This study evaluated the fate of three pharmaceuticals (carbamazepine, roxithromycin, trimethoprim) and two pesticides (azoxystrobin, propiconazole) in a fly larvae composting system and in a control treatment with no larvae. It was found that the half-life of all five substances was shorter in the fly larvae compost (< 10% of control) and no bioaccumulation was detected in the larvae. Fly larvae composting could thus impede the spread of pharmaceuticals and pesticides into the environment. - Highlights: • Degradation of pharmaceuticals and pesticides in fly larvae composting (FLC). • Half-life considerably shorter in FLC than in control with no larvae. • Half-life of carbamazepine was less than two days in FLC. • No bioaccumulation in larvae detected. • FLC could impede the spreading of pharmaceuticals and pesticide in the environment.

  17. Fate of pharmaceuticals and pesticides in fly larvae composting

    International Nuclear Information System (INIS)

    Lalander, C.; Senecal, J.; Gros Calvo, M.; Ahrens, L.; Josefsson, S.; Wiberg, K.; Vinnerås, B.

    2016-01-01

    A novel and efficient organic waste management strategy currently gaining great attention is fly larvae composting. High resource recovery efficiency can be achieved in this closed-looped system, but pharmaceuticals and pesticides in waste could potentially accumulate in every loop of the treatment system and spread to the environment. This study evaluated the fate of three pharmaceuticals (carbamazepine, roxithromycin, trimethoprim) and two pesticides (azoxystrobin, propiconazole) in a fly larvae composting system and in a control treatment with no larvae. It was found that the half-life of all five substances was shorter in the fly larvae compost (< 10% of control) and no bioaccumulation was detected in the larvae. Fly larvae composting could thus impede the spread of pharmaceuticals and pesticides into the environment. - Highlights: • Degradation of pharmaceuticals and pesticides in fly larvae composting (FLC). • Half-life considerably shorter in FLC than in control with no larvae. • Half-life of carbamazepine was less than two days in FLC. • No bioaccumulation in larvae detected. • FLC could impede the spreading of pharmaceuticals and pesticide in the environment.

  18. Nutritional condition and vertical distribution of Baltic cod larvae

    DEFF Research Database (Denmark)

    Grønkjær, P.; Clemmesen, C.; St. John, Michael

    1997-01-01

    Newly hatched Baltic cod Gadus morhua larvae are typically found at depths >60 m. This is a region of low light and prey availability, hence generating the hypothesis that larvae have to migrate from hatching depth to the surface layer to avoid starvation and improve their nutritional condition...... aged 2-25 days (median 10 days) ranged from 0.4 to 6.2, corresponding to levels exhibited by starving and fast growing larvae in laboratory calibration studies (starvation, protein growth rate, G(pi)=-12.2% day(-1); fast-growing larvae, G(pi)=14.1% day(-1)) respectively. Seventy per cent of the field...

  19. Fish larvae from the Gulf of California

    Directory of Open Access Journals (Sweden)

    Gerardo Aceves-Medina

    2003-03-01

    Full Text Available Taxonomic composition of fish larvae was analysed from 464 plankton samples obtained during 10 oceanographic surveys in the Gulf of California between 1984 and 1988. We identified 283 taxa: 173 species, 57 genera, and 53 families. Tropical and subtropical species predominated except during the winter, when temperate-subarctic species were dominant. The most abundant species were the mesopelagic Benthosema panamense, Triphoturus mexicanus and Vinciguerria lucetia, but the coastal pelagic species Engraulis mordax, Opisthonema spp., Sardinops caeruleus and Scomber japonicus were also prominent. The taxonomic composition of the ichthyoplankton shows the seasonality of the Gulf as well as environmental changes that occurred between the 1984-1987 warm period and the 1956-1957 cool period previously reported. The presence of E. mordax larvae as one of the most abundant species in the Gulf provides evidence of the reproduction of this species two years before the development of the northern anchovy fishery and the decline of the sardine fishery in the Gulf of California.

  20. A Model of Drosophila Larva Chemotaxis.

    Directory of Open Access Journals (Sweden)

    Alex Davies

    2015-11-01

    Full Text Available Detailed observations of larval Drosophila chemotaxis have characterised the relationship between the odour gradient and the runs, head casts and turns made by the animal. We use a computational model to test whether hypothesised sensorimotor control mechanisms are sufficient to account for larval behaviour. The model combines three mechanisms based on simple transformations of the recent history of odour intensity at the head location. The first is an increased probability of terminating runs in response to gradually decreasing concentration, the second an increased probability of terminating head casts in response to rapidly increasing concentration, and the third a biasing of run directions up concentration gradients through modulation of small head casts. We show that this model can be tuned to produce behavioural statistics comparable to those reported for the larva, and that this tuning results in similar chemotaxis performance to the larva. We demonstrate that each mechanism can enable odour approach but the combination of mechanisms is most effective, and investigate how these low-level control mechanisms relate to behavioural measures such as the preference indices used to investigate larval learning behaviour in group assays.

  1. Feeding behaviour of snake head fish, Channa striatus larvae

    Directory of Open Access Journals (Sweden)

    Thumronk Amornsakun1*

    2011-12-01

    Full Text Available Feeding scheme experiments were done in a 15-liter glass aquarium (water volume 10 liters containing 500 of two-dayold larvae (stage at first feeding. It was found that larval snake head fish aged 3-11 days (average total length 6.08-10.86 mmconsumed Moina. Larvae aged 12-15 days (average total length 10.79-14.61 mm consumed both Moina and commercialpellet (40 % crude protein. Larvae aged more than 16 days consumed only commercial pellet.Determining the daily food uptake by the larvae and juveniles was done in a 15-liter glass aquarium (water volume 10liters containing 1,000 larvae. The larvae consumed Moina ,provide of a density of Moina 10 individual/ml. The amount offood intake was calculated based on changes of food density in the aquarium with and without fish larvae at 2-hour intervals.It was found that larvae aged 3-15 days consumed Moina. The average uptake of Moina in digestive tract per day of larvaeage 3, 6, 9, 12 and 15 days old was 28.7, 115.70, 162.27, 195.30 and 227.30 individual/larva, respectively at water temperaturesranging between 25 and 28°C.A starvation experiment was carried out using a 15-liter glass aquarium (water volume 10 liters with three replications.Two hundred newly hatched larvae were kept without feeding. Larvae started to die at 216 hr and totally died within 326 hrafter hatching at water temperature ranging between 28.0 and 30.5°C.

  2. Preliminary screening of plant essential oils against larvae of Culex ...

    African Journals Online (AJOL)

    Preliminary screenings of 22 plant essential oils were tested for mortality of the mosquito larvae Culex quinquefasciatus under laboratory conditions. Percent (%) mortality of the mosquito larvae were obtained for each essential oil. At different exposure periods, viz. 1, 3, 6, 12 and 24 h among the 22 plant oils tested, eight ...

  3. Biological control agent for mosquito larvae: Review on the killifish ...

    African Journals Online (AJOL)

    Jane

    2011-08-15

    Aug 15, 2011 ... Biological control of mosquito larvae by using fish has shown many advantages over ... number of malaria cases in India that has been reduced from 75 million to 150,000 and deaths from 750,000 to ... aquatic weeds and G. affinis on the mosquito larvae. In addition to that G. affinis has some adverse effects ...

  4. Temporal dynamics of Chaoborus larvae (Diptera : Chaoboridae) in ...

    African Journals Online (AJOL)

    Chaoborus larvae are voracious predators of zooplankton able to change their specific composition and size structure. Thus they appear as competitors of fish. They also represent food for planktophage fish. The temporal dynamics of Chaoborus larvae was studied (from january to october 1997) in the fishery of Bakro ...

  5. Activity of Bacillis thuringiensis toxins against cocoa pod borer larvae

    NARCIS (Netherlands)

    Santoso, D.; Chaidamsari, T.; Wiryadiputra, S.; Maagd, de R.A.

    2004-01-01

    Twelve Cry proteins from Bacillus thuringiensis Berliner were tested in bioassays on cacao plantations in Indonesia for activity against the larvae of cocoa pod borer (Conopomorpha cramerella (Snellen)), an insect pest of the cacao tree. Through the damage caused by their feeding, the larvae of

  6. Protein Metabolism in Lecithotrophic Larvae (Gastropoda: Haliotis rufescens).

    Science.gov (United States)

    Vavra, J; Manahan, D T

    1999-04-01

    Rates of protein depletion, synthesis, and turnover were measured in larvae of the abalone Haliotis rufescens as an approach to understanding macromolecular metabolism during lecithotrophic development. Protein content decreased linearly during development to metamorphic competence, with 34% of the initial protein in eggs depleted during the 8-day larval life span. Fractional rates of protein synthesis (percentage of total body-protein synthesized per day) decreased during development, from 40% (1-day-old trochophore larva) to 14% (7-day-old veliger larva). Separation of proteins by one-dimensional gel electrophoresis showed that protein pools in larvae are dominated by two high-molecular-weight protein classes (88 and 121 kDa). When the proteins of 1- and 3-day-old larvae were labeled with a mixture of 35S-methionine and cysteine, the pattern on two-dimensional gels showed that the turnover process (protein synthesis and degradation) involved hundreds of different proteins. The energy gained from loss of protein could account for 20% of the protein turnover rates for trochophore larvae and 79% of the lower turnover costs for late-stage veligers. Lecithotrophic larvae of H. rufescens maintained high biosynthetic activities, with up to 40% of their whole-body protein being turned over each day. Such dynamic processes during development of nonfeeding larvae would contribute significantly to maintenance metabolism.

  7. Structure and occurrence of cyphonautes larvae (Bryozoa, Ectoprocta)

    DEFF Research Database (Denmark)

    Nielsen, Claus; Worsaae, Katrine

    2010-01-01

    We have studied larvae of the freshwater ctenostome Hislopia malayensis with scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and LM of serial sections. Some additional observations on larvae of M. membranacea using SEM and CLSM are also reported. The overall configu...

  8. Composition, Abundance and Distribution of Brachyuran Larvae in ...

    African Journals Online (AJOL)

    ... Ocypodidae, Grapsidae and Xanthidae. Abundance of brachyuran larvae was significantly positively correlated with total zooplankton abundance (r2 = 0.8) and salinity (r2 = 0.71). Keywords: Brachyuran larvae, abundance, composition, Mida creek, Kenya West Indian Ocean Journal of Marine Science Vol. 3 (2) 2004: pp.

  9. Occurrence of digenean larvae in freshwater snails in the Ruvu ...

    African Journals Online (AJOL)

    Occurrence of digenean larvae in freshwater snails in the Ruvu basin, Tanzania. G Nkwengulila, ESP Kigadye. Abstract. A survey was carried out on digenean larvae infecting freshwater snails in five habitats in Dar es Salaam, Ruvu and Morogoro. 9424 snails belonging to 12 species from five families were examined for ...

  10. The occurrence of digenean larvae in freshwater snails at Mbezi ...

    African Journals Online (AJOL)

    The occurrence of digenean larvae in freshwater snails at Mbezi-Temboni pond, Dar es Salaam. ESP Kigadye, G Nkwengulila. Abstract. The abundance of digenean larvae in snails at a pond in Mbezi-Temboni, Dar es Salaam, was investigated from July 1996 to June 1997. A total of 2,112 snails belonging to three species, ...

  11. Larvicidal effects of lemon peels on mosquito larvae | ANYANWU ...

    African Journals Online (AJOL)

    Methanol extract of the dry peels of the common edible plant, Citrus limon (family, Rutaceae), was obtained using a Soxhlet extractor and its larviciding effect evaluated against the larvae of two household mosquitoes: Aedes aegypti and Culex quinquefasciatus. Each batch of larvae (20-30) were treated with 3.90, 15.63, ...

  12. Shrinkage Rates In Newly Hatched Larvae Of Macrobrachium ...

    African Journals Online (AJOL)

    The effect of formalin/sea-water solution (2% and 4% formalin conc. buffered with borax) on the total lengths of preserved samples of newly hatched Macrobrachium vollenhovenii larvae was investigated. The influence of an aesthesia on larvae in 2% and 4% formal in was also studied to determine the combine influence of ...

  13. Rapid bioassay to screen potential biopesticides in Tenebrio molitor larvae

    Science.gov (United States)

    A simplified assay was devised to evaluate the response of Tenebrio molitor larvae to potential insect control products. The assay incorporates punched disks of flattened whole-grain bread placed in 96-well plates, with treatments applied topically, and neonate larvae added to each well. To evalua...

  14. Visceral larva migrans: migratory pattern of Toxocara canis in pigs

    DEFF Research Database (Denmark)

    Helwigh, Birgitte; Lind, Peter; Nansen, Peter

    1999-01-01

    of uninfected pigs was used as negative controls for blood parameters and weight gain. Toxocara canis migrated well in the pig, although the relative numbers of larvae recovered decreased significantly during the experiment. On day 7 p.i., high numbers of larvae were recovered from the lymph nodes around...

  15. Nutritional condition of fish larvae in South African estuaries: an ...

    African Journals Online (AJOL)

    It is concluded that the individual RNA/DNA ratio can provide a reliable, sensitive and cost-effective method to assess the immediate effects of environmental changes on the nutritional condition of estuarine fish larvae. Keywords: estuarine ecology, Gilchristella aestuaria larvae, lipid content, protein content, RNA/DNA ratio, ...

  16. Observations on the seasonal dynamics of Caddisfly larvae ...

    African Journals Online (AJOL)

    The Trichoptera fauna in the water body consisted of two genera, Cheumatopsyche and Amphipsyche, which closely associated with the moss, Fontinalis (Bryophyta). The density of larvae increased with the occurrence and bloom of moss. The changes in density of larvae are discussed with reference to the resources ...

  17. Preliminary notes on the decapod larvae of the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Menon, M.K.; Menon, P.G.; Paulinose, V.T.

    fairly good numbers were captured are described and illustrated with suitable charts The possible effect of the time of haul and the season on the number of larvae caught is explained The probable parentage of the more commonly encountered types of larvae...

  18. Freshly squeezed: anaphylaxis caused by drone larvae juice.

    Science.gov (United States)

    Stoevesandt, J; Trautmann, A

    2017-11-30

    Drone larvae are mostly considered a by-product of beekeeping, but have recently been advo-cated as a high-protein source of food. There are as yet no data concerning their allergenic po-tential. We report on a 29-year old bee keeper who experienced an anaphylactic reaction following the consumption of a freshly prepared beverage from raw drone larvae. Larvae-specific sensitization was confirmed by prick-to-prick and basophil activation testing. Bee stings and classical bee products including honey and royal jelly were tolerated. This is the hitherto first report on IgE-mediated allergy to drone larvae. We suggest that a certain awareness towards the allergenicity of bee larvae is required.

  19. External Ophthalmomyiasis Caused by a Rare Infesting Larva, Sarcophaga argyrostoma

    Directory of Open Access Journals (Sweden)

    Shmuel Graffi

    2013-01-01

    Full Text Available Purpose. External ophthalmomyiasis (EO is caused by infesting larvae belonging to various species of flies. Most documented cases result from sheep (Oestrus ovis and Russian (Rhinoestrus purpureus botfly larvae, but we recently discovered a rare case of EO caused by flesh fly (Sarcophaga argyrostoma larvae. Here, we report the case of a patient with EO who had been hospitalized and sedated for 1 week because of unrelated pneumonia. Methods. Case report. Results. A total of 32 larvae were removed from the adnexae of both eyes. Larvae identification was confirmed through DNA analysis. Treatment with topical tobramycin resulted in complete resolution of EO. Conclusion. EO can be caused by S. argyrostoma, and the elderly and debilitated may require extra ocular protection against flies during sedation.

  20. Sulfolipid in mulberry leaves and faeces of silkworm larvae

    International Nuclear Information System (INIS)

    Yamashita, Tadaaki

    1975-01-01

    Sulfoquinovosyl diglyceride (sulfolipid) were separated by chromatography on a ECTEOLA cellulose column from the extracts of mulberry leaves and faeces of silkworm larvae. Lipid from the leaves which had been labeled with 35 S-sulfuric acid for 24 hours separated to five 35 S containing fractions on column chromatography. Most of the 35 S in the lipid fraction was recovered as sulfolipid. No appreciable amounts of 35 S, however, were recognized as sulfolipid in the extract of the faeces of silkworm larvae which were fed 35 S-containing mulberry leaves. These results suggest that silkworm larvae actively dissimilate sulfolipid, which is the most abundant among the sulfur containing lipids in mulberry leaves. When 35 S labeled sulfolipid which was recovered from the extract of mulberry leaves was fed to the larvae, 35 S was not incorporated into the cell constituent of the larvae and 35 S of sulfolipid was entirely excreted. (auth.)

  1. Fixation of Ilyanassa snail embryos and larvae.

    Science.gov (United States)

    Gharbiah, Maey; Cooley, James; Leise, Esther M; Nakamoto, Ayaki; Rabinowitz, Jeremy S; Lambert, J David; Nagy, Lisa M

    2009-04-01

    The marine gastropod Ilyanassa obsoleta is a long-standing and very useful model for studies of embryonic development. It is an especially important model for spiralian development, and for studies of asymmetric cell division. The embryos are amenable to classic embryological manipulation techniques, as well as a growing number of molecular approaches. Ilyanassa is also an important model for studies of metamorphosis, the ecology of parasitism, the effects of environmental contaminants on morphology and sexual function, and comparative neurobiology. Ilyanassa embryos are particularly well suited for RNA and protein localization studies because of the relatively large cells and favorable properties for imaging. This protocol describes how to fix and store Ilyanassa embryos and larvae for use in whole-mount in situ hybridization and immunohistochemical studies.

  2. The other gastropod larvae: larval morphogenesis in a marine neritimorph.

    Science.gov (United States)

    Page, Louise R; Ferguson, Samuel J

    2013-04-01

    Two of the three major gastropod clades with feeding larvae are sister groups and larval morphogenesis for members of these clades, the Caenogastropoda and Heterobranchia, has been well studied. The third clade, the Neritimorpha, has an unstable phylogenetic position and little is known about development of their planktotrophic larvae. Information about larval morphology of neritimorphs and resolution of their controversial phylogenetic placement is critically important for understanding evolution of larval feeding within the Gastropoda. We describe larval morphogenesis to metamorphic competence for laboratory-reared larvae of Nerita melanotragus (Smith, 1884) (Neritimorpha: Neritidae). Preliminary observations suggest that prehatch larvae are capable of delayed hatching, possibly by entering a diapause state. Our description of larval morphogenesis, as based on tissue sections for light and transmission electron microscopy, scanning electron microscopy, three-dimensional-reconstructions of sectioned tissue, and labeling of muscles with fluorphore-tagged phalloidin, revealed four features that are unprecedented among both feeding and nonfeeding gastropod larvae. Larvae of N. melanotragus have muscles on the left and right side that both meet current criteria of a larval retractor muscle; shell-anchored muscles with oblique striations that project inside the visceral nerve loop to insert mainly on the velar lobes. They also have left and right digestive glands of similar size and a left and right hypobranchial gland. A larval "heart" is absent, but water circulation through the mantle cavity may be facilitated by large circular orifices, lined by patches of motile cilia, leading in and out of the mantle cavity. Comparison of larval traits among all three groups of gastropods with feeding larvae indicates that larvae of N. melanotragus have many unique characteristics, but they show more similarities to caenogastropod than to heterobranch larvae. These results are a

  3. Effects of various diets on the calcium and phosphorus composition of mealworms (Tenebrio molitor larvae) and superworms (Zophobas morio larvae).

    Science.gov (United States)

    Latney, La'Toya V; Toddes, Barbara D; Wyre, Nicole R; Brown, Dorothy C; Michel, Kathryn E; Briscoe, Johanna A

    2017-02-01

    OBJECTIVE To evaluate whether the nutritive quality of Tenebrio molitor larvae and Zophobas morio larvae, which are commonly cultured as live food sources, is influenced by 4 commercially available diets used as nutritional substrates; identify which diet best improved calcium content of larvae; and identify the feeding time interval that assured the highest calcium intake by larvae. ANIMALS 2,000 Zophobas morio larvae (ie, superworms) and 7,500 Tenebrio molitor larvae (ie, mealworms). PROCEDURES Larvae were placed in control and diet treatment groups for 2-, 7-, and 10-day intervals. Treatment diets were as follows: wheat millings, avian hand feeding formula, organic avian mash diet, and a high-calcium cricket feed. Control groups received water only. After treatment, larvae were flash-frozen live with liquid nitrogen in preparation for complete proximate and mineral analyses. Analyses for the 2-day treatment group were performed in triplicate. RESULTS The nutrient composition of the high-calcium cricket feed groups had significant changes in calcium content, phosphorus content, and metabolizable energy at the 2-day interval, compared with other treatment groups, for both mealworms and superworms. Calcium content and calcium-to-phosphorus ratios for larvae in the high-calcium cricket feed group were the highest among the diet treatments for all treatment intervals and for both larval species. CONCLUSIONS AND CLINICAL RELEVANCE A 2-day interval with the high-calcium cricket feed achieved a larval nutrient composition sufficient to meet National Research Council dietary calcium recommendations for nonlactating rats. Mealworm calcium composition reached 2,420 g/1,000 kcal at 48 hours, and superworm calcium composition reached 2,070g/1,000 kcal at 48 hours. These findings may enable pet owners, veterinarians, insect breeders, and zoo curators to optimize nutritive content of larvae fed to insectivorous animals.

  4. Larvas migrans ganglionar: Presentación de un caso

    Directory of Open Access Journals (Sweden)

    María del Carmen Luis Álvarez

    2003-04-01

    Full Text Available Las larvas migrans visceral cuya causa radica en la infestación con larvas de toxocara canis o cati, ocurre más frecuentemente en niños menores de 10 años. Se presenta el caso de un niño de 8 años de edad en el cual se diagnosticó larvas migrans ganglionar. Se comentan aspectos etioepidemiológicos de la enfermedad, su cuadro clínico y evolución. Se hace énfasis en las medidas higiénicas sanitarias de control y manipulación de excretas de animales domésticos, en este caso de perros y gatos.Visceral larvae migrans caused by the infestation with larvae of toxocara canis or cati are more frequent among children under 10. The case of an 8-year-old boy who was diagnosed ganglionar larva migrans is presented. Comments are made on some etioepidemiological aspects of the disease, as well as on his clinical picture and evolution. Emphasis is made on the hygienic and sanitary measures of control and manipulation of stools from pegs as dogs and cats. Las larvas migrans visceral cuya causa radica en la infestación con larvas de toxocara canis o cati, ocurre más frecuentemente en niños menores de 10 años. Se presenta el caso de un niño de 8 años de edad en el cual se diagnosticó larvas migrans ganglionar. Se comentan aspectos etioepidemiológicos de la enfermedad, su cuadro clínico y evolución. se hace énfasis en las medidas higiénicas sanitarias de control y manipulación de excretas de animales domésticos, en este caso de perros y gatos.

  5. Tools for automating the imaging of zebrafish larvae.

    Science.gov (United States)

    Pulak, Rock

    2016-03-01

    The VAST BioImager system is a set of tools developed for zebrafish researchers who require the collection of images from a large number of 2-7 dpf zebrafish larvae. The VAST BioImager automates larval handling, positioning and orientation tasks. Color images at about 10 μm resolution are collected from the on-board camera of the system. If images of greater resolution and detail are required, this system is mounted on an upright microscope, such as a confocal or fluorescence microscope, to utilize their capabilities. The system loads a larvae, positions it in view of the camera, determines orientation using pattern recognition analysis, and then more precisely positions to user-defined orientation for optimal imaging of any desired tissue or organ system. Multiple images of the same larva can be collected. The specific part of each larva and the desired orientation and position is identified by the researcher and an experiment defining the settings and a series of steps can be saved and repeated for imaging of subsequent larvae. The system captures images, then ejects and loads another larva from either a bulk reservoir, a well of a 96 well plate using the LP Sampler, or individually targeted larvae from a Petri dish or other container using the VAST Pipettor. Alternative manual protocols for handling larvae for image collection are tedious and time consuming. The VAST BioImager automates these steps to allow for greater throughput of assays and screens requiring high-content image collection of zebrafish larvae such as might be used in drug discovery and toxicology studies. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  6. Vaccination of lambs with irradiated larvae of Bunostomum trigonocephalum

    International Nuclear Information System (INIS)

    Srivastava, V.K.; Singh, K.S.; Subramanian, G.

    1987-01-01

    Vaccination with a single dose of 2,000 infective larvae of Bunostomum trigonocephalum, irradiated at 40 kR, caused 80 per cent reduction in worm establishment and such lambs withstood a challenge infection which was otherwise fatal to non-vaccinated lambs. The female worms, which developed from irradiated larvae, were irregular in shape, had cuticular thickening at the genital opening and in many male worms the copulatory bursa was rudimentary. The sex ratio was adversely affected in worms developing from irradiated larvae. The population had preponderant sterile females and a very few male worms. (author)

  7. Accelerated larvae development of Ascaris lumbricoides eggs with ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Aladawi, M.A. [Syrian Atomic Energy Commission, Radiation Technology Department, P.O. Box 6091, Damascus (Syrian Arab Republic)]. E-mail: Scientific@aec.org.sy; Albarodi, H. [Syrian Atomic Energy Commission, Radiation Technology Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Hammoudeh, A. [Syrian Atomic Energy Commission, Radiation Technology Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Shamma, M. [Syrian Atomic Energy Commission, Radiation Technology Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Sharabi, N. [Syrian Atomic Energy Commission, Radiation Technology Department, P.O. Box 6091, Damascus (Syrian Arab Republic)

    2006-01-15

    In order to investigate the effect of UV radiation on the development of Ascaris lumbricoides larvae, eggs were exposed to increasing UV doses. Filtered wastewater from the secondary effluent taken from the Damascus wastewater treatment plant (DWTP) was used as irradiation and incubation medium. The progressive and accelerated embryonation stages were microscopically observed and the percentages of completely developed larvae were determined weekly. Results indicated that the UV radiation accelerated the development of larvae with increasing UV dose. Preliminary information about the relationship between the UV radiation dose and rate of embryonation is also presented.

  8. Accelerated larvae development of Ascaris lumbricoides eggs with ultraviolet radiation

    Science.gov (United States)

    Aladawi, M. A.; Albarodi, H.; Hammoudeh, A.; Shamma, M.; Sharabi, N.

    2006-01-01

    In order to investigate the effect of UV radiation on the development of Ascaris lumbricoides larvae, eggs were exposed to increasing UV doses. Filtered wastewater from the secondary effluent taken from the Damascus wastewater treatment plant (DWTP) was used as irradiation and incubation medium. The progressive and accelerated embryonation stages were microscopically observed and the percentages of completely developed larvae were determined weekly. Results indicated that the UV radiation accelerated the development of larvae with increasing UV dose. Preliminary information about the relationship between the UV radiation dose and rate of embryonation is also presented.

  9. Microbial interference with hatch and survival of European eel larvae

    DEFF Research Database (Denmark)

    Sørensen, Sune Riis; Lauesen; Tomkiewicz, Jonna

    Recent research has significantly improved our knowledge and capabilities in the field of in vitro production of yolk sac larvae from European eel (Anguilla anguilla). Female broodstock European eels are matured by weekly administration of pituitary extract and male eels with hCG (human chorionic...... gonadotropin), which afford gametes for in vitro fertilization studies. The maturing process may lead to mass hatchings of up to ½ million larvae of which some survive the entire yolk sac phase. However, the rearing of larvae suffers from high larval mortalities, and water quality might be a crucial factor...

  10. Foraging strategy switching in an antlion larva.

    Science.gov (United States)

    Tsao, Yu-Jen; Okuyama, Toshinori

    2012-09-01

    Antlion larvae are typically considered as trap-building predators, but some species of antlions always forage without using pits or only sometimes use pits to capture prey; they can ambush prey without pits. This study examined a species that switches its strategy between pit-trapping and ambushing and asked the mechanism behind the switching behaviour. A dynamic optimization model incorporating tradeoffs between the two strategies was built. The tradeoffs were prey capture success and predation risk (both are higher when pit-trapping). The model predicted that antlions should use the trap-building strategy when their energy status is low and should use the ambush strategy when their energy status is high. These predictions as well as an assumption (i.e., predation risk associated with pit-trapping is higher than that associated with ambushing) of the model were empirically confirmed. The results suggest that antlions flexibly switch between pit-trapping and ambushing to maximize their fitness by balancing the costs and benefits of the two strategies. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Amino Acid Absorption by Tiger Grouper Fish (Epinephelus fuscoguttatus Larvae. (Absorbsi Asam Amino oleh Larva Ikan Kerapu Macan (Epinephelus fuscoguttatus

    Directory of Open Access Journals (Sweden)

    Ambariyanto Ambariyanto

    2013-12-01

    Full Text Available Ikan Kerapu merupakan salah satu ikan unggulan yang ditargetkan sebagai komoditi eksport Indonesia. Usaha budidayanya saat ini sangat terganggu dengan tingginya mortalitas pada stadia larva. Usaha untuk mengatasi masalah tersebut adalah dengan menggunakan obat seperti antibiotik yang ternyata tidak membuahkan hasil maksimal tetapi justru menimbulkan resistensi beberapa jenis bakteria. Salah satu aspek yang belum pernah dilihat dalam rangka mengatasi masalah ini adalah dengan mengusahakan percepatan pertumbuhan pada stadia larva sehingga akan lebih mampu menghindari dari beberapa penyebab mortalitas. Salah satu sumber energi yang terdapat dalam perairan namun dalam jumlah yang tidak besar adalah dissolved organic matter (DOM. Penelitian ini ditekankan untuk melihat kemampuan larva ikan Kerapu dalam memanfaatkan DOM (digunakan asam amino terlarut ;ATT yang terdapat di air laut. Sebanyak 16 (enam belas jenis asam amino yang terdiri dari tiga klas yakni neutral, basic, dan acidic digunakan dalam penelitian ini. Sedangkan larva ikan Kerapu yang digunakan berumur 2 hari. Hasil penelitian menunjukkan bahwa larva ikan Kerapu menyerap seluruh jenis asam amino baik neutral, basic, dan acidic. Namun jenis asam amino yang diserap adalah glutamat, histidin, lisin, serin, metionin, tritopan dan iso leusin. Sedangkan yang paling banyak diserap oleh larva ikan ini adalah lisin. Hal yang menarik dalam penelitian ini adalah terdapat beberapa jenis asam amino yang diduga justru dikeluarkan oleh larva ikan tersebut yakni glysin, alanin, tyrosin, valin, phenil alanin dan leusin. Penyerapan beberapa jenis asam amino ini diduga dimanfaatkan oleh larva ikan Kerapu dalam proses pertumbuhannya. Kata kunci : asam amino terlarut, larva, Kerapu Macan, Epinephelus fuscoguttatus   Kerapu (grouper fish is known as an important and highly economic value fish and a good candidate for major export commodity for Indonesia. However, there is an important problem faced by its

  12. Automated high-throughput behavioral analyses in zebrafish larvae.

    Science.gov (United States)

    Richendrfer, Holly; Créton, Robbert

    2013-07-04

    We have created a novel high-throughput imaging system for the analysis of behavior in 7-day-old zebrafish larvae in multi-lane plates. This system measures spontaneous behaviors and the response to an aversive stimulus, which is shown to the larvae via a PowerPoint presentation. The recorded images are analyzed with an ImageJ macro, which automatically splits the color channels, subtracts the background, and applies a threshold to identify individual larvae placement in the lanes. We can then import the coordinates into an Excel sheet to quantify swim speed, preference for edge or side of the lane, resting behavior, thigmotaxis, distance between larvae, and avoidance behavior. Subtle changes in behavior are easily detected using our system, making it useful for behavioral analyses after exposure to environmental toxicants or pharmaceuticals.

  13. Bacteria and fungi isolated from housefly ( Musca domestica L.) larvae

    African Journals Online (AJOL)

    A variety of microorganisms, which includes the pathogenic Staphylococcus aureus, Pseudomonas aerruginosa, Aspergillus tamarii and Bacullus cereus were found. Also, nonpathogenic microbes werer recovered including Bacillus subtilis and Stroplococcus faecalis. Keywords: Microorganism, isolation, housefly larvae.

  14. Spatial habitat for eel larva at Cimandiri estuary, West Java

    Science.gov (United States)

    Takarina, N. D.; Supriatna

    2017-07-01

    The estuarine ecosystem is known as suitable breeding sites for fishes because this particular habitat is receiving continuous organic matters from river ways and constant sunlight due to its depth that allows sunlight penetration. Cimandiri estuary is one of the estuaries located in the south of Java Island close to the Indian Ocean and known as a suitable habitat for eel larva that routinely collected by local people. Eel habitat has a relationship with the dynamic of space. This dynamic influenced by season, water flow, tide, bathymetry, salinity and dissolved oxygen (DO). The geographic information system is an approach in studying habitat dynamic, through modeling. Furthermore, the spatial model for eel larva habitat is required for land use planning that aimed to achieve sustainable eels larva rearing and conserve estuarine habitat as well. The aim of this research was to investigate dynamics on spatial habitat of eel larva at Cimandiri estuary, West Java.

  15. Visceral larva migrans: migratory pattern of Toxocara canis in pigs

    DEFF Research Database (Denmark)

    Helwigh, Birgitte; Lind, Peter; Nansen, Peter

    1999-01-01

    The migratory pattern of Toxocara canis was investigated following infection of pigs with 60 000 infective eggs. Groups of six pigs were slaughtered at 7, 14 and 28 days after infection (p.i.), and the number of larvae in selected organs and muscles was determined by digestion. A group...... of uninfected pigs was used as negative controls for blood parameters and weight gain. Toxocara canis migrated well in the pig, although the relative numbers of larvae recovered decreased significantly during the experiment. On day 7 p.i., high numbers of larvae were recovered from the lymph nodes around...... towards T. canis L2/L3 ES products was observed from day 14 p.i. until termination of the experiment, and the maximum eosinophil response was observed 14 days p.i. The pig is a useful non-primate model for human visceral larva migrans, since T. canis migrate well and induce a strong immunological response...

  16. Culturing Embryos and Larvae of Marine Molluscs and Protochordates.

    Science.gov (United States)

    Healey, R.; Turner, S. C.

    1979-01-01

    Presents a description for maintaining adult forms of molluscs and protochordates in order to obtain gametes for laboratory studies of animal development. The methods also include those for culturing embryonic larvae forms in vitro. (Author/SA)

  17. Antimicrobial activity of essential oils against Paenibacillus larvae

    OpenAIRE

    Gende, L.B.; Pires, Sância; Fernandez, N.J.; Damiani, M.; Churio, M.S.; Fritz, R.; Eguaras, M.J.

    2012-01-01

    American foulbrood is a serious bacterial disease that affects Apis mellifera colonies; the causative agent is Paenibacillus larvae [1 ]. The aim of the study was to evaluate in vitro the antimicrobial activity of 32 essential oils against P. larvae. Oils from 21 botanical species were analyzed by gas chromatography (CG and CG/EM). All essential oils were classified according to the composition of their main components in two groups: benzene ring compounds (BRC) and terpene com...

  18. Rearing gymnolaemate bryozoan larvae for cellular and molecular analyses.

    Science.gov (United States)

    Temkin, Michael H

    2014-01-01

    Gymnolaemates represent the largest group of extant bryozoans, having more than 3,000 described species. Gymnolaemates display a diverse array of reproductive and developmental patterns including planktotrophy, lecithotrophy, and matrotrophy. The larvae of gymnolaemates have been broadly grouped into three types, cyphonautes (shelled, feeding), pseudocyphonautes (shelled, nonfeeding), and coronate (unshelled, nonfeeding), although each group is heterogeneous and probably includes various morphologies that are largely undescribed. Here, methods for rearing bryozoan colonies and larvae are presented.

  19. The use of fly larvae for organic waste treatment.

    Science.gov (United States)

    Čičková, Helena; Newton, G Larry; Lacy, R Curt; Kozánek, Milan

    2015-01-01

    The idea of using fly larvae for processing of organic waste was proposed almost 100 years ago. Since then, numerous laboratory studies have shown that several fly species are well suited for biodegradation of organic waste, with the house fly (Musca domestica L.) and the black soldier fly (Hermetia illucens L.) being the most extensively studied insects for this purpose. House fly larvae develop well in manure of animals fed a mixed diet, while black soldier fly larvae accept a greater variety of decaying organic matter. Blow fly and flesh fly maggots are better suited for biodegradation of meat processing waste. The larvae of these insects have been successfully used to reduce mass of animal manure, fecal sludge, municipal waste, food scrapes, restaurant and market waste, as well as plant residues left after oil extraction. Higher yields of larvae are produced on nutrient-rich wastes (meat processing waste, food waste) than on manure or plant residues. Larvae may be used as animal feed or for production of secondary products (biodiesel, biologically active substances). Waste residue becomes valuable fertilizer. During biodegradation the temperature of the substrate rises, pH changes from neutral to alkaline, ammonia release increases, and moisture decreases. Microbial load of some pathogens can be substantially reduced. Both larvae and digested residue may require further treatment to eliminate pathogens. Facilities utilizing natural fly populations, as well as pilot and full-scale plants with laboratory-reared fly populations have been shown to be effective and economically feasible. The major obstacles associated with the production of fly larvae from organic waste on an industrial scale seem to be technological aspects of scaling-up the production capacity, insufficient knowledge of fly biology necessary to produce large amounts of eggs, and current legislation. Technological innovations could greatly improve performance of the biodegradation facilities and

  20. Larval structure of Passalus gravelyiand sexual dimorphism in Passalid larvae

    Directory of Open Access Journals (Sweden)

    Ingrid Mattos

    2015-09-01

    Full Text Available The adults and larvae of Passalidae are subsocial insects commonly found in tropical forests, living in decaying wood gallery systems constructed by adults. Currently, few repots on the larvae of Neotropical Passalidae have been published and information is scarce. In this study, the Passalus (Pertinax gravelyiMoreira, 1922 larvae is described for the first time, based on ten larval specimens 1 (1° instar, 4 (2° instar, and 5 (3° instar associated with three adults collected from a single colony at the Parque Nacional do Itatiaia (Itatiaia, Rio de Janeiro, Brazil. The description was carried out based on electronic and digital photographs of diagnostic structures, with some details on the systematic of the species. The larvae of Passalus gravelyihas the general setal 'Pertinax' pattern and differed from others by 16 to 18 setae on the anal ring, the other larvae data from Brazilian species show the anal ring with 10 to 12 setae. A discussion on the presence of sexual dimorphism in 62 species of two and three instars of Passalidae larvae is provided for the first time. Besides, a description of the terminal ampullapresent as a cuticular structure found in the medial-ventral area of the 9th abdominal sternite in males is also given. The terminal ampullawas only observed in the Passalidae male larvae and was not visible in female larvae. The terminal ampullaare acknowledged now in males of 64 passalid species, that are taxonomically distributed in world tropical forests, at the Oriental and Australian subfamily Aulacocyclinae (Aulacocyclini & Ceracupini and the cosmotropical subfamily Passalinae (Solenocyclini, Macrolinini, Passalini, & Proculini.

  1. Potential of turmeric rhizome essential oils against Aedes aegypti larvae

    Directory of Open Access Journals (Sweden)

    Roselina Panghiyangani

    2012-04-01

    Full Text Available BACKGROUND Dengue hemorrhagic fever (DHF has long been a serious health problem in Indonesia, including Kalimantan (Borneo, as is evident from the increased case fatality rate in Banjarbaru city. Synthetic chemical insecticides have frequently been used to eradicate mosquitoes, but are toxic to the body and resistance of adult and larvae mosquito Aedes aegypti has been reported. The present study aims to assess the effect of essential oils of turmeric rhizomes (Curcuma domestica Val against Aedes aegypti larvae Methods This was an experimental study of post test one group design, performed in two phases, using Aedes aegypti larvae as test organisms. In the first phase, laboratory-reared larvae were used for calculation of the LC50 and LC90, while in the second phase the test organisms were larvae taken from 75 buildings that had been designated based on a preliminary survey in four sub-districts in Banjarbaru city with a high incidence of dengue cases. Probit analysis of was used to calculate LC50 and LC90, and the Kruskal-Wallis test to determine the larvicidal potency of turmeric rhizome essential oils. Results This study demonstrates that turmeric rhizome essential oils effectively killed laboratory-reared Aedes aegypti larvae at an LC50 of 9.239 ppm and an LC90 of 13.565 ppm. The effectiveness of the essential oils of turmeric rhizomes (Curcuma domestica Val. for killing Aedes aegypti larvae in residential areas was 68%. Conclusion Turmeric (Curcuma domestica Val. rhizome essential oils can kill Aedes aegypti larvae, are environment friendly and can be used for the control of mosquitoes.

  2. Evaluation of growth performance of Clarias gariepinus larvae fed ...

    African Journals Online (AJOL)

    A feeding trial, involving the use of two starter diets (artemia and aqualis) was carried out in the laboratory, to evaluate the growth performance of C. gariepinus larvae fed artemia and aqualis fish feeds. A total of 200 (48 hours old C. gariepinus larvae) of mean weight 4.8 ± 0.01mg and length 6.16 ± 0.03mm were reared for ...

  3. Characterization of secreted proteases of Paenibacillus larvae, potential virulence factors in honeybee larval infection

    Science.gov (United States)

    Paenibacillus larvae is the causative agent of American Foulbrood (AFB), the most severe bacterial disease that affects honeybee larvae. AFB causes a significant decrease in the honeybee population affecting the beekeeping industry and agricultural production. After infection of larvae, P. larvae se...

  4. Long-duration feedings and caste differentiation in Bombus terrestris larvae

    NARCIS (Netherlands)

    Ribeiro, M.F.

    1998-01-01

    The duration of feedings received by Bombus terrestris larvae was studied using video-recordings. In the last days of development all larvae received feedings mainly of long duration. Worker larvae of the third brood received significantly longer feedings than worker larvae reared in the other

  5. Biorheological action of Ascaris lumbricoides larvae on human erythrocytes.

    Science.gov (United States)

    de León, Patricia Ponce; Del Balzo, Gonzalo; Riquelme, Bibiana

    2013-03-01

    Previous studies have shown that A. lumbricoides extracts capture sialic acid (SA) from human red blood cells (RBC). The aim of this work was to study hemorheological alterations in vitro caused by parasite larvae. The biorheological action of three larva concentrates of first and second larval stage on group O erythrocytes was analyzed by incubating the erythrocyte packed together with an equal volume of larvae (treated RBC) and PBS (control RBC). Distribution and parameters of aggregation (digital image analysis), aggregation kinetics (erythroaggregameter), and viscoelasticity (erythrodeformeter) were measured. The digital image analysis showed that all the larvae diminished the isolated cells percentage and increased the size of the formed aggregates. The aggregate formation velocity was lower in the treated than in the control. The deformability index (ID) values of treated RBC did not present variations with respect to those of the control, but a decrease in the erythrocyte elastic modulus (μ(m)) and membrane surface viscosity (η(m)) values was observed, indicating that the larvae not only induced a diminution in the membrane surface viscosity of RBC but also altered the dynamic viscoelasticity of the membrane. Experiments carried out in vitro support the conclusion that the contact between larvae and RBC produces hemorheological alterations.

  6. Using Real-time PCR for Identification of Paenibacillus larvae

    Directory of Open Access Journals (Sweden)

    Vladimíra Kňazovická

    2011-05-01

    Full Text Available The aim of the study was identification of Paenibacillus larvae that causes American foulbrood disease (AFB in colony of bees (Apis mellifera. Bacterial isolates originated from honey samples, because presence of P. larvae in honey is treated as early diagnostic of AFB. Intense proteolytic activity and no catalase activity are typical for Gram positive rod-shaped bacteria P. larvae. We diluted honey (1:2, heated at 80 °C for 10 min and inoculated on semiselective medium MYPGP agar with nalidixic acid. Plates were cultivated at 37 °C for 48 – 72 h under the aerobic conditions. Selected colonies were transferred on MYT agar and cultivated 24 h. We analysed 30 honey samples and found 27 bacterial isolates. All isolates were Gram positive and mainly rod-shaped. No catalase activity was documented for 6 from 27 isolates. Identification was finished by real-time PCR to detect the 16S rRNA gene of Paenibacillus larvae with real-time cycler Rotor-Gene 6000. As DNA template we used genomic DNA isolated with commercial kit and DNA lysate obtaining by boiled cells. We used 2 strains of P. larvae from CCM (Czech Collection of Microorganisms as positive control. The reliable method of detection P. larvae has important rule for beekeeping.

  7. Abscisic acid enhances cold tolerance in honeybee larvae.

    Science.gov (United States)

    Ramirez, Leonor; Negri, Pedro; Sturla, Laura; Guida, Lucrezia; Vigliarolo, Tiziana; Maggi, Matías; Eguaras, Martín; Zocchi, Elena; Lamattina, Lorenzo

    2017-04-12

    The natural composition of nutrients present in food is a key factor determining the immune function and stress responses in the honeybee ( Apis mellifera ). We previously demonstrated that a supplement of abscisic acid (ABA), a natural component of nectar, pollen, and honey, increases honeybee colony survival overwinter. Here we further explored the role of ABA in in vitro -reared larvae exposed to low temperatures. Four-day-old larvae (L4) exposed to 25°C for 3 days showed lower survival rates and delayed development compared to individuals growing at a standard temperature (34°C). Cold-stressed larvae maintained higher levels of ABA for longer than do larvae reared at 34°C, suggesting a biological significance for ABA. Larvae fed with an ABA-supplemented diet completely prevent the low survival rate due to cold stress and accelerate adult emergence. ABA modulates the expression of genes involved in metabolic adjustments and stress responses: Hexamerin 70b, Insulin Receptor Substrate, Vitellogenin , and Heat Shock Proteins 70. AmLANCL2, the honeybee ABA receptor, is also regulated by cold stress and ABA. These results support a role for ABA increasing the tolerance of honeybee larvae to low temperatures through priming effects. © 2017 The Author(s).

  8. Quantification of vestibular-induced eye movements in zebrafish larvae

    Directory of Open Access Journals (Sweden)

    Mo Weike

    2010-09-01

    Full Text Available Abstract Background Vestibular reflexes coordinate movements or sensory input with changes in body or head position. Vestibular-evoked responses that involve the extraocular muscles include the vestibulo-ocular reflex (VOR, a compensatory eye movement to stabilize retinal images. Although an angular VOR attributable to semicircular canal stimulation was reported to be absent in free-swimming zebrafish larvae, recent studies reveal that vestibular-induced eye movements can be evoked in zebrafish larvae by both static tilts and dynamic rotations that tilt the head with respect to gravity. Results We have determined herein the basis of sensitivity of the larval eye movements with respect to vestibular stimulus, developmental stage, and sensory receptors of the inner ear. For our experiments, video recordings of larvae rotated sinusoidally at 0.25 Hz were analyzed to quantitate eye movements under infrared illumination. We observed a robust response that appeared as early as 72 hours post fertilization (hpf, which increased in amplitude over time. Unlike rotation about an earth horizontal axis, rotation about an earth vertical axis at 0.25 Hz did not evoke eye movements. Moreover, vestibular-induced responses were absent in mutant cdh23 larvae and larvae lacking anterior otoliths. Conclusions Our results provide evidence for a functional vestibulo-oculomotor circuit in 72 hpf zebrafish larvae that relies upon sensory input from anterior/utricular otolith organs.

  9. Observations of the sound producing organs in achelate lobster larvae

    Directory of Open Access Journals (Sweden)

    John A. Fornshell

    2017-06-01

    Full Text Available The Achelata, lobsters lacking claws and having a phyllosoma larva, are divided into two families, the Palinuridae or spiny lobsters and the Scyllaridae or slipper lobsters. Within the Palinuridae adults of two groups were identified by Parker (1884, the Stridentesthat are capable of producing sounds, and the Silentesthat are not known to produce sounds. The Stridentes employ a file-like structure on the dorsal surface of the cephalon and a plectrum consisting of a series of ridges on the proximal segment of the second antenna to produce their sounds. All species of Achelata hatch as an unpigmented thin phyllosoma larva. The phyllosoma larva of the Stridentes have a presumptive file-like structure on the dorsal cephalon. A similar file-like structure is found on the cephalon of one species of Silentes, Palinurellus wienckki, and some but not all of the phyllosoma larvae of the Scyllaridae. No presumptive plectrum is found on the second antenna of any of the phyllosoma larvae. Presence of a presumptive file-like structure on phyllosoma larvae of Silentes and Scyllaridae suggests that the ability to produce sounds may have been lost secondarily in the Silentes and Scyllaridae.

  10. Long-wavelength photosensitivity in coral planula larvae.

    Science.gov (United States)

    Mason, Benjamin M; Cohen, Jonathan H

    2012-04-01

    Light influences the swimming behavior and settlement of the planktonic planula larvae of coral, but little is known regarding the photosensory biology of coral at this or any life-history stage. Here we used changes in the electrical activity of coral planula tissue upon light flashes to investigate the photosensitivity of the larvae. Recordings were made from five species: two whose larvae are brooded and contain algal symbionts (Porites astreoides and Agaricia agaricites), and three whose larvae are spawned and lack algal symbionts (Acropora cervicornis, Acropora palmata,and Montastrea faveolata). Photosensitivity originated from the coral larva rather than from, or in addition to, its algal symbionts as species with and without symbionts displayed similar tissue-level electrical responses to light. All species exhibited as much (or more) sensitivity to red stimuli as to blue/green stimuli, which is consistent with a role for long-wavelength visible light in the preference for substrata observed during settlement and in facilitating vertical positioning of larvae in the water column.

  11. Guppies as predators of common mosquito larvae in Malaysia.

    Science.gov (United States)

    Saleeza, S N R; Norma-Rashid, Y; Sofian-Azirun, M

    2014-03-01

    Observation on predation activities of guppies (Poecilia reticulata) on the larvae of three species of mosquito, namely Aedes albopictus, Aedes aegypti, and Culex quinquefasciatus was carried out under laboratory conditions. Male and female guppies were used as predators for predation experiments on the 4th instars of mosquito larvae. The daily feeding rates comparing male and female guppies on mosquito larvae were different; the female guppies consumed more mosquito larvae than male guppies did. The daily feeding rates of female guppies were 121.3 for Ae. aegypti, 105.6 for Ae. albopictus, and 72.3 for Cx. quinquefasciatus. The daily feeding rates of male guppies were 98.6 for Ae. aegypti, 73.6 for Ae. albopictus, and 47.6 for Cx. quinquefasciatus. In terms of prey preference, there was greater preference towards mosquito larvae of Ae. aegypti, followed by Ae. albopictus, and the least preferred was Cx. quinquefasciatus. Male and female guppies consumed more mosquito larvae during lights on (day time) compared with lights off (night time). The water volume, prey species, number of fish predators available, prey densities, and prey's sex also influenced the predation activities.

  12. A fly larva (Syrphidae: Ocyptamus that preys on adult flies

    Directory of Open Access Journals (Sweden)

    Onanchi Ureña

    2010-12-01

    Full Text Available Predatory syrphid larvae feed on relatively immobile prey, but here we report the first case (as far as we are aware of obligatory predation on very mobile prey. Larvae of an undescribed species of Ocyptamus (Diptera: Syrphidae were found in whitefly (Hemiptera: Aleyrodidae aggregations on the undersides of citrus leaves. However, instead of preying on the whitefly nymphs (as would be expected, the larvae preyed on adult flies (Diptera that were attracted to the honeydew. In the laboratory, larvae captured significantly more flies on whitefly infested leaves than on washed leaves, and generally abandoned leaves that lacked whiteflies. Most cases of successful prey capture involved flies that probed the anterior part of the larva’s body with its proboscis (as if it were honeydew. The syrphid larva lashed out at the fly and entangled it in sticky oral secretion. The prey did not recover when they were removed from the larva, suggesting that this new predatory species also employs venom to subdue its prey. Although the larvae consumed some honeydew, they were unable to complete their development on this diet. Two parasitoids were reared from Ocyptamus puparia, Proaspicera sp. (Hymenoptera: Figitidae and Paracarotomus sp. (Hymenoptera: Pteromalidae, both of which are endoparasitic koinobionts. Rev. Biol. Trop. 58 (4: 1157-1163. Epub 2010 December 01.Las larvas depredadoras de Syrphidae se alimentan de presas relativamente inmóviles, pero aquí reportamos el primer caso (hasta ahora conocido de la depredación obligatoria en presas muy móviles. Se encontraron las larvas de una especie no descrita de Ocyptamus (Diptera: Syrphidae juntas con ninfas de mosca blanca (Hemiptera: Aleyrodidae en el envés de las hojas de cítricos. Sin embargo, en vez de alimentarse de las ninfas de mosca blanca (como debería esperarse, las larvas se alimentaron de moscas adultas (Diptera que fueron atraídas a las excreciones azucaradas de la mosca blanca. En el

  13. Amostragem por larva-única na vigilância de Aedes aegypti Single-larva sampling for Aedes aegypti surveillance

    Directory of Open Access Journals (Sweden)

    José Eduardo Bracco

    1995-04-01

    Full Text Available Com a finalidade de testar a metodologia de amostragem por larva-única na vigilância entomológica do Aedes aegypti, foram pesquisados domicílios do Município de Araraquara, SP (Brasil. Nos criadouros que continham larvas de Aedes uma delas foi coletada. Como controle, após a coleta da larva-única, todas as larvas foram coletadas para identificação posterior. Esse processo foi repetido no laboratório. Dos 447 domicílios visitados, apenas 12 foram considerados positivos e 20 criadouros foram identificados; destes, 13 continham larvas de Aedes; 5, larvas de Aedes e Culex e 2, larvas de Culex. Os resultados mostram o reconhecimento correto, no campo, de todos os criadouros, evidenciando que o método poderia ser utilizado na vigilância entomológica de municípios sem infestação domiciliar ou infestados apenas com uma única espécie de Aedes.Buildings in Araraquara city, Southeastern Brazil, were searched during a year for the presence of Aedes larvae using single larva sampling in order to check the single-larva methodology. In those breeding places in wich Aedes larvae were found, one of them was collected. As a control, after the single larva had been collected, all the larvae from the breeding place were collected for later identification. This process was repeated in the laboratory. Of the 447 domiciles searched, 12 were considered positive and 20 breeding places were found. Of the breeding places, 13 contained Aedes larvae, 5 both Aedes and Culex larvae and 2 Culex larvae only. The results show that all the breeding places in the field were properly recognited showing the method may be used for Aedes surveillance in cities infested with one species only or without any domiciliary infestation.

  14. Image enhancement for tracking the translucent larvae of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Sukant Khurana

    Full Text Available Drosophila melanogaster larvae are model systems for studies of development, synaptic transmission, sensory physiology, locomotion, drug discovery, and learning and memory. A detailed behavioral understanding of larvae can advance all these fields of neuroscience. Automated tracking can expand fine-grained behavioral analysis, yet its full potential remains to be implemented for the larvae. All published methods are unable to track the larvae near high contrast objects, including the petri-dish edges encountered in many behavioral paradigms. To alleviate these issues, we enhanced the larval contrast to obtain complete tracks. Our method employed a dual approach of optical-contrast boosting and post-hoc image processing for contrast enhancement. We reared larvae on black food media to enhance their optical contrast through darkening of their digestive tracts. For image processing we performed Frame Averaging followed by Subtraction then Thresholding (FAST. This algorithm can remove all static objects from the movie, including petri-dish edges prior to processing by the image-tracking module. This dual approach for contrast enhancement also succeeded in overcoming fluctuations in illumination caused by the alternating current power source. Our tracking method yields complete tracks, including at the edges of the behavioral arena and is computationally fast, hence suitable for high-throughput fine-grained behavioral measurements.

  15. Food web changes under ocean acidification promote herring larvae survival.

    Science.gov (United States)

    Sswat, Michael; Stiasny, Martina H; Taucher, Jan; Algueró-Muñiz, Maria; Bach, Lennart T; Jutfelt, Fredrik; Riebesell, Ulf; Clemmesen, Catriona

    2018-05-01

    Ocean acidification-the decrease in seawater pH due to rising CO 2 concentrations-has been shown to lower survival in early life stages of fish and, as a consequence, the recruitment of populations including commercially important species. To date, ocean-acidification studies with fish larvae have focused on the direct physiological impacts of elevated CO 2 , but largely ignored the potential effects of ocean acidification on food web interactions. In an in situ mesocosm study on Atlantic herring (Clupea harengus) larvae as top predators in a pelagic food web, we account for indirect CO 2 effects on larval survival mediated by changes in food availability. The community was exposed to projected end-of-the-century CO 2 conditions (~760 µatm pCO 2 ) over a period of 113 days. In contrast with laboratory studies that reported a decrease in fish survival, the survival of the herring larvae in situ was significantly enhanced by 19 ± 2%. Analysis of the plankton community dynamics suggested that the herring larvae benefitted from a CO 2 -stimulated increase in primary production. Such indirect effects may counteract the possible direct negative effects of ocean acidification on the survival of fish early life stages. These findings emphasize the need to assess the food web effects of ocean acidification on fish larvae before we can predict even the sign of change in fish recruitment in a high-CO 2 ocean.

  16. Activity of Thymus vulgaris essential oil against Anisakis larvae.

    Science.gov (United States)

    Giarratana, F; Muscolino, D; Beninati, C; Giuffrida, A; Panebianco, A

    2014-07-01

    Anisakiasis is an important food-borne disease especially in countries with high fish consumption. The increase of cases of human disease and the virtual absence of effective treatments have prompted the research on new active compounds against Anisakis larvae. As well known, the disease is related to the consumption of raw or almost raw seafood products, but also marinated and/or salted fishery products, if the processing is insufficient to destroy nematode larvae can represent a risks for the consumers. In the light of the biocidal efficacy against different pathogens demonstrated for various essential oils, the aim of this work is to evaluate the effect of Thymus vulgaris essential oil (TEO) against anisakidae larvae. The TEO at 10% and 5% concentration in oil sunflower seeds, caused in vitro the death of all larvae within 14 h, with cuticle and intestinal wall damages. The results obtained showing a significant activity against Anisakis larvae, suggest further investigation on TEO as a larvicidal agent and on its potential use in the industrial marinating process. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Odor-taste learning assays in Drosophila larvae.

    Science.gov (United States)

    Gerber, Bertram; Biernacki, Roland; Thum, Jeannette

    2013-03-01

    The Drosophila larva is an emerging model for studies in behavioral neurogenetics because of its simplicity in terms of cell number. Despite this simplicity, basic features of neuronal organization and key behavior faculties are shared with adult flies and with mammals. Here, we describe a pavlovian-type learning assay in fruit fly larvae. A group of larvae is sequentially exposed to specific odors in the presence or the absence of sugar, and then tested to determine whether they prefer the odor previously experienced with the reward. The protocol uses a two-group, reciprocal training design: One group of Drosophila larvae is exposed to n-amyl acetate (AM) with a sugar reward (+), then subsequently exposed to 1-octanol (OCT) with no reward (denoted AM+/OCT). The other group receives the reciprocal training (AM/OCT+). The two groups of larvae are then tested for their choices between AM and OCT. Relatively higher preferences for AM after AM+/OCT training than after AM/OCT+ training reflect associative learning and are quantified by the learning index (LI). This method offers a robust, simple, cheap, and reasonably quick test for learning ability (an aversive version is available as well, using either high-concentration salt or quinine as punishment). With the concerted efforts of the Drosophila research community, we anticipate it will allow us to unravel the full circuitry underlying odor-taste learning on a single-cell level.

  18. Dimethyl Sulfide is a Chemical Attractant for Reef Fish Larvae.

    Science.gov (United States)

    Foretich, Matthew A; Paris, Claire B; Grosell, Martin; Stieglitz, John D; Benetti, Daniel D

    2017-05-31

    Transport of coral reef fish larvae is driven by advection in ocean currents and larval swimming. However, for swimming to be advantageous, larvae must use external stimuli as guides. One potential stimulus is "odor" emanating from settlement sites (e.g., coral reefs), signaling the upstream location of desirable settlement habitat. However, specific chemicals used by fish larvae have not been identified. Dimethyl sulfide (DMS) is produced in large quantities at coral reefs and may be important in larval orientation. In this study, a choice-chamber (shuttle box) was used to assess preference of 28 pre-settlement stage larvae from reef fish species for seawater with DMS. Swimming behavior was examined by video-tracking of larval swimming patterns in control and DMS seawater. We found common responses to DMS across reef fish taxa - a preference for water with DMS and change in swimming behavior - reflecting a switch to "exploratory behavior". An open water species displayed no response to DMS. Affinity for and swimming response to DMS would allow a fish larva to locate its source and enhance its ability to find settlement habitat. Moreover, it may help them locate prey accumulating in fronts, eddies, and thin layers, where DMS is also produced.

  19. High magnetic field induced otolith fusion in the zebrafish larvae.

    Science.gov (United States)

    Pais-Roldán, Patricia; Singh, Ajeet Pratap; Schulz, Hildegard; Yu, Xin

    2016-04-11

    Magnetoreception in animals illustrates the interaction of biological systems with the geomagnetic field (geoMF). However, there are few studies that identified the impact of high magnetic field (MF) exposure from Magnetic Resonance Imaging (MRI) scanners (>100,000 times of geoMF) on specific biological targets. Here, we investigated the effects of a 14 Tesla MRI scanner on zebrafish larvae. All zebrafish larvae aligned parallel to the B0 field, i.e. the static MF, in the MRI scanner. The two otoliths (ear stones) in the otic vesicles of zebrafish larvae older than 24 hours post fertilization (hpf) fused together after the high MF exposure as short as 2 hours, yielding a single-otolith phenotype with aberrant swimming behavior. The otolith fusion was blocked in zebrafish larvae under anesthesia or embedded in agarose. Hair cells may play an important role on the MF-induced otolith fusion. This work provided direct evidence to show that high MF interacts with the otic vesicle of zebrafish larvae and causes otolith fusion in an "all-or-none" manner. The MF-induced otolith fusion may facilitate the searching for MF sensors using genetically amenable vertebrate animal models, such as zebrafish.

  20. Microplastic ingestion in fish larvae in the western English Channel.

    Science.gov (United States)

    Steer, Madeleine; Cole, Matthew; Thompson, Richard C; Lindeque, Penelope K

    2017-07-01

    Microplastics have been documented in marine environments worldwide, where they pose a potential risk to biota. Environmental interactions between microplastics and lower trophic organisms are poorly understood. Coastal shelf seas are rich in productivity but also experience high levels of microplastic pollution. In these habitats, fish have an important ecological and economic role. In their early life stages, planktonic fish larvae are vulnerable to pollution, environmental stress and predation. Here we assess the occurrence of microplastic ingestion in wild fish larvae. Fish larvae and water samples were taken across three sites (10, 19 and 35 km from shore) in the western English Channel from April to June 2016. We identified 2.9% of fish larvae (n = 347) had ingested microplastics, of which 66% were blue fibres; ingested microfibers closely resembled those identified within water samples. With distance from the coast, larval fish density increased significantly (P microplastic concentrations (P microplastics and the incidence of ingestion in fish larvae. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. An improved brine shrimp larvae lethality microwell test method.

    Science.gov (United States)

    Zhang, Yi; Mu, Jun; Han, Jinyuan; Gu, Xiaojie

    2012-01-01

    This article described an improved brine shrimp larvae lethality microwell test method. A simply designed connecting vessel with alternative photoperiod was used to culture and collect high yield of active Artemia parthenogenetica nauplii for brine shrimp larvae lethality microwell test. Using this method, pure A. parthenogenetica nauplii suspension was easily cultured and harvested with high density about 100-150 larvae per milliliter and the natural mortality was reduced to near zero by elimination of unnecessary artificial disturbance. And its sensitivity was validated by determination of LC(50)-24 h of different reference toxicants including five antitumor agents, two pesticides, three organic pollutants, and four heavy metals salts, most of which exhibited LC(50)-24 h between 0.07 and 58.43 mg/L except for bleomycin and mitomycin C with LC(50)-24 h over 300 mg/L.

  2. Antioxidant activities of protein hydrolysates obtained from the housefly larvae.

    Science.gov (United States)

    Zhang, Huan; Wang, Pan; Zhang, Ai-Jun; Li, Xuan; Zhang, Ji-Hong; Qin, Qi-Lian; Wu, Yi-Jun

    2016-09-01

    The housefly is an important resource insect and the housefly larvae are ideal source of food additives. The housefly larvae protein hydrolysates were obtained by enzymatic hydrolysis by alcalase and neutral proteinase. Their antioxidant activities were investigated, including the superoxide and hydroxyl radicalscavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, reducing power and metal chelating activity. The antioxidant activities of both hydrolysates increased with their increasing concentrations. The alcalase hydrolysate (AH) showed higher scavenging activities against hydroxyl radical and superoxide anion radical at low concentrations and higher metal-chelating activity than the neutral proteinase hydrolysate (NPH). The NPH exhibited higher scavenging activity against DPPH free radical and higher reducing power than the AH. Both hydrolysates showed more than 50% superoxide anion radical-scavenging activity at 10 μg/mL. These results indicate that both housefly larvae protein hydrolysates display high antioxidant activities and they could serve as potential natural antioxidant food additives.

  3. Reorientation and Swimming Stability in Sea Urchin Larvae

    Science.gov (United States)

    Wheeler, J.; Chan, K. Y. K.; Anderson, E.; Helfrich, K. R.; Mullineaux, L. S.; Sengupta, A.; Stocker, R.

    2016-02-01

    Many benthic marine invertebrates have two-phase life histories, relying on planktonic larval stages for dispersal and exchange of individuals between adult populations. The dispersal of planktonic larvae is determined by two factors: passive advection by the ambient flow and active motility. By modifying dispersal and ultimately settlement, larval motility influences where and when individuals recruit into benthic communities. Despite its ecological relevance, our understanding of larval motility and behavior in the plankton remains limited, especially regarding the interactions of larval motility and ambient turbulence. As most larvae are smaller than the Kolmogorov scale, they experience ocean turbulence in part as a time-changing viscous torque produced by local fluid shear. This torque causes larval reorientation, impacting swimming direction and potentially dispersal at the macroscale. It is therefore paramount to understand the mechanisms of larval reorientation and the stability of larvae against reorientation. Here we report on the larval reorientation behavior of the sea urchins Arbacia punctulata and Heliocidaris crassispina. Both species have life histories characterized by ontogenetic changes to internal density structure and morphology, which we hypothesized to impact stability. To test this hypothesis, we performed "flip chamber" experiments, in which larvae swim freely in a small chamber that is intermittently inverted, mimicking the overturning experienced by larvae in turbulence. We investigated the role of larval age, body size, species, morphology (number of arms), and motility (live versus dead) on the reorientation dynamics. Our work contributes to a more mechanistic understanding of the role of hydrodynamics in the motility and transport of planktonic larvae.

  4. Acanthocephala Larvae parasitizing Ameiva ameiva ameiva (Linnaeus, 1758) (Squamata: Teiidae).

    Science.gov (United States)

    Macedo, Lilian Cristina; Melo, Francisco Tiago de Vasconcelos; Ávila-Pires, Teresa Cristina Sauer; Giese, Elane Guerreiro; Santos, Jeannie Nascimento Dos

    2016-03-11

    Knowledge concerning the taxonomy and biology of species of Acanthocephala, helminth parasites of the helminth species of the phylum Acanthocephala, parasites of lizards in Brazilian Amazonia, is still insufficient, but reports of Acanthocephala in reptiles are becoming increasingly common in the literature. Cystacanth-stage Acanthocephalan larvae have been found in the visceral peritoneum during necropsy of Ameiva ameiva ameivalizards from the "Osvaldo Rodrigues da Cunha" Herpetology Collection of the Emílio Goeldi Museum, Belém, Pará, Brazil. The aim of this study was to present the morphological study of the Acanthocephala larvae found in A. ameiva ameiva lizard.

  5. Aquaculture and feeding ecology: Feeding behaviour in turbot larvae

    DEFF Research Database (Denmark)

    Bruno, Eleonora

    , larvae of flatfishes undergo a particularly evident and dramatic metamorphosis, because flatfishes completely reprogram their body to move from the pelagic habitat, in the water column, to the benthic habitat, on the sea floor. Due to the complex morphological and physiological changes, in aquaculture...... capture success. This thesis is part of a large international project aimed at improving the rearing techniques of high value fish species larvae fed with calanoid copepods, their natural prey, to achieve high levels of survival and quality. In fact, fish aquaculture is becoming increasingly important...

  6. Ultrastructural observations of the larva of Tubiluchus corallicola (Priapulida)

    Science.gov (United States)

    Higgins, R. P.; Storch, V.

    1989-03-01

    Larvae of Tubiluchus corallicola van der Land 1968 were investigated by scanning and transmission electron microscopy. The scalids are sensory organs, each has a bipolar receptor cell with a single apical cilium similar to the scalid in the adult. Muscle cells of the larva are more differentiated than previously reported for other Priapulida; the larval arrangement of circular and longitudinal musculature differs from that of the adult, and a diaphragm is reported for the first time in Priapulida. The diaphragm may function in hydrostatic control of eversion and inversion of the introvert and mouth cone. The functional morphology of these two structures is discussed and contrasted with the Kinorhyncha.

  7. Intraguild predation and cannibalism among larvae of detritivorous caddisflies in subalpine wetlands

    Science.gov (United States)

    Wissinger, S.A.; Sparks, G.B.; Rouse, G.L.; Brown, W.S.; Steltzer, Heidi

    1996-01-01

    Comparative data from subalpine wetlands in Colorado indicate that larvae of the limnephilid caddisflies, Asynarchus nigriculus and Limnephilus externus, are reciprocally abundant among habitats - Limnephilus larvae dominate in permanent waters, whereas Asynarchus larvae dominate in temporary basins. The purpose of this paper is to report on field and laboratory experiments that link this pattern of abundance to biotic interactions among larvae. In the first field experiment, growth and survival were compared in single and mixed species treatments in littoral enclosures. Larvae, which eat mainly vascular plant detritus, grew at similar rates among treatments in both temporary and permanent habitats suggesting that exploitative competition is not important under natural food levels and caddisfly densities. However, the survival of Limnephilus larvae was reduced in the presence of Asynarchus larvae. Subsequent behavioral studies in laboratory arenas revealed that Asynarchus larvae are extremely aggressive predators on Limnephilus larvae. In a second field experiment we manipulated the relative sizes of larvae and found that Limnephilus larvae were preyed on only when Asynarchus larvae had the same size advantage observed in natural populations. Our data suggest that the dominance of Asynarchus larvae in temporary habitats is due to asymmetric intraguild predation (IGP) facilitated by a phenological head start in development. These data do not explain the dominance of Limnephilus larvae in permanent basins, which we show elsewhere to be an indirect effect of salamander predation. Behavioral observations also revealed that Asynarchus larvae are cannibalistic. In contrast to the IGP on Limnephilus larvae, Asynarchus cannibalism occurs among same-sized larvae and often involves the mobbing of one victim by several conspecifics. In a third field experiment, we found that Asynarchus cannibalism was not density-dependent and occurred even at low larval densities. We

  8. Diet and prey selection in late-stage larvae of five species of fish in a ...

    African Journals Online (AJOL)

    pelagic prey. All larvae selected P. hessei as a prey item. Myxus capensis and R. holubi also selected this copepod and showed the largest diversity in diet. Keywords: copepod eggs, insect larvae, larval fish assemblage, predation, seasonality

  9. Development of Metarhizium anisopliae and Beauveria bassiana formulations for control of malaria mosquito larvae

    NARCIS (Netherlands)

    Bukhari, S.T.; Takken, W.; Koenraadt, C.J.M.

    2011-01-01

    Background The entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana have demonstrated effectiveness against anopheline larvae in the laboratory. However, utilising these fungi for the control of anopheline larvae under field conditions, relies on development of effective means of

  10. Bothid larvae (Pleuronectiformes - Pisces) of the Gulf of Thailand and South China Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, C.B.L.

    -1 53 BOTHID LARVAE (PLEURONECTIFORMES - PISCES) OF THE GULF OF THAILAND AND SOUTH CHINA SEA. C. B. LALITHAMBIKA DEVI National Institute of Oceanography, Regional Centre, Dr. Salim All Road, Kochi - 682031. ABSTRACTS The larvae of bothids were found...

  11. Migration Of Ancylostoma caninum Larvae Into Lungs Of Mice Fed ...

    African Journals Online (AJOL)

    Two randomly selected groups of Swiss Albino Wistar mice were therefore infected with 1000 infective larvae of Ancylostoma caninum/mouse. Test mice received 250mg Allium sativum/kg body weight daily ... KEY WORDS: Allium sativum, lungs, Ancylostoma caninum. Global Journal of Pure and Applied Sciences Vol.11(2) ...

  12. Response of larvae of Cirina forda Westwood (Lepidoptera ...

    African Journals Online (AJOL)

    Older leaves contained significantly higher (P < 0.05) micronutrients than immature leaves of the same plant, and larvae developed faster with access to foliage of different ages significantly (P < 0.05) than those fed on exclusive diets. Variation in micronutrient content and, probably, phytosterols in the leaves of different ...

  13. Microbial Quality of Roasted Larvae of the Palm Weevil ...

    African Journals Online (AJOL)

    The mean total viable bacterial and fungal counts were 6.24x104 and 4.1x104 cfu/g respectively. Although these larvae are rich sources of protein, their exposure to dust during hawking in motorized traffic is a major route of contamination with bacterial and fungal pathogens. Keyword: Rhyncophorus phoenicis, Microbial ...

  14. Biological control agent for mosquito larvae: Review on the killifish ...

    African Journals Online (AJOL)

    This review attempts to give an account on the recent advances on the killifish Aphanius dispar dispar as a biological control agent for mosquito larvae. Thirty six (36) articles of literature (scientific papers, technical and workshop reports) on this subject covering the period between 1980 and 2009 were reviewed.

  15. (Convolvulaceae) extracts and fractions on larvae of Spodoptera

    African Journals Online (AJOL)

    Hexane, chloroform and methanol extracts of different parts of Ipomoea pauciflora were tested for their effects on the survival and development of Fall Armyworm (Spodoptera frugiperda), a Lepidoptera pest. For seven days, neonatal larvae (grown at 27 ± 2°C with a 16: 8 (L: D) h photoperiod) were exposed to different ...

  16. Ingestion of Nanoplastics and Microplastics by Pacific Oyster Larvae.

    Science.gov (United States)

    Cole, Matthew; Galloway, Tamara S

    2015-12-15

    Plastic debris is a prolific contaminant effecting freshwater and marine ecosystems across the globe. Of growing environmental concern are "microplastics"and "nanoplastics" encompassing tiny particles of plastic derived from manufacturing and macroplastic fragmentation. Pelagic zooplankton are susceptible to consuming microplastics, however the threat posed to larvae of commercially important bivalves is currently unknown. We exposed Pacific oyster (Crassostrea gigas) larvae (3-24 d.p.f.) to polystyrene particles spanning 70 nm-20 μm in size, including plastics with differing surface properties, and tested the impact of microplastics on larval feeding and growth. The frequency and magnitude of plastic ingestion over 24 h varied by larval age and size of polystyrene particle (ANOVA, P plastic, with aminated particles ingested and retained more frequently (ANOVA, P plastic consumption and plastic load per organism was identified (Spearmans, r = 0.95, P micro- and nanoplastics were readily ingested by oyster larvae, exposure to plastic concentrations exceeding those observed in the marine environment resulted in no measurable effects on the development or feeding capacity of the larvae over the duration of the study.

  17. Roasted maggots (Dipteran larvae) as a dietary protein source for ...

    African Journals Online (AJOL)

    Roasted maggots (Dipteran larvae) as a dietary protein source for laboratory animals. ... African Journal of Applied Zoology and Environmental Biology ... One set were fed with the convectional feed (set G,) with Clarias fish as its protein portion while the other set (M) were fed with same diet with maggots from poultry wastes ...

  18. Metabolic alterations and molecular mechanism in silkworm larvae ...

    African Journals Online (AJOL)

    Silkworm larvae, Bombyx mori (L), is an important economic insect and also a tool to convert leaf protein into silk. The industrial and commercial use of silk, the historical and economic importance of production and its application in all over the world finely contributed to the silkworm promotion as a powerful laboratory model ...

  19. Diphyllobothrium nihonkaiense Tapeworm Larvae in Salmon from North America

    Czech Academy of Sciences Publication Activity Database

    Kuchta, Roman; Oros, M.; Ferguson, J.; Scholz, Tomáš

    2017-01-01

    Roč. 23, č. 2 (2017), s. 351-353 ISSN 1080-6040 R&D Projects: GA ČR GAP506/12/1632 Institutional support: RVO:60077344 Keywords : Alaska * Diphyllobothrium * human * larva * nonhuman * Oncorhynchus * seashore Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine OBOR OECD: Parasitology Impact factor: 8.222, year: 2016

  20. Symbiotic Bacteria Enable Olive Fly Larvae to Overcome Host Defenses

    International Nuclear Information System (INIS)

    Ben-Yosef, Michael; Yuval, Boaz; Pasternak, Zohar; Jurkevitch, Edouard

    2016-01-01

    Ripe fruit offer readily available nutrients for many animals, including fruit fly larvae (Diptera: Tephritidae) and their associated rot-inducing bacteria. Yet, during most of their ontogeny, fruit remain chemically defended and effectively suppress herbivores and pathogens by high levels of secondary metabolites. Olive flies (Bactrocera oleae) are uniquely able to develop in unripe olives. Unlike other frugivorous tephritids, the larvae maintain bacteria confined within their midgut caeca. We examined the interaction between larvae, their associated bacteria, and fruit chemical defence, hypothesizing that bacterial contribution to larval development is contingent on the phenology of fruit defensive chemistry. We demonstrate that larvae require their natural complement of bacteria (Candidatus Erwinia dacicola: Enterobacteriaceae) in order to develop in unripe olives. Conversely, when feeding on ripe fruit, larval development proceeds independently of these bacteria. Our experiments suggest that bacteria counteract the inhibitory effect of oleuropein—the principal phenolic glycoside in unripe olives. In light of these results, we suggest that the unique symbiosis in olive flies, compared with other frugivorous tephritids, is understood by considering the relationship between the fly, bacteria and fruit chemistry. When applied in an evolutionary context, this approach may also point out the forces which shaped symbioses across the Tephritidae. (author)

  1. (a photo-activated insecticide) in Culex pipiens larvae

    African Journals Online (AJOL)

    The histopathological effect of hematoporphyrin on the mid-gut and the integument of the fourth larval instar of C. pipiens was studied using a transmission electron microscope. In this study C. pipiens larvae were treated with different concentration of hematoporphyrin. The concentration 5 × 10-4 M/L was found to produce ...

  2. Simple clearing technique as species determination tool in blowfly larvae.

    Science.gov (United States)

    Niederegger, Senta; Wartenberg, Nelly; Spiess, Roland; Mall, Gita

    2011-03-20

    A simple clearing technique is presented by which species specific structures and organs of blowfly larvae can easily be visualized and displayed without any danger of mechanical damages or dislocations of delicate formations and without fixation of the object. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  3. Study of the susceptibility of bacteria Paenibacillus larvae. causative ...

    African Journals Online (AJOL)

    American foulbrood is a very serious disease of the honeybee Apis mellifrea worldwide and Algeria. It caused by the bacterium Paenibacillus larvae, The objective of this study was to evaluate the prevalence of AFB in the central region of Algeria (Algiers, Bouira, Blida, Boumerdes, Tizi Ouzou, Tipaza, Medea and Ain Defla) ...

  4. Diel vertical migration of anchovy Engraulis encrasicolus larvae in ...

    African Journals Online (AJOL)

    The diel vertical migration of anchovy Engraulis encrasicolus larvae was studied in the northern Benguela during a survey in April 2001. The diel pattern is described in relation to the degree of swimbladder inflation and the vertical structure of temperature and dissolved oxygen. During the survey, samples were also ...

  5. Odour avoidance learning in the larva of Drosophila melanogaster

    Indian Academy of Sciences (India)

    2008-12-11

    Dec 11, 2008 ... Drosophila larvae can be trained to avoid odours associated with electric shock. We describe here, an improved method of aversive conditioning and a procedure for decomposing learning retention curve that enables us to do a quantitative analysis of memory phases, short term (STM), middle term (MTM) ...

  6. Bothid larvae (Pleuronectiformes-Pisces) of the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, C.B.L.

    monsoons. In Bay of Bengal E. grandisquamis was dominant during both the seasons with a preference for S.W. monsoon and larvae of E. cocosensis, E. latifrons, Arnoglossus tapeinosoma and Bothus pantherinus dominated during N.E. monsoon. In the Arabian Sea...

  7. POTENSI DAUN PANDAN WANGI UNTUK MEMBUNUH LARVA NYAMUK AEDES AEGYPTI

    Directory of Open Access Journals (Sweden)

    Dewi Susanna

    2012-11-01

    Full Text Available Leaves of umbrella tree (Pandanus amoryllifolius Roxb. contained several compounds that can be used as natural insecticide. It is containing poliphenol, flavonoid, saponin, volatile oil and alkaloid. However, lethal concentration of the leaves extract of pandamus tree was unknown. The objectives of the research was to determine the LC50 of the extract towards Aedes aegypti larvae. A 24600 ppm water suspension of the umbrella tree extract was prepared. A series of suspension was prepared by diluting 16.25 ml; 19.3 ml; 22.36 ml; 25.4 ml respectively to approximately 200 ml, and than transferred them into 250 ml glass aquaria. To each aquarium, 20 larvas were added and the volume of the mixtures was adjusted to 250 ml by adding distill water. Mortality of the larva was observed in 24 to 48 hours. Log probit analysis of the larva mortality showed that the LC50 were 2198.4655 ppm and 1669.1678 ppm for 24 and 48 hours respectively.   Keywords: Pandanus amaryllifolius Roxb, Aedes aegypti, lethal concentration

  8. Defensive enrolment in mantis shrimp larvae (Malacostraca: Stomatopoda)

    NARCIS (Netherlands)

    Haug, C.; Haug, J.T.

    2014-01-01

    We describe a possible new defensive behaviour of larval stages of mantis shrimps (Stomatopoda). Mantis shrimp larvae are rarely observed in nature, thus the study is based on postures of museum material and functional morphological aspects. Specimens described here are tightly enrolled, their pleon

  9. Effect of Root Extracts of Lantana camara (Verbenaceae) on Larvae ...

    African Journals Online (AJOL)

    Larvicidal activity of three solvent root (bark and wood) extracts of Lantana camara Linn. was investigated against first and fourth instars of Aedes aegypti larvae after 24 and 48 h post-treatment exposure to serial concentrations (0.1, 0.05, 0.01, 0.005, 0.001 %) of aqueous, ethanolic and acetone crude extracts. All extracts ...

  10. Mixing and pumping functions of the intestine of zebrafish larvae.

    Science.gov (United States)

    Yang, Jinyou; Shimogonya, Yuji; Ishikawa, Takuji

    2017-04-21

    Due to its transparency, the intestine of zebrafish larvae has been widely used in studies of gastrointestinal diseases and the microbial flora of the gut. However, transport phenomena in the intestine of zebrafish larvae have not been fully clarified. In this study, therefore, transport caused by peristaltic motion in the intestine of zebrafish larvae was investigated by numerical simulation. An anatomically realistic three-dimensional geometric model of the intestine at various times after feeding was constructed based on the experimental data of Field et al. (2009). The flow of digested chyme was analyzed using the governing equations of fluid mechanics, together with peristaltic motion and long-term contraction of the intestinal wall. The results showed that retrograde peristaltic motion was the main contributor to the mixing function. The dispersion caused by peristalsis over 30min was in the order of 10 -12 m 2 /s, which is greater than the Brownian diffusion of a sphere of 0.4µm diameter. In contrast, anterograde peristaltic motion contributed mainly to the pumping function. The pressure decrease due to peristalsis was in the order of millipascals, which may reduce the activation and maintenance heat of intestinal muscle. These findings enhance our understanding of the mixing and pumping functions of the intestine of zebrafish larvae. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. (Convolvulaceae) extracts and fractions on larvae of Spodoptera f

    African Journals Online (AJOL)

    USER

    2010-06-14

    Jun 14, 2010 ... Hexane, chloroform and methanol extracts of different parts of Ipomoea pauciflora were tested for their effects on the survival and development of Fall Armyworm (Spodoptera frugiperda), a Lepidoptera pest. For seven days, neonatal larvae (grown at 27 ± 2°C with a 16: 8 (L: D) h photoperiod) were exposed ...

  12. Anaphe venata larva extract-induced purposeless chewing in rats ...

    African Journals Online (AJOL)

    In this study we investigated the effect of the crude aqueous and Phosphate Buffer Saline (PBS) extracts of this larva on altered spontaneous rat behavior in a novel environment particularly chewing behaviour, with a view to determine the mechanism(s) involved in these behavioural alteration. Animals were randomly ...

  13. Aluminium chloride-induced toxicity in zebrafish larvae.

    Science.gov (United States)

    Monaco, A; Grimaldi, M C; Ferrandino, I

    2017-05-01

    Embryos at shield stage and larvae at protruding mouth stage were exposed to different concentrations of aluminium chloride (AlCl 3 ) for 72 h with the purpose to analyse their phenotype and lethality. After 24, 48 and 72 h of treatment, higher toxicity of the metal was observed on larvae with minimal lethal concentration of 0.25, 0.20 and 0.08 mm, respectively, while for embryos the corresponding values were 40, 25 and 16 mm. We observed pericardial oedema and alteration of heart rate in 50% of larvae after 48 h of exposure to 100 μm. In larvae exposed to the same concentration, there was also a neurological injury at the level of glial cells, with the number of glial fibrillary acidic protein-positive cells being significantly reduced. This study confirms the toxic nature of this metal and shows that aluminium could also interestingly represent a cardiotoxin in addition to its neurotoxic ability. © 2016 John Wiley & Sons Ltd.

  14. Ingestion of microplastic has limited impact on a marine larva.

    Science.gov (United States)

    Kaposi, Katrina L; Mos, Benjamin; Kelaher, Brendan P; Dworjanyn, Symon A

    2014-01-01

    There is increasing concern about the impacts of microplastics (Microplastics may be mistaken for food items and ingested by a wide variety of organisms. While the effects of ingesting microplastic have been explored for some adult organisms, there is poor understanding of the effects of microplastic ingestion on marine larvae. Here, we investigated the ingestion of polyethylene microspheres by larvae of the sea urchin, Tripneustes gratilla. Ingestion rates scaled with the concentration of microspheres. Ingestion rates were, however, reduced by biological fouling of microplastic and in the presence of phytoplankton food. T. gratilla larvae were able to egest microspheres from their stomach within hours of ingestion. A microsphere concentration far exceeding those recorded in the marine environment had a small nondose dependent effect on larval growth, but there was no significant effect on survival. In contrast, environmentally realistic concentrations appeared to have little effect. Overall, these results suggest that current levels of microplastic pollution in the oceans only pose a limited threat to T. gratilla and other marine invertebrate larvae, but further research is required on a broad range of species, trophic levels, and polymer types.

  15. Hydrodynamics of burst swimming fish larvae; a conceptual model approach

    NARCIS (Netherlands)

    Verhagen, J.H.G.

    2004-01-01

    Burst swimming of fish larvae is analysed from a hydrodynamic point of view. A picture of the expected flow pattern is presented based on information in literature on unsteady-flow patterns around obstacles in the intermediate Reynolds number region. It is shown that the acceleration stage of burst

  16. Enantiomerization and enantioselective bioaccumulation of metalaxyl in Tenebrio molitor larvae.

    Science.gov (United States)

    Gao, Yongxin; Wang, Huili; Qin, Fang; Xu, Peng; Lv, Xiaotian; Li, Jianzhong; Guo, Baoyuan

    2014-02-01

    The enantiomerization and enantioselective bioaccumulation of metalaxyl by a single dose of exposure to Tenebrio molitor larvae under laboratory condition were studied by high-performance liquid chromatography tandem mass spectroscopy (HPLC-MS/MS) based on a ChiralcelOD-3R [cellulosetris-tris-(3, 5-dichlorophenyl-carbamate)] column. Exposure of enantiopure R-metalaxyl and S-metalaxyl in Tenebrio molitor larvae exhibited significant enantiomerization, with formation of the R enantiomers from the S enantiomers, and vice versa, which might be attributed to the chiral pesticide catalyzed by a certain enzyme in Tenebrio molitor larvae. Enantiomerization was not observed in wheat bran during the period of 21 d. In addition, bioaccumulation of rac-metalaxyl in Tenebrio molitor larvae was enantioselective with a preferential accumulation of S-metalaxyl. These results showed that enantioselectivity was caused not only by actual degradation and metabolism but also by enantiomerization, which was an important process in the environmental fate and behavior of metalaxyl enantiomers. Copyright © 2013 Wiley Periodicals, Inc.

  17. Tidal exchange of larvae of Sesarma catenata (Decapoda, Brachyura)

    African Journals Online (AJOL)

    The tidal exchange of larvae of the salt-marsh grapsid crab Sesarma catenata was studied in the Swartkops estuary, a tidally driven, shallow estuary in Algoa Bay, South Africa. Plankton samples were collected bimonlhly during spring and neap tides from October to March at the tidal inlet. Samples were collected hourly for ...

  18. Nursing protects honeybee larvae from secondary metabolites of pollen

    Science.gov (United States)

    Lucchetti, Matteo A.; Kilchenmann, Verena; Glauser, Gaetan; Praz, Christophe

    2018-01-01

    The pollen of many plants contains toxic secondary compounds, sometimes in concentrations higher than those found in the flowers or leaves. The ecological significance of these compounds remains unclear, and their impact on bees is largely unexplored. Here, we studied the impact of pyrrolizidine alkaloids (PAs) found in the pollen of Echium vulgare on honeybee adults and larvae. Echimidine, a PA present in E. vulgare pollen, was isolated and added to the honeybee diets in order to perform toxicity bioassays. While adult bees showed relatively high tolerance to PAs, larvae were much more sensitive. In contrast to other bees, the honeybee larval diet typically contains only traces of pollen and consists predominantly of hypopharyngeal and mandibular secretions produced by nurse bees, which feed on large quantities of pollen-containing bee bread. We quantified the transfer of PAs to nursing secretions produced by bees that had previously consumed bee bread supplemented with PAs. The PA concentration in these secretions was reduced by three orders of magnitude as compared to the PA content in the nurse diet and was well below the toxicity threshold for larvae. Our results suggest that larval nursing protects honeybee larvae from the toxic effect of secondary metabolites of pollen. PMID:29563265

  19. Two alternating motor programs drive navigation in Drosophila larva.

    Directory of Open Access Journals (Sweden)

    Subhaneil Lahiri

    Full Text Available When placed on a temperature gradient, a Drosophila larva navigates away from excessive cold or heat by regulating the size, frequency, and direction of reorientation maneuvers between successive periods of forward movement. Forward movement is driven by peristalsis waves that travel from tail to head. During each reorientation maneuver, the larva pauses and sweeps its head from side to side until it picks a new direction for forward movement. Here, we characterized the motor programs that underlie the initiation, execution, and completion of reorientation maneuvers by measuring body segment dynamics of freely moving larvae with fluorescent muscle fibers as they were exposed to temporal changes in temperature. We find that reorientation maneuvers are characterized by highly stereotyped spatiotemporal patterns of segment dynamics. Reorientation maneuvers are initiated with head sweeping movement driven by asymmetric contraction of a portion of anterior body segments. The larva attains a new direction for forward movement after head sweeping movement by using peristalsis waves that gradually push posterior body segments out of alignment with the tail (i.e., the previous direction of forward movement into alignment with the head. Thus, reorientation maneuvers during thermotaxis are carried out by two alternating motor programs: (1 peristalsis for driving forward movement and (2 asymmetric contraction of anterior body segments for driving head sweeping movement.

  20. Abundance, distribution and species composition of fish larvae in ...

    African Journals Online (AJOL)

    An attemptwas made to correlate the data with environmental parameters such as temperature, salinity and rainfall. The ichthyoplankton of the Swartkops is dominated by few species. The family Gobiidae (59,44%) and a clupeid species, Gilchristella aestuarius (31,12%), accounted for 90,56% of all the fish larvae sampled.

  1. Variations in body shape of European seabass larvae ...

    African Journals Online (AJOL)

    High rates of body deformities is one of the most challenging problems in fish culture and is a common source of downgrading the product value of commercially raised fish. The aims of this study are explore the effects of xenic and axenic rearing conditions on the seabass larvae and check whether the rearing condition has ...

  2. The larvae of decapods and fishes of Amba estuary, Maharashtra

    Digital Repository Service at National Institute of Oceanography (India)

    Paulinose, V.T.; Devi, C.B.L.; Govindan, K.; Gajbhiye, S.N.; Nair, V.R.

    larvae to the total zooplankton population were 3.63 and 0.03 respectively. In the assessment of larval stocks environmental parameters and the presence of adult fish caught in the area were considered. The estuarine area supported fairly high fishery...

  3. Effects of gamma irradiation as a quarantine treatment on development of codling moth larvae

    International Nuclear Information System (INIS)

    Burditt, A.K. Jr.; Moffitt, H.R.; Hungate, F.P.

    1985-03-01

    Codling moth, Cydia pomonella (L.), larvae were exposed to gamma radiation at doses upto 160 Gy. Following irradiation the larvae were permited further development, pupation and adult emergence. The number of adults emerging, mature larvae and pupae present were determined. Data from these studies will be used to predict doses of gamma irradiation required as a quarantine treatment to prevent emergence of codling moth adults from fruit infested by larvae. 5 refs., 1 tab

  4. Effects of gamma irradiation as a quarantine treatment on development of codling moth larvae

    Energy Technology Data Exchange (ETDEWEB)

    Burditt, A.K. Jr.; Moffitt, H.R.; Hungate, F.P.

    1985-03-01

    Codling moth, Cydia pomonella (L.), larvae were exposed to gamma radiation at doses upto 160 Gy. Following irradiation the larvae were permited further development, pupation and adult emergence. The number of adults emerging, mature larvae and pupae present were determined. Data from these studies will be used to predict doses of gamma irradiation required as a quarantine treatment to prevent emergence of codling moth adults from fruit infested by larvae. 5 refs., 1 tab.

  5. Trophic ecology of Atlantic bluefin tuna Thunnus thynnus larvae.

    Science.gov (United States)

    Catalán, I A; Tejedor, A; Alemany, F; Reglero, P

    2011-05-01

    Feeding intensity, diet composition, selectivity, energy ingestion and dietary niche breadth of larval Atlantic bluefin tuna Thunnus thynnus were studied on the eastern (Mediterranean) spawning grounds of the species. Larval T. thynnus were collected in the Balearic Archipelago (north-west Mediterranean Sea) during 2004 and 2005 using surveys specific for larval scombrids. Larvae between 2·6 and 8·7 mm standard length (L(S) ) are diurnal feeders, and 94% of the guts collected during daylight hours were full. The mean ±s.d. number of prey per gut was 7·1 ± 5·7, with mean ±s.d. ranging from 3·0 ± 1·6 in the smallest T. thynnus larvae to 11·1 ± 5·8 in 5·0-6·0 mm L(S) larvae. Up to 21 prey were found in a single larval gut (5·0-6·0 mm L(S) ) at the end of the day. Larvae progressively selected larger prey and exhibited increased carbon content concurrent with preflexion development of feeding and locomotory structures. Larvae of 5·0-6·0 mm L(S) exhibited positive selection of cladocerans over other prey (Chesson's index), whereas copepod nauplii dominated the diets of earlier stages. The dietary niche breadth measured increased initially but decreased at c. 5·5 mm L(S) . Appendicularians were found in the diet of larger larval sizes, but no piscivory was observed. Results are discussed in light of the sparse existing data for larval T. thynnus and other larval tuna species. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles. No claim to original US government works.

  6. Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae.

    Science.gov (United States)

    Waldbusser, George G; Hales, Burke; Langdon, Chris J; Haley, Brian A; Schrader, Paul; Brunner, Elizabeth L; Gray, Matthew W; Miller, Cale A; Gimenez, Iria; Hutchinson, Greg

    2015-01-01

    Ocean acidification (OA) is altering the chemistry of the world's oceans at rates unparalleled in the past roughly 1 million years. Understanding the impacts of this rapid change in baseline carbonate chemistry on marine organisms needs a precise, mechanistic understanding of physiological responses to carbonate chemistry. Recent experimental work has shown shell development and growth in some bivalve larvae, have direct sensitivities to calcium carbonate saturation state that is not modulated through organismal acid-base chemistry. To understand different modes of action of OA on bivalve larvae, we experimentally tested how pH, PCO2, and saturation state independently affect shell growth and development, respiration rate, and initiation of feeding in Mytilus californianus embryos and larvae. We found, as documented in other bivalve larvae, that shell development and growth were affected by aragonite saturation state, and not by pH or PCO2. Respiration rate was elevated under very low pH (~7.4) with no change between pH of ~ 8.3 to ~7.8. Initiation of feeding appeared to be most sensitive to PCO2, and possibly minor response to pH under elevated PCO2. Although different components of physiology responded to different carbonate system variables, the inability to normally develop a shell due to lower saturation state precludes pH or PCO2 effects later in the life history. However, saturation state effects during early shell development will carry-over to later stages, where pH or PCO2 effects can compound OA effects on bivalve larvae. Our findings suggest OA may be a multi-stressor unto itself. Shell development and growth of the native mussel, M. californianus, was indistinguishable from the Mediterranean mussel, Mytilus galloprovincialis, collected from the southern U.S. Pacific coast, an area not subjected to seasonal upwelling. The concordance in responses suggests a fundamental OA bottleneck during development of the first shell material affected only by

  7. Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae.

    Directory of Open Access Journals (Sweden)

    George G Waldbusser

    Full Text Available Ocean acidification (OA is altering the chemistry of the world's oceans at rates unparalleled in the past roughly 1 million years. Understanding the impacts of this rapid change in baseline carbonate chemistry on marine organisms needs a precise, mechanistic understanding of physiological responses to carbonate chemistry. Recent experimental work has shown shell development and growth in some bivalve larvae, have direct sensitivities to calcium carbonate saturation state that is not modulated through organismal acid-base chemistry. To understand different modes of action of OA on bivalve larvae, we experimentally tested how pH, PCO2, and saturation state independently affect shell growth and development, respiration rate, and initiation of feeding in Mytilus californianus embryos and larvae. We found, as documented in other bivalve larvae, that shell development and growth were affected by aragonite saturation state, and not by pH or PCO2. Respiration rate was elevated under very low pH (~7.4 with no change between pH of ~ 8.3 to ~7.8. Initiation of feeding appeared to be most sensitive to PCO2, and possibly minor response to pH under elevated PCO2. Although different components of physiology responded to different carbonate system variables, the inability to normally develop a shell due to lower saturation state precludes pH or PCO2 effects later in the life history. However, saturation state effects during early shell development will carry-over to later stages, where pH or PCO2 effects can compound OA effects on bivalve larvae. Our findings suggest OA may be a multi-stressor unto itself. Shell development and growth of the native mussel, M. californianus, was indistinguishable from the Mediterranean mussel, Mytilus galloprovincialis, collected from the southern U.S. Pacific coast, an area not subjected to seasonal upwelling. The concordance in responses suggests a fundamental OA bottleneck during development of the first shell material

  8. Nosema algerae (Nosematidae, Microsporida): laboratory infections of Anopheles larvae and prospects for field application.

    Science.gov (United States)

    Nugud, A D; White, G B

    1985-04-01

    Different larval instars of Anopheles arabiensis were infected experimentally using different dosages of Nosema algerae spores. The N. algerae infections killed most of the exposed larvae at the instar treated. Chronic infections in adults developing from treated larvae decreased fecundity and shortened the life of the adults. The possibility of applying N. algerae as a control agent against An. arabiensis larvae is discussed.

  9. Description of the larva of Triaenodes sp. McLachlan, 1865 ...

    African Journals Online (AJOL)

    ... particular species is at best conjectural. Efforts are ongoing to breed out adult from larva for proper association and determination of the species. Larvae were found in a slow-flowing forested stream, where they were associated with leaf litter accumulations. Keywords: Trichoptera, Leptoceridae, Triaenodes, larva, Nigeria, ...

  10. Diel variation in the sizes of larvae of Bugula neritina in field populations.

    Science.gov (United States)

    Kosman, Ellen T; Pernet, Bruno

    2009-02-01

    The scale of planktonic larval dispersal affects a variety of ecological and evolutionary processes. Recent work suggests that the dispersal ability of obligately lecithotrophic larvae is influenced by the amount of energy supplied to each larva: larger larvae may stay in the plankton longer and thus travel greater distances than smaller larvae. We examined a prediction of this hypothesis in the bryozoan Bugula neritina, which each morning releases brooded larvae that settle within a few hours. If larger larvae stay in the plankton longer than smaller larvae, than larger larvae should increase in frequency in the planktonic population as the day progresses. However, field surveys revealed a negative relationship between time of day and the sizes of planktonic larvae. Because these results may have been complicated by prolonged larval release, we sequestered groups of brooding colonies in field mesocosms to examine release patterns. Larvae were released over a period of 8-9 h, with smaller larvae increasing in frequency as the day progressed. We conclude that populations of larvae of B. neritina may not be homogenous in energetic content throughout the day; this must be taken into consideration when designing studies of many aspects of larval biology.

  11. Distribution and seasonal abundance of carangid larvae in the Arabian sea and Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Peter, K.J.; Balachandran, T.

    Carangid larvae were recorded from 8.8% of the International Indian Ocean Expedition (IIOE) stations in the Arabian Sea and 13.2% in the Bay of Bengal. Their total contribution was 1.1% of the total larvae collected. The highest number of larvae...

  12. Nutrition and related ontogenetic aspects in larvae of the African catfish, Clarias gariepinus

    NARCIS (Netherlands)

    Verreth, J.

    1994-01-01


    The absence of adequate techniques for rearing fish larvae constitutes a bottleneck for sustainable aquacultural growth. Important constraints are the tiny size of the larvae, the dependance on live food organisms and the developmental stage of the fish larvae. The development

  13. Dietary potentials of the edible larvae of Cirina forda (westwood) as ...

    African Journals Online (AJOL)

    An experiment was conducted to determine the performance of broiler chicks to the replacement of fishmeal with the larvae of Cirina forda. Three diets, namely Diet A (100% C. forda larvae and 0% Fish meal); Diet B (50% C. forda larvae and 50% Fish meal); and Diet C, which was the control (100% Fish meal and 0% C.

  14. Software for pattern recognition of the larvae of Aedes aegypti and Aedes albopictus Programa de computador para reconhecimento da larva de Aedes aegypti e Aedes albopictus

    OpenAIRE

    André Iwersen de São Thiago; Emil Kupek; Joaquim Alves Ferreira Neto; Paulo de Tarso São Thiago

    2002-01-01

    Software for pattern recognition of the larvae of mosquitoes Aedes aegypti and Aedes albopictus, biological vectors of dengue and yellow fever, has been developed. Rapid field identification of larva using a digital camera linked to a laptop computer equipped with this software may greatly help prevention campaigns.Foi desenvolvido um programa de computador para reconhecimento da larva de Aedes aegypti e Aedes albopictus, vetores biológicos de dengue e febre amarela. O programa possibilita rá...

  15. Studi Laju Umpan pada Proses Biokonversi Limbah Pengolahan Tuna menggunakan Larva Hermetia illucens

    Directory of Open Access Journals (Sweden)

    Arif Rahman Hakim

    2017-12-01

    Full Text Available Seiring dengan berkembangnya industri tuna, limbah pengolahan yang dihasilkan semakin meningkat. Namun demikian pemanfaatan limbah tersebut belum optimal. Biokonversi bahan organik limbah tuna menjadi biomassa larva sebagai bahan pakan diharapkan mampu mengatasi permasalahan tersebut. Biokonversi menggunakan larva Hermetia illucens atau Black Soldier Fly (BSF memiliki keunggulan dibandingkan proses konversi lain; di antaranya larva BSF mampu mengkonversi berbagai macam bahan organik, memiliki kandungan nutrisi tinggi serta bukan vektor penyakit. Tujuan penelitian ini ialah mempelajari laju umpan larva BSF dalam mengkonversi limbah tuna menjadi biomassa larva. Limbah tuna yang digunakan sebagai umpan larva BSF adalah kepala dan jeroan. Larva dipelihara selama 19 hari dengan pemberian umpan bervariasi (60, 80, 100 mg/larva/hari. Analisa dilakukan terhadap konsumsi umpan, indeks pengurangan limbah (waste reduction index/WRI, efisiensi konversi umpan tercerna (efficiency of conversion of digested-feed/ECD, tingkat kelulusan hidup (survival rates /SR, bobot larva, kandungan protein dan lemak larva. Hasil penelitian menunjukkan kepala dan jeroan tuna dapat digunakan sebagai pakan BSF, dengan nilai SR 41,33 – 98,33%. Laju umpan yang menghasilkan proses biokonversi paling optimum adalah umpan berupa kepala tuna sebesar 60 mg/larva/hari (K60. Nilai parameter pada perlakuan K60 adalah konsumsi umpan 77,09 %, WRI 4,06 % per hari, ECD 8,32 %, bobot larva 72,59 mg dan SR 98,33 %. Limbah berupa kepala tuna menghasilkan konsumsi umpan, WRI, ECD, bobot larva dan SR yang lebih tinggi dibandingkan limbah jeroan tuna. Penggunaan limbah kepala tuna dapat dimanfaatkan untuk mereduksi limbah sekaligus menghasilkan bahan pakan yang potensial. Kandungan larva BSF dengan umpan kepala tuna 60 mg/larva/hari meliputi protein 25,38 %, lemak 6,85 % dan air 62,81 %.

  16. Elemental concentrations of aquatic insect larvae and attached algae on tone surfaces in an uncontaminated stream

    International Nuclear Information System (INIS)

    Momoshima, N.; Sugihara, S.; Hibino, K.; Nakamura, Y.

    2009-01-01

    Elemental concentrations of aquatic insect larvae and attached algae in an uncontaminated river were analyzed by instrumental neutron activation analysis (INAA) via the k 0 -standardization method. The aquatic insect larvae found were all intolerant species. No significant difference was observed int he elemental concentrations of aquatic insect larvae and attached algae long the river. Similar elemental concentrations were observed in the aquatic insect larvae collected at a fixed sampling point for two years. An analysis by the ratio-matching technique indicated a higher generic relationship between aquatic insect larvae and attached algae than river water. (author)

  17. Oesophagostomum columbianum : immunization of young lambs using gamma ray attenuated inefective larvae

    International Nuclear Information System (INIS)

    Sharma, R.L.; Dhar, D.N.

    1987-01-01

    Infective Oesophagostomum columbianum larvae were successfully attenuated by exposing them to a gamma radiation dose levels of either 40 or 50 Krad. Lambs receiving a single vaccination dose of 2000 infective larvae attenuated at 40 Krad developed partial protection, whereas those vaccinated with similar dose of infection with 50 Krad irradiated larvae failed to develop any protection. A double vaccination schedule comprising of 500 and 2000 gamma attenuated (40 Krad) infective larvae induced a significantly higher level of protection against the challenge dose. The possible use of radiation attenuated larvae as vaccine for immunoprophylaxis against ovine Oesophagostomiasis has been discussed. (author). 11 refs., 2 tables

  18. Composting poultry manure by fly larvae (Musca domestica) eliminates Campylobacter jejuni from the manure

    DEFF Research Database (Denmark)

    Nordentoft, Steen; Hald, Birthe

    2013-01-01

    study To monitor fly larvae composting of poultry manure artificially contaminated with C. jejuni, and to investigate a possible transmission route of C. jejuni from the manure through the fly larvae to the adult fly. Conclusions The addition of fly larvae both accelerated the degradation of manure...... and C. jejuni. Pupae or newly hatched flies were not carriers of C. jejuni although larvae were grown in contaminated manure. Impact When composting poultry manure with Md fly larvae, it is possible both to reduce the amount of waste and to sanitize it from C. jejuni, thereby reducing the risk...

  19. MOLECULAR IDENTIFICATION OF Pseudoterranova azarasi LARVAE IN COD (Gadus sp.) SOLD FOR HUMAN CONSUMPTION IN BRAZIL

    Science.gov (United States)

    MARIGO, Juliana; TANIWAKI, Sueli Akemi; PINTO, Pedro Luiz Silva; SOARES, Rodrigo Martins; CATÃO-DIAS, José Luiz

    2015-01-01

    Anisakiasis and Pseudoterranovosis are human diseases caused by the ingestion of live Anisakidae larvae in raw, undercooked or lightly marinated fish. Larvae were collected from one salted cod sold for human consumption in a Sao Paulo market in 2013. One section of one brownish larva was used for molecular analyses. The partial COX2 gene sequence from the larva had a nucleotide identity of 99.8 % with Pseudoterranova azarasi, which belongs to the Pseudoterranova decipiens species complex. The risk of allergy when consuming dead larvae in salted fish is not well known and should be considered. PMID:27049712

  20. The dynamical impact of mesoscale eddies on migration of Japanese eel larvae.

    Directory of Open Access Journals (Sweden)

    Yu-Lin Chang

    Full Text Available In this study, we explore the dynamical role of mesoscale eddies on fish larvae migration using the example of Subtropical Counter Current eddies and the migration of Japanese eel larvae in the western North Pacific Ocean. An idealized experiment is conducted to isolate the effects of eddies, and use a three-dimensional particle-tracking method to simulate virtual eel larvae (v-larvae migration, including both horizontal and vertical swimming behaviors. The impact of eddies strongly depends on the swimming speed of v-larvae relative to the eddy speed. Eddies accelerate the movement of v-larvae that swim slower than the propagation speed of the eddy, whereas faster-swimming v-larvae are dragged by eddies. A modified stream function that incorporates biological swimming ability explains the non-uniform trapping of v-larvae in mesoscale eddies. A high swimming speed and/or a small eddy rotation speed results in a weak trapping capacity. Simulations of v-larvae migration in realistic cases of eddy fields indicate that the abundance of eddies significantly affects the duration of larval migration, with the effects being largely dependent on the larvae swimming speed. We noted a negative relationship between the observed annual eel recruitment index in Taiwan and the eddy index subtropical countercurrent (STCC region, which suggests a potentially important role of mesoscale eddies in eel larvae migration.

  1. Tadpoles of three common anuran species from Thailand do not prey on mosquito larvae.

    Science.gov (United States)

    Weterings, Robbie

    2015-12-01

    Tadpoles are often considered to be predators of mosquito larvae and are therefore beneficial for the control of certain disease vectors. Nevertheless, only a few species have actually been recorded to prey on mosquito larvae. The mosquito larvae predation rates of tadpoles of three common Thai anuran species (Bufo melanostictus, Kaloula pulchra and Hylarana raniceps) were experimentally tested. Tadpoles in varying developmental stages were used to assess a size/age effect on the predation rate. In addition, different instars of Culex quinquefasciatus were used in order to assess a prey size effect on the predation rates. All three species failed to show any evidence of mosquito larvae predation. Neither small nor large tadpoles fed on mosquito larvae. Prey size also did not affect predation. Although tadpoles do not feed on mosquito larvae, there may be other direct or indirect inter-specific interactions that adversely impact the development of larvae in shared habitats with tadpoles. © 2015 The Society for Vector Ecology.

  2. Development of a two photon microscope for tracking Drosophila larvae

    Science.gov (United States)

    Karagyozov, Doycho; Mihovilovic Skanata, Mirna; Gershow, Marc

    Current in vivo methods for measuring neural activity in Drosophila larva require immobilization of the animal. Although we can record neural signals while stimulating the sensory organs, we cannot read the behavioral output because we have prevented the animal from moving. Many research questions cannot be answered without observation of neural activity in behaving (freely-moving) animals. We incorporated a Tunable Acoustic Gradient (TAG) lens into a two-photon microscope to achieve a 70kHz axial scan rate, enabling volumetric imaging at tens of hertz. We then implemented a tracking algorithm based on a Kalman filter to maintain the neurons of interest in the field of view and in focus during the rapid three dimensional motion of a free larva. Preliminary results show successful tracking of a neuron moving at speeds reaching 500 μm/s. NIH Grant 1DP2EB022359 and NSF Grant PHY-1455015.

  3. VISCERAL LARVA MIGRANS AND TROPICAL PYOMYOSITIS: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    LAMBERTUCCI Roberto

    1998-01-01

    Full Text Available We report a case of tropical pyomyositis in a boy who presented with a severe febrile illness associated with diffuse erythema, and swelling in many areas of the body which revealed on operation extensive necrotic areas of various muscles that required repeated débridement. The patient gave a history of contact with dogs, and an ELISA test for Toxocara canis was positive. He also presented eosinophilia and high serum IgE levels. Staphylococcus aureus was the sole bacteria isolated from the muscles affected. We suggest that tropical pyomyositis may be caused by the presence of migrating larvae of this or other parasites in the muscles. The immunologic and structural alterations caused by the larvae, in the presence of concomitant bacteremia, would favour seeding of the bacteria and the development of pyomyositis.

  4. Citrus Seed Oils Efficacy against Larvae of Aedes aegypti.

    Science.gov (United States)

    Bilal, Hazrat; Akram, Waseem; Hassan, Soaib Ali; Din, Sadrud

    2017-09-01

    Dengue fever is a serious public health issue in Pakistan for many years. Globally plants have been reported to contain compounds with insecticidal properties. These properties have been demonstrated more recently on the larval stages of mosquitoes. Therefore, Citrus cultivar seeds were evaluated for larvicidal potential against the primary dengue vector Aedes aegypti . Extraction of oil was done by a steam distillation method and oils were evaluated according to WHO guidelines for larvicides 2005 for evaluation of insecticidal properties of citrus seed extracts against mosquito larvae. Among the Citrus cultivar seed oil, rough lemon ( Citrus jambhiri ) had the lowest LC 50 value (200.79ppm), while musambi ( C. sinensis var musambi ) had the highest LC 50 value (457.30ppm) after 24 h of exposure. Citrus cultivars have some larvicidal potential but C. jambhiri had the greatest potential against A. aegypti larvae. Further small-scale field trials using the extracts of C. jambhiri will be conducted to determine operational feasibility.

  5. The immunogenic effect of irradiated Hemonchus contortus larvae in goats

    International Nuclear Information System (INIS)

    de la Cruz, B.; Perfuse, W.

    1980-01-01

    The development of radiation-attenuated vaccines against parasitic disease has been reported in literature. The use of irradiated larvae as vaccines enables one to take advantage of the special immunological properties of living parasites; the radiation treatment can largely suppress the pathogenic effects of the vaccines and the reproductive capacity of the parasites involved. This report deals with our attempts to produce a radiation-attenuated vaccine against Hemonchus contortus infection in adult goats. Hemonchus contortus infection in ruminants is prevalent in the Philippines, especially among cattle and goats. The results presented indicate that a certain degree of resistance against Hemonchus contortus infection can be induced in adult goats immunized with irradiated larvae. The shelf-life of the vaccine was also determined. (author)

  6. Catching large herring larvae: Gear applicability and larval distribution

    DEFF Research Database (Denmark)

    Munk, Peter

    1988-01-01

    A series of night hauls were made both along a transect from the Danish coast to the Dogger Bank and at a fixed position in the southern North Sea. The aim was to evaluate the suitability of two midwater trawls (IKMT and MIK) for catching large herring larvae (20-40 mm), with special attention...... given to the influence of gear speed on catching effectiveness. An additional objective was to investigate larval distributional patterns of potential importance to sampling strategy. Gear speed had a pronounced influence on the efficiency of the IKMT. Catches per unit volume filtered decreased to one...... third when speed was increased by one knot. The efficiency of the MIK did not change in the speed range investigated, and this gear was in every case more efficient than the IKMT. Larvae were found to be patchily distributed at the scale of sampling, and the degree of patchiness did not increase when...

  7. Architecture of the primary taste center of Drosophila melanogaster larvae

    OpenAIRE

    Colomb, Julien; Grillenzoni, Nicola; Ramaekers, Ariane; Stocker, Reinhard F.

    2007-01-01

    A simple nervous system combined with stereotypic behavioral responses to tastants, together with powerful genetic and molecular tools, have turned Drosophila larvae into a very promising model for studying gustatory coding. Using the Gal4/UAS system and confocal microscopy for visualizing gustatory afferents, we provide a description of the primary taste center in the larval central nervous system. Essentially, gustatory receptor neurons target different areas of the subesophageal ganglion (...

  8. Cockchafer larvae smell host root scents in soil.

    Directory of Open Access Journals (Sweden)

    Sonja Weissteiner

    Full Text Available In many insect species olfaction is a key sensory modality. However, examination of the chemical ecology of insects has focussed up to now on insects living above ground. Evidence for behavioral responses to chemical cues in the soil other than CO(2 is scarce and the role played by olfaction in the process of finding host roots below ground is not yet understood. The question of whether soil-dwelling beetle larvae can smell their host plant roots has been under debate, but proof is as yet lacking that olfactory perception of volatile compounds released by damaged host plants, as is known for insects living above ground, occurs. Here we show that soil-dwelling larvae of Melolontha hippocastani are well equipped for olfactory perception and respond electrophysiologically and behaviorally to volatiles released by damaged host-plant roots. An olfactory apparatus consisting of pore plates at the antennae and about 70 glomeruli as primary olfactory processing units indicates a highly developed olfactory system. Damage induced host plant volatiles released by oak roots such as eucalyptol and anisol are detected by larval antennae down to 5 ppbv in soil air and elicit directed movement of the larvae in natural soil towards the odor source. Our results demonstrate that plant-root volatiles are likely to be perceived by the larval olfactory system and to guide soil-dwelling white grubs through the dark below ground to their host plants. Thus, to find below-ground host plants cockchafer larvae employ mechanisms that are similar to those employed by the adult beetles flying above ground, despite strikingly different physicochemical conditions in the soil.

  9. Maya Index and Larva Density Aedes Aegypti Toward Dengue Infection

    Directory of Open Access Journals (Sweden)

    Sang G. Purnama

    2012-12-01

    Full Text Available South Denpasar District was of there as with the highest dengue cases in Bali province. The number of mosquito breeding places and larvae density become risk factor that influenced the spreading of mosquitoes. Maya index was an indicator to measure the amount of waterreservoirs can be breeding places for mosquitoes. Knowing the relationship between maya index and density of larvae and pupae of Ae.aegypti toward dengue infection in South Denpasar District. The study was observational analytic with case-control design. Data was collected through interviews and field observations to 150 respondents. The survey entomologist with indicators maya index, house index (HI, container index (CI, breteau index (BI and pupa index (PI to see the density of larvae and pupae in survey area. Dengue transmission risk was categorized mild, moderate and severe based on density figure. Water storage containers inspected in 1215 containers that as many as 675 containers in the case and 540 containers in control. Water reservoirs (TPA that the most larvae was tub (29.27%, dispenser (18.29%, container tirta (10.98%, wells (10.98%. Maya index status was lower in the case (24% smaller thancontrols (37.33%. Value of HI = 23.33; CI=10.69; BI=55; PI=15.33. Based on HI and CI indicator South Denpasar District means have moderate the risk of transmission spread of dengue disease. Based on the BI, have a high risk of transmission to the spread of dengue disease. Based on the maya index showed house cases have highest risk as breeding place compare than control house. House index, Breteau index, container index, pupa index and maya index have correlation with dengue infection. Kind of breeding place have the high risk is bath tub

  10. Salinity tolerance of larvae of African catfish Clarias gariepinus ( ) X ...

    African Journals Online (AJOL)

    Fourteen and twenty one day larvae were exposed to abrupt stepwise change in salinity (2, 4, 6, 8, 10 and 12 ppt) for 96 hours to determine mortality, median lethal mortality, MLS and median lethal time, MLT. The fourteen day-old fry that were exposed to 0 – 6 ppt recorded 90%, 87.5% 77.5% and 10% survival at the end of ...

  11. Observations of cocooned Hydrobaenus (Diptera: Chironomidae) larvae in Lake Michigan

    Science.gov (United States)

    Tucker, Taaja R.; Hudson, Patrick L.; Riley, Stephen

    2016-01-01

    Larvae of the family Chironomidae have developed a variety of ways to tolerate environmental stress, including the formation of cocoons, which allows larvae to avoid unfavorable temperature conditions, drought, or competition with other chironomids. Summer cocoon formation by younger instars of the genus Hydrobaenus Fries allows persistence through increased temperatures and/or intermittent dry periods in arid regions or temporary habitats, but this behavior was not observed in the Great Lakes until the current study. Cocoon-aestivating Hydrobaenus sp. larvae were found in benthic grab samples collected in 2010–2013 near Sleeping Bear Dunes National Lakeshore in northern Lake Michigan with densities up to 7329/m2. The aestivating species was identified as Hydrobaenus johannseni (Sublette, 1967), and the associated chironomid community was typical for an oligotrophic nearshore system. Hydrobaenus cocoon formation in the Great Lakes was likely previously unnoticed due to the discrepancies between the genus' life history and typical benthos sampling procedures which has consequences for describing chironomid communities where Hydrobaenus is present.

  12. Unique rostrate larvae and basidiomycophagy in the beetle family Corylophidae.

    Science.gov (United States)

    Yavorskaya, Margarita I; Leschen, Richard A B; Polilov, Alexey A; Beutel, Rolf G

    2014-03-01

    The head morphology of larvae of two undescribed species of the corylophid genus Holopsis were examined. Both are associated with the same basidiomycete host Ganoderma cf applanatum. Whereas the round and convex adults are very similar, one of the disc-shaped larvae is characterized by an elongate weevil-like snout, which is a unique feature in larval beetles. The posterior head region, the mouthparts and the general configuration of the musculature are similar in the larvae of both species. However, in the rostrate Holopsis sp. 1 most muscles are either widened along the longitudinal axis or elongated. Moreover, an additional bundle of M. frontobuccalis posterior is present, which strengthens the pharyngeal pumping apparatus. Both species share an unusual connection between the prepharynx and pharynx. This is a potential autapomorphy of the genus. The larval cephalic morphology of Holopsis sp. 2 and the corylophine genus Sericoderus is quite similar. However, they differ in some muscular features and in the configuration of the foregut. Holopsis species are associated with Basidiomycetes. Whether this is an ancestral condition in Corylophidae remains ambiguous due to conflicting phylogenetic hypotheses and the largely unknown biology of the Australian subfamily Periptyctinae. Several features of Holopsis are likely plesiomorphic and possibly related with the association with basidiomycetes. However, the larval rostrum of sp. 1 is doubtlessly derived, and could have a performance advantage over other species feeding on the spores of Ganoderma cf applanatum including Holopsis sp. 2. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Macroevolutionary interplay between planktic larvae and benthic predators

    Science.gov (United States)

    Peterson, Kevin J.

    2005-12-01

    Many marine invertebrates have a complex life cycle in which the egg develops into an intermediate planktic larval form rather than developing directly to the benthic juvenile stage. Because of the evolutionary and ecological complexity of pelagic-benthic life cycles, the reasons behind the origin of larvae and their subsequent maintenance over geological time are not well understood. Using both a molecular clock and the fossil record, I show that the initial exploitation of the predator-free pelagic realm by lecithotrophic larvae was achieved independently multiple times by the end of the Early Cambrian, and that the convergent evolution of planktotrophy from lecithotrophic ancestors evolved between the latest Cambrian and Middle Ordovician at least four, and possibly as many as eight, times. Both the exploitation of the pelagic realm by nonfeeding larvae and the acquisition of planktotrophy correlate in time with novel modes of benthic predation, including the dramatic rise in the number and type of epifaunal suspension feeders in the Early Ordovician.

  14. Identification of Ruffe larvae (Gymnocephalus cernuus) in the ...

    Science.gov (United States)

    Non-native Ruffe (Gymnocephalus cernua; family Percidae) were first detected in the Laurentian Great Lakes in 1986, and are not included in the Great Lakes larval fish key which was published several years prior to their discovery. In addition, subsequent scientific literature has inconsistently described Ruffe larvae. As a result, identification of larval Ruffe remains challenging. We used traditional morphology paired with DNA technology to develop diagnostics for Ruffe larvae collected in the lower St. Louis River, and compared them to similar species. Ruffe < 6 mm total length have myomere counts and a phenotype that more closely resemble centrarchids like Black Crappie, Bluegill and Pumpkinseed rather than percids. However, morphometrics and pigment patterns can be used to distinguish Ruffe from similar centrarchids at this size. As Ruffe larvae develop, they increasingly resemble other percids such as Yellow Perch, but can be distinguished using myomere counts and morphological features. The findings presented here clarify conflicting descriptions in the scientific literature, and provide additional data to support more confident morphological identification of larval Ruffe. The impact of invasive Ruffe (Gymnocephalus cernuus) on the ecology of Great Lakes systems is currently being studied. Reproduction and early life history data, however, may be hampered by a general lack of information regarding their early life stage morphological description.

  15. Feeding rates of the jellyfish Aurelia aurita on fish larvae

    DEFF Research Database (Denmark)

    Titelman, J.; Hansson, L.J.

    2006-01-01

    We quantified feeding rates of field caught Aurelia aurita feeding on yolk sac cod (Gadus morhua) larvae in a series of incubation experiments. A short-time (similar to 1 h) functional response experiment with a wide range of prey concentrations (0.5-16 prey l(-1)supercript stop, initial concentr......We quantified feeding rates of field caught Aurelia aurita feeding on yolk sac cod (Gadus morhua) larvae in a series of incubation experiments. A short-time (similar to 1 h) functional response experiment with a wide range of prey concentrations (0.5-16 prey l(-1)supercript stop, initial...... of prey captured by A. aurita during 2.5 h of feeding at extremely high prey concentration (> 200 prey l(-1)). Clearance rate in darkness scaled with jellyfish diameter to a power of similar to 1.7 for jellyfish 3.9-9.5 cm in diameter. The jellyfish did not alter their umbrella pulse frequency in response...... to presence of fish larvae. There were no significant differences between A. aurita feeding rates in light and darkness for yolk sac prey ages 0-7 days (at 7.5 degrees C). Although prey vision and escape abilities of fish may develop rapidly during early larval ontogeny, these factors apparently have little...

  16. Nutritional Transition Period in Early Larvae Clarias Gariepinus

    International Nuclear Information System (INIS)

    Ing, N.S.; Chew, H.H.

    2015-01-01

    The nutritional transition period of Clarias gariepinus were described based on the early development from hatching to 120 hours after hatching (hAH) reared at 27.5 - 28.6 degree Celsius. Newly hatched larvae had a large greenish yolk sac volume (0.99 ± 0.31 mm 3 ) located below a straight undeveloped digestive tract, mouth not opened, eyes unpigmented and the larvae lie on the bottom of rearing tank. During endogenous feeding period, the larval feeding system has developed rapidly with development oesophagus. Yolk sac were not completely depleted at the onset of exogenous feeding (36 hAH, 0.19 ± 0.11 mm 3 ), and a period of mixed nutrition was observed up to 68 hAH when yolk was completely exhausted. Yolk sac volume was significantly different by time at hatching, 6, 12 and 18 to 36 hAH (ANOVA, P<0.05). At 36 hAH, the larvae commenced feeding once morphologically developed with opened anus, functional jaw and intestine, and demonstrated horizontally swimming. The rudimentary chemoreceptors like olfactory organs and taste buds that were found on the barbels and oral cavity assisted in food detection and commenced feeding without vision. Due to the cannibalistic behaviour at early stage, feed are suggested to be provided during 36 hAH and avoided delay feeding in the larval rearing. (author)

  17. Carbohydrate digestion in Lutzomyia longipalpis' larvae (Diptera - Psychodidae).

    Science.gov (United States)

    Vale, Vladimir F; Moreira, Bruno H; Moraes, Caroline S; Pereira, Marcos H; Genta, Fernando A; Gontijo, Nelder F

    2012-10-01

    Lutzomyia longipalpis is the principal species of phlebotomine incriminated as vector of Leishmania infantum, the etiological agent of visceral leishmaniasis in the Americas. Despite its importance as vector, almost nothing related to the larval biology, especially about its digestive system has been published. The objective of the present study was to obtain an overview of carbohydrate digestion by the larvae. Taking in account that phlebotomine larvae live in the soil rich in decaying materials and microorganisms we searched principally for enzymes capable to hydrolyze carbohydrates present in this kind of substrate. The principal carbohydrases encountered in the midgut were partially characterized. One of them is a α-amylase present in the anterior midgut. It is probably involved with the digestion of glycogen, the reserve carbohydrate of fungi. Two other especially active enzymes were present in the posterior midgut, a membrane bound α-glucosidase and a membrane bound trehalase. The first, complete the digestion of glycogen and the other probably acts in the digestion of trehalose, a carbohydrate usually encountered in microorganisms undergoing hydric stress. In a screening done with the use of p-nitrophenyl-derived substrates other less active enzymes were also observed in the midgut. A general view of carbohydrate digestion in L. longipalpis was presented. Our results indicate that soil microorganisms appear to be the main source of nutrients for the larvae. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Mananoligossacarídeo em dietas para larvas de tilápia Mannanoligosaccharides in diets for tilapia larvae

    Directory of Open Access Journals (Sweden)

    Kátia Kalko Schwarz

    2011-12-01

    Full Text Available Este experimento foi realizado para avaliar níveis crescentes de mananoligossacarídeo (MOS na dieta de larvas de tilápias-do-nilo (linhagem Supreme® na fase de reversão sexual durante 30 dias. Larvas de tilápia-do-nilo (n=1500, P=0,01 g ± 0,001 g foram distribuídas aleatoriamente em 30 tanques de 100 litros. Os peixes foram distribuídos em delineamento inteiramente casualizado, composto por seis tratamentos e cinco repetições. A dieta controle (isenta de MOS foi elaborada para conter aproximadamente 35% de proteína bruta e 3.100 kcal de ED/kg. As demais foram suplementadas com 0; 0,15; 0,30; 0,45; 0,60 e 0,75% de MOS em substituição ao milho da dieta controle. Com o aumento nos níveis de MOS nas dietas, foi observado aumento linear sobre o comprimento do intestino, a altura das vilosidades intestinais e a densidade dos vilos. Não houve diferença na composição corporal, no ganho em peso, no peso final, no comprimento final, no fator de condição, na taxa de sobrevivência e no número de células caliciformes do intestino das larvas. Os níveis de MOS tiveram efeito quadrático sobre a conversão alimentar, cujos melhores resultados foram obtidos com 0,34% de MOS. A utilização de MOS no nível de 0,34% em dietas para larvas de tilápia-do-nilo melhora a conversão alimentar e promove aumento do comprimento do intestino, da altura das vilosidades e da densidade de vilos intestinal.This experiment was conducted to evaluate increasing levels of mannanoligosaccharides (MOS in the diet of Nile tilapia larvae (Supreme® at the sex reversal stage for 30 days. Nile tilapia larvae (n = 1500, p = 0.01 ± 0.001 g, were randomly distributed in 30 tanks of 100 liters each, for 30 days. The fish were distributed in a randomized design with six treatments and five replicates. The control diet (no MOS was elaborated to contain approximately 35% of crude protein and 3,100 kcal DE/kg. Mannanoligosaccharides were included in the other diets

  19. Development and functional morphology of the mouthparts and foregut in larvae and post-larvae of Macrobrachium jelskii (Decapoda: Palaemonidae).

    Science.gov (United States)

    Rocha, Cristina Pantoja; Souza, Adelson Silva de; Maciel, Murilo; Maciel, Cristiana R; Abrunhosa, Fernando Araújo

    2016-05-01

    The morphology of the mouthparts and foregut of the larvae and post-larvae of Macrobrachium jelskii was investigated to determine their functional roles in feeding, in order to understand the larval feeding behaviour and the changes that occur during its development. The mouthparts and foregut of the zoea I and II are morphologically similar, rudimentary and non-functional in feeding. Only in the final larval stage, zoea III, do the external mouthparts and foregut become structurally more complex and thus likely to play a potential role in feeding. Two behavioral trials (point of no return, point of reserve saturation) evaluated the resistance to starvation in zoea I, II, and III. The results indicate that they have sufficient nutritional reserves to permit them to complete metamorphosis without feeding. Overall, our results suggest that the zoea I and II of Macrobrachium jelskii engage in obligate lecithotrophy and zoea III in facultative lecithotrophy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Morphological and behavioral development of the piracanjuba larvae Desenvolvimento morfológico e comportamental de larvas de piracanjuba

    Directory of Open Access Journals (Sweden)

    Cláudia Maria Reis Raposo Maciel

    2010-05-01

    Full Text Available The objective of this work was to study the morphologic development and the swimming and feeding behaviors of piracanjuba larvae, Brycon orbignyanus Valenciennes (1849 (Characiformes, Characidae, Bryconinae, during the period from zero to 172 hours after hatching (standard length = 3.62 - 11.94 mm. The morphological analyses were accomplished by using a trinocular stereo microscope, while the behavioral analyses were performed through periodic observations. In 28 hours after hatching, the larvae (standard length = 6.25 ± 0.13 mm showed the following structural and behavioral characteristics that made them become active predators able to overcome a larval critical phase, the beginning of exogenous feeding: presence of pigmented eyes, terminal and wide mouth, developed oral dentition, developing digestive tube, yolk sac reduction, fins and swim bladder formation, horizontal swimming, cannibalism, and predation. Intense cannibalism among larvae was verified from 26 to 72 hours. At the end of the metamorphosis - 172 hours after hatching - the larvae measuring 11.94 + 0.80 mm in standard length presented a flexed notochord, caudal fin bifurcation, dorsal and anal fin formation, synchronized movements, and formation of shoals, characteristics that together allow enhanced perception and locomotio in exploration of the environment, determining the best moment for transfering to the fishponds. New studies can contribute to commercial fish farming by improving feeding management, performance, survival, and productivity of this species.Objetivou-se estudar o desenvolvimento morfológico e os comportamentos natatório e alimentar de larvas de piracanjuba, Brycon orbignyanus Valenciennes (1849 (Characiformes, Characidae, Bryconinae no período de 0 a 172 horas após a eclosão (comprimento-padrão = 3,62 - 11,94 mm. As análises morfológicas foram realizadas com auxílio de um microscópio estereoscópico trinocular e as comportamentais, por meio de

  1. Whole-body gene expression pattern registration in Platynereis larvae.

    Science.gov (United States)

    Asadulina, Albina; Panzera, Aurora; Verasztó, Csaba; Liebig, Christian; Jékely, Gáspár

    2012-12-03

    Digital anatomical atlases are increasingly used in order to depict different gene expression patterns and neuronal morphologies within a standardized reference template. In evo-devo, a discipline in which the comparison of gene expression patterns is a widely used approach, such standardized anatomical atlases would allow a more rigorous assessment of the conservation of and changes in gene expression patterns during micro- and macroevolutionary time scales. Due to its small size and invariant early development, the annelid Platynereis dumerilii is particularly well suited for such studies. Recently a reference template with registered gene expression patterns has been generated for the anterior part (episphere) of the Platynereis trochophore larva and used for the detailed study of neuronal development. Here we introduce and evaluate a method for whole-body gene expression pattern registration for Platynereis trochophore and nectochaete larvae based on whole-mount in situ hybridization, confocal microscopy, and image registration. We achieved high-resolution whole-body scanning using the mounting medium 2,2'-thiodiethanol (TDE), which allows the matching of the refractive index of the sample to that of glass and immersion oil thereby reducing spherical aberration and improving depth penetration. This approach allowed us to scan entire whole-mount larvae stained with nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate (NBT/BCIP) in situ hybridization and counterstained fluorescently with an acetylated-tubulin antibody and the nuclear stain 4'6-diamidino-2-phenylindole (DAPI). Due to the submicron isotropic voxel size whole-mount larvae could be scanned in any orientation. Based on the whole-body scans, we generated four different reference templates by the iterative registration and averaging of 40 individual image stacks using either the acetylated-tubulin or the nuclear-stain signal for each developmental stage. We then registered to these templates the

  2. Whole-body gene expression pattern registration in Platynereis larvae

    Directory of Open Access Journals (Sweden)

    Asadulina Albina

    2012-12-01

    Full Text Available Abstract Background Digital anatomical atlases are increasingly used in order to depict different gene expression patterns and neuronal morphologies within a standardized reference template. In evo-devo, a discipline in which the comparison of gene expression patterns is a widely used approach, such standardized anatomical atlases would allow a more rigorous assessment of the conservation of and changes in gene expression patterns during micro- and macroevolutionary time scales. Due to its small size and invariant early development, the annelid Platynereis dumerilii is particularly well suited for such studies. Recently a reference template with registered gene expression patterns has been generated for the anterior part (episphere of the Platynereis trochophore larva and used for the detailed study of neuronal development. Results Here we introduce and evaluate a method for whole-body gene expression pattern registration for Platynereis trochophore and nectochaete larvae based on whole-mount in situ hybridization, confocal microscopy, and image registration. We achieved high-resolution whole-body scanning using the mounting medium 2,2’-thiodiethanol (TDE, which allows the matching of the refractive index of the sample to that of glass and immersion oil thereby reducing spherical aberration and improving depth penetration. This approach allowed us to scan entire whole-mount larvae stained with nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate (NBT/BCIP in situ hybridization and counterstained fluorescently with an acetylated-tubulin antibody and the nuclear stain 4’6-diamidino-2-phenylindole (DAPI. Due to the submicron isotropic voxel size whole-mount larvae could be scanned in any orientation. Based on the whole-body scans, we generated four different reference templates by the iterative registration and averaging of 40 individual image stacks using either the acetylated-tubulin or the nuclear-stain signal for each developmental

  3. Radiolabeling of infective third-stage larvae of Strongyloides stercoralis by feeding [75Se]selenomethionine-labeled Escherichia coli to first- and second-stage larvae

    International Nuclear Information System (INIS)

    Aikens, L.M.; Schad, G.A.

    1989-01-01

    A technique is described for radiolabeling Strongyloides stercoralis larvae with [ 75 Se]selenomethionine. Cultures of an auxotrophic methionine-dependent stain of Escherichia coli were grown in a medium containing Dulbecco's modified Eagle's medium supplemented with 5% nutrient broth, amino acids, and [ 75 Se]selenomethionine. When the 75 Se-labeled bacterial populations were in the stationary phase of growth, cultures were harvested and the bacteria dispersed on agar plates to serve as food for S. stercoralis larvae. Use of nondividing bacteria is important for successful labeling because the isotope is not diluted by cell division and death of larvae attributable to overgrowth by bacteria is prevented. First-stage S. stercoralis larvae were recovered from feces of infected dogs and reared in humid air at 30 C on agar plates seeded with bacteria. After 7 days, infective third-stage larvae were harvested. The mean specific activity of 6 different batches of larvae ranged from 75 to 330 counts per min/larva with 91.8 +/- 9.5% of the population labeled sufficiently to produce an autoradiographic focus during a practicable, 6-wk period of exposure. Labeled infective larvae penetrated the skin of 10-day-old puppies and migrated to the small intestine, where the developed to adulthood

  4. Annual and spatial variability in endo- and ectoparasite infections of North Sea cod (Gadus morhua Linnaeus, 1758) larvae, post-larvae and juveniles

    DEFF Research Database (Denmark)

    Mehrdana, Foojan; Bahlool, Qusay Z. M.; Skovgaard, Alf

    2014-01-01

    A parasitological investigation was performed on a total of 5380 Atlantic cod larvae, post-larvae and small juveniles sampled from the North Sea during a period of five years. The copepod Caligus elongatus (Von Nordmann, 1832) and the nematode Hysterothylacium aduncum (Rudolphi, 1802) were found ...

  5. Alimentação e comportamento de larvas de pacu, Piaractus mesopotamicus (Holmberg, 1887 Feeding and behavior of pacu, Piaractus mesopotamicus (Holmberg, 1887 larvae

    Directory of Open Access Journals (Sweden)

    Eduardo Lopes Beerli

    2004-02-01

    Full Text Available Conduziu-se este trabalho com o objetivo de avaliar o efeito da utilização de dietas naturais e artificiais sobre o desempenho e comportamento de larvas de pacu (Piaractus mesopotamicus, entre o 2º e o 10º dia de vida. Foram utilizadas 30 caixas plásticas, cada uma com 30 litros de água e renovação contínua, onde as larvas foram mantidas durante o período experimental. Cada caixa recebeu 10 larvas por litro, totalizando 300 larvas/caixa. Foram testados 6 tratamentos, cada qual com 5 repetições. Os tratamentos foram: T1-ração, T2-plâncton, T3-artêmia, T4-plâncton + ração, T5-artêmia + ração e T6-artêmia + plâncton. As larvas foram alimentadas 6 vezes ao dia, nos horários de 4, 8, 12, 16, 20 e 24 horas. A temperatura da água foi mantida constante a 27ºC, o oxigênio dissolvido permaneceu na faixa de 6,16 ± 0,34 e o pH, entre 7,16 ± 0,22. Aos 2, 4, 6, 8 e 10 dias de vida, foram coletadas amostras de 30 larvas para determinação do comprimento total e peso. No final do experimento (10º dia, as larvas que receberam artêmia + plâncton (T6 alcançaram os maiores valores de comprimento total (8,35 mm e peso corporal (3518 µg, em relação a todas as outras dietas testadas. As larvas devem permanecer em laboratório por um período de 6 dias após a eclosão, recebendo alimento do terceiro ao sexto dia. A partir do sexto dia, as larvas estão com a vesícula gasosa completamente inflada e apresentam nado contínuo.The objective of this research was to evaluate the effect of natural and artificial diets on the development and behavior of pacu (Piaractus mesopotamicus larvae, between the 2nd and 10th day post hatch. The larvaes were kept in 30L - plastic boxes (n = 30 boxes, in constant flow-through. The larvae density was 10 post-larvae/L (300 larvae/box. Six diets with 4 sampling days (4, 6, 8 and 10 days post-hatch, n = 30 larvae using 5 repetitions were tested. The diets were: T1- commercial feed, T2- plancton, T3

  6. Skin penetration of infective hookworm larvae. II. The path of migration of infective larvae of Ancylostoma braziliense in the metacarpal foot pads of dogs.

    Science.gov (United States)

    Vetter, J C; van der Linden, M E

    1977-11-10

    The hairless metacarpal foot pads of six hookworm-free puppies were exposed to infective larvae of Ancylostoma braziliense. Serial sections of the biopts stained with Harris' haematoxylin and eosin showed that the infective larvae are able to penetrate the toughest region of canine skin. Pores of eccrine sweat glands did not seem to constitute sites of entry and no larvae were detected in these glands. Larvae were only observed in the epidermis. The histopathology of the infected skin of the foot pads of the puppies was similar to that in human skin with "creeping eruption" as described by Fülleborn (1927). The biopts appeared to consist of hairy skin as well. In the unexposed adjacent hairy skin of the foot pads, larvae were also observed. They were found in the epidermis, hair follicle systems and dermis, suggesting that the migration from the epidermis into deeper tissue depends on the presence of the hair follicle systems.

  7. Production of the Catechol Type Siderophore Bacillibactin by the Honey Bee Pathogen Paenibacillus larvae

    Science.gov (United States)

    Garcia-Gonzalez, Eva; Poppinga, Lena; Süssmuth, Roderich D.; Genersch, Elke

    2014-01-01

    The Gram-positive bacterium Paenibacillus larvae is the etiological agent of American Foulbrood. This bacterial infection of honey bee brood is a notifiable epizootic posing a serious threat to global honey bee health because not only individual larvae but also entire colonies succumb to the disease. In the recent past considerable progress has been made in elucidating molecular aspects of host pathogen interactions during pathogenesis of P. larvae infections. Especially the sequencing and annotation of the complete genome of P. larvae was a major step forward and revealed the existence of several giant gene clusters coding for non-ribosomal peptide synthetases which might act as putative virulence factors. We here present the detailed analysis of one of these clusters which we demonstrated to be responsible for the biosynthesis of bacillibactin, a P. larvae siderophore. We first established culture conditions allowing the growth of P. larvae under iron-limited conditions and triggering siderophore production by P. larvae. Using a gene disruption strategy we linked siderophore production to the expression of an uninterrupted bacillibactin gene cluster. In silico analysis predicted the structure of a trimeric trithreonyl lactone (DHB-Gly-Thr)3 similar to the structure of bacillibactin produced by several Bacillus species. Mass spectrometric analysis unambiguously confirmed that the siderophore produced by P. larvae is identical to bacillibactin. Exposure bioassays demonstrated that P. larvae bacillibactin is not required for full virulence of P. larvae in laboratory exposure bioassays. This observation is consistent with results obtained for bacillibactin in other pathogenic bacteria. PMID:25237888

  8. Exposure to lead induces hypoxia-like responses in bullfrog larvae (Rana catesbeiana)

    Energy Technology Data Exchange (ETDEWEB)

    Rice, T.M.; Blackstone, B.J.; Nixdorf, W.L.; Taylor, D.H.

    1999-10-01

    Amphibians collected around mining sites, areas with extensive automobile traffic, and shooting ranges have been documented to contain high levels of lead. Lead-exposed amphibians might respond as if in hypoxic conditions because exposure is known to decrease hemoglobin levels, damage erythrocytes, and alter respiratory surfaces. Therefore, the authors exposed bullfrog larvae to either 0 or 780 {micro}g/L Pb and either 3.50 or 7.85 mg/L oxygen for 7 d and monitored activity, trips to the surface, and buccal ventilation rates. Activity was significantly decreased in larvae exposed to low oxygen, Pb, or both compared to activity of larvae in high oxygen with no Pb. Larvae exposed to both Pb and low oxygen displayed higher buccal ventilation rates than larvae exposed to either treatment separately. Lead-exposed larvae surfaced significantly more often than unexposed larvae even under high-oxygen conditions. Lead-exposed larvae decreased in mass during the exposure period, whereas unexposed larvae increased in mass. Lead exposure could decrease survival of larvae in the field not only because of physiological problems due to decreased oxygen uptake but also because of greater predation pressure due to increased presence at the surface and reduced growth rates.

  9. Seasonality of larvae of Brachyura and Anomura (Crustacea Decapoda in the Beagle Channel, Argentina

    Directory of Open Access Journals (Sweden)

    Gustavo A. Lovrich

    1999-12-01

    Full Text Available This is the first study in the Beagle Channel that reports the larval seasonal distribution, abundance and duration of the larval stages of Anomura and Brachyura, on the basis of a fortnightly sampling programme. An identification key to the specific level of zoeal stages is included. Between September 1987 and March 1989, 304 plankton samples were taken by means of oblique hauls from the bottom to the sea-surface. Eighty-five percent of the samples were taken shallower than 60 m depth. Decapod larvae occurred only in spring and summer. All but two taxa showed a single cohort of larvae which emerge at the beginning of the spring. A second cohort of Munida spp. and Halicarcinus planatus also occurred during summer. The most abundant taxa were Munida spp. (312 larvae ? 10 m-3, Peltarion spinosulum (288 larvae ? 10 m-3,, H. planatus (143 larvae ? 10 m-3, and Pagurus spp. (79 larvae ? 10 m-3, which represented 97% of the total larvae collected. Larvae of Pinnotheridae, Eurypodius latreillii, Libidoclaea granaria, and Paralomis granulosa were about an order of magnitude less abundant. Relative abundances of larvae correspond to relative abundances of the respective benthic stages. The absence of certain larval stages or of certain species (Acanthocyclus albatrossis and Lithodes santolla probably indicates their differential distribution within the Beagle Channel. Particularly, lithodid larvae may have benthic or epibenthic habits.

  10. First record of larvae of the water mite Hydrachna processifera Piersig, 1895 from Turkey (Acari, Hydrachnidia, Hydrachnidae

    Directory of Open Access Journals (Sweden)

    Medeni Aykut

    2018-02-01

    Full Text Available Larvae of water mite Hydrachna processifera Piersig, 1895 (Acari, Hydrachnidiae were reported on diving beetles Dytiscus marginalis Linnaeus, 1758 (Coleoptera, Dytiscidae from Turkey. The redescription of the larva was made. Earlier, the larva H. processifera was described as H. inermis, but it was subsequently synonymized with H. processifera. The larva of H. processifera is a new record for the Turkish fauna. All larvae of H. processifera were found on the mesosternum of the one specimens (prevalence = 16.7%.

  11. Predatory efficiency of the sewage drain inhabiting larvae of Toxorhynchites splendens Wiedemann on Culex quinquefasciatus Say and Armigeres subalbatus (Coquillett) larvae.

    Science.gov (United States)

    Aditya, Gautam; Bhattacharyya, Sankar; Kundu, Niloy; Kar, Pradip Kumar; Saha, Goutam Kumar

    2007-09-01

    The rate of predation by stage IV instar Toxorhynchites splendens larvae on the equivalent instar stage larvae of Culex quinquefasciatus and Armigeres subalbatus, co-occurring in sewage drains, were noted for a period of three consecutive days in the laboratory using different prey densities and combinations. The rate of predation varied by age of the predator, density of prey, and prey type. The number of Ar. subalbatus larvae consumed by a single Tx. splendens larva ranged between 0.50 +/- 0.71 and 16.40 +/- 2.01; while for Cx. quinquefasciatus larvae, the number consumed ranged from 0.20 +/- 0.42 to 20.40 +/- 1.43 per day. The pupation rates of the prey species varied in respect to control, with a minimum of 0.20 +/- 0.42 pupa/day to a maximum of 12.20 +/- 2.30 pupa/day in the presence of Tx. splendens. The values for the controls were 1.00 +/- 0.87 and 14.44 +/- 2.83 pupa/day, respectively. Irrespective of prey densities and combinations, a single Tx. splendens fourth instar larvae was found to consume on average 10.07 larvae on the first day 16.57 larvae on the second day and 4.38 larvae on the third day, killing a total of 17.70 to 45.10 larvae, in three days. In the presence of Tx. splendens, the cumulative pupation, irrespective of prey, remained between 12.20 and 45.10, and differed significantly from control where the values were between 13.90 and 54.70. The results indicate that Tx. splendens can significantly reduce immature numbers and lower the rate of pupation of Cx. quinquefasciatus and Ar. subalbatus. Tx. splendens may be a potential biological resource in the control of mosquitoes inhabiting sewage drains.

  12. Description of the third instar larva of Megadytes latus (Fabricius (Coleoptera, Dytiscidae, with an identification key for described larvae of the genus Descrição da larva de terceiro ínstar de Megadytes latus (Fabricius (Coleoptera, Dytiscidae

    Directory of Open Access Journals (Sweden)

    Nelson Ferreira-Jr

    2006-09-01

    Full Text Available The last instar larva of M. latus (Fabricius, 1801 is described and figured, based on reared specimens from Serra dos Órgãos, Teresópolis, state of Rio de Janeiro, Brazil. Some notes on the biotope are provided.A larva de terceiro ínstar de M. latus (Fabricius, 1801 é descrita e ilustrada, baseado em espécimes criados da Serra dos Órgãos, Teresópolis, Rio de Janeiro, Brasil. Algumas notas acerca do biótopo onde as larvas foram coletadas são incluídas.

  13. Vertical migrations of herring, Clupea harengus, larvae in relation to light and prey distribution

    DEFF Research Database (Denmark)

    Munk, Peter; Kiørboe, Thomas; Christensen, Villy

    1989-01-01

    towards the surface at dawn larvae stayed in the upper water column during the day. The observations suggest that the daytime vertical distribution of larvae in calm weather is mainly determined by feeding conditions: the larvae move to depths were light is sufficient for feeding, and refinement within......The influence of light and prey abundance on the vertical distribution of herring larvae was evaluated by three investigations made under calm weather conditions in the North Sea off the Scottish coast. The investigations took place at different time after hatching and the vertical distributions...... density peaked at the pycnocline (40 m). Larvae concentrated at this depth at noon. At dawn and dusk larvae migrated towards the surface and the vertical distributions fluctuated semidielly. In the two other investigations, copepods were homogeneously distributed in the water column and after migration...

  14. Effect of irradiation on development of the larvae of Anoplophora glabripennis

    International Nuclear Information System (INIS)

    Wang Yuejin; Wang Xin; Zhan Guoping; Xu Liang; Liu Bo; Zhe Chunmei; Huang Xiaoxu; Liu Zhijie; Sun Zhichao

    2006-01-01

    The third-fifth instar larvae of Anoplophora glabripennis were irradiated at the dose of 20-140 Gy by high energy X-rays (9 MeV), the results showed that irradiation at the dose of 20-60 Gy prolonged the developmental duration of irradiated larvae, and the radio-resistance was increased with the increase of instars, where the 5th instar larvae was the most resistant larvae, the irradiation dose for preventing pupation was 55-60 Gy. 60 Co-γ rays irradiation at the dose of 60 Gy also prevent the mature larvae of A. glabripennis in poplar wood from pupation completely. Thus, the minimum effective dose of 60 Gy could be suggested for quarantine treatment of the larvae of A. glabripennis in logs and wood packing materials. (authors)

  15. Coral larvae settle at a higher frequency on red surfaces

    Science.gov (United States)

    Mason, B.; Beard, M.; Miller, M. W.

    2011-09-01

    Although chemical cues serve as the primary determinants of larval settlement and metamorphosis, light is also known to influence the behavior and the settlement of coral planulae. For example, Porites astreoides planulae settle preferentially on unconditioned red substrata. In order to test whether this behavior was a response to color and whether other species also demonstrate color preference, settlement choice experiments were conducted with P. astreoides and Acropora palmata. In these experiments, larvae were offered various types of plastic substrata representing three to seven different color choices. Both species consistently settled on red (or red and orange) substrata at a higher frequency than other colors. In one experiment, P. astreoides settled on 100% of red, plastic cable ties but failed to settle on green or white substrata. In a second experiment, 24% of larvae settled on red buttons, more than settled on six other colors combined. A. palmata settled on 80% of red and of orange cables ties but failed to settle on blue in one experiment and settled on a greater proportion of red acrylic squares than on four other colors or limestone controls in a second experiment. The consistency of the response across a variety of plastic materials suggests the response is related to long-wavelength photosensitivity. Fluorescence and reflectance spectra of experimental substrata demonstrated that the preferred substrata had spectra dominated by wavelengths greater than 550 nm with little or no reflection or emission of shorter wavelengths. These results suggest that some species of coral larvae may use spectral cues for fine-scale habitat selection during settlement. This behavior may be an adaptation to promote settlement in crustose coralline algae (CCA)-dominated habitats facilitating juvenile survival.

  16. Tracheopulmonary Myiasis Caused by a Mature Third-Instar Cuterebra Larva: Case Report and Review

    OpenAIRE

    Cornet, Muriel; Florent, Martine; Lefebvre, Aurélie; Wertheimer, Christophe; Perez-Eid, Claudine; Bangs, Michael J.; Bouvet, Anne

    2003-01-01

    Myiasis is the infestation of vertebrate tissues with fly larvae (Diptera). Most human cases in North America are subcutaneous forms due to Dermatobia hominis imported from Central and South America. Human cases of myiasis acquired in North America are rare and are primarily subdermal or ophthalmologic forms of infestation caused by early stages of Cuterebra larvae. We report an unusual case of tracheopulmonary myiasis, resulting from the in situ development of a mature cuterebrine larva asso...

  17. Gastrointestinal symptoms resembling ulcerative proctitis caused by larvae of the drone fly Eristalis tenax.

    Science.gov (United States)

    Desoubeaux, Guillaume; Gaillard, Julien; Borée-Moreau, Diane; Bailly, Éric; Andres, Christian R; Chandenier, Jacques

    2014-04-01

    We report a case of facultative intestinal myiasis due to larvae of the drone fly Eristalis tenax, also named the rat-tailed maggots. The development of larvae in the lower bowel was responsible for non-specific gastrointestinal symptoms that resembled ulcerative proctitis. The diagnosis was established upon the observation of four spontaneously excreted mobile larvae. The definite identification of the E. tenax species was made possible by scanning electron microscopy. The clinical outcome was satisfactory.

  18. Illustrated Taxonomic Keys to Genera and Species of Mosquito Larvae of Korea. Part 2

    Science.gov (United States)

    1987-08-01

    Culicine Mosquito Larva Key to the Genera of Culicidae. . . Genus Anopheles . Genus Toxorhynchites . Genus Tripteroides. Genus Mansonia. . Genus...ILLUSTRATED TAXONOMIC KEYS TO GENERA AND SPECIES OF MOSQUITO LARVAE OF KOREA PART II DEPARTMENT OF THE ARMY BY 5TH PREVENTIVE MEDICINE UNIT...1987 4. TITLE AND SUBTITLE Illustrated Taxonomic Keys to Genera and Species of Mosquito Larvae of Korea. Part II 5a. CONTRACT NUMBER 5b. GRANT

  19. Insecticidal activity of some essential oils against larvae of Spodoptera littoralis.

    Science.gov (United States)

    Pavela, Roman

    2005-12-01

    Thirty-four essential oils were tested for insecticidal activity (fumigation or topical application) against larvae Spodoptera littoralis. Twenty essential oils applied by fumigation were highly toxic to the third instar of S. littoralis larvae. Two essential oils Nepeta cataria and Thuja occidentalis were highly toxic, with LC50cataria, S. sclarea, O. vulgare, O. compactum, Melissa officinalis, T. mastichina, and Lavandula angustifolia were highly toxic with LD50 < or =0.05 microl/larvae.

  20. Effects of Foodstuffs on Intestinal Length in Larvae of Rhacophorus arboreus (Anura: Rhacophoridae) : Developmental Biology

    OpenAIRE

    SHINRI, HORIUCHI; YUTAKA, KOSHIDA; Department of Biology, College of General Education, Osaka University; Department of Biology, College of General Education, Osaka University

    1989-01-01

    Correlation between foodstuffs and intestinal length was examined in larvae of Rhacophorus arboreus (Anura: Rhacophoridae). The larva, being heterophagous, has a tube-like intestine provided with neither epithelial outfoldings nor villi, and intestinal length is found to be a good morphological index of digestive and absorptive functions of the intestine. The results obtained were summarized as follows: The grown larva fed on boiled spinach had an intestine more than 1.5 times as long as that...

  1. PENGARUH EKSTRAK BATANG BROTOWALI (Tinospora crispa) TERHADAP KEMATIAN LARVA NYAMUK Aedes aegypti

    OpenAIRE

    Agustiani Dumeva; Syarifah Syarifah; Syahidah Fitriah

    2016-01-01

    Aedes aegypti mosquito, which acts as a vector in the spread of dengue disease. One of the effort to reduce the spread of dengue disease is using larvicides. Brotowali thought to have an effect as larvicides against Aedes aegypti larvae because they have the alkaloid compounds and tinokrisposid that can cause death in larvae. This study aims to determine the effect extract brotowali (Tinospora crispa) against Aedes aegypti larvae of death so as to provide information to the public...

  2. Immunization with irradiated larvae against Dictyocaulus filaria in young lambs

    International Nuclear Information System (INIS)

    Dhar, D.N.; Sharma, R.L.

    1981-01-01

    In the lungworm-endemic areas of Kashmir, 6-10 week old lambs of Karnah and Kashmir Merino breeds were vaccinated with two doses of 50 kR gamma-irradiated larvae of Dictyocaulus filaria, given a month apart. Assessed on the basis of reduced prevalence and significantly lower faecal larval output over an eight-month observation period, vaccinated lambs showed a high degree of resistance to naturally acquired D. filaria infection. The results also show that vaccination against D. filaria provided some degree of protection against infection with other lungworm species. (Auth.)

  3. Defesa quimica em larvas da borboleta Mechanitis polymnia (Nymphalidae : Ithomiinae)

    OpenAIRE

    Augusto Henrique Arantes Portugal

    2001-01-01

    Resumo: Os imaturos de lepidópteros estão sujeitos a altas taxas de mortalidade no ambiente natural. Uma das formas de defesa mais utilizadas e estudadas é a defesa química, envolvendo, por exemplo, substâncias tóxicas ou impalatáveis. Estas substâncias podem ser adquiridas pelos lepidópteros de suas fontes alimentares ou biosintetisadas de novo. Através de um acompanhamento dos imaturos de Mechanitis po/ymnia no campo observou-se que larvas apresentam as taxas mais altas de sobrevivência qua...

  4. What do barnacle larvae feed on ? Implications in biofouling ecology

    Digital Repository Service at National Institute of Oceanography (India)

    Gaonkar, C.; Anil, A.C.

    copepods which are collected from the field as well as from laboratory reared copepods fed with different mono-algal cultures (Honjo & Roman, 1978; Morales, 1987; Urban-Rich et al., 1998; Fleddum et al., 2001; Frangoulis et al., 2001; Schnetzer... in the laboratory rearing, the chlorophyll a content is 15 times higher than the maximum values observed in the field. This shows the capability of larvae to survive in the 7    field in spite of observed low chlorophyll a concentration in the water column...

  5. Sex Reversal on Congo Tetra Fish (Micraleptus intterruptus Larvae

    Directory of Open Access Journals (Sweden)

    Harton Arfah

    2007-08-01

    Full Text Available ABSTRACTExperiment was performed to assess the effect of 17a-methyltestosterone (MT treatment on Congo tetra fish larvae.  To evaluate the optimal pattern of MT treatment, three different treatments were administrated.  Three months old larvae were submerged in three different doses of MT; 1, 2 and 4 mg/l.  These studies showed that the highest percentage of male fish was obtained by 4 mg/l MT treatment, 87,17%.  The 2 mg/l and 1 mg/l MT treatments obtained 77,53% and 69,86% male respectively, two times higher than control, 38,96%.  On the other hand, the 4 mg/l MT treatment also resulted the highest percentage of hermaphrodite fishes, 17,58%.  The highest survival rate was shown by 1 mg/l MT treatment, 62,77% and the lowest was shown by the 4 mg/l MT treatment, 47,20%.  The highest rate of fish length and weight was shown by the 4 mg/l MT treatment, 4,4 cm and 1,65 gram respectively.  These findings suggest that MT treatment offers an advantage in growth of  tetra Congo larvae. Key word :  Sex reversal, methyltestosterone, Congo tetra fish, Micraleptus intterruptus. ABSTRAKPenelitian ini bertujuan untuk mengetahui pengaruh perendaman larva di dalam larutan hormon 17a-metiltestosteron pada dosis 1, 2 dan 4 mg/l larutan.  Persentase tertinggi ikan jantan dihasilkan  oleh perlakuan 4 mg/l, yaitu 87,17%.  Perlakuan 2 mg/l dan 1 mg/l masing-masing menghasilkan 77,53% dan 69,86% sedangkan kontrol menghasilkan 38,96% jantan.  Efek lain dari perlakuan MT ini adalah hermafroditisme.  Perlakuan 4 mg/l menghasilkan persentase hermafrodit tertinggi yaitu 17,58%, sedangkan pada kontrol kelangsungan hidup tertinggi diperoleh pada perlakuan 1 mg/l (62,77% dan terendah pada perlakuan 4 mg/l (47,20%.  Hasil tersebut menunjukkan adanya pengaruh dosis hormon terhadap kelangsungan hidup ikan.  Pengukuran bobot dan panjang ikan pada setiap perlakuan menunjukkan nilai tertinggi dihasilkan oleh perlakuan 4 mg/l  yaitu 1,65 gram dan 4,40 cm.  Hal

  6. Lobesia botrana larvae develop faster in the presence of parasitoids.

    Directory of Open Access Journals (Sweden)

    Fanny Vogelweith

    Full Text Available To combat parasitism hosts often rely on their immune system, which is the last line of defense. However, the immune system may not always be effective, and other non-immunological defenses might be favored to reduce the cost of parasite infection. Here we report that larvae of the moth Lobesia botrana can rapidly accelerate their development and reach maturity earlier in response to cues perceived at a distance from parasitoids. Such a phenotypically plastic life history shift, induced by the perception of deadly enemies in the environment, is likely to be an adaptive defensive strategy to prevent parasitoid attack, and has important implications in host-parasite dynamics.

  7. The Antigenic Structure Characterization of Oestrus Ovis Larvae

    Directory of Open Access Journals (Sweden)

    Daniela Moţ

    2012-05-01

    Full Text Available With the aim of proteic components definition from Oestrus ovis larvae, endowed with antigenic properties, able to induce immune responses in vivo and to react in vitro with induced molecular effectors were been performed: electrophoresis in poliacrilamid gel, western blot technique preceded by immunotransfer, immunoassay test. Total soluble larval antigens of O. ovis were been prepared through ultrasonic disintegration, from all three larval stages. Western blot technique allowed and emphasized the specific antigens with a superior sensitivity in comparison with SDS-PAGE electrophoresis. After antigenic characteristics demonstration of investigated larval antigens were been performed the immunoassay test to emphasized the antibodies dozes for O. ovis infestation diagnosis.

  8. The use of morphological and histological features as nutritional condition indices of Pagrus pagrus larvae

    Directory of Open Access Journals (Sweden)

    Marina Vera Diaz

    Full Text Available Morphometrical and histological techniques were employed to characterize Pagrus pagrus larvae nutritional condition. Larvae were reared in laboratory under controlled conditions with the main objective of testing whether these methodologies allowed finding differences between larvae from different feeding treatments. Once yolk was consumed (three days after hatching larvae were assigned to a feeding treatment: starved during the whole experiment; delayed feeding, starved during three days; fed during the entire experiment. Algae (Nannochloropsis oculata and rotifers (Brachionus plicatilis were provided to larvae for feed treatments. Larvae were fixed daily; for morphometrical purposes in 5% formaldehyde solution, and in Bouin for histological sections. Results herein obtained showed that both methodologies are sensitive enough to distinguish larvae characterized by different nutritional condition states obtained from the feeding treatments. Consequently, these methodologies could be employed in wild red porgy larvae in order to asses their nutritional condition. These techniques could also be employed to check larval quality obtained with aquaculture purposes to estimate the effects of changes in rearing protocols or kind of food supply and thus, to guaranty a higher survival of early developmental stages of reared larvae.

  9. Number of malpighian tubules in larvae and adults of stingless bees (Hymenoptera: Apidae) from Amazonia.

    Science.gov (United States)

    Barbosa-Costa, K; Kerr, W E; Carvalho-Zilse, G A

    2012-02-01

    The number of Malpighian tubules in larvae and adults of bees is variable. Larvae of Apis mellifera L. have four Malpighian tubules, while adults have 100 tubules. In stingless bees, this number varies from four to eight. The objectives of this study were to provide characteristics of the Malpighian tubules as well as to quantify their number in larvae and adults of six species of Meliponinae, Melipona seminigra merrillae Cockerell, Melipona compressipes manaosensis Schwarz, Melipona rufiventris Lepeletier, Scaptotrigona Moure, Frieseomelitta Ihering, and Trigona williana Friese. Malpighian tubules were dissected from larvae and adults, measured, quantified, and maintained in microtubes with Dietrich's solution. The numbers of Malpighian tubules were constant only for larvae of M. rufiventris (four and eight) and Scaptotrigona sp. (four). The most frequent number of tubules in the Melipona group was seven and eight in larvae, and 70 and 90 in adults. In the Trigona group were four and 20 to 40, for larvae and adults, respectively. The results showed differences in the number of Malpighian tubules among the species analyzed and also between the larvae and adults of the same species. Despite the variation observed, species of the group Melipona always have a larger number and longer Malpighian tubules in both larvae and adults as compared to the Trigona group, which may indicate an evolutionary trend of differentiation between these groups.

  10. [Morphology of III stage larvae of Angiostrongylus cantonensis in Pomacea canaliculata].

    Science.gov (United States)

    Zhang, Chao-Wei; Zhou, Xiao-Nong; Lv, Shan; Zhang, Yi; Liu, He-Xiang

    2008-06-30

    To observe the morphologic characteristics of III stage larvae of Angiostrongylus cantonensis from Pomacea canaliculata. P. canaliculata, the intermediate host snail of A. cantonensis, was infected with I stage larvae of A. cantonensis in laboratory. After 61 days, III stage larvae of A. cantonensis were harvested from snail's lungs and muscle of head-foot, followed by HE stain to observe morphological characteristics. The whole body of III stage larva was curling with obtuse head. Its pharyngeal canal extends from the buccal hole on the top of the head to the intestines at the pharyngeal intestine joint place, with apex cauda and clear anal tube. The tegument of the III stage larva was eosin-stained, with a transparent sheath outside of tegument. Some of the larvae cauda showed in circular cylinder, and some larvae presented ventral gland with two very short uterine which used to be the feature only showed in early IV stage larva. Morphologically characteristics of the III stage larvae is helpful to better understand the life-cycle and the control of A. cantonensis.

  11. Description of the third instar larvae of five species of Cyclocephala (Coleoptera, Melolonthidae, Dynastinae from Mexico

    Directory of Open Access Journals (Sweden)

    Miguel A. Morón

    2014-09-01

    Full Text Available Description of the third instar larvae of five species of Cyclocephala (Coleoptera, Melolonthidae, Dynastinae from Mexico. Larvae of four species of Cyclocephala are described for the first time based on specimens collected in Mexican localities: C. barrerai Martínez, 1969 from Puebla, C. sinaloae Howden & Endrödi, 1966 from Sinaloa, C. fasciolata Bates, 1888 from Veracruz, and C. jalapensis Casey, 1915 from Hidalgo. Larva of C. lunulata Burmeister, 1847, is redescribed based on specimens from the Mexican states of Morelos, Puebla, and Veracruz. Diagnostic structures are illustrated and the differences and similarities of each species with other previously described larvae of the genus are commented.

  12. Sensitivity of larvae, pupae, and adults of the driedfruit beetle (Coleoptera: Nitidulidae) to gamma radiation

    International Nuclear Information System (INIS)

    Johnson, J.A.

    1987-01-01

    Raisins infested with three different ages of larvae of dried fruit beetle, Carpophilus hemipterus (L.), were treated with gamma radiation doses of 130-798 Gy. Pupae and unmated adults were also treated at 338 and 486 Gy. All doses to larvae prevented adult development. Only the oldest treated larvae were able to develop to the wandering stage (late third instar) before dying. Complete larval mortality occurred sooner at higher doses. Most younger larvae died within the raisins. Mortality of irradiated pupae at both doses was 90%, and adults emerging from treated pupae died within 48 h. Irradiated adults produced no progeny and died within 1 wk after treatment

  13. Effect of gamma radiation on the Mediterranean flour moth, Ephestia Kuehniella, mature larvae and acceptability of irradiated larvae by Bracon hebetor female

    International Nuclear Information System (INIS)

    Mansour, M.

    2012-01-01

    Mediterranean flour moth, Ephestia kuehniella, mature 5 t h instar larvae were exposed to gamma radiation dosages ranging from 50-350 Gy at 50 Gy increment and the effects of gamma radiation on pupation, adult emergence and sex ratio were investigated. In addition, effects of irradiation on the rate of development to pupae and adults and the acceptance of irradiated larvae by B. hebetor females were examined. Results showed that the radio-sensitivity of E. kuehniella larvae increased with increasing dose. Pupation was significantly affected at 100 Gy dose, and completely prevented at 350 Gy dose. Adult emergence was only slightly different from pupation; emergence was significantly affected at 100 Gy dose and completely prevented at 300 Gy dose. Irradiation also negatively affected the rate of development of larvae to pupae and adults. While more than 98% of control larvae pupated within 10 days of treatment, this ratio decreased to about 79% in larvae exposed to 50 Gy and less than 4% in larvae exposed to 100 Gy dose. The rate of development to the adult stage was also similarly affected. While 97% of control insects emerged as adults in the 1st 20 days of treatment, this ratio decreased to about 53, 2 and zero percent in larvae exposed to 50, 100 and 150 Gy dose respectively. In addition, irradiation significantly affected male: female ratio; sex ratio was skewed in favor of males, and at 250 Gy dose all emerged moths were males. Furthermore, irradiation had no adverse effect on the degree of acceptance of mature larvae to parasitization; irradiated insects were as acceptable to B. hebetor females as unirradiated ones. (author)

  14. Redescripción de la Larva y la Pupa de Toxorhynchites ( Lynchiella guadeloupensis (Diptera: Culicidae Redescription of the larva and pupa of Toxorhynchites ( Lynchiella guadeloupensis (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Lucrecia M. Augier

    2003-07-01

    Full Text Available El objetivo de la presente contribución es redescribir, en forma completa, la quetotaxia de larva y pupa de Toxorhynchites guadeloupensis (Dyar & Knab. Además se describe por primera vez el aparato bucal de la larva. El material estudiado procede de la provincia de Tucumán en el noroeste argentino.The objetive of the present contribution is to redescribe the quetotaxia of the larva and the pupa of Toxorhynchites guadeloupensis (Dyar & Knab. The larval mouthpart is described for the first time. The material examined is from Tucumán province in the Argentina northwestern.

  15. Surto de larva migrans cutnea em uma creche de belo horizonte, minas gerais (Brasil Outbreak of cutaneous Larva migrans in a private nursery in Belo Horizonte, Brazil

    Directory of Open Access Journals (Sweden)

    Walter Dos Santos Lima

    1984-04-01

    Full Text Available O presente trabalho relata a ocorrência de um surto de Larva migrans cutânea, em 17 crianças de uma creche em Belo Horizonte, MG. As crianças adquiriram esta dermatose quando brincavam em uma caixa de areia contaminada com larvas infectantes de ancilostomídeos de cão.An outbreak of cutaneous Larva migrans in six months to four years old children in a private nursery in Belo Horizonte, Brazil, is reported. The source of infection was a sand box contaminated with dog faeces.

  16. Decapod larvae dynamics on Berlengas Biosphere Reserve (UNESCO - Portugal

    Directory of Open Access Journals (Sweden)

    Lénia Da Fonseca Alexandre Rato

    2014-05-01

    Total decapoda abundance ranged from 0,06 ind.m-3 in May 2011 to 64,28ind.m-3 in August 2012, and significantly different between summer/winter and winter/spring months (P(perm≤0,05. The data obtained on this study revealed that Infraorders Brachyura, Anomura and Caridea are the most common. All three are significantly different between months (P(perm≤0,05 but not between sampling stations (P(perm>0,05. Brachyuran abundance was significantly affected by the Oceanograhic Conditions (P(perm≤0,05. Abundances were higher in spring and summer months, when Chlorophyl a values (mg.m-3, Temperature (ºC and Salinity (ppt were also higher. Decapoda community is directly affected by the surrounding environmental conditions in Berlengas Biosphere Reserve and abundance might also be related with specific larvae release throughout the year. Each sampling station was considered a replica from the study area. The ecological importance of Berlengas was also verified by the presence of non-frequent larvae of Achelata and Stomatopoda.

  17. The hemolymph proteome of fed and starved Drosophila larvae.

    Directory of Open Access Journals (Sweden)

    Björn Handke

    Full Text Available The co-operation of specialized organ systems in complex multicellular organisms depends on effective chemical communication. Thus, body fluids (like blood, lymph or intraspinal fluid contain myriads of signaling mediators apart from metabolites. Moreover, these fluids are also of crucial importance for immune and wound responses. Compositional analyses of human body fluids are therefore of paramount diagnostic importance. Further improving their comprehensiveness should increase our understanding of inter-organ communication. In arthropods, which have trachea for gas exchange and an open circulatory system, the single dominating interstitial fluid is the hemolymph. Accordingly, a detailed analysis of hemolymph composition should provide an especially comprehensive picture of chemical communication and defense in animals. Therefore we used an extensive protein fractionation workflow in combination with a discovery-driven proteomic approach to map out the detectable protein composition of hemolymph isolated from Drosophila larvae. Combined mass spectrometric analysis revealed more than 700 proteins extending far beyond the previously known Drosophila hemolymph proteome. Moreover, by comparing hemolymph isolated from either fed or starved larvae, we provide initial provisional insights concerning compositional changes in response to nutritional state. Storage proteins in particular were observed to be strongly reduced by starvation. Our hemolymph proteome catalog provides a rich basis for data mining, as exemplified by our identification of potential novel cytokines, as well as for future quantitative analyses by targeted proteomics.

  18. The Macroevolutionary Interplay Between Planktic Larvae and Benthic Predators

    Science.gov (United States)

    Peterson, K. J.

    2004-12-01

    Many marine invertebrates have a complex life cycle whereby the egg, rather than developing directly to the juvenile stage, develops instead into a intermediate larval form which may spend weeks to months feeding in the plankton before it becomes competent to undergo metamorphosis into the benthic juvenile. Because the selective advantages provided to the animal by having a planktotrophic larval stage are largely unknown, the reasons behind their origin and subsequent maintenance over geological time are not well understood. Using both a molecular clock and the fossil record, I show that four primitively non-feeding larval forms evolved sometime between the late Ediacaran and Early Cambrian, and feeding larvae appear to have evolved from non-feeding ancestors sometime between the Late Cambrian and Middle Ordovician in at least five, if not eight, of eight different clades analyzed. Thus, the initial exploitation of the predator-free pelagos by larvae was achieved independently multiple times by the end of the Early Cambrian, most likely driven by benthic predation pressures upon developing eggs and embryos. Then, because the evolution of larval planktotrophy from lecithotrophic ancestors correlates with the dramatic rise in the generic number of benthic suspension feeders in the Early Ordovician, it seems likely that benthic suspension feeding selected for fecundity, and thus indirectly for planktotrophy, in multiple lineages of marine invertebrates by the end of the Middle Ordovician.

  19. Iodine binding in the endostyle of larvae Branchiostoma lanceolatum (Cephalochordata)

    Energy Technology Data Exchange (ETDEWEB)

    Fredriksson, G.; Ericson, L.E.; Olsson, R.

    1984-11-01

    The asymmetrical endostyle of Branchiostoma larvae contains two different zones of mucus-producing cells which metamorphose to the paired zones 2 and 4 respectively in the endostyle of the adult. In both the larva and the adult these zones are parts of the food-trapping mechanism. An endostyle zone, which has a position corresponding to that of the paired iodinating zones in the endostyle of the adult, binds iodine selectively. The ultrastructure and labeling pattern indicate that the labeled cells in the larval endostyle belong to functionally different types. In one region of the iodinating zone iodine is mainly bound extracellularly at the apical cell surface. Also in the second region grains are located at the apical cell surface as well as over the cytoplasm and extracellularly at the basal plasma membrane. It is possible that iodination takes place in the lumen close to cells in the first region and that the labeled product is taken up and eventually released by cells of the second region. Our observations show that this primitive endostyle already has iodinating capacity and may synthesize and release thyroid hormones.

  20. Citrus Seed Oils Efficacy against Larvae of Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Hazrat Bilal

    2017-10-01

    Full Text Available Background: Dengue fever is a serious public health issue in Pakistan for many years. Globally plants have been reported to contain compounds with insecticidal properties. These properties have been demonstrated more recently on the larval stages of mosquitoes. Therefore, Citrus cultivar seeds were evaluated for larvicidal potential against the primary dengue vector Aedes aegypti.Methods: Extraction of oil was done by a steam distillation method and oils were evaluated according to WHO guidelines for larvicides 2005 for evaluation of insecticidal properties of citrus seed extracts against mosquito larvae.Result: Among the Citrus cultivar seed oil, rough lemon (Citrus jambhiri had the lowest LC50 value (200.79ppm, while musambi (C. sinensis var musambi had the highest LC50 value (457.30ppm after 24 h of exposure.Conclusion: Citrus cultivars have some larvicidal potential but C. jambhiri had the greatest potential against A. ae­gypti larvae. Further small-scale field trials using the extracts of C. jambhiri will be conducted to determine opera­tional feasibility.

  1. The chemical defense in larvae of the earwig Forficula auricularia.

    Science.gov (United States)

    Gasch, Tina; Vilcinskas, Andreas

    2014-08-01

    Larvae of the European earwig, Forficula auricularia, possess a paired pygidial gland with yet unknown content and function. We used gas chromatography-mass spectrometry to analyze the larval secretions revealing the presence of 2-methyl-1,4-benzoquinone, 2-ethyl-1,4-benzoquinone, n-tridecane and n-pentadecane. Based on our recent discovery that the morphologically-distinct abdominal glands of adult earwigs produce secretions with antibacterial, antifungal and nematicidal activity, we propose that the pygidial glands mediate chemical defenses in the larvae. We next considered whether the defensive functions of larval secretions include repellent activity against sympatric predators. Therefore, we tested the effects of larval secretions on foraging workers of the ant species Myrmica rubra, the actively hunting spiders Anyphaena accentuata and Philodromus aureolus and the net-hunting spider Pholcus phalangioides in laboratory feeding assays. The secretion is released in response to ant attacks, and discourages feeding in M. rubra, however, it does not discourage feeding in spiders. Our results suggest that earwigs use different glands during ontogenesis to produce secretions that play roles in chemical defense against predators such as ants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Dengue virus detection in Aedes aegypti larvae from southeastern Brazil.

    Science.gov (United States)

    Cecílio, Samyra Giarola; Júnior, Willer Ferreira Silva; Tótola, Antônio Helvécio; de Brito Magalhães, Cíntia Lopes; Ferreira, Jaqueline Maria Siqueira; de Magalhães, José Carlos

    2015-06-01

    The transmission of dengue, the most important arthropod-borne viral disease in Brazil, has been intensified over the past decades, along with the accompanying expansion and adaptation of its Aedes vectors. In the present study, we mapped dengue vectors in Ouro Preto and Ouro Branco, Minas Gerais, by installing ovitraps in 32 public schools. The traps were examined monthly between September, 2011 through July, 2012 and November, 2012 to April, 2013. The larvae were reared until the fourth stadium and identified according to species. The presence of dengue virus was detected by real time PCR and agarose gel electrophoresis. A total of 1,945 eggs was collected during the 17 months of the study. The Ovitrap Positivity Index (OPI) ranged from 0 to 28.13% and the Eggs Density Index (EDI) ranged from 0 to 59.9. The predominant species was Aedes aegypti, with 84.9% of the hatched larvae. Although the collection was low when compared to other ovitraps studies, vertical transmission could be detected. Of the 54 pools, dengue virus was detected in four Ae. aegypti pools. © 2015 The Society for Vector Ecology.

  3. Otolith geochemistry does not reflect dispersal history of clownfish larvae

    KAUST Repository

    Berumen, Michael L.

    2010-07-01

    Natural geochemical signatures in calcified structures are commonly employed to retrospectively estimate dispersal pathways of larval fish and invertebrates. However, the accuracy of the approach is generally untested due to the absence of individuals with known dispersal histories. We used genetic parentage analysis (genotyping) to divide 110 new recruits of the orange clownfish, Amphiprion percula, from Kimbe Island, Papua New Guinea, into two groups: "self-recruiters" spawned by parents on Kimbe Island and "immigrants" that had dispersed from distant reefs (>10 km away). Analysis of daily increments in sagittal otoliths found no significant difference in PLDs or otolith growth rates between self-recruiting and immigrant larvae. We also quantified otolith Sr/Ca and Ba/Ca ratios during the larval phase using laser ablation inductively coupled plasma mass spectrometry. Again, we found no significant differences in larval profiles of either element between self-recruits and immigrants. Our results highlight the need for caution when interpreting otolith dispersal histories based on natural geochemical tags in the absence of water chemistry data or known-origin larvae with which to test the discriminatory ability of natural tags. © 2010 Springer-Verlag.

  4. Sorghum, Miscanthus & Co: Energy crops as potential host plants of western corn rootworm larvae

    Directory of Open Access Journals (Sweden)

    Gloyna, Kai

    2014-02-01

    Full Text Available In a series of greenhouse experiments the host status and quality of 49 biofuel plants for the larvae of WCR were evaluated. The plants tested (18 species and varieties of Sorghum, 16 forage grasses, 6 Miscanthus genotypes, 6 Panicum varieties and 3 broadleaf species were grown for at least three weeks before they were used in the bioassays. The insects used in the experiments were obtained from a non diapausing laboratory strain originally from the US and maintained by BTL since 2006. Only neonate larvae (not older than 24 hours were used in the bioassays. In each experiment up to six species or varieties of plants were tested each with 10 replicates (containers. A susceptible maize variety was used as a positive control in each experiment. Each plant container was infested with ten neonate WCR larvae using a fine art brush. After inoculation the plants were not watered for at least 24 hours to facilitate the establishment of the larvae. The experiments were terminated after 18 days. To extract surviving larvae the soil and roots of test plants were carefully examined by hand and then transferred to a modified MacFadyen heat extractor with an extraction temperature of 45 °C. To assess the host quality the number of larvae recovered, the widths of their head capsules and dry weights were recorded. The larvae were dried at 40 °C for at least 72 hours and then weighed on an electronic micro balance. Of the 21 forage and switch grasses examined 16 hosted WCR larvae. However, the percentage of larvae that survived for 18 days, their dry weights and head capsule widths were significantly less than that recorded for larvae that developed on maize roots. The roots of most (i.e. 15 of the 18 Sorghum species or varieties tested were unsuitable for the development of WCR larvae. For the remaining three Sorghum species a maximum of only two larvae (of 100 inoculated were recovered. These results indicate that species of Sorghum are very poor quality

  5. Resistance to OsHV-1 infection in Crassostrea gigas larvae

    Directory of Open Access Journals (Sweden)

    Lionel eDégremont

    2016-02-01

    Full Text Available The ostreid herpesvirus (OsHV-1 is one of the major diseases that affect the Pacific oyster Crassostrea gigas. Selective breeding programs were recently shown to improve resistance easily to OsHV-1 infections in spat, juvenile and adult oysters. Nevertheless, this resistance has never been investigated in larvae, whereas this developmental stage has crucial importance for the production of commercial hatcheries, as well as explaining the abundance of spatfall. A first trial tested several viral suspensions at several concentrations using contaminated water with OsHV-1 in four-day-old and ten-day-old larvae that were produced from an unselected broodstock. In follow up on the results, one viral suspension at a final concentration of 10+6 OsHV-1 DNA copies per L was used to assess resistance to OsHV-1 infection in C. gigas larvae that were produced from selected and unselected broodstock. A second trial evaluated OsHV-1 resistance in larvae from both broodstocks in trials 2a, 2b and 2c with 4, 10 and 16-day-old larvae for 7 days, which corresponded to post D larvae, umbo larvae and eyed larvae, respectively. The mortality of unchallenged larvae for both stocks were low (<15% at day 7 in trials 2a and 2b, whereas it ranged from 48 to 56% in trial 2c. More interestingly, selected larvae had significantly lower mortality than unselected larvae when exposed to OsHV-1 in all of the trials. Thus, the mortality was 11% and 49% for the selected larvae at day 7 post-exposure in trials 2a and 2c, respectively, in comparison with 84% and 97% for the unselected larvae. Although this difference in mortality was observed at day 5 in trial 2b, it was reduced at day 7, to 86% and 98% for the selected and unselected larvae, respectively. For the first time in the literature, the difference in mortality or the delayed onset of mortality between selected and unselected larvae have indicated a genetic resistance to OsHV-1 infection at the larval stage. Such finding

  6. Temporal and Spatial Distribution Patterns of Echinoderm Larvae in La Parguera, Puerto Rico

    Directory of Open Access Journals (Sweden)

    Stacey M Williams

    2010-10-01

    Full Text Available This study describes temporal and spatial abundance patterns of echinoderm larvae in La Parguera, Puerto Rico. For the temporal study, larvae were sampled by a series of monthly tows taken with a 64μm mesh net between the new and full moon from April 2005 to July 2006, September 2006 and August 2007. In order to measure spatial variation of echinoderm larval bundances, oblique tows were taken with 64 and 202μm mesh nets at seven different sites within the shelf, at the shelf-edge, and at a nearby oceanic stations during August 2007. Overall, Echinoidea (sea urchin exhibited the highest abundance with a total of 11 921 larvae, representing 52.5% of the total collection. Ophiuroidea (brittle star ranked second in abundance with 45.6% of the total larvae. Holothuroidea (sea cucumber and Asteroidea larvae (sea star accounted for less than 2% of the total echinoderm larval collection. Early larval stages (2-8 day old of Diadema antillarum represented 20% of the total Echinoidea larvae. There was no marked seasonal trend of echinoderm larval abundance; Echinoidea and Ophiuroidea larvae were present in all monthly samples indicating that reproduction occurs year-round. Peak abundances of later-stage Echinoidea larvae were observed during January, July and October and of later-stage Ophiuroidea larvae during June, August and October. The observed peaks of later-stage larval abundances may be indicative of higher recruitment activity during these months. There was a significant difference of echinoderm larval abundance between spatial stations, with higher abundances collected at the shelf-edge. Later-stage (~24 day old D. antillarum larvae were mostly collected at shelf-edge and oceanic locations. In addition, the 64mm mesh net was more efficient for collection of echinoderm larvae than the 202mm mesh net. Rev. Biol. Trop. 58 (Suppl. 3: 81-88. Epub 2010 October 01.

  7. Temporal and spatial distribution patterns of echinoderm larvae in La Parguera, Puerto Rico.

    Science.gov (United States)

    Williams, Stacey M; Jorge, García-Sais

    2010-10-01

    This study describes temporal and spatial abundance patterns of echinoderm larvae in La Parguera, Puerto Rico. For the temporal study, larvae were sampled by a series of monthly tows taken with a 64 microm mesh net between the new and full moon from April 2005 to July 2006, September 2006 and August 2007. In order to measure spatial variation of echinoderm larval abundances, oblique tows were taken with 64 and 202 microm mesh nets at seven different sites within the shelf, at the shelf-edge, and at a nearby oceanic stations during August 2007. Overall, Echinoidea (sea urchin) exhibited the highest abundance with a total of 11 921 larvae, representing 52.5% of the total collection. Ophiuroidea (brittle star) ranked second in abundance with 45.6% of the total larvae. Holothuroidea (sea cucumber) and Asteroidea larvae (sea star) accounted for less than 2% of the total echinoderm larval collection. Early larval stages (2-8 day old) of Diadema antillarum represented 20% of the total Echinoidea larvae. There was no marked seasonal trend of echinoderm larval abundance; Echinoidea and Ophiuroidea larvae were present in all monthly samples indicating that reproduction occurs year-round. Peak abundances of later-stage Echinoidea larvae were observed during January, July and October and of later-stage Ophiuroidea larvae during June, August and October. The observed peaks of later-stage larval abundances may be indicative of higher recruitment activity during these months. There was a significant difference of echinoderm larval abundance between spatial stations, with higher abundances collected at the shelf-edge. Later-stage (approximately 24 day old) D. antillarum larvae were mostly collected at shelf-edge and oceanic locations. In addition, the 64 microm mesh net was more efficient for collection of echinoderm larvae than the 202 microm mesh net.

  8. Schinus terebinthifolius Leaf Extract Causes Midgut Damage, Interfering with Survival and Development of Aedes aegypti Larvae.

    Science.gov (United States)

    Procópio, Thamara Figueiredo; Fernandes, Kenner Morais; Pontual, Emmanuel Viana; Ximenes, Rafael Matos; de Oliveira, Aline Rafaella Cardoso; Souza, Carolina de Santana; Melo, Ana Maria Mendonça de Albuquerque; Navarro, Daniela Maria do Amaral Ferraz; Paiva, Patrícia Maria Guedes; Martins, Gustavo Ferreira; Napoleão, Thiago Henrique

    2015-01-01

    In this study, a leaf extract from Schinus terebinthifolius was evaluated for effects on survival, development, and midgut of A. aegypti fourth instar larvae (L4), as well as for toxic effect on Artemia salina. Leaf extract was obtained using 0.15 M NaCl and evaluated for phytochemical composition and lectin activity. Early L4 larvae were incubated with the extract (0.3-1.35%, w/v) for 8 days, in presence or absence of food. Polymeric proanthocyanidins, hydrolysable tannins, heterosid and aglycone flavonoids, cinnamic acid derivatives, traces of steroids, and lectin activity were detected in the extract, which killed the larvae at an LC50 of 0.62% (unfed larvae) and 1.03% (fed larvae). Further, the larvae incubated with the extract reacted by eliminating the gut content. No larvae reached the pupal stage in treatments at concentrations between 0.5% and 1.35%, while in the control (fed larvae), 61.7% of individuals emerged as adults. The extract (1.0%) promoted intense disorganization of larval midgut epithelium, including deformation and hypertrophy of cells, disruption of microvilli, and vacuolization of cytoplasms, affecting digestive, enteroendocrine, regenerative, and proliferating cells. In addition, cells with fragmented DNA were observed. Separation of extract components by solid phase extraction revealed that cinnamic acid derivatives and flavonoids are involved in larvicidal effect of the extract, being the first most efficient in a short time after larvae treatment. The lectin present in the extract was isolated, but did not show deleterious effects on larvae. The extract and cinnamic acid derivatives were toxic to A. salina nauplii, while the flavonoids showed low toxicity. S. terebinthifolius leaf extract caused damage to the midgut of A. aegypti larvae, interfering with survival and development. The larvicidal effect of the extract can be attributed to cinnamic acid derivatives and flavonoids. The data obtained using A. salina indicates that caution

  9. Schinus terebinthifolius Leaf Extract Causes Midgut Damage, Interfering with Survival and Development of Aedes aegypti Larvae.

    Directory of Open Access Journals (Sweden)

    Thamara Figueiredo Procópio

    Full Text Available In this study, a leaf extract from Schinus terebinthifolius was evaluated for effects on survival, development, and midgut of A. aegypti fourth instar larvae (L4, as well as for toxic effect on Artemia salina. Leaf extract was obtained using 0.15 M NaCl and evaluated for phytochemical composition and lectin activity. Early L4 larvae were incubated with the extract (0.3-1.35%, w/v for 8 days, in presence or absence of food. Polymeric proanthocyanidins, hydrolysable tannins, heterosid and aglycone flavonoids, cinnamic acid derivatives, traces of steroids, and lectin activity were detected in the extract, which killed the larvae at an LC50 of 0.62% (unfed larvae and 1.03% (fed larvae. Further, the larvae incubated with the extract reacted by eliminating the gut content. No larvae reached the pupal stage in treatments at concentrations between 0.5% and 1.35%, while in the control (fed larvae, 61.7% of individuals emerged as adults. The extract (1.0% promoted intense disorganization of larval midgut epithelium, including deformation and hypertrophy of cells, disruption of microvilli, and vacuolization of cytoplasms, affecting digestive, enteroendocrine, regenerative, and proliferating cells. In addition, cells with fragmented DNA were observed. Separation of extract components by solid phase extraction revealed that cinnamic acid derivatives and flavonoids are involved in larvicidal effect of the extract, being the first most efficient in a short time after larvae treatment. The lectin present in the extract was isolated, but did not show deleterious effects on larvae. The extract and cinnamic acid derivatives were toxic to A. salina nauplii, while the flavonoids showed low toxicity. S. terebinthifolius leaf extract caused damage to the midgut of A. aegypti larvae, interfering with survival and development. The larvicidal effect of the extract can be attributed to cinnamic acid derivatives and flavonoids. The data obtained using A. salina indicates

  10. Host gut microorganisms' cues mediate orientation behaviour in the larva of the parasitoid Mallophora ruficauda.

    Science.gov (United States)

    Groba, H F; Castelo, M K

    2016-02-01

    The robber fly Mallophora ruficauda is one of the most important apicultural pests in the Pampas region of Argentina. This species is a parasitoid of scarab beetle larvae. Females lay eggs away from the host, and the larvae perform active search behaviour toward Cyclocephala signaticollis third instar larvae, parasitoid's preferred host. This behaviour is mediated by host-related chemical cues produced in hosts' fermentation chamber. Also, C. signaticollis larvae are attracted to fermentation chamber extracts. As scarab larvae have microbe-rich fermentation chamber, it has been suggested that microorganisms could be involved in the production of these semiochemicals. The aims of this work were first to ascertain the presence of microorganisms in the fermentation chamber of C. signaticollis larvae and second to determine the role of microorganisms in the orientation response of parasitoid and host larvae. We found that microorganisms-free C. signaticollis larvae showed deterioration in their development and did not produce the attractive semiochemicals. Therefore, we isolated fermentation chamber microorganisms of host larvae by means of different cultures media, and then, assayed different microorganisms' stimuli by binary choice tests. We were able to isolate microorganisms and determine that M. ruficauda larvae are attracted to semiochemicals from protein degradation in the fermentation chamber. However, C. signaticollis larvae were not attracted to any semiochemicals associated with microorganisms' activity in the fermentation chamber. Although we were unable to elucidate the exact role of gut microorganisms in host behaviour, we discuss their relevance in parasitoid host-seeking behaviour and host conspecific interaction in M. ruficauda-C. signaticollis system.

  11. An unprecedented role reversal: ground beetle larvae (Coleoptera: Carabidae lure amphibians and prey upon them.

    Directory of Open Access Journals (Sweden)

    Gil Wizen

    Full Text Available Amphibians often feed on beetle larvae, including those of ground beetles (Carabidae. Preliminary reports have detailed an unusual trophic interaction in which, in contrast, larvae of the ground beetle Epomis prey upon juvenile and adult amphibians. While it is known that these larvae feed exclusively on amphibians, how the predator-prey encounter occurs to the advantage of the beetle larvae had been unknown to date. Using laboratory observations and controlled experiments, we recorded the feeding behavior of Epomis larvae, as well as the behavior of their amphibian prey. Here we reveal that larvae of two species of Epomis (E. circumscriptus and E. dejeani lure their potential predator, taking advantage of the amphibian's predation behavior. The Epomis larva combines a sit-and-wait strategy with unique movements of its antennae and mandibles to draw the attention of the amphibian to the presence of a potential prey. The intensity of this enticement increases with decreasing distance between the larva and the amphibian. When the amphibian attacks, the larva almost always manages to avoid the predator's protracted tongue, exploiting the opportunity to attach itself to the amphibian's body and initiate feeding. Our findings suggest that the trophic interaction between Epomis larvae and amphibians is one of the only natural cases of obligatory predator-prey role reversal. Moreover, this interaction involves a small insect larva that successfully lures and preys on a larger vertebrate. Such role reversal is exceptional in the animal world, extending our perspective of co-evolution in the arms race between predator and prey, and suggesting that counterattack defense behavior has evolved into predator-prey role reversal.

  12. Vulnerability of the mosquito larvae to the guppies (Poecilia reticulata) in the presence of alternative preys.

    Science.gov (United States)

    Manna, Barnali; Aditya, Gautam; Banerjee, Samir

    2008-09-01

    The predatory potential of the larvivorous fishes can be affected by the presence of alternative preys. In the present study the predation pattern of the sewage dwelling Poecilia reticulata (Peters 1872) on the larvae of Culex quinquefasciatus Say 1823 (Diptera: Culicidae) was evaluated in the presence of alternative preys. The predation of Cx. quinquefasciatus larvae by different size groups of R. reticulata fishes was evaluated. In addition to this, the niche breadth (N) and diet breadth (B) were measured following Manly's selectivity index (Si) as an indicator of variation of such predation pattern in the presence of alternative prey types, like chironomid larvae and tubificid worms. The consumption of IV instar Cx. quinquefasciatus larvae by individual P. reticulata ranged between 65 and 84 in a 3 h feeding period and varied with the size of fish (F2,33 = 34.91; p < 0.001). The selectivity coefficient revealed a significantly low preference for the Cx. quinquefasciatus larvae (0.16, CL: 0.05-0.27; p < 0.05) compared to the chironomid larvae and tubificid worms, when all the three prey types were present. The niche breadth (N) and diet breadth (B) ranged from 0.77 to 0.92 and 0.69 to 0.93, respectively. The total consumption of all the prey types varied with the predator density, but the selectivity index for the mosquito larvae was significantly low in all the instances. P. reticulata can consume a good number of mosquito larvae, with the consumption rate varying with the body size. P. reticulata fishes exhibit low preference for mosquito larvae as prey in the presence of alternative controphic preys like chironomid larvae and tubificid worms. Though establishment and sustenance of P. reticulata in new habitats will be favoured by the presence of alternative preys, but vulnerability of mosquito larvae may be reduced with availability of multiple preys in natural conditions.

  13. Oviposition Behavior in Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in Response to the Presence of Heterospecific and Conspecific Larvae.

    Science.gov (United States)

    Gonzalez, Paula V; González Audino, Paola A; Masuh, Héctor M

    2016-03-01

    In mosquitoes, location of suitable sites for oviposition requires a set of visual, tactile, and olfactory cues that influences females before laying their eggs. The ability of gravid females to distinguish among potential oviposition sites that will or will not support the growth, development, and survival of their progeny is critical. Aedes aegypti (L.) and Aedes albopictus (Skuse) share ecological niches, being highly competitive in larval stage. We studied the oviposition behavior of both species in the presence of larvae of one or the other species (heterospecific or conspecific larvae). The number of eggs laid by gravid females on oviposition sites (water with different or the same species of Aedes larvae) were compared. The presence and density of heterospecific or conspecific larvae had a positive or negative effect on the ovipositional responses, measured as an oviposition activity index. For both species, the oviposition was not affected by heterospecific larvae with densities between 10 and 100 larvae in water, but a strong attractant behavior was observed for a density of 500 larvae in water. For Ae. albopictus in the presence of larvae of the same species (conspecific oviposition), we observed an attractant effect for larvae density of 10 but not for 100 or 500 larvae in water. Instead, for Ae. aegypti, we observed attraction only for 100 larvae, not for 10 or 500 larvae. Results presented here provide an additional insight about oviposition behavior responses of gravid females in the presence of conspecific and heterospecific larvae in breeding sites.

  14. Bifidogenic effect of grain larvae extract on serum lipid, glucose and ...

    Indian Academy of Sciences (India)

    Keywords. Bifidogenic effect; blood lipid; cecal microflora; grain larvae; IgG; organic acid ... grain larvae ethanol extract (GLE) had a bifidogenic effect in normal rats. Male Sprague–Dawley rats were divided into a negative control group (CO) and GLE orally administered (5.0, 7.0 and 9.0 mg/100 g body weight) groups.

  15. Host Recognition Responses of Western (Family: Chrysomelidae) Corn Rootworm Larvae to RNA Interference and Bt Corn.

    Science.gov (United States)

    Zukoff, Sarah N; Zukoff, Anthony L

    2017-01-01

    Western corn rootworm Diabrotica virgifera virgifera LeConte is an important pest of corn whose larvae exhibit particular quantifiable patterns of locomotion after exposure to, and removal from, host roots and nonhost roots. Using EthoVision software, the behavior and locomotion of the western corn rootworm larvae was analyzed to determine the level of host recognition to germinated roots of differing corn hybrids containing either rootworm targeted Bt genes, RNA interference (RNAi) technology, the stack of both Bt and RNAi, or the isoline of these. The behavior of the rootworm larvae indicated a significant host preference response to all corn hybrids (with or without insecticidal traits) compared to the filter paper and oat roots. A weaker host response to the RNAi corn roots was observed in the susceptible larvae when compared to the resistant larvae, but not for the Bt + RNAi vector stack. Additionally, the resistant larvae demonstrated a weaker host response to the isoline corn roots when compared to the susceptible larvae. Although weaker, these host responses were significantly different from those observed in the negative controls, indicating that all hybrids tested do contain the contact cues necessary to elicit a host preference response by both Cry3Bb1-resistant and Cry3Bb1-susceptible larvae that would work to hinder resistance development in refuge in a bag fields. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  16. Morphogenesis of Strongyloides stercoralis infective larvae requires the DAF-16 ortholog FKTF-1.

    Directory of Open Access Journals (Sweden)

    Michelle L Castelletto

    2009-04-01

    Full Text Available Based on metabolic and morphological similarities between infective third-stage larvae of parasitic nematodes and dauer larvae of Caenorhabditis elegans, it is hypothesized that similar genetic mechanisms control the development of these forms. In the parasite Strongyloides stercoralis, FKTF-1 is an ortholog of DAF-16, a forkhead transcription factor that regulates dauer larval development in C. elegans. Using transgenesis, we investigated the role of FKTF-1 in S. stercoralis' infective larval development. In first-stage larvae, GFP-tagged recombinant FKTF-1b localizes to the pharynx and hypodermis, tissues remodeled in infective larvae. Activating and inactivating mutations at predicted AKT phosphorylation sites on FKTF-1b give constitutive cytoplasmic and nuclear localization of the protein, respectively, indicating that its post-translational regulation is similar to other FOXO-class transcription factors. Mutant constructs designed to interfere with endogenous FKTF-1b function altered the intestinal and pharyngeal development of the larvae and resulted in some transgenic larvae failing to arrest in the infective stage. Our findings indicate that FKTF-1b is required for proper morphogenesis of S. stercoralis infective larvae and support the overall hypothesis of similar regulation of dauer development in C. elegans and the formation of infective larvae in parasitic nematodes.

  17. Estimating reproductive success of Aethina tumida (Coleoptera: Nitidulidae) in honey bee colonies by trapping emigrating larvae.

    Science.gov (United States)

    Arbogast, Richard T; Torto, Baldwyn; Willms, Steve; Fombong, Ayuka T; Duehl, Adrian; Teal, Peter E A

    2012-02-01

    The small hive beetle (Aethina tumida Murray) is a scavenger and facultative predator in honey bee colonies, where it feeds on pollen, honey, and bee brood. Although a minor problem in its native Africa, it is an invasive pest of honey bees in the United States and Australia. Adult beetles enter bee hives to oviposit and feed. Larval development occurs within the hive, but mature larvae leave the hive to pupate in soil. The numbers leaving, which can be estimated by trapping, measure the reproductive success of adult beetles in the hive over any given period of time. We describe a trap designed to intercept mature larvae as they reach the end of the bottom board on their way to the ground. Trap efficiency was estimated by releasing groups of 100 larvae into empty brood boxes and counting the numbers trapped. Some larvae escaped, but mean efficiency ranged from 87.2 to 94.2%. We envision the trap as a research tool for study of beetle population dynamics, and we used it to track numbers of larvae leaving active hives for pupation in the soil. The traps detected large increases and then decreases in numbers of larvae leaving colonies that weakened and died. They also detected small numbers of larvae leaving strong European and African colonies, even when no larvae were observed in the hives.

  18. Description of the larvae of Hydroporus ferrugineus Stephens and H-polaris fall (Coleoptera: Adephaga: Dytiscidae)

    NARCIS (Netherlands)

    Alarie, Y.; Wood, P.J.; Bruyn, de A.M.H.; Cuppen, J.G.M.

    2001-01-01

    Description of structures of the larvae of Hydroporus ferrugineus Stephens and H. polaris Fall is provided including detailed chaetotaxal and porotaxal analyses. Larvae of H. ferrugineus are distinguished from all other species of Hydroporus Clairville by the presence of 1–2 secondary setae on

  19. Differential utilization of ash phloem by emerald ash borer larvae: Ash species and larval stage effects

    Science.gov (United States)

    Yigen Chen; Michael D. Ulyshen; Therese M. Poland

    2012-01-01

    Two experiments were performed to determine the extent to which ash species (black, green and white) and larval developmental stage (second, third and fourth instar) affect the efficiency of phloem amino acid utilization by emerald ash borer (EAB) Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) larvae. EAB larvae generally utilized green ash...

  20. Efficacy of Three Funnel Traps for Capturing Amphibian Larvae in Seasonal Forest Ponds

    Science.gov (United States)

    Richard R. Buech; Leanna M. Egeland

    2002-01-01

    Among the many techniques that have been used to study amphibians, funnel traps are commonly recommended to determine species presence, breeding success, and relative abundance of amphibian larvae in aquatic habitats. Several authors have discussed the advantages and disadvantages of funnel traps for sampling amphibian larvae (Adams et al. 1997; Fronzuto and Verrell...

  1. Chemical Composition and Food Potential of Pachymerus nucleorum Larvae Parasitizing Acrocomia aculeata Kernels

    Science.gov (United States)

    Alves, Ariana Vieira; Sanjinez Argandoña, Eliana Janet; Linzmeier, Adelita Maria; Cardoso, Claudia Andrea Lima; Macedo, Maria Lígia Rodrigues

    2016-01-01

    Insect consumption as food is culturally practiced in various regions of the world. In Brazil, there are more than 130 species of edible insects registered, from nine orders, among which stands out the Coleoptera. The larva of the beetle Pachymerus nucleorum Fabricius, 1792, grows into the bocaiuva fruit (Acrocomia aculeata (Jacq.) Lodd. Ex Mart., 1845), which has proven nutritional quality. The aim of this work was to evaluate the nutritional potential of P. nucleorum larvae compared to bocaiuva kernels for human consumption. Proteins were the second largest portion of the larvae nutritional composition (33.13%), with percentage higher than the bocaiuva kernels (14.21%). The larval lipid content (37.87%) was also high, very close to the kernels (44.96%). The fraction corresponding to fatty acids in the oil extracted from the larvae was 40.17% for the saturated and 46.52% for the unsaturated. The antioxidant activity value was 24.3 uM trolox/g of oil extracted from larvae. The larvae tryptic activity was 0.032±0.006 nmol BAPNA/min. Both the larvae and the bocaiuva kernel presented absence of anti-nutritional factors. These results favor the use of P. nucleorum larvae as food, which are a great protein and lipid sources with considerable concentrations of unsaturated fatty acids compared to the bocaiuva kernel. PMID:27031500

  2. Secreted and immunogenic proteins produced by the honey bee bacterial pathogen, Paenibacillus larvae

    Science.gov (United States)

    American Foulbrood is a severe disease affecting larvae of honeybee Apis mellifera, causing significant decrease in the honeybee population, beekeeping industries and agricultural production. In spite of its importance, little is known about the virulence factors secreted by Paenibacillus larvae dur...

  3. The larva of Tricholeon relictus Hölzel & Monserrat, 2002 a synanthropic antlion (Neuroptera, Myrmeleontidae).

    Science.gov (United States)

    Acevedo, Fernando; Badano, Davide; Monserrat, Víctor J

    2014-07-11

    The larva of Tricholeon relictus, a Spanish endemic antlion of Afrotropical affinities, is described and illustrated for the first time also providing a comparison with the only other European member of the tribe Dendroleontini, Dendroleon pantherinus. The larva of this species is synanthropic but probably originally lived in cave-like habitats.

  4. First report of antennular attachment organs in a barnacle nauplius larva

    DEFF Research Database (Denmark)

    Watanabe, H.; Høeg, Jens Thorvald; Chan, B.K.K.

    2008-01-01

    Larvae released from Newmaniverruca albatrossiana were cultured in the laboratory until the cypris stage. The brood size of individuals was low, about 60 larvae per brood. The exact number of instars was not determined. Early instars had the morphology normally seen in lecithotrophic nauplii...

  5. Gregarious settlement in cypris larvae: the effects of cyprid age and assay duration

    NARCIS (Netherlands)

    Head, R.M.; Berntsson, K.M.; Dahlström, M.; Overbeke, J.C.; Thomason, J.C.

    2004-01-01

    Gregarious behaviour of marine larvae is perhaps most clearly associated with finding a suitable habitat in a changeable or restricted environment, or with finding other conspecifics with which to mate. Prior work has shown that in settlement assays using cypris larvae of the barnacle Balanus

  6. Snail Larvae From Turbulent Inlets and the Wavy Continental Shelf Use Different Physical Behavioral Cues

    Science.gov (United States)

    Fuchs, H. L.; Gerbi, G. P.

    2016-02-01

    Dispersing larvae experience hydrodynamic signals from turbulence and waves; these signals vary geographically in their intensity and may cue behaviors enhancing transport to suitable habitats. Turbulence dominates the production of spatial velocity gradients (strain or vorticity), whereas waves often dominate the production of accelerations. Spatial patterns in these two signal types create a potential mechanism for larvae to distinguish or navigate among habitats. We quantified flow-induced behaviors in late-stage larvae of congeneric snails from turbulent coastal inlets (Ilyanassa obsoleta) and from the wavy continental shelf (Ilyanassa trivittata). Larvae were exposed to turbulence and to simpler flows dominated by strain, vorticity, or wave-generated acceleration. Fluid flow and individual larvae were observed simultaneously using infrared, particle-image velocimetry. In turbulence, larvae of both species sank or swam downward more frequently at higher dissipation rates, but the average vertical velocities of I. obsoleta became more negative (downward) than those of I. trivittata. In simpler flows, larvae of I. obsoleta reacted more strongly to vorticity-induced rotation relative to gravity, whereas only I. trivittata exhibited a strong reaction to wave-generated accelerations. Both species reacted to vorticity or acceleration in the absence of large strain rates, indicating that larvae likely sense flow using the statocysts. Although statocysts can sense two signal types, these closely related species responded differently to those signals, suggesting that behavior is attuned to the physical signals that dominate their respective adult habitats.

  7. Young and old honey bee (Apis mellifera) larvae differentially prime the developmental maturation of their caregivers

    Science.gov (United States)

    In eusocial insects daughters rear the offspring of the queen to adulthood. In the honey bee, Apis mellifera, nurses differentially regulate larval nutrition. Among worker-destined larvae, younger instars receive an unrestricted diet paralleling that of queen larvae in protein composition but with r...

  8. Chemically mediated group formation in soil-dwelling larvae and pupae of the beetle Trypoxylus dichotomus

    Science.gov (United States)

    Kojima, Wataru; Ishikawa, Yukio; Takanashi, Takuma

    2014-09-01

    Many insects form groups through interactions among individuals, and these are often mediated by chemical, acoustic, or visual cues and signals. In spite of the diversity of soil-dwelling insects, their aggregation behaviour has not been examined as extensively as that of aboveground species. We investigated the aggregation mechanisms of larvae of the Japanese rhinoceros beetle Trypoxylus dichotomus, which live in groups in humus soil. In two-choice laboratory tests, 2nd- and 3rd-instar larvae gathered at conspecific larvae irrespective of the kinship. The ablation of maxillae, which bear chemosensilla, abolished aggregation behaviour. Intact larvae also exhibited aggregation behaviour towards a larval homogenate. These results suggest that larval aggregation is mediated by chemical cues. We also demonstrated that the mature larvae of T. dichotomus built their pupal cells close to a mesh bag containing a conspecific pupal cell, which indicated that larvae utilize chemical cues emanating from these cells to select the pupation site. Thus, the larvae of T. dichotomus may use chemical cues from the conspecifics in two different contexts, i.e. larval aggregation and pupation site selection. Using conspecific cues, larvae may be able to choose suitable locations for foraging or building pupal cells. The results of the present study highlight the importance of chemical information in belowground ecology.

  9. A strain of Serratia marcescens pathogenic for larvae of Lymantria dispar: Infectivity and mechanisms of pathogenicity

    Science.gov (United States)

    J.D. Podgwaite; B.J. Cosenza

    1976-01-01

    The ED50 of a strain of Serratia marcescens for microinjected instar III and IV gypsy moth larvae was 7.5 and 14.5 viable cells, respectively. Percentage and rate of mortality were found to be highly variable among replicates of the same instar and between instars in free-feeding bioassays. Mortality in second instar larvae...

  10. Software for pattern recognition of the larvae of Aedes aegypti and Aedes albopictus

    OpenAIRE

    São Thiago André Iwersen de; Kupek Emil; Ferreira Neto Joaquim Alves; São Thiago Paulo de Tarso

    2002-01-01

    Software for pattern recognition of the larvae of mosquitoes Aedes aegypti and Aedes albopictus, biological vectors of dengue and yellow fever, has been developed. Rapid field identification of larva using a digital camera linked to a laptop computer equipped with this software may greatly help prevention campaigns.

  11. Software for pattern recognition of the larvae of Aedes aegypti and Aedes albopictus

    Directory of Open Access Journals (Sweden)

    São Thiago André Iwersen de

    2002-01-01

    Full Text Available Software for pattern recognition of the larvae of mosquitoes Aedes aegypti and Aedes albopictus, biological vectors of dengue and yellow fever, has been developed. Rapid field identification of larva using a digital camera linked to a laptop computer equipped with this software may greatly help prevention campaigns.

  12. Software for pattern recognition of the larvae of Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Sao Thiago, André Iwersen de; Kupek, Emil; Ferreira Neto, Joaquim Alves; Sao Thiago, Paulo de Tarso

    2002-01-01

    Software for pattern recognition of the larvae of mosquitoes Aedes aegypti and Aedes albopictus, biological vectors of dengue and yellow fever, has been developed. Rapid field identification of larva using a digital camera linked to a laptop computer equipped with this software may greatly help prevention campaigns.

  13. Surto de larva migrans cutnea em uma creche de belo horizonte, minas gerais (Brasil

    Directory of Open Access Journals (Sweden)

    Walter Dos Santos Lima

    1984-04-01

    Full Text Available O presente trabalho relata a ocorrência de um surto de Larva migrans cutânea, em 17 crianças de uma creche em Belo Horizonte, MG. As crianças adquiriram esta dermatose quando brincavam em uma caixa de areia contaminada com larvas infectantes de ancilostomídeos de cão.

  14. Vertical distribution of small pelagic fish eggs and larvae on the ...

    African Journals Online (AJOL)

    Vertical distributions of anchovy Engraulis encrasicolus and sardine Sardinops sagax eggs and larvae within the upper 50 m of the water column on the eastern Agulhas Bank, South Africa, were examined using discrete depth samples collected with a multiple, opening/closing plankton net. Eggs and larvae of sardine and ...

  15. Acute toxicity of five pesticides to Apis mellifera larvae reared in vitro.

    Science.gov (United States)

    Dai, Pingli; Jack, Cameron J; Mortensen, Ashley N; Ellis, James D

    2017-11-01

    The reported high loss rates of managed honey bee colonies have been attributed to diverse stressors including pesticides. Honey bee larvae can be exposed to pesticides in contaminated nectar, pollen and wax. Due to the difficulties of rearing larvae in vitro, research focusing on adult bee exposure to pesticides is more common than that on larva exposure to pesticides. Herein, we aimed to assess the acute toxicity of five insecticides to honey bee larvae using an improved in vitro rearing method. LC 50 and LD 50 were calculated for larvae at 72 h following a single diet exposure administered when the larvae were 84 ± 12 h old. Solvent control larval mortalities were less than 15% at 72 h. The LC 50 values (mg L -1 ) for each tested pesticide were as follows: amitraz, 494.27; chlorpyrifos, 15.39; coumaphos, 90.01; fluvalinate, 27.69; and imidacloprid, 138.84. The LD 50 values in µg per larva were 14.83 (amitraz), 0.46 (chlorpyrifos), 2.70 (coumaphos), 0.83 (fluvalinate) and 4.17 (imidacloprid). The toxicity of the test pesticides to honey bee larvae from most to least toxic was chlorpyrifos > fluvalinate > coumaphos = imidacloprid > amitraz. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  16. Radiolabeling and autoradiographic tracing of Toxocara canis larvae in male mice

    International Nuclear Information System (INIS)

    Wade, S.E.; Georgi, J.R.

    1987-01-01

    Artificially hatched infective larvae of Toxocara canis were labeled with 75 Se in Medium 199 (Gibco) containing 75 Se-methionine. Male CD-1 mice were infected with radiolabeled larvae by intragastric intubation or by intraperitoneal injection. At intervals of 3-56 days mice were killed and the organs prepared for compressed organ autoradiography. Radioactivity of parasitic larvae showed an exponential decrease with time, reflecting catabolism of label with a biological half life of 26 days (effective half life of 21 days) making possible experiments lasting several months. Total body larva counts, estimated by total body autoradiography, displayed an overall downward trend, but the rate of reduction was probably not constant because no significant positive or negative trends were noted from day 14 onward in the numbers of larvae. The carcass accumulated the greatest number of larvae followed by the central nervous system, liver, and lung in that order. When the numbers of larvae were considered in relationship to the mass of tissue, there were 4 groupings: central nervous system, liver, lung, carcass, and kidney, and genito-urinary organ, pelt, and intestine. No significant difference between intragastric and intraperitoneal administration was observed in the larval distribution after the larvae had left the initial site of deposition

  17. Radiolabeling and autoradiographic tracing of Toxocara canis larvae in male mice

    Energy Technology Data Exchange (ETDEWEB)

    Wade, S.E.; Georgi, J.R.

    1987-02-01

    Artificially hatched infective larvae of Toxocara canis were labeled with /sup 75/Se in Medium 199 (Gibco) containing /sup 75/Se-methionine. Male CD-1 mice were infected with radiolabeled larvae by intragastric intubation or by intraperitoneal injection. At intervals of 3-56 days mice were killed and the organs prepared for compressed organ autoradiography. Radioactivity of parasitic larvae showed an exponential decrease with time, reflecting catabolism of label with a biological half life of 26 days (effective half life of 21 days) making possible experiments lasting several months. Total body larva counts, estimated by total body autoradiography, displayed an overall downward trend, but the rate of reduction was probably not constant because no significant positive or negative trends were noted from day 14 onward in the numbers of larvae. The carcass accumulated the greatest number of larvae followed by the central nervous system, liver, and lung in that order. When the numbers of larvae were considered in relationship to the mass of tissue, there were 4 groupings: central nervous system, liver, lung, carcass, and kidney, and genito-urinary organ, pelt, and intestine. No significant difference between intragastric and intraperitoneal administration was observed in the larval distribution after the larvae had left the initial site of deposition.

  18. Cold hardiness and supercooling capacity in the overwintering larvae of the codling moth, Cydia pomonella.

    Science.gov (United States)

    Khani, Abbas; Moharramipour, Saeid

    2010-01-01

    The codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), a worldwide apple pest, is classified as a freeze-intolerant organism and one of the most cold-tolerant pests. The objectives of this study were to examine the supercooling point of overwintering and non-diapausing larvae of C. pomonella as an index of its cold hardiness, and to assess larval mortality following 24 h exposure to extreme low temperatures ranging from -5 to -25 degrees C. The mean (+/-SE) supercooling point for feeding larvae (third through fifth instars) was -12.4 +/- 1.1 degrees C. The mean supercooling point for cocooned, non-diapausing larvae (i.e., non-feeding stages) decreased as the days that the arvae were cocooned increased and changed between -15.1 +/- 1.2 degrees C for one to two day cocooned arvae and -19.2 +/- 1.8 degrees C for less than five day cocooned larvae. The mean (+/-SE) supercooling point for other non-feeding stages containing pupae and overwintering larvae were -19.9 +/- 1.0 degrees C and -20.2 +/- 0.2 degrees C, respectively. Mean supercooling points of C. pomonella larvae were significantly lower during the winter months than the summer months, and sex had no effect on the supercooling point of C. pomonella larvae. The mortality of larvae increased significantly after individuals were exposed to temperatures below the mean supercooling point of the population. The supercooling point was a good predictor of cold hardiness.

  19. Weight changes and organ pathology in rats given edible larvae of ...

    African Journals Online (AJOL)

    The effects of oral administration of extracts of raw and processed larvae of Cirina forda (Westwood) on morphometry and histo pathology were studied in albino rats. Weights of rats in the control group and in the group that were fed the processed larvae were significantly higher (p<0.05) than those of the group that received ...

  20. Feeding by larvae of intertidal invertebrates: assessing their position in pelagic food webs.

    Science.gov (United States)

    Vargas, Cristian A; Manríquez, Patricio H; Navarrete, Sergio A

    2006-02-01

    One of the leading determinants of the structure and dynamics of marine populations is the rate of arrival of new individuals to local sites. While physical transport processes play major roles in delivering larvae to the shore, these processes become most important after larvae have survived the perils of life in the plankton, where they usually suffer great mortality. The lack of information regarding larval feeding makes it difficult to assess the effects of food supply on larval survival, or the role larvae may play in nearshore food webs. Here, we examine the spectrum of food sizes and food types consumed by the larvae of two intertidal barnacle species and of the predatory gastropod Concholepas concholepas. We conducted replicated experiments in which larvae were exposed to the food size spectrum (phytoplankton, microprotozoan and autotrophic picoplankton) found in nearshore waters in central Chile. Results show that barnacle nauplii and gastropod veligers are omnivorous grazers, incorporating significant fractions of heterotrophs in their diets. In accordance with their feeding mechanisms and body size, barnacle nauplii were able to feed on autotrophic picoplankton (concholepas larvae also consumed picoplankton cells, while competent larvae of this species ingested mostly the largest phytoplankton cells and heterotrophic protozoans. Results suggest that persistent changes in the structure of pelagic food webs can have important effects on the species-specific food availability for invertebrate larvae, which can result in large-scale differences in recruitment rates of a given species, and in the relative recruitment success of the different species that make up benthic communities.

  1. Description of the Larva of a New Species of the Genus Afronurus ...

    African Journals Online (AJOL)

    A new species of Afronurus, A. opa sp. n., (Ephemeroptera: Heptageniidae), from Opa River catchment basin, Nigeria is described from the larval stage. The diagnostic morphological characters of the larva are illustrated and discussed. Keywords: Afronurus opa sp. n. larva, Heptageniidae, Ephemeroptera, Nigeria. Tropical ...

  2. A new species of Luchoelmis Spangler & Staines (Coleoptera: Elmidae) from Argentina and its probable larva.

    Science.gov (United States)

    Archangelsky, Miguel; Brand, Cecilia

    2014-03-19

    A new species of riffle beetle from southwestern Argentina, Luchoelmis kapenkemkensis, is described. Its diagnostic characters are illustrated and the key for the identification the species of the genus is updated. A larva, very likely belonging to this species, is also described and compared to other related larvae.

  3. Genes Expressed Differentially in Hessian Fly Larvae Feeding in Resistant and Susceptible Plants

    Directory of Open Access Journals (Sweden)

    Ming-Shun Chen

    2016-08-01

    Full Text Available The Hessian fly, Mayetiola destructor, is a destructive pest of wheat worldwide and mainly controlled by deploying resistant cultivars. In this study, we investigated the genes that were expressed differentially between larvae in resistant plants and those in susceptible plants through RNA sequencing on the Illumina platform. Informative genes were 11,832, 14,861, 15,708, and 15,071 for the comparisons between larvae in resistant versus susceptible plants for 0.5, 1, 3, and 5 days, respectively, after larvae had reached the feeding site. The transcript abundance corresponding to 5401, 6902, 8457, and 5202 of the informative genes exhibited significant differences (p ≤ 0.05 in the respective paired comparisons. Overall, genes involved in nutrient metabolism, RNA and protein synthesis exhibited lower transcript abundance in larvae from resistant plants, indicating that resistant plants inhibited nutrient metabolism and protein production in larvae. Interestingly, the numbers of cytochrome P450 genes with higher transcript abundance in larvae from resistant plants were comparable to, or higher than those with lower transcript abundance, indicating that toxic chemicals from resistant plants may have played important roles in Hessian fly larval death. Our study also identified several families of genes encoding secreted salivary gland proteins (SSGPs that were expressed at early stage of 1st instar larvae and with more genes with higher transcript abundance in larvae from resistant plants. Those SSGPs are candidate effectors with important roles in plant manipulation.

  4. Notes on the first instar larvae of Ctenophora and Nephrotoma (Diptera, Tipulidae).

    Science.gov (United States)

    Podeniene, Virginija; Naseviciene, Nijole; Podenas, Sigitas

    2014-02-10

    1830 egg-larvae of 7 species belonging to long palped crane flies (Tipulidae): Ctenophora guttata Meigen, Nephrotoma pratensis Linnaeus, N. dorsalis Fabricius, N. scurra Meigen, N. flavescens Linnaeus, N. submaculosa Edwards and N. crocata Linnaeus were obtained from 22 females captured in Lithuania in 2011-2012. It took from five days to more than three weeks for eggs to hatch. Crane flies have four instars of larvae. Second, third and the last instar larvae are very similar, when the first instar or egg-larvae differs radically. Descriptions and illustrations of external morphology, chaetotaxy of abdominal segments, characters of head capsules and last abdominal segments are given for the previously unknown first instar larvae of Ct. guttata, N. crocata, N. dorsalis, N. flavescens, N. pratensis, N. scurra and poorly known N. submaculosa. It was found out that difference of head capsule and last abdominal segment among the first instar larvae of above mentioned species of genus Nephrotoma are more obvious than in last instar. During this study it was found, that such characters as shape of apical teeth of mandible, shape of basal segment of antenna and number of sensillae, shape of hypostomium and arrangement of sensory structures on labrum, differ among egg-larvae of Nephrotoma. It was found, that pads on frontal part of prothorax and shape of lateral plates of egg-larvae labrum of Nephrotoma differ significantly from that of Ctenophora and could be used as genus separating characters. 

  5. A note on the record of Rastrelliger (Mackerel) larvae from the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Peter, K.J.

    from Gulf of Thailand and South China Sea They resemble the larvae of a scombrid relative, the Pacific mackerel Pneumatophorous diego, but differ in having less pigmentation and deeper body The larvae have a fairly stubby body, with 30 myomeres big eyes...

  6. Assessment of Clarias gariepinus as a biological control agent against mosquito larvae.

    Science.gov (United States)

    Chala, Buze; Erko, Berhanu; Animut, Abebe; Degarege, Abraham; Petros, Beyene

    2016-05-31

    The emergence and spread of insecticide resistant mosquitoes renewed interest in investigating the use of larvivorous fish as a biological control agent. The potential of Clarias gariepinus fish in controlling Anopheles arabiensis and culicine larvae was assessed under laboratory and semi-field conditions. Small size (15-20 cm) C. gariepinus fish consumed greater number of mosquito larvae than the large size fish (25-40 cm) in the multivariate regression model (β = 13.36, 95 % CI = 4.57, 22.15). The Anopheles larvae consumed was greater in number than the culicines larvae consumed by the fish (β = 12.10, 95 % CI = 3.31, 20.89). The number of larvae consumed was greater during the night hours than during the light hours (β = 30.06, 95 % CI = 21.27, 38.85). Amount of supplementary fish food did not cause significant differences in the number of mosquito larvae consumed by the fish among different groups. C. gariepinus was observed to feed on mosquito larvae under laboratory and semi-field conditions. C. gariepinus fed on the larvae of An. arabiensis and culicines readily. Hence, it can be used as an alternative mosquito control agent in Ethiopia where the breeding habitats are small and localized.

  7. PENGARUH PAKAN ALAMI Chaetoceros spp. TERHADAP PERKEMBANGAN DAN SINTASAN LARVA UDANG WINDU, Penaeus monodon

    Directory of Open Access Journals (Sweden)

    Samuel Lante

    2015-09-01

    Full Text Available Pakan alami berupa mikroalga merupakan salah satu faktor pendukung dalam keberhasilan usaha pembenihan udang windu, Penaeus monodon. Penelitian ini bertujuan untuk mengetahui jenis pakan alami, Chaetoceros spp., yang dapat meningkatkan pertumbuhan dan sintasan larva udang windu. Penelitian ini menggunakan 15 buah bak fiber berukuran 60 cm x 40 cm x 50 cm dengan volume 120 liter yang disi air sebanyak 100 liter. Kepadatan naupli adalah 90 ekor/liter atau 9.000 ekor/bak dan lima jenis pakan alami Chaetoceros spp. yang diuji yaitu: Chaetoceros simplex, Chaetoceros ceratosporum, Chaetoceros calcitrans, Chaetoceros amami, dan Chaetoceros gracilis. Hasil penelitian menunjukkan bahwa aplikasi kelima jenis pakan alami memberikan laju perkembangan larva yang relatif sama sampai stadia PL-1. Aplikasi Chaetoceros gracilis memberikan sintasan larva udang windu tertinggi yaitu 41,48% dan dengan Chaetoceros simplex memberikan sintasan larva terendah (28,02%. Hasil penelitian ini mengindikasikan bahwa aplikasi Chaetoceros spp. yang berbeda pada pemeliharaan larva berpengaruh terhadap sintasan larva udang windu, namun tidak berpengaruh terhadap laju metamorfosis larva. Aplikasi Chaetoceros gracilis sebagai pakan alami adalah terbaik untuk sintasan larva udang windu.

  8. A preliminary account on the distribution of decapod larvae in the Konkan waters

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.; Nair, S.R.S.

    was the most common species. It was observed that Ratnagiri area (Maharashtra, India) was rich in decapod larvae (40.97%) followed by Rajapur (26.48%). Penaeid larvae were totally absent between Kalbadevi and Pavas during the period of study. Distribution...

  9. Fine structure of selected mouthpart sensory organs of gypsy moth larvae

    Science.gov (United States)

    Vonnie D.C. Shields

    2011-01-01

    Gypsy moth larvae, Lymantria dispar (L.), are major pest defoliators in most of the United States and destroy millions of acres of trees annually. They are highly polyphagous and display a wide host plant preference, feeding on the foliage of hundreds of plants, such as oak, maple, and sweet gum. Lepidopteran larvae, such as the gypsy moth, depend...

  10. Proteomic analysis of skin invasion by blood fluke larvae.

    Directory of Open Access Journals (Sweden)

    Elizabeth Hansell

    2008-07-01

    Full Text Available During invasion of human skin by schistosome blood fluke larvae (cercariae, a multicellular organism breaches the epidermis, basement membrane, and dermal barriers of skin. To better understand the pathobiology of this initial event in schistosome infection, a proteome analysis of human skin was carried out following invasion by cercariae of Schistosoma mansoni.Human skin samples were exposed to cercariae for one-half hour to two hours. Controls were exposed to water used to collect cercariae in an identical manner, and punctured to simulate cercarial tunnels. Fluid from both control and experimental samples was analyzed by LC/MS/MS using a linear ion trap in "triple play" mode. The coexistence of proteins released by cercariae and host skin proteins from epidermis and basement membrane confirmed that cercarial tunnels in skin were sampled. Among the abundant proteins secreted by cercariae was the cercarial protease that has been implicated in degradation of host proteins, secreted proteins proposed to mediate immune invasion by larvae, and proteins implicated in protection of parasites against oxidative stress. Components of the schistosome surface tegument, previously identified with immune serum, were also released. Both lysis and apoptosis of epidermal cells took place during cercarial invasion of the epidermis. Components of lysed epidermal cells, including desmosome proteins which link cells in the stratum granulosum and stratum spinosum, were identified. While macrophage-derived proteins were present, no mast cell or lymphocyte cytokines were identified. There were, however, abundant immunoglobulins, complement factors, and serine protease inhibitors in skin. Control skin samples incubated with water for the same period as experimental samples ensured that invasion-related proteins and host protein fragments were not due to nonspecific degeneration of the skin samples.This analysis identified secreted proteins from invasive larvae that

  11. Anopheles stephensi and Toxorhynchites amboinensis: aseptic rearing of mosquito larvae on cultured cells.

    Science.gov (United States)

    Munderloh, U G; Kurtti, T J; Maramorosch, K

    1982-12-01

    Aseptic larvae of Anopheles stephensi and Toxorhynchites amboinensis were reared on a continuous cell line (RU TAE 12 V) from the mosquito, T. amboinensis, that grew in suspension as multicellular vesicles. Surface-sterilized eggs were hatched in a 24-well plate containing 0.2 ml of Leibovitz's L-15 medium per well and incubated in a humidified atmosphere. Toxorhynchites amboinensis eggs of 36 hr or older were placed singly to assure hatching and avoid cannibalism. Hatching rates were over 80%. All larval instars were maintained in L-15 medium at 28 C with a 12-hr photoperiod. Anopheles stephensi larvae were reared in 25-cm2 tissue culture flasks containing 10 ml of L-15 medium with 30 to 50 first and second instar larvae or 10 third and fourth instar larvae per flask. Toxorhynchites amboinensis larvae remained in the 24-well plate in 1.5 ml of medium through the second instar; third instar larvae were kept in 12-well plates (3 ml of medium per well) and transferred to 25-cm2 flasks (10 ml per flask) when they reached the fourth instar. First and second instar A. stephensi larvae were fed cultured cells once, and third or fourth instar larvae twice a day. Toxorhynchites amboinensis larvae were fed vesicles once during the first 4 days after hatching, and every 1 or 2 days thereafter. Each A. stephensi larva consumed approximately 2 X 10(6) cells, and T. amboinensis larvae 10 times more cells before pupating. Anopheles stephensi pupated after 7 to 8 days and adults emerged during days 9 to 11. Pupation in T. amboinensis began on day 21 after hatching and adults emerged 5 days later. Cell lines isolated from A. stephensi larvae or embryos of the ticks Rhipicephalus sanguineus and Anocentor (Dermacentor) nitens supported only limited growth of A. stephensi larvae. Defibrinated hamster (Mesocricetus auratus) blood, though readily ingested, did not support the growth of A. stephensi whereas larvae reared on blood cells plus T. amboinensis cells showed limited growth.

  12. Effects of pesticides on DNA and protein of shrimp larvae Litopenaeus stylirostris of the California Gulf.

    Science.gov (United States)

    Galindo Reyes, J Guillermo; Leyva, Nancy R; Millan, Olivia A; Lazcano, Guadalupe A

    2002-10-01

    Recently, diverse pathologies and massive mortalities have been presented in shrimp hatcheries located along the California Gulf; therefore, toxic responses of shrimp larvae were used as biomarkers of pesticide pollution, because in this region intensive agriculture is practiced. Shrimp larvae were exposed to DDT, azinphosmethyl, permethrine, parathion, chlorpyrifos, malathion, endosulfan, and carbaryl, in order to determine LC50, DNA adducts and/or breaks, and total protein in larvae. The results indicate reductions in protein and DNA in larvae exposed to these pesticides, and in those exposed to DDT, breaks and/or adducts were registered. It is possible that pesticide pollution is a cause of these problems, because reduction in protein indicates a decrease in larvae growth rate and DNA breaks or adducts have been related to pathologies and carcinogenesis in many aquatic organisms.

  13. Scanning electron microscope observations of brine shrimp larvae from space shuttle experiments

    Science.gov (United States)

    DeBell, L.; Paulsen, A.; Spooner, B.

    1992-01-01

    Brine shrimp are encysted as gastrula stage embryos, and may remain dehydrated and encysted for years without compromising their viability. This aspect of brine shrimp biology is desirable for studying development of animals during space shuttle flight, as cysts placed aboard a spacecraft may be rehydrated at the convenience of an astronaut, guaranteeing that subsequent brine shrimp development occurs only on orbit and not on the pad during launch delays. Brine shrimp cysts placed in 5 ml syringes were rehydrated with salt water and hatched during a 9 day space shuttle mission. Subsequent larvae developed to the 8th larval stage in the sealed syringes. We studied the morphogenesis of the brine shrimp larvae and found the larvae from the space shuttle experiments similar in rate of growth and extent of development, to larvae grown in sealed syringes on the ground. Extensive differentiation and development of embryos and larvae can occur in a microgravity environment.

  14. Uncommon Human Urinary Tract Myiasis Due to Psychoda Sp. Larvae, Kashan, Iran: A Case Report

    Directory of Open Access Journals (Sweden)

    Sima RASTI

    2016-10-01

    Full Text Available Contamination of human and animal body tissues with flies’ larvae and diptera cause myiasis. A 26 yr old female patient refers to Kashan Shahid Beheshti Hospital, central Iran because of urogenital infection, pain in the right part of stomach, smelly and reddish vaginal discharge and frequent urination. In the first checking, urine sample was taken. In the sample, active and alive larvae were seen. The live samples were taken to the Environmental Health Department Lab of Kashan University of Medical Sciences in clean glass jars. In the morphological survey, Psychoda sp larvae were identified. In Iran, this study is the first report of this species of larva that causes urinary myiasis. This fly larva is not carnivore or bloodsucker and feeds on bacterial agents. Observance of personal hygiene especially during defecation and urination is essential to prevent contamination of this type of myiasis.

  15. Cannibalism among Myrmeleon brasiliensis larvae (Návas, 1914 (Neuroptera, Myrmeleontidae

    Directory of Open Access Journals (Sweden)

    Tatiane do Nascimento Lima

    2016-12-01

    Full Text Available Cannibalism is influenced by various intrinsic and extrinsic factors of the population, such as density, population structure, prey availability, habitat structure and famine. These factors acting either independently or in synergy determine the frequency of cannibalism. The aims of the present study were to evaluate the effect of density and food availability on the occurrence of cannibalism among Myrmeleon brasiliensis larvae (Neuroptera, Myrmeleontidae. In the present study, the occurrence of cannibalism among M. brasiliensis larvae was greater in the treatments that simulated an absence of food in situations of both high and low density. The search for food makes a larva move about to forage, thereby increasing the risk of falling into the trap of a neighboring larva. Thus, the cannibalistic behavior of M. brasiliensis larvae may be associated with opportunity rather than a direct attempt to pray on the same species.

  16. Preliminary Results On the Efficacy of Macroalgal Extracts Against Larvae of Aedes albopictus.

    Science.gov (United States)

    Minicante, Simona Armeli; Carlin, Sara; Stocco, Marica; Sfriso, Adriano; Capelli, Gioia; Montarsi, Fabrizio

    2017-12-01

    Activity of ethanolic extracts of the algae Ulva rigida, Asparagopsis taxiformis, Dictyota dichotoma, and Cystoseira barbata, collected along Italian coasts, was tested against larvae of the Asian tiger mosquito ( Aedes albopictus), a vector of pathogens for animals and humans. Tests were carried out using 10 specimens of 3rd-stage larvae per test, following the World Health Organization standard protocol with minor modifications. Among algal extracts, only D. dichotoma was active against the larvae of Ae. albopictus. Ethanolic extracts of that species showed LC 90 (the concentration that kills 90% of larvae) and LC 50 (the concentration that kills 50% of larvae) values at 44.32 and 85.92 mg/liter, respectively. Based on the data obtained, D. dichotoma biometabolic extracts could be potential candidates as larvicide compounds to control Ae. albopictus, encouraging the use of macroalgae as natural resources in integrated vector management strategies.

  17. Behavior on approach to surface prey by larvae of Toxorhynchites amboinensis and T. brevipalpis (Diptera: Culicidae).

    Science.gov (United States)

    Linley, J R

    1995-01-01

    Behavior of Toxorhynchites amboinensis (Doleschall) and Toxorhynchites brevipalpis (Theobald) larvae (starved 48 h) as they approach and capture surface prey is described quantitatively from videotaped records. Of 106 T. amboinensis and 82 T. brevipalpis larvae observed, 84.9 and 97.6%, respectively, responded to the presence of surface prey within 2 min (most Toxorhynchites larvae are able to assess both the angle to surface prey and its distance and that they interpolate this information to optimize the approach path. The degree of refinement in this behavior indicates that it is well adapted to take advantage of the important surface food source in nature. In this phase of their feeding, Toxorhynchites larvae are active hunters and are not entirely the passive ambush predators they have seemed to be from many studies that have used other mosquito larvae as (subsurface) prey.

  18. Irradiation effect of electronic beam on older larvae of Lasioderma serricorne (Fabricius)

    International Nuclear Information System (INIS)

    Chen Yuntang; Guo Dongquan; Zhang Jianwei; Yang Baoan

    2010-01-01

    Cigarette beetle [ Lasioderma serricorne (Fabricius) ] is an important pest of stored tobacco distributing over the world, and it is also one of the most serious pests in the tobacco warehouse. The larvae is the most serious detriment in the four states of cigarette beetle. The objective of this study was to control the damage on tobacco from cigarette beetle. The irradiation effects of electronic beam on the older larvae of cigarette beetle in tobacco were studied. The results showed that the older larvae irradiated by the doses higher than 480 Gy could prevent the development to adults; and no new generation was found after 300 Gy irradiation for older larvae. Thus 300Gy irradiation could prevent the reproduction of cigarette beetle for the older larvae in the tobacco. (authors)

  19. Starvation-Induced Dietary Behaviour in Drosophila melanogaster Larvae and Adults.

    Science.gov (United States)

    Ahmad, Muhammad; Chaudhary, Safee Ullah; Afzal, Ahmed Jawaad; Tariq, Muhammad

    2015-09-24

    Drosophila melanogaster larvae are classified as herbivores and known to feed on non-carnivorous diet under normal conditions. However, when nutritionally challenged these larvae exhibit cannibalistic behaviour by consuming a diet composed of larger conspecifics. Herein, we report that cannibalism in Drosophila larvae is confined not only to scavenging on conspecifics that are larger in size, but also on their eggs. Moreover, such cannibalistic larvae develop as normally as those grown on standard cornmeal medium. When stressed, Drosophila melanogaster larvae can also consume a carnivorous diet derived from carcasses of organisms belonging to diverse taxonomic groups, including Musca domestica, Apis mellifera, and Lycosidae sp. While adults are ill-equipped to devour conspecific carcasses, they selectively oviposit on them and also consume damaged cadavers of conspecifics. Thus, our results suggest that nutritionally stressed Drosophila show distinct as well as unusual feeding behaviours that can be classified as detritivorous, cannibalistic and/or carnivorous.

  20. Infectivity and development of X-irradiated third-stage larvae of Angiostrongylus cantonensis in rats

    International Nuclear Information System (INIS)

    Fujiu, Yoshinori

    1989-01-01

    Angiostrongylus cantonensis third-stage larvae were exposed to less than 10Krad of X-radiation and then given orally to white rats to examine the effects of X-radiation on infectivity and development of the irradiated third-stage larvae and on fecundity of adults developing from the irradiated third-stage larvae. The deleterious effects of X-radiation were observed at relatively lower dosage in the above three parameters. A degree in susceptibility on X-radiation was shown to be radiation-dose-dependent. Comparing to the irradiation of larvae in vitro, the irradiation of larvae in snails caused less deleterious effects at the same dose of X-irradiation. Application of X-radiation to food hygiene was also discussed. (author)

  1. Poisoning symptoms of silkworm larvae, Bombyx mori L. , by the oral application of fluorine compound

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, M.

    1974-04-01

    Physiological damages caused by the oral administration of fluorine in Bombyx mori were investigated. Results obtained are summarized as follows: The alimentary canal of the larvae damaged by the fluorine became light green or light brown containing few mulberry leaves and the larvae were light brown. The growth and molting of the larvae were delayed. When larvae were affected by the fluorine, the increasing rate in body weight declined at first, followed by a reduction in the amount of food ingested, and then their development was prolonged. In chemical analyses, ingested fluorine was mostly retained in alimentary canal, digestive juice and blood, and was seldom found in the integument and the silkgland. From these results, it may be presumed that the death of silkworm larvae, caused by the oral administration of fluorine, can be mainly attributed to physiological damages of the alimentary canal caused by the fluorine toxicity, because a large amount of fluorine is accumulated in the wall of the alimentary canal.

  2. Ultrastructural characteristics of nurse cell-larva complex of four species of Trichinella in several hosts

    Directory of Open Access Journals (Sweden)

    Sacchi L.

    2001-06-01

    Full Text Available The nurse cell-larva complex of nematodes of the genus Trichinella plays an Important role in the survival of the larva in decaying muscles, frequently favouring the transmission of the parasite in extreme environmental conditions. The ultrastructure of the nurse cell-larva complex in muscles from different hosts infected with T. nativa (a walrus and a polar bear, T. spiralis (horses and humans, T. pseudospiralis (a laboratory mouse and T. papuae (a laboratory mouse were examined. Analysis with transmission electron microscope showed that the typical nurse cell structure was present in all examined samples, irrespective of the species of larva, of the presence of a collagen capsule, of the age of infection and of the host species, suggesting that there exists a molecular mechanism that in the first stage of larva invasion is similar for encapsulated and non-encapsulated species.

  3. Occurrence of Paraprionospio sp. (form A) larvae (polychaeta: spionidae) in hypoxic water of an enclosed bay

    Science.gov (United States)

    Yokoyama, Hisashi

    1995-01-01

    Spatial and temporal distribution of larvae of Paraprionospio sp. (form A), an indicator of organic pollution in Japanese coastal waters, was investigated from May 1982 to November 1982 in Kumihama Bay, an area where oxygen-deficient water develops from late spring through autumn. This species has a less opportunistic life history represented by a seasonal peak in recruitment (September-October 1982). Simultaneously with the deoxygenation in May, larvae appeared in the bottom layer and were subsequently found through November almost exclusively in water layers with oxygen levels below 1 mg l -1. Larvae displayed no changes in vertical distribution in a 24-h study conducted in August 1980. These observations indicate that larvae have the ability to tolerate anoxic or hypoxic water throughout their entire development. It is hypothesized that the adaptation of larvae to hypoxic water may explain the high abundances of Paraprionospio sp. (form A) in organically polluted sediments.

  4. Female Fertilization: Effects of Sex-Specific Density and Sex Ratio Determined Experimentally for Colorado Potato Beetles and Drosophila Fruit Flies

    Science.gov (United States)

    Vahl, Wouter K.; Boiteau, Gilles; de Heij, Maaike E.; MacKinley, Pamela D.; Kokko, Hanna

    2013-01-01

    If males and females affect reproduction differentially, understanding and predicting sexual reproduction requires specification of response surfaces, that is, two-dimensional functions that relate reproduction to the (numeric) densities of both sexes. Aiming at rigorous measurement of female per capita fertilization response surfaces, we conducted a multifactorial experiment and reanalyzed an extensive data set. In our experiment, we varied the density of male and female Leptinotarsa decemlineata (Colorado potato beetles) by placing different numbers of the two sexes on enclosed Solanum tuberosum (potato plants) to determine the proportion of females fertilized after 3 or 22 hours. In the reanalysis, we investigated how the short-term fertilization probability of three Drosophila strains (melanogaster ebony, m. sepia, and simulans) depended on adult sex ratio (proportion of males) and total density. The fertilization probability of female Leptinotarsa decemlineata increased logistically with male density, but not with female density. These effects were robust to trial duration. The fertilization probability of female Drosophila increased logistically with both sex ratio and total density. Treatment effects interacted in m. sepia, and simulans. These findings highlight the importance of well-designed, multifactorial experiments and strengthen previous experimental evidence for the relevance of sex-specific densities to understanding and prediction of female fertilization probability. PMID:23593206

  5. Female fertilization: effects of sex-specific density and sex ratio determined experimentally for Colorado potato beetles and Drosophila fruit flies.

    Directory of Open Access Journals (Sweden)

    Wouter K Vahl

    Full Text Available If males and females affect reproduction differentially, understanding and predicting sexual reproduction requires specification of response surfaces, that is, two-dimensional functions that relate reproduction to the (numeric densities of both sexes. Aiming at rigorous measurement of female per capita fertilization response surfaces, we conducted a multifactorial experiment and reanalyzed an extensive data set. In our experiment, we varied the density of male and female Leptinotarsa decemlineata (Colorado potato beetles by placing different numbers of the two sexes on enclosed Solanum tuberosum (potato plants to determine the proportion of females fertilized after 3 or 22 hours. In the reanalysis, we investigated how the short-term fertilization probability of three Drosophila strains (melanogaster ebony, m. sepia, and simulans depended on adult sex ratio (proportion of males and total density. The fertilization probability of female Leptinotarsa decemlineata increased logistically with male density, but not with female density. These effects were robust to trial duration. The fertilization probability of female Drosophila increased logistically with both sex ratio and total density. Treatment effects interacted in m. sepia, and simulans. These findings highlight the importance of well-designed, multifactorial experiments and strengthen previous experimental evidence for the relevance of sex-specific densities to understanding and prediction of female fertilization probability.

  6. Biocidal Compounds from Mentha sp. Essential Oils and Their Structure-Activity Relationships.

    Science.gov (United States)

    Kimbaris, Athanasios C; González-Coloma, Azucena; Andrés, Maria Fe; Vidali, Veroniki P; Polissiou, Moschos G; Santana-Méridas, Omar

    2017-03-01

    Essential oils from Greek Mentha species showed different chemical compositions for two populations of M. pulegium, characterized by piperitone and pulegone. Mentha spicata essential oil was characterized by endocyclic piperitenone epoxide, piperitone epoxide, and carvone. The bioactivities of these essential oils and their components have been tested against insect pests (Leptinotarsa decemlineata, Spodoptera littoralis and Myzus persicae), root-knot nematodes (Meloydogine javanica) and plants (Lactuca sativa, Lolium perenne, Solanum lycopersicum). The structure-activity relationships of these compounds have been studied including semi-synthetic endocyclic trans-carvone epoxide, exocyclic carvone epoxide, a new exocyclic piperitenone epoxide and trans-pulegone epoxide. Leptinotarsa decemlineata feeding was affected by piperitenone and piperitone epoxide. Spodoptera littoralis was affected by piperitone epoxide and pulegone. The strongest nematicidal agent was piperitenone epoxide, followed by piperitone epoxide, piperitenone and carvone. Germination of S. lycopersicum and L. perenne was significantly affected by piperitenone epoxide. This compound and carvone epoxide inhibited L. perenne root and leaf growth. Piperitenone epoxide also inhibited the root growth of S. lycopersicum. The presence of a C(1) epoxide resulted in strong antifeedant, nematicidal and phytotoxic compounds regardless of the C(4) substituent. New natural crop protectants could be developed through appropriate structural modifications in the p-menthane skeleton. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  7. Adaptation to Variance of Stimuli in Drosophila Larva Navigation

    Science.gov (United States)

    Wolk, Jason; Gepner, Ruben; Gershow, Marc

    In order to respond to stimuli that vary over orders of magnitude while also being capable of sensing very small changes, neural systems must be capable of rapidly adapting to the variance of stimuli. We study this adaptation in Drosophila larvae responding to varying visual signals and optogenetically induced fictitious odors using an infrared illuminated arena and custom computer vision software. Larval navigational decisions (when to turn) are modeled as the output a linear-nonlinear Poisson process. The development of the nonlinear turn rate in response to changes in variance is tracked using an adaptive point process filter determining the rate of adaptation to different stimulus profiles. Supported by NIH Grant 1DP2EB022359 and NSF Grant PHY-1455015.

  8. Eggs containing larvae of Enterobius vermicularis in vaginal smear

    Science.gov (United States)

    Shetty, Jyothi B; Kulkarni, Dhanashri V; Prabhu, VL

    2012-01-01

    Enterobius vermicularis also known commonly as pinworm is the most common intestinal parasite. It is a nematode that inhabits the human terminal ileum, colon and appendix. The fertilized female migrates to the perianal area where eggs are deposited but occasionally introduces itself into adjacent orifices, most commonly the female genitourinary tract. Thus the eggs can be seen in the vaginal smear as a result of contamination. We report a case wherein the patient presented with signs and symptoms of vulvovaginitis. In her vaginal smear there were eggs of Enterobius vermicularis which showed a coiled larva within it. In the background there were plenty of acute inflammatory cells. This patient responded favorably to antihelminthics. We report this case to highlight the morphology of the parasite and also to emphasize that such findings should not be neglected. Timely reporting and appropriate treatment of such cases will prevent further complications of this parasite including endometritis, salphingitis and peritonitis. PMID:22438633

  9. Eggs containing larvae of Enterobius vermicularis in vaginal smear

    Directory of Open Access Journals (Sweden)

    Jyothi B Shetty

    2012-01-01

    Full Text Available Enterobius vermicularis also known commonly as pinworm is the most common intestinal parasite. It is a nematode that inhabits the human terminal ileum, colon and appendix. The fertilized female migrates to the perianal area where eggs are deposited but occasionally introduces itself into adjacent orifices, most commonly the female genitourinary tract. Thus the eggs can be seen in the vaginal smear as a result of contamination. We report a case wherein the patient presented with signs and symptoms of vulvovaginitis. In her vaginal smear there were eggs of Enterobius vermicularis which showed a coiled larva within it. In the background there were plenty of acute inflammatory cells. This patient responded favorably to antihelminthics. We report this case to highlight the morphology of the parasite and also to emphasize that such findings should not be neglected. Timely reporting and appropriate treatment of such cases will prevent further complications of this parasite including endometritis, salphingitis and peritonitis.

  10. Evaluation of Lethal Giant Larvae as a Schistosomiasis Vaccine Candidate

    Directory of Open Access Journals (Sweden)

    Yufan Cao

    2016-01-01

    Full Text Available Schistosomiasis is a neglected tropical disease of humans, and it is considered to be the second most devastating parasitic disease after malaria. Eggs produced by normally developed female worms are important in the transmission of the parasite, and they responsible for the pathogenesis of schistosomiasis. The tumor suppressor gene lethal giant larvae (lgl has an essential function in establishing apical-basal cell polarity, cell proliferation, differentiation, and tissue organization. In our earlier study, downregulation of the lgl gene induced a significant reduction in the egg hatching rate of Schistosoma japonicum (Sj eggs. In this study, the Sjlgl gene was used as a vaccine candidate against schistosomiasis, and vaccination achieved and maintained a stable reduction of the egg hatching rate, which is consistent with previous studies, in addition to reducing the worm burden and liver egg burden in some trials.

  11. Morphology and diversity of exocrine glands in lepidopteran larvae.

    Science.gov (United States)

    Vegliante, Francesca; Hasenfuss, Ivar

    2012-01-01

    The morphology of 21 exocrine glands and 13 supposedly exocrine structures recorded for lepidopteran larvae is reviewed. The epitracheal glands, for which a double role (exocrine and endocrine) has been demonstrated, are examined as well. Function is well known for at least 8 glands but completely unknown for 6 glands, for 10 putative glandular structures, and for the exocrine component of the epitracheal glands. Functional studies on the remaining structures are insufficient; in some cases (mandibular gland and adenosma) homologous glands may play a different role depending on the species, and only a few taxa have been examined. The secretions of 13 glandular types have been analyzed chemically. The histology of 11 glands is known at the ultrastructural level, whereas that of 6 glands and 7 putative glandular structures is completely unknown. Comparative anatomical studies of the osmeterium, adenosma, and Verson's glands may yield useful information for phylogenetic reconstructions. Copyright © 2012 by Annual Reviews. All rights reserved.

  12. Digenean larvae parasitizing Ruditapes decussatus (Bivalvia from Tunisianan coasts

    Directory of Open Access Journals (Sweden)

    Dhrif E.

    2015-06-01

    Full Text Available Eleven species of trematode larvae (sporocysts and cercariae of Bucephalus labracis Paggi et Orecchia, 1965 and Cercaria lata Lespes, 1857 and metacercariae of Acanthoparyphium sp. Dietz , 1909, Caecincola parvulus Marshall et Gilbert, 1905, Curtuteria australis Allison, 1979, Gymnophallus fossarum Bartoli, 1965, Gymnophallus rebecqui Bartoli, 1983, Lepocreadium pegorchis Stossich, 1901, Parazoogonus sp. Looss, 1901, Psilostomum brevicolle Creplin, 1829 and Robphildollfusium fractum Rudolphi, 1819 were found in the clam (Ruditapes decussatus from Tunisian coasts. A part from B. labracis and Cercaria lata, the other trematode species were recorded for the first time in Tunisia. The examination of the frequency of recorded parasites reveals some monthly variation. This variation is statistically significant by comparing the sampling sites. These results indicate that more frequent parasites (G. fossarum, Cercaria lata, Curtuteria australis and Acanthoparyphium sp. could be considered as biological indicators making it possible to predict the capture localities of the clams.

  13. Seasonal fluctuation in the distribution of eggs and larvae of flat fishes (Pleuronectiformes - Pisces) in the Cochin Backwater

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, C.B.L.

    Attempts have been made to correlate the abundance of eggs and larvae of flat fishes belonging to families Cynoglossidae and Soleidae with the hydrographical parameters of the environment, particularly the salinity. The eggs and larvae were found...

  14. Impact of ultraviolet-B radiation on planktonic fish larvae: Alteration of the osmoregulatory function

    Energy Technology Data Exchange (ETDEWEB)

    Sucre, Elliott, E-mail: elliott.sucre@univ-montp2.fr [AEO Team (Adaptation Ecophysiologique et Ontogenese), UMR 5119 Ecosym UM2, CNRS, IRD, Ifremer, UM1, Universite Montpellier 2, cc092, Pl. Eugene Bataillon, 34095 Montpellier, Cx 05 (France); Vidussi, Francesca [RESEAUX Team (Reseaux Planctoniques et Changement Environnemental), UMR 5119 Ecosym UM2, CNRS, IRD, Ifremer, UM1, Universite Montpellier 2, cc093, Pl. Eugene Bataillon, 34095 Montpellier, Cx 05 (France); Mostajir, Behzad [RESEAUX Team (Reseaux Planctoniques et Changement Environnemental), UMR 5119 Ecosym UM2, CNRS, IRD, Ifremer, UM1, Universite Montpellier 2, cc093, Pl. Eugene Bataillon, 34095 Montpellier, Cx 05 (France); Centre d' ecologie marine experimentale MEDIMEER (Mediterranean centre for Marine Ecosystem Experimental Research), Universite Montpellier 2-CNRS (UMS 3301), Station Mediterraneenne de l' Environnement Littoral, MEDIMEER, 2 Rue des Chantiers, 34200 Sete (France); Charmantier, Guy; Lorin-Nebel, Catherine [AEO Team (Adaptation Ecophysiologique et Ontogenese), UMR 5119 Ecosym UM2, CNRS, IRD, Ifremer, UM1, Universite Montpellier 2, cc092, Pl. Eugene Bataillon, 34095 Montpellier, Cx 05 (France)

    2012-03-15

    Coastal marine ecosystems are submitted to variations of several abiotic and biotic parameters, some of them related to global change. Among them the ultraviolet-B (UV-B) radiation (UVBR: 280-320 nm) may strongly impact planktonic fish larvae. The consequences of an increase of UVBR on the osmoregulatory function of Dicentrarchus labrax larvae have been investigated in this study. In young larvae of D. labrax, as in other teleosts, osmoregulation depends on tegumentary ion transporting cells, or ionocytes, mainly located on the skin of the trunk and of the yolk sac. As early D. labrax larvae passively drift in the top water column, ionocytes are exposed to solar radiation. The effect of UVBR on larval osmoregulation in seawater was evaluated through nanoosmometric measurements of the blood osmolality after exposure to different UV-B treatments. A loss of osmoregulatory capability occured in larvae after 2 days of low (50 {mu}W cm{sup -2}: 4 h L/20 h D) and medium (80 {mu}W cm{sup -2}: 4 h L/20 h D) UVBR exposure. Compared to control larvae kept in the darkness, a significant increase in blood osmolality, abnormal behavior and high mortalities were detected in larvae exposed to UVBR from 2 days on. At the cellular level, an important decrease in abundance of tegumentary ionocytes and mucous cells was observed after 2 days of exposure to UVBR. In the ionocytes, two major osmoeffectors were immunolocalized, the Na{sup +}/K{sup +}-ATPase and the Na{sup +}/K{sup +}/2Cl{sup -} cotransporter. Compared to controls, the fluorescent immunostaining was lower in UVBR-exposed larvae. We hypothesize that the impaired osmoregulation in UVBR-exposed larvae originates from the lower number of tegumentary ionocytes and mucous cells. This alteration of the osmoregulatory function could negatively impact the survival of young larvae at the surface water exposed to UVBR.

  15. Feeding of Marbled Goby, Oxyeleotris marmorata (Blkr., Larvae in the Two Weeks of Their Early Life

    Directory of Open Access Journals (Sweden)

    Irzal Effendi

    2007-12-01

    Full Text Available ABSTRACTThe experiment was carried out at the Laboratory of Aquaculture System and Technology, Faculty of Fisheries, Institut Pertanian Bogor, Bogor. Factorial arrangement in randomised block design was used in this experiment with two factors: kind of feed and feed density for sand goby, Oxyeleotris marmorata (Blkr. larvae. There were 3 kinds of feed: rotifer, enriched-rotifer, and egg yolk-premix. Rotifer density of 20, 30, and 40 individuals/ml were maintained troughout the experiment. Egg yolk-premix were given per day in equivalent quantity as those rotifers in the treatment. Larvae of 40 individuals/l were kept in the 250 l plastic tanks, filled with 200 l of aerated ground water for 15 days indoor. Larvae fed rotifer showed better survival and growth rate than those fed egg yolk-premix. Increased rotifer density tended to increase survival and growth rate of larvae.Key words :  marbled goby, Oxyeleotris marmorata, larvae, feeding, rotifers ABSTRAKPercobaan ini dilakukan di Kolam Percobaan Babakan, Laboratorium Bogor, Bogor, dan dirancang berbentuk factorial dalam rancangan acak kelompok, dengan faktor: (1 jenis pakan dan (2 kepadatan pakan. Jenis pakan dibedakan menjadi: rotifera, rotifera-diperkaya, dan kuning telur-premiks, sedangkan kepadatan rotifera dibedakan menjadi : 20,30, dan 40 individu/ml, dipertahankan setiap hari. Kuning telur-premiks diberikan kepada larva ikan betutu, Oxyeleotris marmorata setiap hari yang setara dengan bobot rotifera setiap perlakuan, berdasarkan bobot kering keduanya. Larva sebanyak 40 ekor/l dipelihara dalam tangki plastik bervolume 250 l yang diisi air 200 l selama 15 hari dalam ruangan. Larva yang diberi rotifera cenderung memiliki kelangsungan hidup dan pertumbuhan lebih besar daripada kuning telur-premiks. Kepadatan rotifera yang semakin tinggi cenderung dapat meningkatkan kelangsungan hidup dan pertumbuhan larva.Kata kunci :  ikan betutu, Oxyeleotris marmorata, larva, pemberian pakan, rotifera

  16. Composition of agarose substrate affects behavioral output of Drosophila larvae

    Directory of Open Access Journals (Sweden)

    Anthi Aristomenis Apostolopoulou

    2014-01-01

    Full Text Available In the last decade the Drosophila larva has evolved into a simple model organism offering the opportunity to integrate molecular genetics with systems neuroscience. This led to a detailed understanding of the functional neuronal networks for a number of sensory functions and behaviors including olfaction, vision, gustation and learning and memory. Typically, behavioral assays in use exploit simple Petri dish setups with either agarose or agar as a substrate. However, neither the quality nor the concentration of the substrate is generally standardized across these experiments and there is no data available on how larval behavior is affected by such different substrates. Here, we have investigated the effects of different agarose concentrations on several larval behaviors. We demonstrate that agarose concentration is an important parameter, which affects all behaviors tested: preference, feeding, learning and locomotion. Larvae can discriminate between different agarose concentrations, they feed differently on them, they can learn to associate an agarose concentration with an odor stimulus and crawl faster on a substrate of higher agarose concentration. Additionally, we have investigated the effect of agarose concentration on three quinine based behaviors: preference, feeding and learning. We show that in all cases examined the behavioral output changes in an agarose concentration-dependent manner. Our results suggest that comparisons between experiments performed on substrates differing in agarose concentration should be done with caution. It should be taken into consideration that the agarose concentration can affect the behavioral output and thereby the experimental outcomes per se potentially due to an increased escape response on more rigid substrates.

  17. Effects of environmental factors on growth, survival, and metamorphosis of geoduck clam (Panopea japonica A. Adams, 1850 larvae

    Directory of Open Access Journals (Sweden)

    Zhongming Huo

    2017-11-01

    Full Text Available A series of experiments were conducted to evaluate the effects of temperature, salinity, diet, and stocking density on the growth, survival, and metamorphosis of geoduck clam Panopea japonica larvae. The larvae all died at a temperature of 22 °C after day 12, suggesting that the larvae of P. japonica could not survive when the temperature was higher than 22 °C. P. japonica could be incubated at 19 °C for the fast growth, high survival and metamorphosis of larvae. The embryos all died when the salinity was below 25 ppt. The larvae showed poor survival when the salinity was below 25 ppt, with all larvae dying before day 12, suggesting that larvae are sensitive to low salinity. The optimum salinity for the growth, survival and metamorphosis of larvae was 32 ppt. The use of a mixture of Isochrysis galbana and Nitzschia closterium (1:1 as a food source for the P. japonica larvae improved their growth, survival, and metamorphosis. A density of 20 individuals/ml appeared to be optimal for normal D-larvae of Panopea japonica, and 3–9 larvae/ml was optimal for the growth and survival of the P. japonica larvae raised in the hatchery.

  18. Localized search cues in corn roots for western corn rootworm (Coleoptera: Chrysomelidae) larvae.

    Science.gov (United States)

    Bernklau, E J; Bjostad, L B; Meihls, L N; Coudron, T A; Lim, E; Hibbard, B E

    2009-04-01

    Cues that elicit a characteristic localized search behavior by neonate larvae of the western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), were extracted from living corn, Zea mays L., roots with acetone. Larvae were exposed to corn roots or to an acetone extract of corn roots and then transferred into a bioassay arena where their movements were tracked and recorded. After a 5-min exposure to live corn roots, larvae produced highly convoluted tracks that were indicative of a localized search behavior, and these distinctive tracks were also produced by larvae exposed to an acetone extract of corn roots. Larvae exposed to a filter paper control moved in relatively straight paths that were indicative of ranging behavior. Larval tracks were recorded by means of a videocamera and tracking software, and four parameters of movement were used to quantify the tracks: mean turn angle, mean meander, total distance, and maximum distance from origin. For every parameter measured, tracks resulting from exposure to the control were significantly different from tracks resulting from exposure to live corn roots and to all doses of the corn root extract. In a separate experiment, larvae exposed to corn root pieces or corn root juice exhibited the localized search behavior, but larvae exposed to oat root pieces and oat root juice (nonhost) exhibited ranging behavior.

  19. Inclusion of copepod Acartia tonsa nauplii in the feeding of Centropomus undecimalis larvae increases stress resistance

    Directory of Open Access Journals (Sweden)

    Wanessa de Melo-Costa

    2015-09-01

    Full Text Available This research represents the first result of studies of the common snook Centropomus undecimalis larvae from broodstock matured in captivity in Brazil. The aim of this study was to evaluate if the inclusion of Acartia tonsa nauplii improves stress resistance of common snook larvae. The larvae were fed with: rotifers Brachionus plicatilis (10 to 15 mL-1; A. tonsa nauplii (0.25 to 0.5 mL-1 and rotifers (5 to 7.5 mL-1, and A. tonsa nauplii (0.12 to 0.25 mL-1. The average percentage of survival of the treatments was 11.9%. At 20 days of age, larvae were subjected to thermal stress. Subsequently, the stress resistance was evaluated. Common snook larvae fed B. plicatilis+A. tonsa reached a higher weight and length (7.5 ± 0.00 mg and 9.1 ± 0.23 mm, respectively and resisted more heat stress (87.4% than larvae fed other foods, indicating that the feed mixture is satisfactory as a starter diet for larvae of common snook. However, more research is needed to confirm these results.

  20. Pengaruh ukuran tubuh ikan Poecilia reticulata pada daya pemangsaannya terhadap larva Culex quinquefasciatus

    Directory of Open Access Journals (Sweden)

    Noer Moehammadi

    1999-06-01

    Full Text Available The research aimed to know the influence of poecilia reticulata body size, in the feeding capacity on Culex quinquifasciatus larvae. The research was experimental method with Complete Random Design., each treatment with 5 replications. The taken body size of Poecilia reticulata were; 1,50 cm; 2.50 cm; and 3.50 cm. the size of fish €™s body was measured from the tip of snout up to the end of fin (cm. The feeding capacity was determined by subtracting the first amount of larvae which was given the rest of larvae after 24 hours. The result showed that the difference of size of Poecilia reticulate body was significantly different in the feeding capacity on Culex quinquifasciatus larvae. The fish whose body size was 1.50 cm had the lowest feeding capacity by eating 77.2 larvae for average, and the highest one was the fist which body size was 2.50 cm by eating 113.6 larvae for average, subsequently the feeding capacity decrease to the fish which body size was 3.50 cm because of eating 100,6 larvae for 24 hours.

  1. Larvacidal Effect of Imperata Cylindrical Root Decoction against Culex sp. Larvae

    Directory of Open Access Journals (Sweden)

    Afini Tiara Resi

    2014-08-01

    Full Text Available Background: Filariasis is one of the neglected tropical diseases. About 337 of 401 districts in Indonesia are endemic areas for filariasis, especially in Sumatera, Kalimantan, and Papua. Culex sp. is one of the lymphatic filariasis vectors which can be controlled by insecticide, including larvacide. This study was conducted to determine the larvacidal effect of Imperata cylindrical root decoction against Culex sp. larvae. Methods: This study was conducted at the Laboratory of Parasitology, Faculty of Medicine, Universitas Padjadjaran during the period of September to November 2012. The study object was Culex sp. larvae III/IV instars. The design of this study was experimental laboratory using true experimental approach. The larvae were divided into three groups: negative control (distilled water, reference (Abate®, and decoction. The number of larvae in each group was 25 larvae, and the effects were evaluated by the total number of dead larvae in 48 hours under observation. The data were then analyzed by Mann-Whitney test and Probit test. Results: The result of the Mann-Whitney test to compare Imperata cylindrica root decoction treatment to distilled water as control was significant (p<0.05. However, Abate® gave a better result. The Probit test resultwas LC50: 63% and LC90: 489%. Conclusions: Imperata cylindrical root decoction has a larvacidal effect against Culex sp. larvae.

  2. Behaviour of damselfly larvae (Enallagma cyathigerum) (Insecta, Odonata) after long-term exposure to PFOS

    Energy Technology Data Exchange (ETDEWEB)

    Gossum, Hans van [Evolutionary Ecology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: hans.vangossum@ua.ac.be; Bots, Jessica [Evolutionary Ecology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: jessica.bots@ua.ac.be; Snijkers, Tom [Evolutionary Ecology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: tom.snijkers@gmail.com; Meyer, Johan [Research group of Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: izak.meyer@ua.ac.be; Van Wassenbergh, Sam [Laboratory for Functional Morphology, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium)], E-mail: sam.vanwassenbergh@ua.ac.be; De Coen, Wim [Research group of Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)], E-mail: wim.decoen@ua.ac.be; De Bruyn, Luc [Evolutionary Ecology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Research Institute for Nature and Forest, Kliniekstraat 25, 1070 Brussels (Belgium)], E-mail: luc.debruyn@ua.ac.be

    2009-04-15

    Perfluorooctane sulfonic acid (PFOS) is a persistent and ubiquitous environmental contaminant that has been detected in organisms worldwide. Here, we evaluate whether long-term (1 and 4 months) exposure to PFOS contamination affects the behavioural performance of freshwater larvae of the damselfly Enallagma cyathigerum (Insecta: Odonata). Our results show reduced behavioural performance with increasing PFOS concentration. In 1 month exposed larvae, no observed effect concentrations (NOECs) were 100 {mu}g/L for general activity. In 4 months exposed larvae, NOECs were 10 {mu}g/L, for each behavioural trait, except swimming acceleration of male larvae where the NOEC was 100 {mu}g/L. When faced with PFOS concentrations above the NOEC, E. cyathigerum larvae were less active, less capable to escape a simulated predator attack and less efficient in foraging. Together, our results show that damselfly larvae suffer reduced survival-related behavioural performance. - Long-term laboratory exposure to perfluorooctane sulfonic acid decreases behavioural performance of damselfly larvae (Insecta: Odonata)

  3. Effects of nutrition (herbivore vs carnivore) on energy charge and nucleotide composition in Hyas araneus larvae

    Science.gov (United States)

    Harms, J.

    1992-03-01

    Growth rate expressed as dry weight, elemetnal composition (C, N, H), protein content and nucleotide composition (ATP, ADP, AMP, CTP, GTP and UTP) as well as adenosine were measured in laboratory cultured Hyas araneus larvae fed two different diets. One group was fed freshly hatched Artemia sp. nauplii, the other the diatom Odontella (Biddulphia) sinensis. Growth rate was reduced in the O. sinensis-fed group, reaching 20 to 50% of the growth rate of Artemia-fed larvae. In all cases, some further development to the next instar occurred when larvae were fed O. sinensis, although at reduced levels compared to Artemia-fed larvae. The adenylic energy charge was quite similar for the two nutritional conditions tested and therefore does not reflect the reduced growth rate in O. sinensis-fed larvae. The individual nucleotide content was clearly reduced in O. sinensis-fed larvae, reflecting the nutritional conditions already during early developmental periods. These reduced amount of nucleotides in O. sinensis-fed larvae were most obvious when adenylic nucleotide contents were pooled. Pooled adenylic nucleotides were found to be correlated with the individual content of carbon and protein, showing significant differences at both nutritional conditions tested.

  4. Effects of irradiation on the biology of the infective larvae of Toxocara canis in the mouse

    Energy Technology Data Exchange (ETDEWEB)

    Barriga, O.O.; Myser, W.C.

    1987-02-01

    Mice were infected with either 2000 normal or irradiated embryonated eggs of Toxocara canis and the number of larvae in their livers, lungs, brains, and carcasses investigated at 5, 20, and 33 days of infection. Mortality of mice infected with normal eggs was 33% between day 4 and 8 postinfection but there was no mortality among mice infected with irradiated eggs. Irradiation with 60, 90, or 150 kr of X-rays inhibited the migration of larvae from the livers and lungs and their accumulation in brain and carcass in proportion to the irradiation dose. By day 33 of infection, the ratio of larvae in liver and lungs to larvae in brain and carcass was 0.16 in normal mice, 0.42 in 60-kr mice, 0.98 in 90-kr mice, and 23.3 in 150-kr mice. Irradiated larvae, particularly those migrating through the peritoneal cavity, died faster than normal larvae until day 20. Irradiation favored survival after day 20. By days 20 and 33 postinfection the total parasite load was 29% and 8%, respectively, of the administered dose in control mice, 18% and 12% in 60-kr mice, 8% and 4% in 90-kr mice, and 0.9% and 0.3% in 150-kr mice. Irradiation of infective T. canis larvae, then, reduces their pathogenicity, inhibits their migration from liver and lungs, kills some of the parasites during the first 3 weeks of infection, but favors their late survival in the host.

  5. Spatial and temporal distribution of anopheline larvae in two malarious areas in Sucre State, Venezuela.

    Science.gov (United States)

    Berti, J; Zimmerman, R; Amarista, J

    1993-01-01

    The spatial and temporal distribution of anopheline larvae was studied in two coastal malarious areas of Sucre, State, Venezuela. Seven habitat types were sampled in the village of Guayana and eight species of Anopheles were collected. Anopheles aquasalis was the predominant species collected and was most abundant in the brackish marsh habitat (71 larvae per 100 samples). It was most abundant during the rainy season. At the second location, Santa Fé, six habitat types were sampled and four anopheline species were collected. Habitats where An. aquasalis was most abundant were temporary freshwater ponds (34 larvae per 100 samples) and mangroves (10.5 larvae per 100 samples). At this location it was also most abundant in the rainy season. During the dry season it was collected in small numbers in river pools (1.3 larvae per 100 samples) along with large numbers of An. pseudopunctipennis (479 larvae per 100 samples). Larval control could be an important component of the malaria control program because major habitats could be defined and presence and abundance of larvae was limited to specific times of year.

  6. [Effects of fermented cattle dung on the growth and development of Tenebrio molitor larvae].

    Science.gov (United States)

    Zeng, Xiang-Wei; Wang, Xia; Guo, Li-Yue; Zhan, Li-Jie; Bo, Wen-Jing; Li, Zhan; Wu, Guang-Lei; Jiang, Gao-Ming

    2012-07-01

    In order to make use of and industrialize the animal dung from large cattle farms, this paper explored the feasibility of using Tenebrio molitor to digest and utilize cattle dung. Cattle dung was mixed with the conventional feed (65% wheat bran, 30% corn flour, and 5% bean pulp) of T. molitor in definite proportions, and fermented with effective microorganisms (EM). The fermented products containing 60% and 80% of cattle dung (FD1 and FD2, respectively) were selected to feed T. molitor larvae, and the effects of the fermented products on the growth curve, death rate, pupation rate, and antioxidant system of the larvae were compared. Compared with CK (conventional deed), the FD1 made the developmental duration of the larvae prolonged by 10 days and the larvae's death rate upraised somewhat, but made the single larva's total food intake, average body mass, crude fat content, and ratio of unsaturated to saturated fat acids increased by 49%, 28%, 26%, and 32%, respectively (P molitor larvae had weak adaptability to FD2. Our findings suggested that using FD1 to feed the 3rd instar of T. molitor larvae would have good practical prospects in industrializing cattle dung.

  7. PENGOLAHAN SAMPAH ORGANIK PERKOTAAN MENGGUNAKAN LARVA BLACK SOLDIER FLY (Hermetia illucens

    Directory of Open Access Journals (Sweden)

    Lena Monita

    2017-12-01

    Full Text Available Black soldier fly (BSF larvae (Hermetia illucens can be used as insect based municipal organic waste recycling technology. The purpose of this research was to examine the utilization of BSF larvae as bio-processors of organic waste in order to produce compost and nutritious larvae biomass. Larvae feeds as treatments of experiment consist of restaurant organic waste mixed with fish silage 6% as treatment A, restaurant organic waste with dairy blood waste 6% as treatment B, and restaurant organic waste as treatment C. The result of this research showed that the highest larvae growth according to its length, width and body weigth was resulted by treatment B, followed by treatments A and C. Total metamorphic development time from egg to imago was 35 days; comprised of as larvae, prepupa, pupa, and imago for 12-13, 6, 6, and 15 days, respectively. Proximate analysis showed that BSF larvae had protein content 33.31 to 33.88%, and fat content 30.07 to 34.39%. Final solid residues of the three treatments was ranged from 90.3-90.6% after 10-11 days of bio-processing.

  8. Prey preference of Myopopone castanea (hymenoptera: formicidae) toward larvae Oryctes rhinoceros Linn (coleoptera: scarabidae)

    Science.gov (United States)

    Widihastuty; Tobing, M. C.; Marheni; Kuswardani, R. A.

    2018-02-01

    Myopoponecastanea (Hymenoptera: Formicidae) ant is a predator for larvae Oryctes rhinoceros (Coleoptera: Scarabidae) which is a pest on oil palm. These ants are able to prey on all stadia of O. rhinoceros larvae. This study was conducted to determine prey preference of M. castaneatoward its prey O. rhinoceros larvae.. The study was conducted using a Factorial Complete Random Design with two factors (using log and no log) and five replications. Preferences test was done by choice test and no choice test. The results of no choice preference test on the log treatment, M. castaneaprefer preyed on firstinstar larvae of O. rhinoceros (\\bar{X}=2.6 individual) with a preference index was 0.194 and on no log treatment, M. castanea prefer for both first instar larvae and second instarlarvae (\\bar{X}=4.6 individual) with a preference index 0.197. The results of the choice preference test using logs, showed that M. castanea prefer the firstinstar larvae of O. rhinoceros (\\bar{X}=2.6 individual), with a preference index (0.35), and on no log treatment, M. castaneaprefer the second instar larvae(\\bar{X}=1.4 individual) with a preference index 0.189. Both first and secondinstarlarvaeof O. rhinoceros were preferred by predator M. castanea

  9. Delivery of marine larvae to shore requires multiple sequential transport mechanisms.

    Science.gov (United States)

    Pfaff, Maya C; Branch, George M; Fisher, Jennifer L; Hoffmann, Vera; Ellis, Allan G; Largier, John L

    2015-05-01

    Most sedentary marine animals disperse from their place of origin during their initial life stages as larvae. The delivery of planktonic larvae back to coastal adult habitats after weeks or months of offshore development is commonly thought to be stochastic, resulting in large recruitment fluctuations and making predictive understanding of population dynamics difficult. Time series of invertebrate settlement on intertidal shores have been used to infer how various oceanographic processes deliver planktonic larvae ashore. However, the possibility that successful settlement may involve a series of different transport mechanisms, which are sequentially utilized by late-stage larvae, has received little attention. To address this, we monitored both the delivery of mussel and barnacle larvae to inner-shelf moorings positioned 200-1400 m from the shore, and larval settlement in the intertidal adult habitat, at two contrasting sites: a headland forming an upwelling center and a downstream bay. Model selection was employed to determine the most likely scenario(s) of larval onshore transport from four a priori transport mechanisms individually and in combination: (1) upwelling or relaxation/downwelling, (2) tidal motions, (3) diurnal sea breezes, and (4) surface waves. Mussel larvae were delivered to the inner shelf during upwelling in the bay, but during downwelling at the headland, and were further transported to the shore by surface waves at both locales. In contrast, the delivery of barnacle larvae to the inner shelf occurred during relaxation/downwelling events at both sites, and intertidal settlement coincided with spring tides, suggesting a role for internal tides in their onshore transport. Thus, sequential mechanisms appear to be utilized by larvae to get to the shore, involving interactions of regional-scale upwelling/downwelling processes and local-scale tidal and surface-wave processes, which differ among taxa and among sites with different topography. A

  10. Responses of the metabolism of the larvae of Pocillopora damicornis to ocean acidification and warming.

    Directory of Open Access Journals (Sweden)

    Emily B Rivest

    Full Text Available Ocean acidification and warming are expected to threaten the persistence of tropical coral reef ecosystems. As coral reefs face multiple stressors, the distribution and abundance of corals will depend on the successful dispersal and settlement of coral larvae under changing environmental conditions. To explore this scenario, we used metabolic rate, at holobiont and molecular levels, as an index for assessing the physiological plasticity of Pocillopora damicornis larvae from this site to conditions of ocean acidity and warming. Larvae were incubated for 6 hours in seawater containing combinations of CO2 concentration (450 and 950 µatm and temperature (28 and 30°C. Rates of larval oxygen consumption were higher at elevated temperatures. In contrast, high CO2 levels elicited depressed metabolic rates, especially for larvae released later in the spawning period. Rates of citrate synthase, a rate-limiting enzyme in aerobic metabolism, suggested a biochemical limit for increasing oxidative capacity in coral larvae in a warming, acidifying ocean. Biological responses were also compared between larvae released from adult colonies on the same day (cohorts. The metabolic physiology of Pocillopora damicornis larvae varied significantly by day of release. Additionally, we used environmental data collected on a reef in Moorea, French Polynesia to provide information about what adult corals and larvae may currently experience in the field. An autonomous pH sensor provided a continuous time series of pH on the natal fringing reef. In February/March, 2011, pH values averaged 8.075 ± 0.023. Our results suggest that without adaptation or acclimatization, only a portion of naïve Pocillopora damicornis larvae may have suitable metabolic phenotypes for maintaining function and fitness in an end-of-the century ocean.

  11. Variation in brain organization of coral reef fish larvae according to life history traits.

    Science.gov (United States)

    Lecchini, David; Lecellier, Gael; Lanyon, Rynae Greta; Holles, Sophie; Poucet, Bruno; Duran, Emilio

    2014-01-01

    In coral reefs, one of the great mysteries of teleost fish ecology is how larvae locate the relatively rare patches of habitat to which they recruit. The recruitment of fish larvae to a reef, after a pelagic phase lasting between 10 and 120 days, depends strongly on larval ability to swim and detect predators, prey and suitable habitat via sensory cues. However, no information is available about the relationship between brain organization in fish larvae and their sensory and swimming abilities at recruitment. For the first time, we explore the structural diversity of brain organization (comparative sizes of brain subdivisions: telencephalon, mesencephalon, cerebellum, vagal lobe and inferior lobe) among larvae of 25 coral reef fish species. We then investigate links between variation in brain organization and life history traits (swimming ability, pelagic larval duration, social behavior, diel activity and cue use relying on sensory perception). After accounting for phylogeny with independent contrasts, we found that brain organization covaried with some life history traits: (1) fish larvae with good swimming ability (>20 cm/s), a long pelagic duration (>30 days), diurnal activity and strong use of cues relying on sensory perception for detection of recruitment habitat had a larger cerebellum than other species. (2) Fish larvae with a short pelagic duration (fish larvae exhibiting solitary behavior during their oceanic phase had larger inferior and vagal lobes. Overall, we hypothesize that a well-developed cerebellum may allow fish larvae to improve their chances of successful recruitment after a long pelagic phase in the ocean. Our study is the first one to bring together quantitative information on brain organization and the relative development of major brain subdivisions across coral reef fish larvae, and more specifically to address the way in which this variation correlates with the recruitment process.

  12. Color variability and body size of larvae of two Epomis species (Coleoptera: Carabidae in Israel

    Directory of Open Access Journals (Sweden)

    Gil Wizen

    2011-07-01

    Full Text Available Species identification using the characteristics of developmental stages is challenging. However, for insect taxonomy the coloration of larval stages can be an informative feature. The use of live specimens is recommended for this because the color fades in preserved specimens. In this study we examine the possibility of using variation in coloration and color pattern of larvae in order to distinguish between two ground beetles species Epomis dejeani Dejean, 1831 and E. circumscriptus Duftschmid, 1812. We present an atlas and describe the coloration and body size of the three larval stages of the above species based on live specimens. The first instar larvae of the two Epomis species can be easily distinguished based on their color. From the second instar on, the variability in coloration and color patterns increases, creating an overlap in these attributes between larvae of the two species. Except for minor differences in color of the antennae and the base of the mandibles, larvae of the two species are indistinguishable at the second and third larval stages. To the best of our knowledge this is the first attempt to use variation in coloration and color pattern in live larvae in order to identify coleopterans. The color atlas of the larvae enables simple separation of the two Epomis species without requiring sophisticated magnifying devices, although it is less straightforward at the second and third larval stages. We found similar body lengths between the two species for all developmental stages, except for third instar larvae prior to pupation. In the two species the difference in larval body length before pupation positively correlated with that of the adult beetles. More than 70% of the adults' length can be explained by the length of the late third-instar larva; i.e. the large larvae develop into large adults. The larger specimens are the females.

  13. Cold Hardiness of Overwintering Larvae of Sphenoptera sp. (Coleoptera: Buprestidae) in Western China.

    Science.gov (United States)

    Feng, Yuqian; Zhang, Lu; Li, Wenbo; Yang, Xuan; Zong, Shixiang

    2018-02-09

    An undetermined species of Sphenoptera sp. is an important pest of Artemisia ordosica Krasch, and recently, an outbreak of this insect has spread throughout Ningxia, Inner Mongolia, Shanxi, and other regions in western China. The cold hardiness of overwintering larvae of Sphenoptera sp. was determined by measuring their supercooling point (SCP) and their mortality at sub-zero temperatures. Additionally, quantitative changes in sugars and low molecular weight sugar alcohols in larvae were determined following exposure of larvae to low temperatures. Mean SCP of overwintering larvae (i.e., collected in January) was -30.2 ± 0.60°C. The mortality rate of larvae approached 100% at -30°C, whereas mortality rates of larvae in the higher temperature treatments were generally less than 25%. Five sugars and sugar alcohols (i.e., glycerol, fructose, glucose, inositol, and trehalose) were detected in larvae. When larvae were exposed to low temperatures for 4 h, inositol, trehalose and total content was generally higher at the highest incubation temperature (-10°C) than at lower incubation temperatures. Following a longer exposure (30 d), content of fructose, glucose, trehalose and total content generally increased with decreasing temperature down to -25°C. Thus it appears that Sphenoptera sp. larvae are freeze avoidant, and their cold hardiness may be achieved by accumulation low molecular weight sugars and sugar alcohols. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. PENGARUH AKTIVITAS ANTROPOGENIK DI SUNGAI CILIWUNG TERHADAP KOMUNITAS LARVA TRICHOPTERA (Effect of Anthropogenic Activities on Trichoptera Larvae Community in Ciliwung River

    Directory of Open Access Journals (Sweden)

    Jojok Sudarso

    2013-03-01

    Full Text Available ABSTRAK Sungai Ciliwung merupakan salah satu sungai besar di Propinsi Jawa Barat yang sekarang telah mengalami pencemaran organik dan kontaminasi oleh logam merkuri. Adanya pencemaran di Sungai Ciliwung dikhawatirkan dapat mengganggu keseimbangan ekologi dari larva serangga Trichoptera. Oleh sebab itu tujuan dari penelitian ini adalah mengungkap pengaruh aktivitas antropogenik pada Sungai Ciliwung terhadap komunitas larva Trichoptera. Pengambilan larva dilakukan dengan menggunakan jala surber dengan limakali ulangan setiap lokasi. Analisis korelasi pearson-product moment menunjukkan adanya korelasi yang kuat (r > 0,5 antara metrik biologi jumlah taksa, jumlah skor Stream Invertebrate Grade Number-Average level SIGNAL, % kelimpahan dominansi 3, dan indeks SIGNAL dengan variabel lingkungan: suhu air, coarse particulate organic matter (CPOM, kandungan oksigen terlarut (DO, konduktivitas, total padatan tersuspensi (TDS, C dan N dalam partikulat, nitrat, amonium, ortofosfat, COD, logam merkuri di air dan sedimen, indeks habitat, distribusi partikel, turbiditas, indeks kimia Kirchoff, dan indeks pencemaran logam merkuri di sedimen. Larva Trichoptera Helicopsyche, Apsilochorema, Caenota, Ulmerochorema, Chimarra, Antipodoecia, Diplectrona, Anisocentropus, Lepidostoma, Genus Hel.C cenderung dicirikan oleh tingkat pencemaran organik yang rendah, tingginya komposisi % kerikil dan CPOM, dan kondisi habitat yang minim mengalami gangguan. Sebaliknya Glososomatidae genus 1, Cheumatopsyche, Setodes, dan Tinodes cenderung lebih toleran terhadap polutan organik, rendahnya CPOM, tingginya variabel turbiditas, konsentrasi merkuri di sedimen, TDS, dan % clay.     ABSTRACT Ciliwung River is one of the major rivers in the area of West Java which is influenced by organic pollution and mercury contamination. The contamination may disrupt the ecological balance of Trichoptera insect larvae. Therefore, the aim of this study is to reveal the influence of anthropogenic

  15. Identification of entomopathogenic Bacillus isolated from Simulium (Diptera, Simuliidae larvae and adults

    Directory of Open Access Journals (Sweden)

    Cavados CFG

    2001-01-01

    Full Text Available Entomopathogenic bacteria isolated from Simulium larvae and adults from breeding sites in the states of São Paulo and Rio de Janeiro, Brazil, were identified as 18 strains of Bacillus thuringiensis and one of B. sphaericus. Most of these strains were serotyped according to their flagellar antigens. However, nine of the B. thuringiensis samples, could not be serotyped and were designated as "autoagglutinating"; they were also shown to be toxic in preliminary tests against Aedes aegypti larvae. Additionally, B. sphaericus was also shown to be toxic towards Culex quinquefasciatus larvae.

  16. A new mutant, White larva, of the mosquito Toxorhynchites splendens: genetics and cannibalism.

    Science.gov (United States)

    Horio, M; Tsukamoto, M; Miyagi, I

    1990-09-01

    A strain of a new body-color mutant, white larva (wl), was established from a field-collected wild-type strain of Toxorhynchites splendens. The mutant can be distinguished from the wild type in both the larval and pupal stages, but not in the adult. Crossing experiments confirmed its mode of inheritance to be a single recessive system. This is the first visible mutant found in Tx. splendens. Larvae of the wl phenotype seem to be recognized as prey by other individuals in mass larvae rearing.

  17. Mortality in hibernating turnip moth larvae, Agrotis segetum, caused by Tolypocladium cylindrosporum

    DEFF Research Database (Denmark)

    Steenberg, Tove; Øgaard, Leif

    2000-01-01

    At one sampling site an entomopathogenic fungus, tentatively identified as Tolypocladium cylindrosporum, was found to severely reduce populations of hibernating turnip moth larvae (Agrotis segetum) in consecutive winters, while it was never recorded from other collection sites. It produced...... mouldy smell. The infectivity of the fungus was tested in a semi-field trial, where suspensions of conidia were applied to hibernating turnip moth larvae in plastic buckets. The experiment also included buckets with larvae and/or soil from the infested site in order to study the natural fungal...... studies with 10 insect species indicated that the fungus is probably specific to hibernating cutworms....

  18. Description of larvae of genera Stenelmis, Ordobrevia and Nomuraelmis (Coleoptera: Elmidae: Elminae) of Japan with their molecular taxonomy.

    Science.gov (United States)

    Hayashi, Masakazu; Kamite, Yuuki; Kobayashi, Takuya; Sota, Teiji

    2016-10-26

    Larvae of 10 elmid species of the genera Stenelmis, Ordobrevia and Nomuraelmis were described based on SEM observation. Of these, S. hisamatsui, S. ishiharai, S. hayashii, O. amamiensis were described for the first time, and N. amamiensis was redescribed. The morphological types of the larvae corresponded to the monophyletic groups defined by the mitochondrial COI gene tree. A new key for larvae of all species from Japan with known larva is given. The larvae of the type species of Stenelmis and Ordobrevia are also described.

  19. Modulation of nutrient composition of black soldier fly (Hermetia illucens larvae by feeding seaweed-enriched media.

    Directory of Open Access Journals (Sweden)

    Nina S Liland

    Full Text Available Black soldier fly (Hermetia illucens larvae are a promising source of protein and lipid for animal feeds. The nutritional composition of the BSF larvae depend partly on the composition of the feeding medium. The BSF lipid profile in part mimics the feeding media lipid profile, and micronutrients, like minerals and vitamins, can readily accumulate in black soldier fly larvae. However, investigative studies on bioconversion and accumulation of nutrients from media to black soldier fly larvae are scarce. Here we show that inclusion of the brown algae Ascophyllum nodosum in the substrate for black soldier fly larvae can introduce valuable nutrients, commonly associated with the marine environment, into the larvae. The omega-3 fatty acid eicosapentaenoic acid (20:5n-3, iodine and vitamin E concentrations increased in the larvae when more seaweed was included in the diet. When the feeding media consisted of more than 50% seaweed, the larvae experienced poorer growth, lower nutrient retention and lower lipid levels, compared to a pure plant based feeding medium. Our results confirm the plasticity of the nutritional make-up of black soldier fly larvae, allowing it to accumulate both lipid- and water-soluble compounds. A broader understanding of the effect of the composition of the feeding media on the larvae composition can help to tailor black soldier fly larvae into a nutrient profile more suited for specific feed or food purposes.

  20. Modulation of nutrient composition of black soldier fly (Hermetia illucens) larvae by feeding seaweed-enriched media.

    Science.gov (United States)

    Liland, Nina S; Biancarosa, Irene; Araujo, Pedro; Biemans, Daan; Bruckner, Christian G; Waagbø, Rune; Torstensen, Bente E; Lock, Erik-Jan

    2017-01-01

    Black soldier fly (Hermetia illucens) larvae are a promising source of protein and lipid for animal feeds. The nutritional composition of the BSF larvae depend partly on the composition of the feeding medium. The BSF lipid profile in part mimics the feeding media lipid profile, and micronutrients, like minerals and vitamins, can readily accumulate in black soldier fly larvae. However, investigative studies on bioconversion and accumulation of nutrients from media to black soldier fly larvae are scarce. Here we show that inclusion of the brown algae Ascophyllum nodosum in the substrate for black soldier fly larvae can introduce valuable nutrients, commonly associated with the marine environment, into the larvae. The omega-3 fatty acid eicosapentaenoic acid (20:5n-3), iodine and vitamin E concentrations increased in the larvae when more seaweed was included in the diet. When the feeding media consisted of more than 50% seaweed, the larvae experienced poorer growth, lower nutrient retention and lower lipid levels, compared to a pure plant based feeding medium. Our results confirm the plasticity of the nutritional make-up of black soldier fly larvae, allowing it to accumulate both lipid- and water-soluble compounds. A broader understanding of the effect of the composition of the feeding media on the larvae composition can help to tailor black soldier fly larvae into a nutrient profile more suited for specific feed or food purposes.

  1. Cultures of skin fragments of Salamandra salamandra salamandra (L.) larvae.

    Science.gov (United States)

    Pederzoli, A; Restani, C

    1998-04-01

    As part of a study on the pigmentary system of Salamandra salamandra salamandra (L.), we cultured skin fragments of 7-10-day-old larvae in order to examine the expression of molecules implicated in cellular adhesion and migration and in regulating cell-cell relationships. Keratinocytes, fibroblasts, Leydig cells, xanthophores, and melanophores migrated from the fragments and were observed in the outgrowth. Keratinocytes and fibroblasts organized into an epidermal layer and an underlying "dermal portion." The chromatophores were always located below the epithelial cells, often with fibroblasts. We examined by immunocytochemistry the expression of fibronectin, beta1-integrin, L-CAM, and A-CAM in the cultures. Many keratinocytes, fibroblasts, and Leydig cells expressed all the signal molecules tested. Xanthophores and melanophores were only immunoreactive to the anti-adhesion molecules antisera. Since the molecules tested are known to play a role in cell adhesion, growth, and spreading, as well as in regulating tissue differentiation and in maintaining normal tissue morphology, we may hypothesize that in Salamandra salamandra salamandra fibronectin, beta1-integrin, L-, and A-CAMs concertedly act to stabilize the architecture of the outgrowth and regulate the relationships between chromatophores and those between chromatophores and the other elements of the skin culture.

  2. Synergistic activity of Bacillus thuringiensis toxins against Simulium spp. larvae.

    Science.gov (United States)

    Monnerat, Rose; Pereira, Eleny; Teles, Beatriz; Martins, Erica; Praça, Lilian; Queiroz, Paulo; Soberon, Mario; Bravo, Alejandra; Ramos, Felipe; Soares, Carlos Marcelo

    2014-09-01

    Species of Simulium spread diseases in humans and animals such as onchocerciasis and mansonelosis, causing health problems and economic loses. One alternative for controlling these insects is the use of Bacillus thuringiensis serovar israelensis (Bti). This bacterium produces different dipteran-active Cry and Cyt toxins and has been widely used in blackfly biological control programs worldwide. Studies on other insect targets have revealed the role of individual Cry and Cyt proteins in toxicity and demonstrated a synergistic effect among them. However, the insecticidal activity and interactions of these proteins against Simulium larvae have not been reported. In this study we demonstrate that Cry4Ba is the most effective toxin followed by Cry4Aa and Cry11Aa. Cry10Aa and Cyt1Aa were not toxic when administered alone but both were able to synergise the activity of Cry4B and Cry11Aa toxins. Cyt1Aa is also able to synergise with Cry4Aa. The mixture of all toxin-producing strains showed the greatest level of synergism, but still lower than the Bti parental strain. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Architecture of the primary taste center of Drosophila melanogaster larvae.

    Science.gov (United States)

    Colomb, Julien; Grillenzoni, Nicola; Ramaekers, Ariane; Stocker, Reinhard F

    2007-06-10

    A simple nervous system combined with stereotypic behavioral responses to tastants, together with powerful genetic and molecular tools, have turned Drosophila larvae into a very promising model for studying gustatory coding. Using the Gal4/UAS system and confocal microscopy for visualizing gustatory afferents, we provide a description of the primary taste center in the larval central nervous system. Essentially, gustatory receptor neurons target different areas of the subesophageal ganglion (SOG), depending on their segmental and sensory organ origin. We define two major and two smaller subregions in the SOG. One of the major areas is a target of pharyngeal sensilla, the other one receives inputs from both internal and external sensilla. In addition to such spatial organization of the taste center, circumstantial evidence suggests a subtle functional organization: aversive and attractive stimuli might be processed in the anterior and posterior part of the SOG, respectively. Our results also suggest less coexpression of gustatory receptors than proposed in prior studies. Finally, projections of putative second-order taste neurons seem to cover large areas of the SOG. These neurons may thus receive multiple gustatory inputs. This suggests broad sensitivity of secondary taste neurons, reminiscent of the situation in mammals.

  4. Toxic effects of silica nanoparticles on zebrafish embryos and larvae.

    Directory of Open Access Journals (Sweden)

    Junchao Duan

    Full Text Available Silica nanoparticles (SiNPs have been widely used in biomedical and biotechnological applications. Environmental exposure to nanomaterials is inevitable as they become part of our daily life. Therefore, it is necessary to investigate the possible toxic effects of SiNPs exposure. In this study, zebrafish embryos were treated with SiNPs (25, 50, 100, 200 µg/mL during 4-96 hours post fertilization (hpf. Mortality, hatching rate, malformation and whole-embryo cellular death were detected. We also measured the larval behavior to analyze whether SiNPs had adverse effects on larvae locomotor activity. The results showed that as the exposure dosages increasing, the hatching rate of zebrafish embryos was decreased while the mortality and cell death were increased. Exposure to SiNPs caused embryonic malformations, including pericardial edema, yolk sac edema, tail and head malformation. The larval behavior testing showed that the total swimming distance was decreased in a dose-dependent manner. The lower dose (25 and 50 µg/mL SiNPs produced substantial hyperactivity while the higher doses (100 and 200 µg/mL SiNPs elicited remarkably hypoactivity in dark periods. In summary, our data indicated that SiNPs caused embryonic developmental toxicity, resulted in persistent effects on larval behavior.

  5. Development of Connectivity in a Motoneuronal Network in Drosophila Larvae

    Science.gov (United States)

    Couton, Louise; Mauss, Alex S.; Yunusov, Temur; Diegelmann, Soeren; Evers, Jan Felix; Landgraf, Matthias

    2015-01-01

    Summary Background Much of our understanding of how neural networks develop is based on studies of sensory systems, revealing often highly stereotyped patterns of connections, particularly as these diverge from the presynaptic terminals of sensory neurons. We know considerably less about the wiring strategies of motor networks, where connections converge onto the dendrites of motoneurons. Here, we investigated patterns of synaptic connections between identified motoneurons with sensory neurons and interneurons in the motor network of the Drosophila larva and how these change as it develops. Results We find that as animals grow, motoneurons increase the number of synapses with existing presynaptic partners. Different motoneurons form characteristic cell-type-specific patterns of connections. At the same time, there is considerable variability in the number of synapses formed on motoneuron dendrites, which contrasts with the stereotypy reported for presynaptic terminals of sensory neurons. Where two motoneurons of the same cell type contact a common interneuron partner, each postsynaptic cell can arrive at a different connectivity outcome. Experimentally changing the positioning of motoneuron dendrites shows that the geography of dendritic arbors in relation to presynaptic partner terminals is an important determinant in shaping patterns of connectivity. Conclusions In the Drosophila larval motor network, the sets of connections that form between identified neurons manifest an unexpected level of variability. Synapse number and the likelihood of forming connections appear to be regulated on a cell-by-cell basis, determined primarily by the postsynaptic dendrites of motoneuron terminals. PMID:25702582

  6. MRI findings of spinal visceral larva migrans of Toxocara canis

    International Nuclear Information System (INIS)

    Lee, In Ho; Kim, Sung Tae; Oh, Dae Kun; Kim, Hyung-Jin; Kim, Keon Ha; Jeon, Pyoung; Byun, Hong Sik

    2010-01-01

    Purpose: The purpose of this study is to investigate the MRI findings of visceral larva migrans (VLS) of Toxocara canis in spinal cord. Materials and methods: We retrospectively reviewed spinal MRI findings in eight patients with serologically proven Toxocara canis between 2005 and 2008. We evaluated the location, length, extent and migration of the lesion, MR signal intensity (SI), enhancement pattern, and swelling of the spinal cord. We evaluated clinical features including presenting symptoms and signs and treatment response. Results: Total 8 patients (M = 8; age range 36-79 years) were included. The lesions were located in the cervical or thoracic spinal cord in all patients. All lesions showed high SI and minimal or mild swelling of involved spinal cord on T2WI and focal nodular enhancement on posterior or posterolateral segment of spinal cord. The length of involved lesion was relatively short in most patients. There was a migration of lesion in one patient. In spite of albendazole or steroid treatment, neurological symptoms or signs were not significantly improved in all patients. Conclusion: Although all lesions show non-specific imaging findings like non-tumorous myelopathy mimicking transverse myelitis, single lesion, focal nodular enhancement on posterior or posterolateral segment of spinal cord, relatively short segmental involvement and migration of lesion may be characteristic findings of spinal VLM of Toxocara canis. In addition, the reluctant response to the treatment may be characteristic of spinal VLM of Toxocara canis.

  7. MRI findings of spinal visceral larva migrans of Toxocara canis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In Ho, E-mail: leeinho1974@hanmail.ne [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Department of Radiology, Chungnam National University Hospital, 33 Munhwa-ro, Jung-gu, Daejeon 301-721 (Korea, Republic of); Kim, Sung Tae, E-mail: st7.kim@hotmail.co [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Oh, Dae Kun, E-mail: odk6464@nate.co [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Kim, Hyung-Jin, E-mail: hyungkim@skku.ed [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Kim, Keon Ha, E-mail: somatom@skku.ed [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Jeon, Pyoung, E-mail: drpjeon@gmail.co [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of); Byun, Hong Sik, E-mail: byun5474@skku.ed [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-Gu, Seoul 135-710 (Korea, Republic of)

    2010-08-15

    Purpose: The purpose of this study is to investigate the MRI findings of visceral larva migrans (VLS) of Toxocara canis in spinal cord. Materials and methods: We retrospectively reviewed spinal MRI findings in eight patients with serologically proven Toxocara canis between 2005 and 2008. We evaluated the location, length, extent and migration of the lesion, MR signal intensity (SI), enhancement pattern, and swelling of the spinal cord. We evaluated clinical features including presenting symptoms and signs and treatment response. Results: Total 8 patients (M = 8; age range 36-79 years) were included. The lesions were located in the cervical or thoracic spinal cord in all patients. All lesions showed high SI and minimal or mild swelling of involved spinal cord on T2WI and focal nodular enhancement on posterior or posterolateral segment of spinal cord. The length of involved lesion was relatively short in most patients. There was a migration of lesion in one patient. In spite of albendazole or steroid treatment, neurological symptoms or signs were not significantly improved in all patients. Conclusion: Although all lesions show non-specific imaging findings like non-tumorous myelopathy mimicking transverse myelitis, single lesion, focal nodular enhancement on posterior or posterolateral segment of spinal cord, relatively short segmental involvement and migration of lesion may be characteristic findings of spinal VLM of Toxocara canis. In addition, the reluctant response to the treatment may be characteristic of spinal VLM of Toxocara canis.

  8. A digestive prolyl carboxypeptidase in Tenebrio molitor larvae.

    Science.gov (United States)

    Goptar, Irina A; Shagin, Dmitry A; Shagina, Irina A; Mudrik, Elena S; Smirnova, Yulia A; Zhuzhikov, Dmitry P; Belozersky, Mikhail A; Dunaevsky, Yakov E; Oppert, Brenda; Filippova, Irina Yu; Elpidina, Elena N

    2013-06-01

    Prolyl carboxypeptidase (PRCP) is a lysosomal proline specific serine peptidase that also plays a vital role in the regulation of physiological processes in mammals. In this report, we isolate and characterize the first PRCP in an insect. PRCP was purified from the anterior midgut of larvae of a stored product pest, Tenebrio molitor, using a three-step chromatography strategy, and it was determined that the purified enzyme was a dimer. The cDNA of PRCP was cloned and sequenced, and the predicted protein was identical to the proteomic sequences of the purified enzyme. The substrate specificity and kinetic parameters of the enzyme were determined. The T. molitor PRCP participates in the hydrolysis of the insect's major dietary proteins, gliadins, and is the first PRCP to be ascribed a digestive function. Our collective data suggest that the evolutionary enrichment of the digestive peptidase complex in insects with an area of acidic to neutral pH in the midgut is a result of the incorporation of lysosomal peptidases, including PRCP. Published by Elsevier Ltd.

  9. Transcriptional response of Musca domestica larvae to bacterial infection.

    Directory of Open Access Journals (Sweden)

    Ting Tang

    Full Text Available The house fly Musca domestica, a cosmopolitan dipteran insect, is a significant vector for human and animal bacterial pathogens, but little is known about its immune response to these pathogens. To address this issue, we inoculated the larvae with a mixture of Escherichia coli and Staphylococcus aureus and profiled the transcriptome 6, 24, and 48 h thereafter. Many genes known to controlling innate immunity in insects were induced following infection, including genes encoding pattern recognition proteins (PGRPs, various components of the Toll and IMD signaling pathways and of the proPO-activating and redox systems, and multiple antimicrobial peptides. Interestingly, we also uncovered a large set of novel immune response genes including two broad-spectrum antimicrobial peptides (muscin and domesticin, which might have evolved to adapt to house-fly's unique ecological environments. Finally, genes mediating oxidative phosphorylation were repressed at 48 h post-infection, suggesting disruption of energy homeostasis and mitochondrial function at the late stages of infection. Collectively, our data reveal dynamic changes in gene expression following bacterial infection in the house fly, paving the way for future in-depth analysis of M. domestica's immune system.

  10. Benthic food webs support the production of sympatric flatfish larvae in estuarine nursery habitat

    Science.gov (United States)

    Identifying nursery habitats is of paramount importance to define proper management and conservation strategies for flatfish species. Flatfish nursery studies usually report upon habitat occupation, but few attempted to quantify the importance of those habitats to larvae developm...

  11. IDENTIFICATION OF VIBRIO BACTERIA CAUSED VIBRIOSIS ON FRESHWATER PRAWN LARVAE (Macrobrachium rosenbergii (de Man

    Directory of Open Access Journals (Sweden)

    Ni Wayan Desi Bintari

    2016-12-01

    Full Text Available Freshwater prawn (Macrobrachium rosenbergii (de Man farming in Bali needs to be supported by the provisionof healthy prawn larvae. Vibriosis infection can be a limiting factor on larval production system which cause highmass mortality in larvae. Therefore a bacteriological study is very important to identify of Vibrio species whichcan cause vibriosis in freshwater prawn larvae. Screening of Vibrio bacteria carried on larval rearing water atUPT Pembenihan Dinas Kelautan dan Perikanan Provinsi Bali which located in Pesinggahan Village, Klungkung.During study, 5 Vibrio isolates can be characterized (VSP01, VSP02, VSP04, VSP05 and VSP06 which wereisolated as dominant Vibrio bacteria in larval rearing water. Koch postulate test results showed that VSP06 cancause vibriosis in freshwater prawn larvae. The result of identification by BBL Cystal™ Identification Systems andidentification book Bergeys’s Manual of Determinative Bacteriology Ninth Edition (Holt et al., 1994, BL6 wasidentified as Vibrio anguillarum.

  12. IDENTIFICATION OF VIBRIO BACTERIA CAUSED VIBRIOSIS ON FRESHWATER PRAWN LARVAE (Macrobrachium rosenbergii (de Man

    Directory of Open Access Journals (Sweden)

    Ni Wayan Desi Bintari

    2017-02-01

    Full Text Available Freshwater prawn (Macrobrachium rosenbergii (de Man farming in Bali needs to be supported by the provisionof healthy prawn larvae. Vibriosis infection can be a limiting factor on larval production system which cause highmass mortality in larvae. Therefore a bacteriological study is very important to identify of Vibrio species whichcan cause vibriosis in freshwater prawn larvae. Screening of Vibrio bacteria carried on larval rearing water atUPT Pembenihan Dinas Kelautan dan Perikanan Provinsi Bali which located in Pesinggahan Village, Klungkung.During study, 5 Vibrio isolates can be characterized (VSP01, VSP02, VSP04, VSP05 and VSP06 which wereisolated as dominant Vibrio bacteria in larval rearing water. Koch postulate test results showed that VSP06 cancause vibriosis in freshwater prawn larvae. The result of identification by BBL Cystal™ Identification Systems andidentification book Bergeys’s Manual of Determinative Bacteriology Ninth Edition (Holt et al., 1994, BL6 wasidentified as Vibrio anguillarum.

  13. Swim-training changes the spatio-temporal dynamics of skeletogenesis in zebrafish larvae (Danio rerio)

    NARCIS (Netherlands)

    Fiaz, A.W.; Leon-Kloosterziel, K.M.; Gort, G.; Schulte-Merker, S.; van Leeuwen, J.L.; Kranenbarg, S.

    2012-01-01

    Fish larvae experience many environmental challenges during development such as variation in water velocity, food availability and predation. The rapid development of structures involved in feeding, respiration and swimming increases the chance of survival. It has been hypothesized that mechanical

  14. Crown-of-Thorns Starfish Larvae Can Feed on Organic Matter Released from Corals

    Directory of Open Access Journals (Sweden)

    Ryota Nakajima

    2016-10-01

    Full Text Available Previous studies have suggested that Crown-of-Thorns starfish (COTS larvae may be able to survive in the absence of abundant phytoplankton resources suggesting that they may be able to utilize alternative food sources. Here, we tested the hypothesis that COTS larvae are able to feed on coral-derived organic matter using labeled stable isotope tracers (13C and 15N. Our results show that coral-derived organic matter (coral mucus and associated microorganisms can be assimilated by COTS larvae and may be an important alternative or additional food resource for COTS larvae through periods of low phytoplankton biomass. This additional food resource could potentially facilitate COTS outbreaks by reducing resource limitation.

  15. Larvae of fouling organisms and macrofouling at New Mangalore Port, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Khandeparker, D.C.; Anil, A.C.; Venkat, K.

    Polychaetes, bryozoans, barnacles and ascidians were the dominant groups in the fouling community at New Mangalore Port. Polychaete and cirripede larvae were encountered throughout the year. Even though bivalve were present in the planktonic hauls...

  16. Aspects of excretion of antlion larvae (Neuroptera: myrmeleontidae) during feeding and non-feeding periods.

    Science.gov (United States)

    Van Zyl, A; Van Der Westhuizen, M C.; De K Van Der Linde, T C.

    1998-12-01

    The main nitrogenous excretory products were determined for third instar Cueta sp. and Furgella intermedia larvae during periods of food abundance and for F. intermedia during starvation periods. Biochemical analysis indicated that allantoin was the main nitrogenous excretory product, with smaller quantities of ammonia, urea and uric acid. Respectively 9 and 13amino acids of low concentrations (0.005-0.329g/l) were detected by high pressure liquid chromatography in the excreta of Cueta sp. and F. intermedia larvae. The volume of urine produced and concentrations of the nitrogenous excretory products of fed Cueta sp. and fed F. intermedia larvae did not differ. F. intermedia excreted smaller volumes of urine and smaller quantities of nitrogenous excretory products during starvation than during periods of food abundance. Feeding conditions rather than the pitbuilding or non-pitbuilding lifestyles seem to be the major influence on the excretory products of these antlion larvae.

  17. Effects and mechanisms of Bacillus thuringiensis crystal toxins for mosquito larvae.

    Science.gov (United States)

    Zhang, Qi; Hua, Gang; Adang, Michael J

    2017-10-01

    Bacillus thuringiensis is a Gram-positive aerobic bacterium that produces insecticidal crystalline inclusions during sporulation phases of the mother cell. The virulence factor, known as parasporal crystals, is composed of Cry and Cyt toxins. Most Cry toxins display a common 3-domain topology. Cry toxins exert intoxication through toxin activation, receptor binding and pore formation in a suitable larval gut environment. The mosquitocidal toxins of Bt subsp. israelensis (Bti) were found to be highly active against mosquito larvae and are widely used for vector control. Bt subsp. jegathesan is another strain which possesses high potency against broad range of mosquito larvae. The present review summarizes characterized receptors for Cry toxins in mosquito larvae, and will also discuss the diversity and effects of 3-D mosquitocidal Cry toxin and the ongoing research for Cry toxin mechanisms generated from investigations of lepidopteran and dipteran larvae. © 2016 Institute of Zoology, Chinese Academy of Sciences.

  18. Toxocara cati larvae in the eye of a child: a case report

    Directory of Open Access Journals (Sweden)

    Mohammad Zibaei

    2014-05-01

    Full Text Available Toxocariasis is a consequence of human infection by Toxocara larvae. There are symptomatic (visceral, ocular and asymptomatic course of toxocariasis. The ocular form is very rare. We present a 6-year-old patient who developed an ocular form of toxocariasis caused by Toxocara cati. He demonstrated lesions in the peripheral retina of the right eye. White granuloma was present in the superior peripheral retina. A positive immunological assay for toxocariasis essentially completed the outcomes. On the basis of clinical manifestations and conducted examinations, a diagnosis of ocular form of toxocariasis was established. Albendazole and corticosteroids were applied in treatment. Current results clearly highlight the usefulness of excretory-secretory antigens derived from larvae of Toxocara cati for the fine diagnosis ocular larva migrans caused by Toxocara larvae.

  19. Infectivity of Trichinella spiralis larvae in pork buried in the ground

    Directory of Open Access Journals (Sweden)

    Jovic S.

    2001-06-01

    Full Text Available Time of survival and infectivity of Trichinella spiralis larvae in pig muscle tissue, buried at various depths in the ground were assessed. In the pork pieces the number of infective larvae was 250 ML/g. Meat originated from pig halves was divided in 39 equal pieces, 0.7 kg each, disposed in three groups of 1 3, and buried in depths of 30, 50, and 100 centimeters respectively. The pork was dug up at 13 intervals, approximately every week, until 91st day of the experiment. After each time interval, infectivity of larvae was assessed by bioassay on rats. The artificially infected rats were sacrificed on 42nd day after the infection and meat was examined by the following methods - artificial digestion and trichinoscopy. It was found that the larvae during all 90 days preserved infectivity in each depth.

  20. A Laboratory Practical on the House Building Behaviour of Caddis Larvae

    Science.gov (United States)

    Hansell, M. H.

    1973-01-01

    Describes a laboratory practical on animal behavior suitable for senior secondary school or university biology classes. Several separate exercises relating to the house building behavior of caddis fly larvae are detailed, together with the time required for preparation. (JR)

  1. Development of larvae of suborders Strongylata and Rhabditata in differently mineralized soils

    Directory of Open Access Journals (Sweden)

    О. О. Bojko

    2008-04-01

    Full Text Available Dependence of suborders Strongylata and Rhabditata larvae development from the mineralization level of soil has been established. With increase of concentration of salt the period of the larvae viability decreases. The lowest larvae number was found in the Tsarychanka district of the Dnipropetrovs’k province, which is characterized by high mineralization level of the soil. The larvae of the genera Dictyocaulus Raill. et Hen., Bunostomum Raill., Haemonchus Cobb., Oesophagostomum Mol. was found in the P’yatykhatki district; Strongуloides Wedl. and Dictyocaulus Raill. – in the Shyrokovo district; Dictyocaulus Raill. – in the Dnipropetrovsk district; Dictyocaulus Raill., Haemonchus Cobb., Oesophagostomum Mol. and Chabertia Raill. et Hen. – in the Novomoskovs’k district and Haemonchus Cobb. – in theTsarychanka district.

  2. Toxic effects of coastal and marine plant extracts on mosquito larvae

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Solimabi; DeSouza, L.; Kamat, S.Y.

    (Halophila ovalis, Syringodium isoetifolium), and a lichen (Umbilicaria aprine) were studied for their toxicity against larvae of the mosquito Culex quinquefasciatus. Petroleum-ether fractions (PE) were more effective than chloroform fractions (C) in all...

  3. Artemia sp. NA ALIMENTAÇÃO DE LARVAS DE JUNDIÁ (Rhamdia quelen

    Directory of Open Access Journals (Sweden)

    Odair Diemer

    2012-06-01

    Full Text Available A considerable problem in the catfish larvae rearing is related to the first feeding. This study aimed to determine the larvae growth and the survival of silver catfish submitted to feeding with Artemia sp. in different time periods. The study was conducted in the Aquaculture Laboratory of the Universidade Estadual do Oeste do Paraná, with four treatments and five replications, constituted by feeding with Artemia sp. in 5, 10, 15 and 20 days, and after each period of time, by its replacement by ration. We used 200 larvae distributed into 20 aquariums, soon after the eggs hatched. The larvae were fed 4 times a day until apparent satiation for 30 days. The Artemia sp. feeding for 15 days provided the best results on weight gain, final length and survival.

  4. Blood feeding of Ornithodoros turicata larvae using an artificial membrane system.

    Science.gov (United States)

    Kim, H J; Filatov, S; Lopez, J E; Pérez DE León, A A; Teel, P D

    2017-06-01

    An artificial membrane system was adapted to feed Ornithodoros turicata (Ixodida: Argasidae) larvae from a laboratory colony using defibrinated swine blood. Aspects related to larval feeding and moulting to the first nymphal instar were evaluated. A total of 55.6% of all larvae exposed to the artificial membrane in two experimental groups fed to repletion and 98.0% of all fed larvae moulted. Mortality rates of first instar nymphs differed significantly depending on the sorting tools used to handle engorged larvae (χ 2  = 35.578, P artificial membrane feeding system. Applications of the artificial membrane feeding system to fill gaps in current knowledge of soft tick biology and the study of soft tick-pathogen interactions are discussed. © 2017 The Royal Entomological Society.

  5. Cholesterol oxidase interference on the emergence and viability of cotton boll weevil larvae

    Directory of Open Access Journals (Sweden)

    Santos Roseane Cavalcanti

    2002-01-01

    Full Text Available The aim of this work was to evaluate the influence of the enzyme cholesterol oxidase (Coase on emergence and viability of larvae of the cotton boll weevil (Anthonomus grandis Boheman, 1843. A series of bioassays was performed with eggs and neonate larvae exposed to different enzyme concentrations in artificial diet. Larval survival was affected at all enzyme concentrations tested, and the six-day LD50 was 53 mug/mL (CI 95%: 43-59. Coase also interfered with hatching of larvae after eggs were floated for 15 min in Coase solution at different concentrations. Observations at the light and electronic microscopic level of midguts from larvae fed on artificial diet containing 53 mug/mL of Coase and collected at six days revealed highly vacuolated regions in the epithelial cells as well as partial degradation of the basal membrane and microvilli.

  6. Identification of Balanus amphitrite larvae from field zooplankton using species-specific primers

    Digital Repository Service at National Institute of Oceanography (India)

    Gaonkar, C.C.; Khandeparker, L.; Desai, D.V.; Anil, A.C.

    Identification of marine invertebrate larvae using morphological characters is laborious and complicated by phenotypic plasticity. Balanus amphitrite is a dominant barnacle, important in the context of intertidal ecology and biofouling of manmade...

  7. [Cutaneous myiasis caused by a double infestation with larvae of Dermatobia hominis and Cochliomyia hominivorax].

    Science.gov (United States)

    Zupan-Kajcovski, B; Simonian, H; Keller, J J; Faber, W R

    2004-10-16

    In a 51-year-old man who had visited Surinam, cutaneous myiasis was diagnosed, caused by simultaneous infestation with the larvae of two different species of flies: Dermatobia hominis and Cochliomyia hominivorax. On his right lower arm the man had two solitary, furuncle-like lesions with a central breathing hole. Two days after these holes had been occluded with vaseline, two white larvae of D. hominis emerged. On both ankles the man had large, undermined ulcers containing hundreds of creeping larvae about 2 cm in length with a salmon-like colour: C. hominivorax. The larvae were removed from the ulcers by hand and by rinsing with physiological saline, after which the wounds healed rapidly. Myiasis is seen in the Netherlands mostly in people returning from a holiday in myiasis-endemic areas.

  8. Development of patent Ascaris suum infections in pigs following intravenous administration of larvae hatched in vitro

    DEFF Research Database (Denmark)

    Jungersen, Gregers; Fagerholm, H.P.; Nansen, P.

    1999-01-01

    is bypassed by inoculation of pigs with an intravenous dose of larvae hatched in vitro, the larvae not only complete migration and return to the small intestine, but they also seem to have a greater chance of survival to adulthood. This technique offers new possibilities for studies on specific lung......The normal tissue migration of Ascaris suum in the pig host involves larval development in the liver accompanied by considerable pathological changes. The vast majority of larvae that reach the small intestine are later expelled by unknown mechanisms. We show that when migration through the liver...... involvement in protective immunity, provides valuable information for the understanding of self cure by larval expulsion, and adds to our understanding of the evolution of migration of Ascaris larvae in tissues....

  9. Variability in the distribution of planktonic fish eggs and larvae in the nearshore waters off Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; Nair, V.R.; Desai, B.N.

    Distribution of planktonic fish eggs and larvae in the nearshore waters off Bombay was studied during November 1979 to December 1980. Monthly samples were collected along three transects (Versova, Mahim and Thana) covering eleven stations which...

  10. Induction of Metamorphosis of Larvae of the Green Sea Urchin, Strongylocentrotus droebachiensis, by Coralline Red Algae.

    Science.gov (United States)

    Pearce, C M; Scheibling, R E

    1990-12-01

    The coralline red algae, Lithothamnion glaciale, Phymatolithon laevigatum, P. rugulosum, and Corallina officinalis, induced >85% of laboratory-reared larvae of Strongylocentrotus droebachiensis to metamorphose. Larvae must contact live L. glaciale or its spores for metamorphosis to occur; the inducer is not sensed in the water column. However, aqueous extracts of L. glaciale can induce metamorphosis, suggesting that the inducing factor is chemical. Neither ashed nor boiled L. glaciale induces metamorphosis, indicating that the factor is heat-labile and that thigmotaxis, per se, is not important in the response. The amino-acid, γ-aminobutyric acid (GABA), which induces settlement of other marine invertebrate larvae, also induces significant rates of metamorphosis of S. droebachiensis at concentrations ≥ 10-4 M. A reduction (with antibiotics) in the number of live bacteria on the surface of L. glaciale does not affect the rate of metamorphosis of larvae.

  11. Structure of recombinant human carboxylesterase 1 isolated from whole cabbage looper larvae

    International Nuclear Information System (INIS)

    Greenblatt, Harry M.; Otto, Tamara C.; Kirkpatrick, Melanie G.; Kovaleva, Elena; Brown, Susan; Buchman, George; Cerasoli, Douglas M.; Sussman, Joel L.

    2012-01-01

    Large quantities of recombinant human carboxylesterase 1 have been produced in an economical whole insect larvae system. The crystal structure of this enzyme is essentially identical to that produced by cell culture techniques. The use of whole insect larvae as a source of recombinant proteins offers a more cost-effective method of producing large quantities of human proteins than conventional cell-culture approaches. Human carboxylesterase 1 has been produced in and isolated from whole Trichoplusia ni larvae. The recombinant protein was crystallized and its structure was solved to 2.2 Å resolution. The results indicate that the larvae-produced enzyme is essentially identical to that isolated from cultured Sf21 cells, supporting the use of this expression system to produce recombinant enzymes for crystallization studies

  12. Entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana reduce the survival of Xenopsylla brasiliensis larvae (Siphonaptera: Pulicidae).

    Science.gov (United States)

    Mnyone, Ladslaus L; Ng'habi, Kija R; Mazigo, Humphrey D; Katakweba, Abdul A; Lyimo, Issa N

    2012-09-19

    Entomopathogenic fungi, particularly those belonging to the genera Metarhizium and Beauveria have shown great promise as arthropod vector control tools. These agents, however, have not been evaluated against flea vectors of plague. A 3-h exposure to the fungi coated paper at a concentration of 2 × 108 conidia m-2 infected >90% of flea larvae cadavers in the treatment groups. The infection reduced the survival of larvae that had been exposed to fungus relative to controls. The daily risk of dying was four- and over three-fold greater in larvae exposed to M. anisopliae (HR = 4, pfungi can successfully infect and kill larvae of X. brasiliensis with a pooled median survival time (MST±SE) of 2 ± 0.31 days post-exposure. These findings justify further research to investigate the bio-control potential of entomopathogenic fungi against fleas.

  13. Evaluation of Metarhizium brunneum F52 (Hypocreales: Clavicipitaceae) for control of Japanese beetle larvae in turfgrass

    Science.gov (United States)

    Experimental and commercial preparations of Metarhizium brunneum strain F52 were evaluated for control of Japanese beetle Popillia japonica Newman (Coleoptera: Scarbaeidae) larvae (white grubs) in the laboratory and under field conditions. Experimental preparations consisted of granule and liquid f...

  14. Proteins synthesized and secreted by larvae of the ectoparasitic wasp, Eulophus pennicornis.

    Science.gov (United States)

    Richards, E H; Edwards, J P

    2001-03-01

    A microscopic examination of Eulophus pennicornis larvae on their host Lacanobia oleracea, revealed that peristaltic waves travelled from the anterior to posterior end of the feeding wasp larvae, and vice versa. In addition, when wasp larvae were immersed in PBS in vitro, they released a variety of proteins, with molecular weights ranging from (at least) 14 to 200 kDa. Amongst these was a protein with an estimated molecular weight similar to that of the 27 kDa parasitism-specific protein (PSP) detected in plasma from parasitized L. oleracea [Richards and Edwards, Insect Biochem Mol Biol 29:557-569 (1999)]. Similar results were obtained when the wasp larvae were incubated on balls of cotton wool soaked in tissue culture medium or sucrose, i.e., conditions that resemble their natural feeding behaviour. These results (and others) indicate that the wasp larvae release proteins, putatively through their mouth. Protein synthesis studies using (35)S-methionine indicated that the wasp larvae synthesize and secrete a variety of proteins in vitro, including one with a molecular weight corresponding to that of the L. oleracea 27 kDa PSP. As expected, only a portion of the total proteins synthesized by the parasitoid larvae were subsequently secreted. In addition, the autoradiogram of secreted proteins contained significantly fewer bands than silver-stained SDS gels of proteins released into PBS or onto cotton wool. Thus, some of the additional bands detected on the latter gels are thought to represent proteins that were not of wasp origin. Instead, these proteins released by the wasp larvae are speculated to be derived from their gut and, as such, probably represent proteins derived from host haemolymph and ingested during feeding. This possibility was supported by an electrophoretic analysis of homogenate supernatants prepared from wasp larvae with or without their gut contents. These studies indicated that the gut contents of the larval parasitoid contributes several

  15. Characterization of Paenibacillus larvae bacteriophages and their genomic relationships to firmicute bacteriophages.

    Science.gov (United States)

    Merrill, Bryan D; Grose, Julianne H; Breakwell, Donald P; Burnett, Sandra H

    2014-08-30

    Paenibacillus larvae is a Firmicute bacterium that causes American Foulbrood, a lethal disease in honeybees and is a major source of global agricultural losses. Although P. larvae phages were isolated prior to 2013, no full genome sequences of P. larvae bacteriophages were published or analyzed. This report includes an in-depth analysis of the structure, genomes, and relatedness of P. larvae myoviruses Abouo, Davis, Emery, Jimmer1, Jimmer2, and siphovirus phiIBB_Pl23 to each other and to other known phages. P. larvae phages Abouo, Davies, Emery, Jimmer1, and Jimmer2 are myoviruses with ~50 kbp genomes. The six P. larvae phages form three distinct groups by dotplot analysis. An annotated linear genome map of these six phages displays important identifiable genes and demonstrates the relationship between phages. Sixty phage assembly or structural protein genes and 133 regulatory or other non-structural protein genes were identifiable among the six P. larvae phages. Jimmer1, Jimmer2, and Davies formed stable lysogens resistant to superinfection by genetically similar phages. The correlation between tape measure protein gene length and phage tail length allowed identification of co-isolated phages Emery and Abouo in electron micrographs. A Phamerator database was assembled with the P. larvae phage genomes and 107 genomes of Firmicute-infecting phages, including 71 Bacillus phages. Phamerator identified conserved domains in 1,501 of 6,181 phamilies (only 24.3%) encoded by genes in the database and revealed that P. larvae phage genomes shared at least one phamily with 72 of the 107 other phages. The phamily relationship of large terminase proteins was used to indicate putative DNA packaging strategies. Analyses from CoreGenes, Phamerator, and electron micrograph measurements indicated Jimmer1, Jimmer2, Abouo and Davies were related to phages phiC2, EJ-1, KC5a, and AQ113, which are small-genome myoviruses that infect Streptococcus, Lactobacillus, and Clostridium

  16. Utilization Efficiency of Yolk Egg on Maanvis (Pterophyllum scalare Embryos and Larvae in Different Incubation Temperatures

    Directory of Open Access Journals (Sweden)

    T. Budiardi

    2007-01-01

    Full Text Available This study was performed to determine the efficiency of yolk egg utilization in embryos and larvae, hatching rate, incubation time to hatch, and growth rate of maanvis (Pterophyllum scalare larvae incubated at room remperature, 27oC, and 30oC.  Results of study showed that yolk egg utilization efficiency of embryos and larvae incubated at 30oC was 73.70% and 0,18%, respectively, and no different with that of room and 27oC incubation temperatures.  Hatching rate of eggs incubated at 30oC (84.75% was also same with that of other treatments.  However, incubation time to hatch (27.41 hours was shorter than that of other treatments.  The growth rate by length of larvae (2.16% and survival rate (75.28% incubated at 30oC was also higher compared with that of other treatments.  Thus, in general, optimum temperature for egg hatching and larval rearing of maanvis was 30oC. Keywords: maanvis, Pterophyllum scalare, egg yolk, larvae, embryo, temperature   ABSTRAK Penelitian ini dilakukan untuk mengetahui efisiensi pemanfaatan kuning telur pada embrio dan larva, derajat penetasan, lama inkubasi telur hingga menetas, dan laju pertumbuhan serta kelangsungan hidup larva ikan maanvis (Pterophyllum scalare yang diinkubasi pada suhu ruang, 27oC dan 30oC.  Hasil penelitian menunjukkan bahwa nilai efisiensi pemanfaatan kuning telur bila diinkubasi pada suhu 30oCsebesar 73,70% pada fase embrio dan 0,18% pada fase larva, dan tidak berbeda dengan suhu ruang dan 27oC.  Demikian juga dengan derajat penetasan telur  (84,75% tidak berbeda dengan perlakuan lainnya.  Sementara itu, lama inkubasi telur hingga menetas (27,41 jam lebih cepat dibandingkan dengan suhu inkubasi perlakuan lainnya. Demikian juga dengan laju pertumbuhan panjang (2,16% dan kelangsungan hidup larva (75,28% lebih tinggi dibandingkan dengan perlakuan lainnya. Dengan demikian, secara umum suhu optimal untuk penetasan dan pemeliharaan larva ikan maanvis adalah 30°C. Kata kunci: ikan maanvis

  17. Last instar larva of Microstigmus nigrophthalmus Melo (Hymenoptera, Crabronidae, Pemphredoninae, with notes on biology

    Directory of Open Access Journals (Sweden)

    Sandor Christiano Buys

    2002-09-01

    Full Text Available The last instar larva of Microstigmus nigrophthalmus Melo, 1992 is described. It markedly differs from that of M. comes Krombein, 1967 the only other species in the genus whose mature larva have been described, for features as follows: presence of spinnerets; setae on the labrum, maxillae and labium; mandibles with tridentate apex and a bidentate lateral projection; lack of the conical supranal processo Notes on habitat, structure, and content of nests are also presented.

  18. Immune response of rainbow trout (Oncorhynchus mykiss) larvae to Yersinia ruckeri

    DEFF Research Database (Denmark)

    Chettri, Jiwan Kumar; Kania, Per Walter; Raida, Martin Kristian

    Innate immune factors play a crucial role in survival of young fish especially during early stages of life where adaptive immunity is not fully developed. In the present study, we investigated the immune response of rainbow trout larvae (Onchorhynchus mykiss) at an early stage of development. We...... of immune factors at the transcriptional level. It may be speculated that at this stage of life, larvae may combat invading pathogens by using armour consisting of different immune factors without regulating their expression....

  19. Feeding strategy of Downs herring larvae (Clupea harengus L.) in the English Channel and North Sea

    Science.gov (United States)

    Denis, Jeremy; Vallet, Carole; Courcot, Lucie; Lefebvre, Valérie; Caboche, Josselin; Antajan, Elvire; Marchal, Paul; Loots, Christophe

    2016-09-01

    This study aims to characterize the larval feeding strategy of the Downs sub-population of North Sea herring (Clupea harengus L.). Diet composition, vacuity rate and prey selectivity of larvae from 8 to 15 mm collected during the International Bottom Trawl Survey (IBTS) - MIK sampling from 2008 to 2013 were assessed by direct observation of their gut contents using Scanning Electron Microscopy (SEM). The high contribution of protists and small zooplanktonic prey observed in the gut contents proved the relevance of SEM to study the diet of first feeding larvae. The relatively low vacuity rate of 45% suggests that food may not be a limiting factor for Downs herring larvae in winter. These larvae appeared to be omnivorous and there was a clear shift in term of prey composition at a size of 13 mm. Smaller larvae (8-12 mm) fed on a higher diversity of small prey, mainly small copepods (Oncaea spp. and Euterpina acutifrons), invertebrate eggs, diatoms (Psammodicthyon panduriforme and Coscinodiscus spp.) and dinoflagellates (Dinophysis acuminate and Prorocentrum micans) whereas bigger larvae (13-15 mm) fed on a lower diversity of larger prey, mainly copepods (Temora longicornis and Paracalanus parvus) and dinoflagellates (Gonyaulax spp.). Downs herring larvae had clear prey preferences as some dinoflagellates (Pyrophacus spp., Gonyaulax spp., P. micans and Porocentrum lima), invertebrate eggs, copepods (Oncaea spp. and nauplii) and diatoms (Thalassiosira curviseriata) were positively selected and other diatoms (Nitzschia spp., Thalassiosira tenera, Thalassiosira spp. and Chaetoceros spp.) and copepods (Pseudocalanus elongatus, T. longicornis and Unidentified calanoid) were negatively selected. We argue that this shift in term of prey preferences occurring at a size of 13 mm constitutes the critical period for Downs herring larvae.

  20. Oceanographic and behavioural assumptions in models of the fate of coral and coral reef fish larvae.

    Science.gov (United States)

    Wolanski, Eric; Kingsford, Michael J

    2014-09-06

    A predictive model of the fate of coral reef fish larvae in a reef system is proposed that combines the oceanographic processes of advection and turbulent diffusion with the biological process of horizontal swimming controlled by olfactory and auditory cues within the timescales of larval development. In the model, auditory cues resulted in swimming towards the reefs when within hearing distance of the reef, whereas olfactory cues resulted in the larvae swimming towards the natal reef in open waters by swimming against the concentration gradients in the smell plume emanating from the natal reef. The model suggested that the self-seeding rate may be quite large, at least 20% for the larvae of rapidly developing reef fish species, which contrasted with a self-seeding rate less than 2% for non-swimming coral larvae. The predicted self-recruitment rate of reefs was sensitive to a number of parameters, such as the time at which the fish larvae reach post-flexion, the pelagic larval duration of the larvae, the horizontal turbulent diffusion coefficient in reefal waters and the horizontal swimming behaviour of the fish larvae in response to auditory and olfactory cues, for which better field data are needed. Thus, the model suggested that high self-seeding rates for reef fish are possible, even in areas where the 'sticky water' effect is minimal and in the absence of long-term trapping in oceanic fronts and/or large-scale oceanic eddies or filaments that are often argued to facilitate the return of the larvae after long periods of drifting at sea. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  1. Ichneumonidae (Hymenoptera) parasitóides de larvas de Lepidoptera associadas a Croton floribundus Spreng (Euphorbiaceae)

    OpenAIRE

    Fernandes, Luciana Bueno dos Reis; Dias Filho, Manoel Martins; Fernandes, Marcelo Adorna; Penteado-Dias, Angelica Maria

    2010-01-01

    Parasitoids of the family Ichneumonidae (Hymenoptera) were obtained during an inventory of Lepidoptera larvae caught feeding in the wild on Croton floribundus (Euphorbiaceae). The Lepidoptera larvae were collected from host plants along trails inside three preserved forest areas in the Brazilian state of São Paulo. Fifteen different species of Ichneumonidae belonging to five subfamilies (Banchinae, Campopleginae, Cremastinae, Mesochorinae and Metopiinae) were obtained. Seven species of Ichneu...

  2. PENGARUH INTENSITAS CAHAYA TERHADAP PEMANGSAAN LARVA IKAN CLOWN (Amphiprion ocellaris PADA AWAL PEMELIHARAAN

    Directory of Open Access Journals (Sweden)

    Ketut Maha Setiawati

    2016-11-01

    Full Text Available Penelitian pemangsaan larva ikan clown (Amphiprion ocellaris pada awal pemeliharaan dan umur sepuluh hari dilakukan menggunakan tangki serat kaca (fiberglass volume 200 L. Pakan zooplankton rotifera disediakan sejak telur menetas dengan kepadatan 5 ind./mL. Mulai D-8 zooplankton nauplii Artemia ditambahkan dengan kepadatan 1.700 ind./tangki. Pengambilan sampel dilakukan pada umur 1 hari dan sepuluh hari, masing-masing 10 ekor larva/sampling dengan interval waktu 3 jam. Larva diukur kemudian dibedah dan dianalisis jumlah pemangsaaannya dengan bantuan stereoscopic microscope. Hasil analisis menunjukkan peranan intensitas cahaya dalam aktivitas pemangsaannya sebesar 5 individu rotifera dengan intensitas cahaya 70 lux pada pagi hari, sedang pemangsaan tertinggi terjadi pada pukul 13.00—16.00 dengan pemangsaan 57 individu rotifera pada saat intensitas cahaya menurun. Spektrum warna cahaya diduga lebih berperanan pada kemampuan maksimal memangsa dari larva ikan laut. Observation on feeding activity of clown fish (A. ocellaris larvae have been conducted in 200 L. fiberglass tanks. Zooplankton rotifers were used as initial feed at a rate of 5 ind./mL. After eight days culture, nauplii Artemia were added at rate of 1,700 ind./ tank. Sampling was done on D-1 and D-10 at 10 individuals even sampling at three hours interval. The larvae were measured under a stereoscopic microscope, examining the digestion apparatus to count number of rotifers and nauplii Artemia as well. The result showed that the role of light intensity in feeding: 5 individual rotifer at 70 lux in early morning for D-1 larvae. The highest feeding occurred at 13.00-16.00 in the after noon at 57 individual rotifer when light intensity decreased. Color spectrum of light were predicted having more roles related to the maximum feeding rate  of clown fish larvae.

  3. Larvicidal Effects of Tithonia diversifolia (Hemsley) A. Gray Leaf Water Extract against Culex sp. Larvae

    OpenAIRE

    Hasan Ali Abdurrachman; Diah Dhianawaty; Neneng Syarifah

    2015-01-01

    Background: There are various vector mosquitoes that cause filariasis such as Culex sp. Controlling the number of vectors with larvacide can reduce the spread of this disease. The extracts of Tithonia diversifolia (Hemsley) A. Gray leaves are known to have larvicidal effects on Aedes aegypti larvae. The purpose of this study is to determine the larvicidal effects of Tithonia diversifolia (Hemsley) A. Gray leaf water extract against Culex larvae. Methods: This was an experimental study con...

  4. Larval structure of Passalus gravelyi and sexual dimorphism in Passalid larvae.

    Science.gov (United States)

    Mattos, Ingrid; Mermudes, José Ricardo Miras; Reyes-Castillo, Pedro

    2015-09-01

    The adults and larvae of Passalidae are subsocial insects commonly found in tropical forests, living in decaying wood gallery systems constructed by adults. Currently, few repots on the larvae of Neotropical Passalidae have been published and information is scarce. In this study, the Passalus (Pertinax) gravelyi Moreira, 1922 larvae is described for the first time, based on ten larval specimens 1 (1° instar), 4 (2° instar), and 5 (3° instar) associated with three adults collected from a single colony at the Parque Nacional do Itatiaia (Itatiaia, Rio de Janeiro, Brazil). The description was carried out based on electronic and digital photographs of diagnostic structures, with some details on the systematic of the species. The larvae of Passalus gravelyi has the general setal 'Pertinax' pattern and differed from others by 16 to 18 setae on the anal ring, the other larvae data from Brazilian species show the anal ring with 10 to 12 setae. A discussion on the presence of sexual dimorphism in 62 species of two and three instars of Passalidae larvae is provided for the first time. Besides, a description of the terminal ampulla present as a cuticular structure found in the medial-ventral area of the 9th abdominal sternite in males is also given. The terminal ampulla was only observed in the Passalidae male larvae and was not visible in female larvae. The terminal ampulla are acknowledged now in males of 64 passalid species, that are taxonomically distributed in world tropical forests, at the Oriental and Australian subfamily Aulacocyclinae (Aulacocyclini & Ceracupini) and the cosmotropical subfamily Passalinae (Solenocyclini, Macrolinini, Passalini, & Proculini).

  5. Effects of reduced salinity on the biochemical composition (lipid, protein) of zoea 1 decapod crustacean larvae

    OpenAIRE

    Torres, Gabriela; Giménez, L.; Anger, Klaus

    2002-01-01

    Effects of reduced salinities on dry weight (DW) and biochemical composition (total lipid and protein contents) of zoea 1 larvae were evaluated in four decapod crustacean species differing in salinity tolerance (Cancer pagurus, Homarus gammarus, Carcinus maenas, Chasmagnathus granulata). The larvae were exposed to two different reduced salinities (15[permil] and 25[permil] in C. granulata, 20[permil] and 25[permil] in the other species) for a long (ca. 50% of the zoea 1 moulting cycle) or a s...

  6. Development of patent Ascaris suum infections in pigs following intravenous administration of larvae hatched in vitro

    DEFF Research Database (Denmark)

    Jungersen, Gregers; Fagerholm, H.P.; Nansen, P.

    1999-01-01

    The normal tissue migration of Ascaris suum in the pig host involves larval development in the liver accompanied by considerable pathological changes. The vast majority of larvae that reach the small intestine are later expelled by unknown mechanisms. We show that when migration through the liver...... involvement in protective immunity, provides valuable information for the understanding of self cure by larval expulsion, and adds to our understanding of the evolution of migration of Ascaris larvae in tissues....

  7. A PCR Detection Method for Rapid Identification of Melissococcus pluton in Honeybee Larvae

    OpenAIRE

    Govan, V. A.; Brözel, V.; Allsopp, M. H.; Davison, S.

    1998-01-01

    Melissococcus pluton is the causative agent of European foulbrood, a disease of honeybee larvae. This bacterium is particularly difficult to isolate because of its stringent growth requirements and competition from other bacteria. PCR was used selectively to amplify specific rRNA gene sequences of M. pluton from pure culture, from crude cell lysates, and directly from infected bee larvae. The PCR primers were designed from M. pluton 16S rRNA sequence data. The PCR products were visualized by ...

  8. Toxicity of cadmium for silver catfish Rhamdia quelen (Heptapteridae) embryos and larvae at different alkalinities.

    Science.gov (United States)

    Benaduce, Ana Paula S; Kochhann, Daiani; Flores, Erico M M; Dressler, Valderi L; Baldisserotto, Bernardo

    2008-02-01

    The present study evaluated the effect of waterborne Cd in eggs and larvae of silver catfish, Rhamdia quelen, at two alkalinity levels (63 and 92 mg . L(-1) CaCO(3)): 0.5 (control), 4.5, 8, and 18 microg . L(-1) Cd. The fertilization rate was similar in all treatments, but the number of eggs with irregular surface was significantly higher in those exposed to 18 microg . L(-1) Cd and 63 mg . L(-1) CaCO(3). Three days after hatching survival of larvae exposed to 4.5 and 8 microg . L(-1) Cd and 63 mg . L(-1) CaCO(3) was significantly lower than that of control larvae, and 21 days after hatching survival decreased with the increase in waterborne Cd levels and total cadmium accumulation in the larvae. These significant differences and relationships were not observed in larvae maintained at 92 mg . L(-1) CaCO(3). Furthermore, in the lower alkalinity, a higher incidence of barbels and spinal column deformities was observed in the highest waterborne Cd concentration. At the end of the experimental period, 21 days after hatching, larval survival rate, length, weight, head height, membranous layer thickness, and biomass decreased with the increase in waterborne Cd levels in the lower alkalinity. However, these relationships were not observed in larvae maintained at 92 mg . L(-1) CaCO(3). The percentage specific growth rate was lower in larvae exposed to the highest waterborne Cd concentration at 63 mg . L(-1) CaCO(3). These results suggest that alkalinity of 92 mg . L(-1) CaCO(3) reduces waterborne Cd toxicity in silver catfish larvae.

  9. Rate of sediment intake by midge larvae (Chironomus plumosus: diptera) using a 134Cs tracer

    International Nuclear Information System (INIS)

    Gerking, S.D.; Berg, A.; Gerard, P.

    1976-01-01

    The food intake and assimilation of midge larvae (Chironomus plumosus) were determined by a 134 Cs technique which utilized the principle that the rate of excretion can be substituted for the rate of absorption when the larvae are in 134 Cs equilibrium with their environment. The larvae were introduced into contaminated sediments until they reached 134 Cs equilibrium. The time of reaching equilibrium and levels of radioactivity were the same at 10 and at 15 0 C (70 hr at a level of 1367 dpm/mg of larva) and were both significantly different from that at 20 0 C (40 hr at 1062 dpm/mg of larva). Cesium-134 elimination was followed on equilibrated larvae for as long as 330 hr. One egestion compartment (fast) and two excretion (medium and slow) compartments could be recognized at the three experimental temperatures. The loss rates from the second and third compartments at 10 0 C were slower and stretched out over longer time periods compared with those at 15 0 C, while the loss rate from the first compartment was much more comparable at the two temperatures. The first and second compartments merged at 20 0 C, while the slow compartment rose to almost three times that at 15 0 C. The food intake was nearly the same at the three temperatures (0.0986, 0.0893 and 0.0876 mg dry sediment/mg of larva/day). Thus, the larvae relied on an increase in assimilation to meet increased metabolic requirements at higher temperatures rather than depending upon a higher food intake. The gross growth efficiencies varied with temperature from 9.9 percent at 10 0 C to 15.1 percent at 15 0 C

  10. Host Recognition Responses of Western (Family: Chrysomelidae) Corn Rootworm Larvae to RNA Interference and Bt Corn

    OpenAIRE

    Zukoff, Sarah N.; Zukoff, Anthony L.

    2017-01-01

    Western corn rootworm Diabrotica virgifera virgifera LeConte is an important pest of corn whose larvae exhibit particular quantifiable patterns of locomotion after exposure to, and removal from, host roots and nonhost roots. Using EthoVision software, the behavior and locomotion of the western corn rootworm larvae was analyzed to determine the level of host recognition to germinated roots of differing corn hybrids containing either rootworm targeted Bt genes, RNA interference (RNAi) technolog...

  11. Natural resistance of soybean cultivars to the soybean looper larva Chrysodeixis includens (Lepidoptera: Noctuidae)

    OpenAIRE

    Wille, Paulo Eduardo; Pereira, Bruna Angelina; Wille, Cleiton Luiz; Restelatto, Samanta Souza; Boff, Mari Inês Carissimi; Franco, Cláudio Roberto

    2017-01-01

    Abstract: The objective of this work was to evaluate the natural resistance of soybean cultivars to Chrysodeixis includens. For this, four commercial soybean cultivars recommended for the Southern region of Brazil were used: BR 36, NA 5909 RG, BMX Turbo RR, and Benso 1RR. In the laboratory, larvae were subjected to the antixenosis feeding assay, in which they were free or not to choose among old leaves, new leaves, and pods. Neonate larvae were subjected to two antibiosis tests: in the first ...

  12. Clash of kingdoms or why Drosophila larvae positively respond to fungal competitors

    Directory of Open Access Journals (Sweden)

    Rohlfs Marko

    2005-01-01

    Full Text Available Abstract Background Competition with filamentous fungi has been demonstrated to be an important cause of mortality for the vast group of insects that depend on ephemeral resources (e.g. fruit, dung, carrion. Recent data suggest that the well-known aggregation of Drosophila larvae across decaying fruit yields a competitive advantage over mould, by which the larvae achieve a higher survival probability in larger groups compared with smaller ones. Feeding and locomotor behaviour of larger larval groups is assumed to cause disruption of fungal hyphae, leading to suppression of fungal growth, which in turn improves the chances of larval survival to the adult stage. Given the relationship between larval density, mould suppression and larval survival, the present study has tested whether fungal-infected food patches elicit communal foraging behaviour on mould-infected sites by which larvae might hamper mould growth more efficiently. Results Based on laboratory experiments in which Drosophila larvae were offered the choice between fungal-infected and uninfected food patches, larvae significantly aggregated on patches containing young fungal colonies. Grouping behaviour was also visible when larvae were offered only fungal-infected or only uninfected patches; however, larval aggregation was less strong under these conditions than in a heterogeneous environment (infected and uninfected patches. Conclusion Because filamentous fungi can be deadly competitors for insect larvae on ephemeral resources, social attraction of Drosophila larvae to fungal-infected sites leading to suppression of mould growth may reflect an adaptive behavioural response that increases insect larval fitness and can thus be discussed as an anti-competitor behaviour. These observations support the hypothesis that adverse environmental conditions operate in favour of social behaviour. In a search for the underlying mechanisms of communal behaviour in Drosophila, this study highlights

  13. Interrelation between viability of silkworm larvae Bombyx mori and natural electromagnetic fields

    Directory of Open Access Journals (Sweden)

    V. M. Litvin

    2006-12-01

    Full Text Available The interrelation of viability of silkworm larvae with natural electromagnetic fields is investigated. On the large statistical material found by the UAAS Institute of Sericulture for 50 years, it is shown, that the geomagnetic activity is characterized by weak influence on viability of larvae populations (4,7 %. The greatest caterpillars’ viability is observed in years of a high level of geomagnetic activity.

  14. Dipteran larvae and microbes facilitate nutrient sequestration in the Nepenthes gracilis pitcher plant host

    Science.gov (United States)

    Anand, Ganesh S.

    2017-01-01

    The fluid-containing traps of Nepenthes carnivorous pitcher plants (Nepenthaceae) are often inhabited by organisms known as inquilines. Dipteran larvae are key components of such communities and are thought to facilitate pitcher nitrogen sequestration by converting prey protein into inorganic nitrogen, although this has never been demonstrated in Nepenthes. Pitcher fluids are also inhabited by microbes, although the relationship(s) between these and the plant is still unclear. In this study, we examined the hypothesis of digestive mutualism between N. gracilis pitchers and both dipteran larvae and fluid microbes. Using dipteran larvae, prey and fluid volumes mimicking in situ pitcher conditions, we conducted in vitro experiments and measured changes in available fluid nitrogen in response to dipteran larvae and microbe presence. We showed that the presence of dipteran larvae resulted in significantly higher and faster releases of ammonium and soluble protein into fluids in artificial pitchers, and that the presence of fluid microbes did likewise for ammonium. We showed also that niche segregation occurs between phorid and culicid larvae, with the former fragmenting prey carcasses and the latter suppressing fluid microbe levels. These results clarify the relationships between several key pitcher-dwelling organisms, and show that pitcher communities facilitate nutrient sequestration in their host. PMID:28250210

  15. Dipteran larvae and microbes facilitate nutrient sequestration in theNepenthes gracilispitcher plant host.

    Science.gov (United States)

    Lam, Weng Ngai; Chong, Kwek Yan; Anand, Ganesh S; Tan, Hugh Tiang Wah

    2017-03-01

    The fluid-containing traps of Nepenthes carnivorous pitcher plants (Nepenthaceae) are often inhabited by organisms known as inquilines. Dipteran larvae are key components of such communities and are thought to facilitate pitcher nitrogen sequestration by converting prey protein into inorganic nitrogen, although this has never been demonstrated in Nepenthes Pitcher fluids are also inhabited by microbes, although the relationship(s) between these and the plant is still unclear. In this study, we examined the hypothesis of digestive mutualism between N. gracilis pitchers and both dipteran larvae and fluid microbes. Using dipteran larvae, prey and fluid volumes mimicking in situ pitcher conditions, we conducted in vitro experiments and measured changes in available fluid nitrogen in response to dipteran larvae and microbe presence. We showed that the presence of dipteran larvae resulted in significantly higher and faster releases of ammonium and soluble protein into fluids in artificial pitchers, and that the presence of fluid microbes did likewise for ammonium. We showed also that niche segregation occurs between phorid and culicid larvae, with the former fragmenting prey carcasses and the latter suppressing fluid microbe levels. These results clarify the relationships between several key pitcher-dwelling organisms, and show that pitcher communities facilitate nutrient sequestration in their host. © 2017 The Author(s).

  16. SUPLEMENTAÇÃO DE VITAMINA C NA DIETA PARA LARVAS DE JUNDIÁ Rhamdia voulezi

    Directory of Open Access Journals (Sweden)

    Elenice Souza Reis

    2011-03-01

    Full Text Available The aim of this study was to evaluate the supplementation of vitamin C in the diet on the development and survival of catfish larvae Rhamdia voulezi. 375 larvae were distributed in a completely randomized design in aquariums 30L of volume, density of 0.5 larvae per liter. The diets were formulated to make isonitrogenous, isoenergetic, isoaminoacid and isofibrosas, and supplemented with 600 (control, 850, 1100, 1600 and 2600 mg vitamin C per kg feed. The larvae were fed to apparent satiation for a period of 31 days, four times a day (8h, 11h, 14h and 17h. The water temperature was measured daily, while the physical-chemical parameters (dissolved oxygen, pH and conductivity were measured weekly. Not observed significant differences in performance of larvae in relation to the final weight, final length, condition factor, specific growth rate and survival. We conclude that the performance and survival of catfish larvae Rhamdia voulezi are not influenced by supplementation at levels above 600 mg vitamin C per kilogram of diet.

  17. Effects of delayed first feeding on growth of the silver catfish larvae Rhamdia voulezi (Siluriformes: Heptapteridae

    Directory of Open Access Journals (Sweden)

    Ariane F. de Lima

    2017-06-01

    Full Text Available ABSTRACT The effects of the timing of first feeding on the point-of-no-return (PNR and growth of laboratory reared silver catfish Rhamdia voulezi larvae were studied. The experiment began immediately after the complete absorption of the yolk sac, 3 days after hatching (DAH. The food was provided for the first time on 3rd, 4th, 5th, 6th, 7th, 8th, and 9th DAH. Zooplankton and newly-hatched Artemia spp. were used to feed the larvae. To evaluate the effect of food deprivation on growth, the standard length and weight of 594 larvae were assessed. Larval growth was significantly affected by the time of first exogenous feeding. The larvae fed from 3rd to 5th DAH showed a significantly higher development than those fed from 6th DAH. The larvae reached the PNR on 6th DAH. Survival and larval growth strongly depended on the timing of initial feeding. In order to avoid potential mortality by starvation and obtain good growth, the silver catfish larvae R. voulezi must establish successful initial feeding within 5 days after hatching.

  18. The invention of the pilidium larva in an otherwise perfectly good spiralian phylum Nemertea.

    Science.gov (United States)

    Maslakova, Svetlana A

    2010-11-01

    One of the most remarkable larval types among spiralians, and invertebrates in general, is the planktotrophic pilidium. The pilidium is found in a single clade of nemerteans, called the Pilidiophora, and appears to be an innovation of this group. All other nemerteans have either planktotrophic or lecithotrophic juvenile-like planuliform larvae or have direct development. The invention of the pilidium larva is associated with the formation of an extensive blastocoel that supports the delicate larval frame and elaborate ciliary band. Perhaps the most striking characteristic of the pilidium is the way the juvenile worm develops inside the larva from a series of isolated rudiments, called the imaginal discs. The paired cephalic discs, cerebral organ discs, and trunk discs originate as invaginations of larval epidermis and subsequently grow and fuse around the larval gut to form the juvenile. The fully formed juvenile ruptures the larval body and, more often than not, devours the larva during catastrophic metamorphosis. This review is an attempt to examine the pilidium in the context of recent data on development of non-pilidiophoran nemerteans, and speculate about the evolution of pilidial larval development. The author emphasizes the difference between the planuliform larvae of Palaeonemerteans and Hoplonemerteans, and suggest a new name for the hoplonemertean larvae--the decidula.

  19. Apical organs in echinoderm larvae: insights into larval evolution in the Ambulacraria.

    Science.gov (United States)

    Byrne, Maria; Nakajima, Yoko; Chee, Francis C; Burke, Robert D

    2007-01-01

    The anatomy and cellular organization of serotonergic neurons in the echinoderm apical organ exhibits class-specific features in dipleurula-type (auricularia, bipinnaria) and pluteus-type (ophiopluteus, echinopluteus) larvae. The apical organ forms in association with anterior ciliary structures. Apical organs in dipleurula-type larvae are more similar to each other than to those in either of the pluteus forms. In asteroid bipinnaria and holothuroid auricularia the apical organ spans ciliary band sectors that traverse the anterior-most end of the larvae. The asteroid apical organ also has prominent bilateral ganglia that connect with an apical network of neurites. The simple apical organ of the auricularia is similar to that in the hemichordate tornaria larva. Apical organs in pluteus forms differ markedly. The echinopluteus apical organ is a single structure on the oral hood between the larval arms comprised of two groups of cells joined by a commissure and its cell bodies do not reside in the ciliary band. Ophioplutei have a pair of lateral ganglia associated with the ciliary band of larval arms that may be the ophiuroid apical organ. Comparative anatomy of the serotonergic nervous systems in the dipleurula-type larvae of the Ambulacraria (Echinodermata+Hemichordata) suggests that the apical organ of this deuterostome clade originated as a simple bilaterally symmetric nerve plexus spanning ciliary band sectors at the anterior end of the larva. From this structure, the apical organ has been independently modified in association with the evolution of class-specific larval forms.

  20. Brief Exposure to Turbulence Permanently Alters Development of Sand Dollar Larvae

    Science.gov (United States)

    Ferner, M. C.; Hodin, J.; Ng, G.; Lowe, C. J.; Gaylord, B.

    2016-02-01

    Fluid motion underlies interactions between animals and their environment through effects on locomotion, food capture, respiration, information transfer, and other processes. Recent studies of marine invertebrates indicate that metamorphosis and settlement can be altered when swimming larvae experience a change in turbulence intensity, possibly increasing the likelihood that larvae will settle in appropriate habitat. For example, brief exposure to levels of turbulence characteristic of wave-swept coasts causes echinoderm larvae to quickly transition from a non-responsive "pre-competent" stage into a "competent" stage, thereby allowing the larvae to respond to local cues and settle. However, responding to one's entry into the nearshore environment isn't enough, as many such species live as adults in a narrower range of highly specific benthic habitat that is even more rarely encountered. Here we provide an account for this apparent mismatch between larval responses to broadly distributed cues and their need for more specialized settlement locations: turbulence exposure seems to cause larval sand dollars (Dendraster excentricus) to permanently shift from pre-competence to competence. This observation suggests a scenario where turbulence can activate a temporally extensive search image in larvae over a broad habitat range, a seemingly adaptive feature for larvae entering dynamic coastal environments.

  1. Acute ecotoxicology of natural oil and gas condensate to coral reef larvae

    Science.gov (United States)

    Negri, Andrew P.; Brinkman, Diane L.; Flores, Florita; Botté, Emmanuelle S.; Jones, Ross J.; Webster, Nicole S.

    2016-02-01

    Risks posed by oil spills to coral reefs are difficult to evaluate, partially due to the absence of studies that adequately assess toxicity to relevant coral reef species. Here we experimentally tested the acute toxicity of condensate, representing a fraction of light crude oil, to coral (Acropora tenuis) and sponge (Rhopaloeides odorabile) larvae. The metamorphosis of coral larvae was inhibited at total petroleum aromatic hydrocarbon (TPAH) concentrations of water accommodated fractions (WAF) as low as 103 μg l-1, similar to concentrations detected in seawater following large spills. The sensitivity of coral larvae increased by 40% when co-exposed to UV light that they might encounter in shallow reefal systems. Condensate WAF was more toxic to coral larvae than predicted by summing the toxicity of its main components (benzene, toluene, p-xylene and napthalene). In contrast, the sensitivity of sponge larvae to condensate WAF (>10,000 μg l-1 TPAH) was far less than coral in the presence and absence of UV, but similar to that of other marine invertebrates. While these results highlight the relative sensitivity of coral larvae to oil, further research is needed to better understand and predict the impacts and risks posed by hydrocarbons to tropical reef systems.

  2. Predation on Mosquito Larvae by Mesocyclops thermocyclopoides (Copepoda: Cyclopoida) in the Presence of Alternate Prey

    Science.gov (United States)

    Kumar, Ram; Ramakrishna Rao, T.

    2003-11-01

    The cyclopoid copepod Mesocyclops thermocyclopoides, a dominant invertebrate predator in many shallow ponds and temporary water bodies in northern India, feeds on cladocerans, rotifers, ciliates and when present, on mosquito larvae also. We studied in the laboratory the prey consumption rates of the copepod on first and fourth instar larvae of two species of mosquito (Anopheles stephensi and Culex quinquefasciatus) in relation to their density. We also studied its prey selectivity with mosquito larvae in the presence of an alternate prey (the cladocerans-either Moina macrocopa or Ceriodaphnia cornuta) in different proportions. With either mosquito species, the copepod actively selected Instar-I larvae, avoiding the Instar-IV larvae, and with either instar, selected Anopheles stephensi over Culex quinquefasciatus. When prey choice included the cladoceran as an alternate prey, the copepod selected the cladoceran only when the other prey was Instar-IV mosquito larvae. Our results point to the potential and promise of M. thermocyclopoides as a biological agent for controlling larval populations of vectorially important mosquito species.

  3. Correlations of age and growth rate with microbiota composition in Atlantic cod (Gadus morhua) larvae.

    Science.gov (United States)

    Trinh, Ly T T; Bakke, Ingrid; Vadstein, Olav

    2017-08-17

    Little information is available on the link between host development (growth rate and ontogeny) and the composition of the microbiota in fish larvae. This study was carried out to examine potential correlations of microbiota composition with age and growth rate of Atlantic cod larvae. Small and large cod larvae of the same age, representing slow and fast growing individuals, were sampled 10 times during a period of 42 days post hatching (dph), and the composition of the larval microbiota was investigated using a PCR/DGGE (Denaturing Gradient Gel Electrophoresis) strategy. We found significant differences in the intestinal microbiota of small and large larvae of the same age for 4 of the 10 age stages studied. We further found that the variation in the composition of the larval microbiota was more strongly correlated to age than to growth rate for larvae up to 28 dph, whereas for the older larvae growth rate and age was equally correlated to the composition of the microbiota. These results indicate that larval development may structure the microbiota through a change in selection pressure due to host-microbe and microbe-microbe interactions, and that the composition of the microbiota may influence larval development through improved energy gain.

  4. Development changes of cuticular hydrocarbons in Chrysomya rufifacies larvae: potential for determining larval age.

    Science.gov (United States)

    Zhu, G H; Ye, G Y; Hu, C; Xu, X H; Li, K

    2006-12-01

    Age determination is the basis of determining the postmortem interval using necrophagous fly larvae. To explore the potential of using cuticular hydrocarbons for determining the ages of fly larvae, changes of cuticular hydrocarbons in developing larvae of Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae) were investigated using gas chromatography with flame-ionization detection and gas chromatography-mass spectrometry. This study showed that the larvae produced cuticular hydrocarbons typical of insects. Most of the hydrocarbons identified were alkanes with the carbon chain length of 21-31, plus six kinds of alkenes. The hydrocarbon composition of the larvae correlated with age. The statistical results showed that simple peak ratios of n-C29 divided by another eight selected peaks increased significantly with age; their relationships with age could be modelled using exponential or power functions with R(2) close to or > 0.80. These results suggest that cuticular hydrocarbon composition is a useful indicator for determining the age of larval C. rufifacies, especially for post-feeding larvae, which are difficult to differentiate by morphology.

  5. Genomewide analysis indicates that queen larvae have lower methylation levels in the honey bee ( Apis mellifera)

    Science.gov (United States)

    Shi, Yuan Yuan; Yan, Wei Yu; Huang, Zachary Y.; Wang, Zi Long; Wu, Xiao Bo; Zeng, Zhi Jiang

    2013-02-01

    The honey bee is a social insect characterized by caste differentiation, by which a young larva can develop into either a queen or a worker. Despite possessing the same genome, queen and workers display marked differences in reproductive capacity, physiology, and behavior. Recent studies have shown that DNA methylation plays important roles in caste differentiation. To further explore the roles of DNA methylation in this process, we analyzed DNA methylome profiles of both queen larvae (QL) and worker larvae (WL) of different ages (2, 4, and 6 day old), by using methylated DNA immunoprecipitation-sequencing (meDIP-seq) technique. The global DNA methylation levels varied between the larvae of two castes. DNA methylation increased from 2-day- to 4-day-old QL and then decreased in 6-day-old larvae. In WL, methylation levels increased with age. The methylcytosines in both larvae were enriched in introns, followed by coding sequence (CDS) regions, CpG islands, 2 kbp downstream and upstream of genes, and 5' and 3' untranslated regions (UTRs). The number of differentially methylated genes (DMGs) in 2-, 4-, and 6-day-old QL and WL was 725, 3,013, and 5,049, respectively. Compared to 4- and 6-day-old WL, a large number of genes in QL were downmethylated, which were involved in many processes including development, reproduction, and metabolic regulation. In addition, some DMGs were concerned with caste differentiation.

  6. Acute toxicity of two pesticides Diazinon and Deltamethrin on Tench (Tinca tinca larvae and fingerling

    Directory of Open Access Journals (Sweden)

    Mohammad Forouhar Vajargah

    2013-05-01

    Full Text Available Diazinon and deltamethrin are common useful agricultural pesticides in the world. The present research compared the acute toxicity of diazinon and deltamethrin to tench larvae and fingerling. LC50 of 24 h, 48-h, 72 h and 96 h were determined using a probit. Fish samples (21 fish in each test group were exposed to different concentrations of diazinon and deltamethrin (diazinon: for fingerling between1-20 ppm and larvae 0.25-2 ppm, deltamethrin: for fingerling between 0.01-0.2 ppm and larvae 0.0025-0.02 for 96 h and mortality were recorded. The LC50 96 h of diazinon for fingerlings and larvae were 6.77 and 0.63, respectively. The LC50 96 h of deltamethrin for fingerlings and larvae were 0.07 and 0.005 ppm, respectively. According to the results, larvae are more sensitive than fingerlings, LC50 values indicated that deltamethrin is more toxic than diazinon to Tinca tinca, so we suggest to use diazinon instead of deltamethrin in agriculture.

  7. Phage therapy as an approach to prevent Vibrio anguillarum infections in fish larvae production.

    Directory of Open Access Journals (Sweden)

    Yolanda J Silva

    Full Text Available Fish larvae in aquaculture have high mortality rates due to pathogenic bacteria, especially the Vibrio species, and ineffective prophylactic strategies. Vaccination is not feasible in larvae and antibiotics have reduced efficacy against multidrug resistant bacteria. A novel approach to controlling Vibrio infections in aquaculture is needed. The potential of phage therapy to combat vibriosis in fish larvae production has not yet been examined. We describe the isolation and characterization of two bacteriophages capable of infecting pathogenic Vibrio and their application to prevent bacterial infection in fish larvae. Two groups of zebrafish larvae were infected with V. anguillarum (∼106 CFU mL-1 and one was later treated with a phage lysate (∼108 PFU mL-1. A third group was only added with phages. A fourth group received neither bacteria nor phages (fish control. Larvae mortality, after 72 h, in the infected and treated group was similar to normal levels and significantly lower than that of the infected but not treated group, indicating that phage treatment was effective. Thus, directly supplying phages to the culture water could be an effective and inexpensive approach toward reducing the negative impact of vibriosis in larviculture.

  8. Phage therapy as an approach to prevent Vibrio anguillarum infections in fish larvae production.

    Science.gov (United States)

    Silva, Yolanda J; Costa, Liliana; Pereira, Carla; Mateus, Cristiana; Cunha, Angela; Calado, Ricardo; Gomes, Newton C M; Pardo, Miguel A; Hernandez, Igor; Almeida, Adelaide

    2014-01-01

    Fish larvae in aquaculture have high mortality rates due to pathogenic bacteria, especially the Vibrio species, and ineffective prophylactic strategies. Vaccination is not feasible in larvae and antibiotics have reduced efficacy against multidrug resistant bacteria. A novel approach to controlling Vibrio infections in aquaculture is needed. The potential of phage therapy to combat vibriosis in fish larvae production has not yet been examined. We describe the isolation and characterization of two bacteriophages capable of infecting pathogenic Vibrio and their application to prevent bacterial infection in fish larvae. Two groups of zebrafish larvae were infected with V. anguillarum (∼106 CFU mL-1) and one was later treated with a phage lysate (∼108 PFU mL-1). A third group was only added with phages. A fourth group received neither bacteria nor phages (fish control). Larvae mortality, after 72 h, in the infected and treated group was similar to normal levels and significantly lower than that of the infected but not treated group, indicating that phage treatment was effective. Thus, directly supplying phages to the culture water could be an effective and inexpensive approach toward reducing the negative impact of vibriosis in larviculture.

  9. Aedes aegypti survival in the presence of Toxorhynchites violaceus (Diptera: Culicidae fourth instar larvae

    Directory of Open Access Journals (Sweden)

    Daniel S Albeny

    2011-08-01

    Full Text Available The mosquito Aedes aegypti (Linnaeus, 1762 is the main vector of dengue and yellow fever viruses. Different methods have been used to control A. aegypti, including chemical and biological tools. However, chemical control can lead to a subsequent increase in the mosquitoes' insecticide resistance, and biological control represents an important method as an alternative to insecticide usage. Larvae from the Toxorhynchites genus (Diptera: Culicidae are predators of other mosquitoes and represent a potential natural biocontrol agent of A. aegypti larvae. In the present work, A. aegypti larval survival was studied in the presence of the neotropical Toxorhynchites violaceus (Wiedemann, 1821 fourth instar larvae. Toxorhynchites violaceus consumption of A. aegypti increased during the 192 hours of the experiment and was more marked in the intervals between 96 and 120 hours and between 168 and 192 hours, when the A. aegypti survival reached 0%. During the fourth instar, T. violaceus increased its predation on A. aegypti larvae, possibly in order to increase its nutrient storage prior to pupation. Otherwise, low prey consumption can lead to a nutritional deficit for the larvae, delaying the adult's sexual development and reducing its egg production. Here we show that A. aegypti survival can be reduced by the T. violaceus fourth larvae predation under laboratory conditions

  10. On chip cryo-anesthesia of Drosophila larvae for high resolution in vivo imaging applications.

    Science.gov (United States)

    Chaudhury, Amrita Ray; Insolera, Ryan; Hwang, Ran-Der; Fridell, Yih-Woei; Collins, Catherine; Chronis, Nikos

    2017-06-27

    We present a microfluidic chip for immobilizing Drosophila melanogaster larvae for high resolution in vivo imaging. The chip creates a low-temperature micro-environment that anaesthetizes and immobilizes the larva in under 3 minutes. We characterized the temperature distribution within the chip and analyzed the resulting larval body movement using high resolution fluorescence imaging. Our results indicate that the proposed method minimizes submicron movements of internal organs and tissue without affecting the larva physiology. It can be used to continuously immobilize larvae for short periods of time (minutes) or for longer periods (several hours) if used intermittently. The same chip can be used to accommodate and immobilize arvae across all developmental stages (1st instar to late 3rd instar), and loading larvae onto the chip does not require any specialized skills. To demonstrate the usability of the chip, we observed mitochondrial trafficking in neurons from the cell bodies to the axon terminals along with mitochondrial fusion and neuro-synaptic growth through time in intact larvae. Besides studying sub-cellular processes and cellular development, we envision the use of on chip cryo-anesthesia in a wide variety of biological in vivo imaging applications, including observing organ development of the salivary glands, fat bodies and body-wall muscles.

  11. Formetanate toxicity and changes in antioxidant enzyme system of Apis mellifera larvae.

    Science.gov (United States)

    Staroň, Martin; Sabo, Rastislav; Sobeková, Anna; Sabová, Lucia; Legáth, Jaroslav; Lohajová, Ľuboslava; Javorský, Peter

    2017-06-01

    Substantial percentage of world food production depends on pollinating service of honeybees that directly depends on their health status. Among other factors, the success of bee colonies depends on health of developed larvae. The crucial phase of larval development is the first 6 days after hatching when a worker larva grows exponentially and larvae are potentially exposed to xenobiotics via diet. In the present study, we determined the lethal concentration LC 50 (72 h) following single dietary exposure of honeybee larvae to formetanate under laboratory conditions, being also the first report available in scientific literature. Activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) were also measured in the homogenates of in vitro reared honeybee larvae after single formetanate exposure. Decreased specific activity of SOD and increased activities of CAT and GST suggest the induction of oxidative stress. Higher levels of thiobarbituric reactive species in all samples supported this fact. Comparing determined larval toxicity (LC 50 of 206.01 mg a.i./kg diet) with adult toxicity data, we can suppose that the larvae may be less sensitive to formetanate than the adult bees.

  12. Thermal and physical stresses induce a short-term immune priming effect in Galleria mellonella larvae.

    Science.gov (United States)

    Browne, Niall; Surlis, Carla; Kavanagh, Kevin

    2014-04-01

    Exposure of larvae of Galleria mellonella larvae to mild physical (i.e. shaking) or thermal stress for 24h increased their ability to survive infection with Aspergillus fumigatus conidia however larvae stressed in a similar manner but incubated for 72h prior to infection showed no elevation in their resistance to infection with A. fumigatus. Stressed larvae demonstrated an elevated haemocyte density 24h after initiation of the stress event but this declined at 48 and 72h. Larval proteins such as apolipophorin, arylophorin and prophenoloxidase demonstrated elevated expression at 24h but not at 72h. Larvae maintained at 37°C showed increased expression of a range of antimicrobial and immune-related proteins at 24h but these decreased in expression thereafter. The results presented here indicate that G. mellonella larvae are capable of altering their immune response following exposure to mild thermal or physical stress to mount a response capable of counteracting microbial infection which reaches a peak 24h after the initiation of the priming event and then declines by 72h. A short-term immune priming effect may serve to prevent infection but maintaining an immune priming effect for longer periods may be metabolically costly and unnecessary while living within the colony of another insect. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. The promiscuous larvae: flexibility in the establishment of symbiosis in corals

    Science.gov (United States)

    Cumbo, V. R.; Baird, A. H.; van Oppen, M. J. H.

    2013-03-01

    Coral reefs thrive in part because of the symbiotic partnership between corals and Symbiodinium. While this partnership is one of the keys to the success of coral reef ecosystems, surprisingly little is known about many aspects of coral symbiosis, in particular the establishment and development of symbiosis in host species that acquire symbionts anew in each generation. More specifically, the point at which symbiosis is established (i.e., larva vs. juvenile) remains uncertain, as does the source of free-living Symbiodinium in the environment. In addition, the capacity of host and symbiont to form novel combinations is unknown. To explore patterns of initial association between host and symbiont, larvae of two species of Acropora were exposed to sediment collected from three locations on the Great Barrier Reef. A high proportion of larvae established symbiosis shortly after contact with sediments, and Acropora larvae were promiscuous, taking up multiple types of Symbiodinium. The Symbiodinium types acquired from the sediments reflected the symbiont assemblage within a wide range of cnidarian hosts at each of the three sites, suggesting potential regional differences in the free-living Symbiodinium assemblage. Coral larvae clearly have the capacity to take up Symbiodinium prior to settlement, and sediment is a likely source. Promiscuous larvae allow species to associate with Symbiodinium appropriate for potentially novel environments that may be experienced following dispersal.

  14. Morphology of the second- and third-instar larvae of Dermatobia hominis by scanning electron microscopy.

    Science.gov (United States)

    de Filippis, T; Leite, A C

    1998-04-01

    Larvae of Dermatobia hominis 10-27 days old were collected from experimentally infected rats and their morphology was studied by scanning electron microscopy. The moult from the second to third instar occurs at 18 days, with emergence from the host at 30 days post-infection. The second-instar larvae bear on the pseudocephalon, antennae (coeloconic sensilla), and coeloconic and basicoconic sensilla on the maxillary sensory complex. The thoracic segments bear small backwardly-directed spines anteriorly and ventral trichoid and campaniform sensilla. The first four abdominal segments have small and large backwardly-directed spines that are absent on segments five and six. The seventh and eighth abdominal segments have medium-sized forwardly-directed spines. Abdominal segments are encircled by campaniform sensilla. The terminal end of the eighth abdominal segment bears the anus, prominent anal lobes and two spiracular openings on each spiracular plate. Spiracular plates show a radial sun ray pattern. The rear abdomen also bears an ecdysal aperture, several pores and eight coeloconic sensilla. Although there are slight morphological differences, the spines (predominantly flat and thorn-like) and sensilla (campaniform and coeloconic) of the third-instar larvae show a similar arrangement to that of second-instar larvae. Thoracic trichoid sensilla are not seen in third-instar larvae. A perispiracular gland aperture is situated above each posterior spiracular opening. These morphological features are compared with those of other cuterebrid larvae.

  15. Density, Viability Conidia And Symptoms of Metarhizium anisopliae infection on Oryctes rhinoceros larvae

    Science.gov (United States)

    Indriyanti, D. R.; Putri, R. I. P.; Widiyaningrum, P.; Herlina, L.

    2017-04-01

    M. anisopliae is parasitic fungus on insect pests; it is used as a biocontrol agent. M. anisopliae can be propagated on maize or rice substrate. M. anisopliae is currently sold in the form of kaolin powder formulations. Before it is used to check the density, viability and pathogenicity of M. anisopliae. However the problem is the kaolin powder very soft, so it difficult to distinguish between kaolin and conidia. This article gives information on how to calculate conidia density, viability and symptoms of M. anisopliae infection on Oryctes rhinoceros larvae. The study was conducted in the laboratory to determine the density and viability. The pathogenicity testing was done using pots. The Pot is containing soil substrate mixed with M. Anispoliae and ten tails O. Rhinoceros larvae per pot. The results showed that the density of M. anisopliae conidia was 1.81 x 108 conidia mL-1 and the viability was 94% within 24 hours. The larval mortality began to emerge in the 1st week, and all larvae died at the sixth week. The symptom of M. anisopliae infection on Oryctes rhinoceros larvae, there was a black spot on the larval integument. The larvae movements become slow and poor appetite; it will die within 3-7 days. The larvae die hard, and the white hyphae grow on the body surface that turns green.

  16. Temporal and Spatial Distribution Patterns of Echinoderm Larvae in La Parguera, Puerto Rico

    Directory of Open Access Journals (Sweden)

    Stacey M Williams

    2010-10-01

    Full Text Available This study describes temporal and spatial abundance patterns of echinoderm larvae in La Parguera, Puerto Rico. For the temporal study, larvae were sampled by a series of monthly tows taken with a 64μm mesh net between the new and full moon from April 2005 to July 2006, September 2006 and August 2007. In order to measure spatial variation of echinoderm larval bundances, oblique tows were taken with 64 and 202μm mesh nets at seven different sites within the shelf, at the shelf-edge, and at a nearby oceanic stations during August 2007. Overall, Echinoidea (sea urchin exhibited the highest abundance with a total of 11 921 larvae, representing 52.5% of the total collection. Ophiuroidea (brittle star ranked second in abundance with 45.6% of the total larvae. Holothuroidea (sea cucumber and Asteroidea larvae (sea star accounted for less than 2% of the total echinoderm larval collection. Early larval stages (2-8 day old of Diadema antillarum represented 20% of the total Echinoidea larvae. There was no marked seasonal trend of echinoderm larval abundance; Echinoidea and Ophiuroidea larvae were present in all monthly samples indicating that reproduction occurs year-round. Peak abundances of later-stage Echinoidea larvae were observed during January, July and October and of later-stage Ophiuroidea larvae during June, August and October. The observed peaks of later-stage larval abundances may be indicative of higher recruitment activity during these months. There was a significant difference of echinoderm larval abundance between spatial stations, with higher abundances collected at the shelf-edge. Later-stage (~24 day old D. antillarum larvae were mostly collected at shelf-edge and oceanic locations. In addition, the 64mm mesh net was more efficient for collection of echinoderm larvae than the 202mm mesh net. Rev. Biol. Trop. 58 (Suppl. 3: 81-88. Epub 2010 October 01.Este estudio describe patrones de abundancia temporal y espacial de larvas de

  17. AKTIVITAS INSEKTISIDA BAGIAN TUMBUHAN CALOPHYLLUM SOULTTRI BURM.F. (CLU IACEAE TERHADAP LARVA LEPIDOPTERA

    Directory of Open Access Journals (Sweden)

    Edy Syahputra

    2014-08-01

    Full Text Available The objective of this test was evaluate the insecticidal activity of ectract of some parts of Calophyllum soulattri (Clusiaceae against larvae of three species of Lepidoptera, i. e Crocidolomia pavonana, Plutella xylostela, and Pieris sp.. Extraction of plant materials was done by infusion method using ethanol. The bioassays were conducted by leaf-feeding method. Second-instar larvae were fed extract-treated broccoli leaves of 48 hours, then they were presented with untreated leaves until the surviving larvae larvae reached the fourth-instar stage. The number of dead larvae was recorded daily an larval mortality date were analyzed by probit method. The result showed the gummy bark exudates and bark extract of old and young C. soulattri plants were highly active against C. pavonana. The abrk extact of old C. soulattri plant was also effective against P. xilostella and Pieris sp. The gummy exudates possessed strong insecticidal activity against C. pavonana larvae with LC50 of 0.04% and prolonged the developmental time from second to fourth instar of C. soulattri 2.03-7.25 days compared with control. The bark excudate gave positive respon to alkaloid flavonoid, and tannin test. Futher studies are needed to identify insecticidal compound in those active extracts.

  18. Acute ecotoxicology of natural oil and gas condensate to coral reef larvae.

    Science.gov (United States)

    Negri, Andrew P; Brinkman, Diane L; Flores, Florita; Botté, Emmanuelle S; Jones, Ross J; Webster, Nicole S

    2016-02-19

    Risks posed by oil spills to coral reefs are difficult to evaluate, partially due to the absence of studies that adequately assess toxicity to relevant coral reef species. Here we experimentally tested the acute toxicity of condensate, representing a fraction of light crude oil, to coral (Acropora tenuis) and sponge (Rhopaloeides odorabile) larvae. The metamorphosis of coral larvae was inhibited at total petroleum aromatic hydrocarbon (TPAH) concentrations of water accommodated fractions (WAF) as low as 103 μg l(-1), similar to concentrations detected in seawater following large spills. The sensitivity of coral larvae increased by 40% when co-exposed to UV light that they might encounter in shallow reefal systems. Condensate WAF was more toxic to coral larvae than predicted by summing the toxicity of its main components (benzene, toluene, p-xylene and napthalene). In contrast, the sensitivity of sponge larvae to condensate WAF (>10,000 μg l(-1) TPAH) was far less than coral in the presence and absence of UV, but similar to that of other marine invertebrates. While these results highlight the relative sensitivity of coral larvae to oil, further research is needed to better understand and predict the impacts and risks posed by hydrocarbons to tropical reef systems.

  19. Metamorfosis del aparato digestivo de larvas carnívoras de Ceratophrys cranwelli (Anura: Leptodactylidae

    Directory of Open Access Journals (Sweden)

    Ulloa Kreisel, Zandra E.

    2000-12-01

    Full Text Available Las larvas carnívoras de Ceratophrys cranwelli presentan un tubo digestivo más corto que la mayoría de las larvas de anuros, tiene 6 veces la longitud del cuerpo del renacuajo y se caracteriza también por tener un estómago larval. El presente trabajo tiene como objetivo el determinar el grado de transformaciones en la cavidad bucofaríngea y tubo digestivo en larvas de esta especie durante la metamorfosis y comparar las estructuras digestivas estudiadas en otras especies de Leptodactylidae de la subfamilia Ceratophryinae y especies con otros hábitos alimenticios. Carnivorous larvae from Ceratophrys cranwelli present a digestive tube shorter than most of the anuran larvae, have 6 times a tadpole’s body length and they are also characterized by the presence of a larval stomach. The aim of this work is determine the grade of transformations in the buccopharyngeal cavity and digestive tube during the metamorphosis in larvae of this species and compare the digestive structures studied in other species of Leptodactylidae of the subfamily Ceratophryinae and another species with different diets.

  20. A role for eosinophils in the intestinal immunity against infective Ascaris suum larvae.

    Directory of Open Access Journals (Sweden)

    Dries Masure

    Full Text Available The aim of this study was to explore the mechanisms of resistance against invading Ascaris suum larvae in pigs. Pigs received a low dose of 100 A. suum eggs daily for 14 weeks. This resulted in a >99% reduction in the number of larvae that could migrate through the host after a challenge infection of 5000 A. suum eggs, compared to naïve pigs. Histological analysis at the site of parasite entry, i.e. the caecum, identified eosinophilia, mastocytosis and goblet cell hyperplasia. Increased local transcription levels of genes for IL5, IL13, eosinophil peroxidase and eotaxin further supported the observed eosinophil influx. Further analysis showed that eosinophils degranulated in vitro in response to contact with infective Ascaris larvae in the presence of serum from both immune and naïve animals. This effect was diminished with heat-inactivated serum, indicating a complement dependent mechanism. Furthermore, eosinophils were efficient in killing the larvae in vitro when incubated together with serum from immune animals, suggesting that A. suum specific antibodies are required for efficient elimination of the larvae. Together, these results indicate an important role for eosinophils in the intestinal defense against invading A. suum larvae.

  1. A role for eosinophils in the intestinal immunity against infective Ascaris suum larvae.

    Science.gov (United States)

    Masure, Dries; Vlaminck, Johnny; Wang, Tao; Chiers, Koen; Van den Broeck, Wim; Vercruysse, Jozef; Geldhof, Peter

    2013-01-01

    The aim of this study was to explore the mechanisms of resistance against invading Ascaris suum larvae in pigs. Pigs received a low dose of 100 A. suum eggs daily for 14 weeks. This resulted in a >99% reduction in the number of larvae that could migrate through the host after a challenge infection of 5000 A. suum eggs, compared to naïve pigs. Histological analysis at the site of parasite entry, i.e. the caecum, identified eosinophilia, mastocytosis and goblet cell hyperplasia. Increased local transcription levels of genes for IL5, IL13, eosinophil peroxidase and eotaxin further supported the observed eosinophil influx. Further analysis showed that eosinophils degranulated in vitro in response to contact with infective Ascaris larvae in the presence of serum from both immune and naïve animals. This effect was diminished with heat-inactivated serum, indicating a complement dependent mechanism. Furthermore, eosinophils were efficient in killing the larvae in vitro when incubated together with serum from immune animals, suggesting that A. suum specific antibodies are required for efficient elimination of the larvae. Together, these results indicate an important role for eosinophils in the intestinal defense against invading A. suum larvae.

  2. Performance of Anastrepha obliqua (Diptera, Tephritidae larvae fed on artificial diets Desempenho das larvas de Anastrepha obliqua (Diptera, Tephritidae alimentadas com dietas artificiais

    Directory of Open Access Journals (Sweden)

    Tânia M. L. Fontellas-Brandalha

    2010-06-01

    Full Text Available Moscas das frutas do gênero Anastrepha Schiner, 1868 são conhecidas por sua importância econômica devido aos danos que elas causam nos frutos comerciais. As exigências nutricionais dos estágios imaturo e adulto são diferentes e as larvas não se desenvolvem bem utilizando a mesma dieta do adulto. Embora as necessidades nutricionais básicas dos insetos sejam bem conhecidas, existe ainda o problema de elaborar dietas de criação adequadas para espécies com necessidades específicas. O objetivo deste trabalho foi verificar o efeito de diferentes tipos e quantidades de carboidratos na dieta sobre a performance larval de Anastrepha obliqua (Macquart, 1835. Larvas foram criadas individualmente em tubos de ensaio contendo uma das dietas artificiais a serem testadas onde elas foram mantidas até a pupação. A composição básica das dietas testadas incluia 2,5 g de agar, 3,25 g de levedo de cerveja e quantidades variadas de sacarose e farinha de trigo. A adequação do meio artificial para A. obliqua foi testada pela avaliação da sobrevivência larval e pupal (% e o tempo de desenvolvimento larval, pupal e de larva-adulto. A dieta contendo farinha de trigo (2 g e sacarose (2 g e a dieta somente com sacarose (5,5 g foram as que apresentaram melhor performance larval. Todas as dietas testadas apresentaram resultados similares ou superiores às dietas utilizadas em outros trabalhos. A importância da presença da farinha de trigo e seu valor nutricional para as larvas são discutidos.Fruit flies of the genus Anastrepha Schiner, 1868 are well-known for having economical importance since they damage commercially cultivated fruits. Nutritional demands during the immature and adult stages are different, so the larvae do not develop well using the same diet as the adults. Although the insect basic nutritional needs are well-known, there is also the challenge to elaborate rearing diets adequate to species with specific needs. The aim of this study

  3. In Vivo Cardiotoxicity Induced by Sodium Aescinate in Zebrafish Larvae

    Directory of Open Access Journals (Sweden)

    Jinfeng Liang

    2016-02-01

    Full Text Available Sodium aescinate (SA is a widely-applied triterpene saponin product derived from horse chestnut seeds, possessing vasoactive and organ-protective activities with oral or injection administration in the clinic. To date, no toxicity or adverse events in SA have been reported, by using routine models (in vivo or in vitro, which are insufficient to predict all aspects of its pharmacological and toxicological actions. In this study, taking advantage of transparent zebrafish larvae (Danio rerio, we evaluated cardiovascular toxicity of SA at doses of 1/10 MNLC, 1/3 MNLC, MNLC and LC10 by yolk sac microinjection. The qualitative and quantitative cardiotoxicity in zebrafish was assessed at 48 h post-SA treatment, using specific phenotypic endpoints: heart rate, heart rhythm, heart malformation, pericardial edema, circulation abnormalities, thrombosis and hemorrhage. The results showed that SA at 1/10 MNLC and above doses could induce obvious cardiac and pericardial malformations, whilst 1/3 MNLC and above doses could induce significant cardiac malfunctions (heart rate and circulation decrease/absence, as compared to untreated or vehicle-treated control groups. Such cardiotoxic manifestations occurred in more than 50% to 100% of all zebrafish treated with SA at MNLC and LC10. Our findings have uncovered the potential cardiotoxicity of SA for the first time, suggesting more attention to the risk of its clinical application. Such a time- and cost-saving zebrafish cardiotoxicity assay is very valid and reliable for rapid prediction of compound toxicity during drug research and development.

  4. Enantioselective bioaccumulation of diniconazole in Tenebrio molitor larvae.

    Science.gov (United States)

    Liu, Chen; LV, Xiao Tian; Zhu, Wen Xue; QU, Hao Yang; Gao, Yong Xin; Guo, Bao Yuan; Wang, Hui Li

    2013-12-01

    The enantioselective bioaccumulation of diniconazole in Tenebrio molitor Linne larva was investigated with liquid chromatography tandem mass spectrometry based on the ChiralcelOD-3R[cellulose tri-(3,5-dimethylphenyl carbamate)] column. In this study we documented the effects of dietary supplementation with wheat bran contaminated by racemic diniconazole at two dose levels of 20 mg kg(-1) and 2 mg kg(-1) (dry weight) in Tenebrio molitor. The results showed that both doses of diniconazole were taken up by Tenebrio molitor rapidly in the first few days, the concentrations of R-enantiomer and S-enantiomer at high doses reached the highest level of 0.55 mg kg(-1) and 0.48 mg kg(-1) , respectively, on the 1(st) d, and the concentrations of them obtained a maxima of 0.129 mg kg(-1) and 0.128 mg kg(-1) at low dose, respectively, on the 3(rd) d, which means that the concentration of diniconazole was proportional to the time of achieving the highest accumulated level. It afterwards attained equilibrium after a sharp decline at both 20 mg kg(-1) and 2 mg kg(-1) of diniconazole. The determination results from the feces of Tenebrio molitor demonstrated that the extraction recovery (ER) values of the high dose group were higher than that of the low dose group and the values were all above 1; therefore, it could be inferred that enantiomerization existed in Tenebrio molitor. Additionally, the biota accumulation factor was used to evaluate the bioaccumulation of diniconazole enantiomers, showing that the bioaccumulation of diniconazole in Tenebrio molitor was enantioselective with preferential accumulation of S-enantiomer. © 2013 Wiley Periodicals, Inc.

  5. Behavioral Responses of Concholepas concholepas (Bruguière, 1789) Larvae to Natural and Artificial Settlement Cues and Microbial Films.

    Science.gov (United States)

    Rodriguez, S R; Riquelme, C; Campos, E O; Chavez, P; Brandan, E; Inestrosa, N C

    1995-12-01

    The behavioral responses of veliger larvae of the gastropod Concholepas concholepas were studied in the presence of different natural and artificial settlement cues and microbial films. Early pre-competent larvae stopped swimming, sank (due to ciliary arrests, retraction of the velum into the shell, or both), and remained inactive on the substratum when exposed to conspecific mucus and hemolymph. In both cases the effect was time-dependent and the number of larvae showing these behaviors decreased over time. Larvae exposed to NH4Cl (ammonium ion) showed a similar time- and dose-dependent response. A positive and time-dependent response was also observed when larvae were exposed to different extracellular matrix (ECM) components (i.e., collagen, gelatin, and fibronectin) and sulfated polysaccharides (i.e., carrageenan, heparin, and chondroitin sulfate). In this case the larvae remained attached to the substratum. However, the effect of sulfated polysaccharides on C. concholepas larval behavior was faster than that observed with other ECM molecules. We also studied the responses of premetamorphic C. concholepas larvae exposed to different microbial films. In chemotaxis experiments with different films, with glass as the substratum, larvae showed a significant preference for multispecific and diatoms films. When shells of C. concholepas were used as the substratum, the preference for multispecific films was clear and significant. Likewise, larvae showed velar contractions in the presence of all the films tested. Larvae exposed to multispecific films and to the microalga Prasinocladus marinus showed an increased ciliar movement. The finding that mucus and hemolymph of conspecific adults and ECM molecules (mainly sulfated polysaccharides) induce the cessation of swimming of C. concholepas larvae suggests a possible role for cell-surface receptors in mediating the larval response of marine organisms. Likewise, the positive chemotaxis responses of C. concholepas larvae to

  6. Ecdysis Triggering Hormone Signaling (ETH/ETHR-A Is Required for the Larva-Larva Ecdysis in Bactrocera dorsalis (Diptera: Tephritidae

    Directory of Open Access Journals (Sweden)

    Yan Shi

    2017-08-01

    Full Text Available Insects must undergo ecdysis for successful development and growth, and the ecdysis triggering hormone (ETH, released by the Inka cells, is a master hormone in this process. In this study, we determined the sequence of the ETH precursor and receptors in an agriculturally important pest insect, the oriental fruit fly Bactrocera dorsalis (Hendel. We identified two functionally distinct splice receptor isoforms: BdETH-R-A and BdETH-R-B, and when expressed in Chinese hamster ovary (CHO-WTA11 cells, they exhibited a high sensitivity to the two mature peptides BdETH1 and BdETH2. The BdETH transcript was detected in the tracheal tissue of the larvae. Inka cells were identified with immunohistochemical antibody staining against Drosophila melanogaster ETH1, and in situ hybridization with specific DNA probes. Selective RNA silencing of BdETH or BdETH-R-A, but not of BdETH-R-B, caused developmental failure at ecdysis. The dsRNA-treated larvae displayed tracheal defects and could not shed the old cuticle followed by death. Our results demonstrated that BdETH, via activation of BdETH-R-A but not ETH-R-B, plays an essential role in regulating the process of larva-larva ecdysis in B. dorsalis.

  7. Crescimento e sobrevivência de larvas de peixe vermelho (Carassius auratus alimentadas com microdietas comerciais Growth and survival of Carassius auratus larvae fed commercial micro diets

    Directory of Open Access Journals (Sweden)

    P. Rema

    2009-06-01

    Full Text Available Para avaliar o desempenho de dois alimentos comerciais para larvas de peixes ornamentais e analisar o efeito que a suplementação em vitaminas e minerais teria sobre a sobrevivência e o crescimento dessas, foi realizado um ensaio de crescimento de 21 dias, com 4800 larvas de peixe vermelho (Carassius auratus, distribuídas por 24 grupos (200 indivíduos por grupo. Cada grupo foi alojado em tanques de 5L de capacidade, ligados a um sistema de recirculação de água. Quatro grupos foram alocados a um controle de jejum, em que os animais não foram alimentados, e os restantes 20 grupos foram utilizados em cinco tratamentos, em quadruplicado. Em cada um dos cinco tratamentos, os peixes ingeriram uma das seguintes dietas: R (referência, C1 (SERA vipan® baby, C2 (SERA® microgran, C1v e C2v (C1 e C2, respectivamente, reforçadas em vitaminas e minerais. As taxas de sobrevivência e crescimento dos peixes do tratamento R foram maiores que as obtidas nos outros tratamentos (PA 21-day growth trial was performed to evaluate two ornamental fish larvae commercial diets and the effect of mineral and vitamin supplementation of the same commercial microdiets on growth and survival of goldfish larvae (Carassius auratus. A total of 4,800 larvae were randomly distributed in 24 groups of 200 individuals. Each group was housed in a 5L tank, connected to a recirculating water system. Four groups were assigned to a fastening control. The animals in these groups did not receive any food. The remaining 20 groups were distributed in five treatments, in quadruplicate. The animals of each treatment were fed one of five experimental diets: R (reference, C1 (SERA vipan® baby, C2 (SERA® microgran, C1v, and C2v (C1 and C2, respectively, reinforced with minerals and vitamins. At the end of the trial, high survival and growth rates were observed in R treatment. There were significant differences in total length and total weight among dietary treatments. Considering the

  8. The distribution of dragonfly larvae in a South Carolina stream: relationships with sediment type, body size, and the presence of other larvae.

    Science.gov (United States)

    Worthen, Wade B; Horacek, Henry Joseph

    2015-01-01

    Dragonfly larvae were sampled in Little Creek, Greenville, SC. The distributions of five common species were described relative to sediment type, body size, and the presence of other larvae. In total, 337 quadrats (1 m by 0.5 m) were sampled by kick seine. For each quadrat, the substrate was classified as sand, sand-cobble mix, cobble, coarse, or rock, and water depth and distance from bank were measured. Larvae were identified to species, and the lengths of the body, head, and metafemur were measured. Species were distributed differently across sediment types: sanddragons, Progomphus obscurus (Rambur) (Odonata: Gomphidae), were common in sand; twin-spotted spiketails, Cordulegaster maculata Selys (Odonata: Cordulegastridae), preferred a sand-cobble mix; Maine snaketails, Ophiogomphus mainensis Packard (Odonata: Gomphidae), preferred cobble and coarse sediments; fawn darners, Boyeria vinosa (Say) (Odonata: Aeshnidae), preferred coarse sediments; and Eastern least clubtails, Stylogomphus albistylus (Hagen) (Odonata: Gomphidae), preferred coarse and rock sediments. P. obscurus and C. maculata co-occurred more frequently than expected by chance, as did O. mainensis, B. vinosa, and S. albistylus. Mean size varied among species, and species preferences contributed to differences in mean size across sediment types. There were significant negative associations among larval size classes: small larvae (15 mm) than expected by chance, and large larvae were alone in quadrats more frequently than other size classes. Species may select habitats at a large scale based on sediment type and their functional morphology, but small scale distributions are consistent with competitive displacement or intraguild predation. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

  9. Evaluation of culture media for Paenibacillus larvae applied to studies of antimicrobial activity Evaluación de medios de cultivo para el crecimiento de Paenibacillus larvae aplicables en estudios de actividad antimicrobiana

    OpenAIRE

    L. B. Gende; M. J. Eguaras; R. Fritz

    2008-01-01

    This study was conducted to compare different liquid culture media for Paenibacillus larvae growth in order to find the best one to be used in studies on activity of antimicrobial substances, such as essential oils. P. larvae presented poor growth in usual broths such as Mueller-Hinton, commonly employed in antimicrobial activity assays. Growth in liquid media was evaluated using Paenibacillus larvae strains isolated from hives located in different geographical zones. The MYT medium (Mueller-...

  10. Identification of feeding stimulants in corn roots for western corn rootworm (Coleoptera: Chrysomelidae) larvae.

    Science.gov (United States)

    Bernklau, E J; Bjostad, L B

    2008-04-01

    Using a bioassay-driven approach, we have isolated and identified a blend of compounds from the roots of germinating corn, Zea mays L., that serve as feeding stimulants for neonate western corn rootworm larvae, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae). The active blend is a combination of simple sugars (30:4:4 mg/ml glucose:fructose:sucrose in the corn root) plus at least one of the free fatty acids in germinating corn roots (2:5 mg/ml oleic acid:linoleic acid in the corn root). When an extract of germinating corn was partitioned into an ethyl acetate fraction and an aqueous fraction, full feeding occurred only when the two fractions were recombined, indicating that the phagostimulant was comprised of both polar and nonpolar components. Gas chromatography-mass spectrometry analysis of root extracts from germinating corn seedlings revealed a blend of 20 compounds from a variety of chemical classes, including small sugars, diacids, amino acids, inorganic compounds, and free fatty acids. When the major components were tested in feeding bioassays, the sugars and lipids were shown to be essential for feeding by larvae, but the two classes of compounds were only effective when combined. The sugars alone elicited feeding by only 40% of larvae, but the percentage of larvae feeding was increased significantly with the addition of linoleic acid (91.7% larvae feeding) or oleic acid (85.8% larvae feeding). The amino acids alone were not essential elements for feeding by western corn rootworm larvae.

  11. Effect of titanium dioxide nanoparticles on the bioavailability, metabolism, and toxicity of pentachlorophenol in zebrafish larvae

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Qi [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Shi, Xiongjie [College of Life Sciences, Wuhan University, Wuhan 430072 (China); Zhang, Liping [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Wang, Qiangwei; Wang, Xianfeng [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Guo, Yongyong [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Zhou, Bingsheng, E-mail: bszhou@ihb.ac.cn [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China)

    2015-02-11

    Highlights: • Effects of n-TiO{sub 2} on toxicity of PCP in zebrafish larvae were investigated. • Co-exposure n-TiO{sub 2} enhanced metabolism of PCP to tetrachlorohydroquinone in larvae. • Co-exposure n-TiO{sub 2} increased oxidative damage and developmental toxicity in larvae. • NPs may influence toxicity of associated organic pollutants in the aquatic environment. - Abstract: This study investigated the influence of titanium dioxide nanoparticles (n-TiO{sub 2}) on the bioavailability, metabolism, and toxicity of pentachlorophenol (PCP) in fish. Zebrafish (Danio rerio) embryos or larvae (2-h post-fertilization) were exposed to PCP (0, 3, 10, and 30 μg/L) alone or in combination with n-TiO{sub 2} (0.1 mg/L) until 6 days post-fertilization. Results showed that n-TiO{sub 2} treatment alone did not induce lipid peroxidation, DNA damage, as well as the generation of reactive oxygen species (ROS) in the larvae. As compared with PCP treatment, the co-exposure of PCP and n-TiO{sub 2} enhanced the induction of ROS generation, eventually leading to lipid peroxidation and DNA damage. The nuclear factor erythroid 2-related factor 2 gene transcriptions were significantly upregulated in both PCP treatment alone and in combination with n-TiO{sub 2}. Chemical analysis and histological examination showed that n-TiO{sub 2} adsorb PCP, and n-TiO{sub 2} are taken up by developing zebrafish larvae; however, PCP content was not enhanced in the presence of n-TiO{sub 2}, but the metabolism of PCP to tetrachlorohydroquinone was enhanced in larvae. The results indicate that n-TiO{sub 2} enhanced the metabolism of PCP and caused oxidative damage and developmental toxicity, suggesting that NPs can influence the fate and toxicity of associated organic pollutants in the aquatic environment.

  12. Differential Protein Expression in Honeybee (Apis mellifera L.) Larvae: Underlying Caste Differentiation

    Science.gov (United States)

    Li, Jianke; Wu, Jing; Begna Rundassa, Desalegn; Song, Feifei; Zheng, Aijuan; Fang, Yu

    2010-01-01

    Honeybee (Apis mellifera) exhibits divisions in both morphology and reproduction. The queen is larger in size and fully developed sexually, while the worker bees are smaller in size and nearly infertile. To better understand the specific time and underlying molecular mechanisms of caste differentiation, the proteomic profiles of larvae intended to grow into queen and worker castes were compared at 72 and 120 hours using two dimensional electrophoresis (2-DE), network, enrichment and quantitative PCR analysis. There were significant differences in protein expression between the two larvae castes at 72 and 120 hours, suggesting the queen and the worker larvae have already decided their fate before 72 hours. Specifically, at 72 hours, queen intended larvae over-expressed transketolase, aldehyde reductase, and enolase proteins which are involved in carbohydrate metabolism and energy production, imaginal disc growth factor 4 which is a developmental related protein, long-chain-fatty-acid CoA ligase and proteasome subunit alpha type 5 which metabolize fatty and amino acids, while worker intended larvae over-expressed ATP synthase beta subunit, aldehyde dehydrogenase, thioredoxin peroxidase 1 and peroxiredoxin 2540, lethal (2) 37 and 14-3-3 protein epsilon, fatty acid binding protein, and translational controlled tumor protein. This differential protein expression between the two caste intended larvae was more pronounced at 120 hours, with particular significant differences in proteins associated with carbohydrate metabolism and energy production. Functional enrichment analysis suggests that carbohydrate metabolism and energy production and anti-oxidation proteins play major roles in the formation of caste divergence. The constructed network and validated gene expression identified target proteins for further functional study. This new finding is in contrast to the existing notion that 72 hour old larvae has bipotential and can develop into either queen or worker based on

  13. Oxidative Stress and Digestive Enzyme Activity of Flatfish Larvae in a Changing Ocean

    Science.gov (United States)

    Pimentel, Marta S.; Faleiro, Filipa; Diniz, Mário; Machado, Jorge; Pousão-Ferreira, Pedro; Peck, Myron A.; Pörtner, Hans O.; Rosa, Rui

    2015-01-01

    Until now, it is not known how the antioxidant and digestive enzymatic machinery of fish early life stages will change with the combined effects of future ocean acidification and warming. Here we show that high pCO2 (~1600 μatm) significantly decreased metabolic rates (up to 27.4 %) of flatfish larvae, Solea senegalensis, at both present (18 °C) and warmer temperatures (+4 °C). Moreover, both warming and hypercapnia increased the heat shock response and the activity of antioxidant enzymes, namely catalase (CAT) and glutathione S-transferase (GST), mainly in post-metamorphic larvae (30 dph). The lack of changes in the activity of CAT and GST of pre-metamorphic larvae (10 dph) seems to indicate that earlier stages lack a fully-developed antioxidant defense system. Nevertheless, the heat shock and antioxidant responses of post-metamorphic larvae were not enough to avoid the peroxidative damage, which was greatly increased under future environmental conditions. Digestive enzymatic activity of S. senegalensis larvae was also affected by future predictions. Hypercapnic conditions led to a decrease in the activity of digestive enzymes, both pancreatic (up to 26.1 % for trypsin and 74.5 % for amylase) and intestinal enzymes (up to 36.1 % for alkaline phosphatase) in post-metamorphic larvae. Moreover, the impact of ocean acidification and warming on some of these physiological and biochemical variables (namely, lower OCR and higher HSP and MDA levels) were translated into larvae performance, being significantly correlated with decreased larval growth and survival or increased incidence of skeletal deformities. The increased vulnerability of flatfish early life stages under future ocean conditions is expected to potentially determine recruitment and population dynamics in marine ecosystems. PMID:26221723

  14. PFOS induces behavioral alterations, including spontaneous hyperactivity that is corrected by dexamfetamine in zebrafish larvae.

    Directory of Open Access Journals (Sweden)

    Stefan Spulber

    Full Text Available Perfluorooctane sulfonate (PFOS is a widely spread environmental contaminant. It accumulates in the brain and has potential neurotoxic effects. The exposure to PFOS has been associated with higher impulsivity and increased ADHD prevalence. We investigated the effects of developmental exposure to PFOS in zebrafish larvae, focusing on the modulation of activity by the dopaminergic system. We exposed zebrafish embryos to 0.1 or 1 mg/L PFOS (0.186 or 1.858 µM, respectively and assessed swimming activity at 6 dpf. We analyzed the structure of spontaneous activity, the hyperactivity and the habituation during a brief dark period (visual motor response, and the vibrational startle response. The findings in zebrafish larvae were compared with historical data from 3 months old male mice exposed to 0.3 or 3 mg/kg/day PFOS throughout gestation. Finally, we investigated the effects of dexamfetamine on the alterations in spontaneous activity and startle response in zebrafish larvae. We found that zebrafish larvae exposed to 0.1 mg/L PFOS habituate faster than controls during a dark pulse, while the larvae exposed to 1 mg/L PFOS display a disorganized pattern of spontaneous activity and persistent hyperactivity. Similarly, mice exposed to 0.3 mg/kg/day PFOS habituated faster than controls to a new environment, while mice exposed to 3 mg/kg/day PFOS displayed more intense and disorganized spontaneous activity. Dexamfetamine partly corrected the hyperactive phenotype in zebrafish larvae. In conclusion, developmental exposure to PFOS in zebrafish induces spontaneous hyperactivity mediated by a dopaminergic deficit, which can be partially reversed by dexamfetamine in zebrafish larvae.

  15. The innate immune and systemic response in honey bees to a bacterial pathogen, Paenibacillus larvae

    Directory of Open Access Journals (Sweden)

    Foster Leonard J

    2009-08-01

    Full Text Available Abstract Background There is a major paradox in our understanding of honey bee immunity: the high population density in a bee colony implies a high rate of disease transmission among individuals, yet bees are predicted to express only two-thirds as many immunity genes as solitary insects, e.g., mosquito or fruit fly. This suggests that the immune response in bees is subdued in favor of social immunity, yet some specific immune factors are up-regulated in response to infection. To explore the response to infection more broadly, we employ mass spectrometry-based proteomics in a quantitative analysis of honey bee larvae infected with the bacterium Paenibacillus larvae. Newly-eclosed bee larvae, in the second stage of their life cycle, are susceptible to this infection, but become progressively more resistant with age. We used this host-pathogen system to probe not only the role of the immune system in responding to a highly evolved infection, but also what other mechanisms might be employed in response to infection. Results Using quantitative proteomics, we compared the hemolymph (insect blood of five-day old healthy and infected honey bee larvae and found a strong up-regulation of some metabolic enzymes and chaperones, while royal jelly (food and energy storage proteins were down-regulated. We also observed increased levels of the immune factors prophenoloxidase (proPO, lysozyme and the antimicrobial peptide hymenoptaecin. Furthermore, mass spectrometry evidence suggests that healthy larvae have significant levels of catalytically inactive proPO in the hemolymph that is proteolytically activated upon infection. Phenoloxidase (PO enzyme activity was undetectable in one or two-day-old larvae and increased dramatically thereafter, paralleling very closely the age-related ability of larvae to resist infection. Conclusion We propose a model for the host response to infection where energy stores and metabolic enzymes are regulated in concert with direct

  16. Distribution and transport patterns of northern rock sole, Lepidopsetta polyxystra, larvae in the southeastern Bering Sea

    Science.gov (United States)

    Lanksbury, Jennifer A.; Duffy-Anderson, Janet T.; Mier, Kathryn L.; Busby, Morgan S.; Stabeno, Phyllis J.

    2007-01-01

    We report the size, abundance, and distribution (horizontal, vertical) of northern rock sole, Lepidopsetta polyxystra, larvae collected from ichthyoplankton surveys on the southeastern Bering Sea shelf near Unimak Island, in Unimak Pass, and in the Gulf of Alaska south of Unimak Island. The greatest abundances of larvae occurred within Unimak Pass and in the Bering Sea northeast of Unimak Island. Larvae were smaller and more abundant in 2002 than in 2003. Larval abundance and size varied with depth. Highest abundances were at depths of 10-30 m during the day, and larger fish appeared to migrate from below 20 m to 0-10 m at night. There was evidence of multiple spawning locales and larval dispersal pathways that were depth- and area-specific. Northern rock sole larvae spawned west of Unimak Pass along the Aleutian Islands may be transported northward by the Bering Slope Current. Larvae spawned in the Gulf of Alaska and advected through Unimak Pass are differentially dispersed, primarily to the middle and outer shelves along the 100 m and 200 m isobaths, or along the Alaska Peninsula. Larvae spawned along the Alaska Peninsula east of Unimak Island appear to have the greatest chance of being transported to nursery areas in the coastal domain. Dispersal of near-surface northern rock sole larvae in any of these locations is likely influenced by wind-driven advection, but below-surface (>10 m) northern rock sole larval transport is probably more affected by factors that modulate geostrophic flow rather than wind-driven surface currents.

  17. Oxidative Stress and Digestive Enzyme Activity of Flatfish Larvae in a Changing Ocean.

    Directory of Open Access Journals (Sweden)

    Marta S Pimentel

    Full Text Available Until now, it is not known how the antioxidant and digestive enzymatic machinery of fish early life stages will change with the combined effects of future ocean acidification and warming. Here we show that high pCO2 (~1600 μatm significantly decreased metabolic rates (up to 27.4 % of flatfish larvae, Solea senegalensis, at both present (18 °C and warmer temperatures (+4 °C. Moreover, both warming and hypercapnia increased the heat shock response and the activity of antioxidant enzymes, namely catalase (CAT and glutathione S-transferase (GST, mainly in post-metamorphic larvae (30 dph. The lack of changes in the activity of CAT and GST of pre-metamorphic larvae (10 dph seems to indicate that earlier stages lack a fully-developed antioxidant defense system. Nevertheless, the heat shock and antioxidant responses of post-metamorphic larvae were not enough to avoid the peroxidative damage, which was greatly increased under future environmental conditions. Digestive enzymatic activity of S. senegalensis larvae was also affected by future predictions. Hypercapnic conditions led to a decrease in the activity of digestive enzymes, both pancreatic (up to 26.1 % for trypsin and 74.5 % for amylase and intestinal enzymes (up to 36.1 % for alkaline phosphatase in post-metamorphic larvae. Moreover, the impact of ocean acidification and warming on some of these physiological and biochemical variables (namely, lower OCR and higher HSP and MDA levels were translated into larvae performance, being significantly correlated with decreased larval growth and survival or increased incidence of skeletal deformities. The increased vulnerability of flatfish early life stages under future ocean conditions is expected to potentially determine recruitment and population dynamics in marine ecosystems.

  18. Aras kerusakan ekonomi (AKE larva Ostrinia furnacalis (Lepidoptera: Crambidae pada tiga fase pertumbuhan tanaman jagung

    Directory of Open Access Journals (Sweden)

    Subiadi Subiadi

    2015-09-01

    Full Text Available The Asian corn borer, Ostrinia furnacalis (Guenée is an important economic pest of corn and is widely distributed in the Asia-Pacific region, including Indonesia. The objective of this research is to investigate the effect of infestation levels of O. furnacalis larvae per plant on corn grain yield reductions, and to determine economic injury levels (EIL of O. furnacalis larvae at three growth stages (V10, R1, and R2 of corn. The experiment was designed in a split-plot randomized complete block with blocks replicated three times. Differences in grain weight between the uninfested and highest infestation levels (six larvae per plant V10, R1, and R2 were 59.81; 58.76; and 49.20 g/plant, respectively. For each additional infestation by one larvae per plant at V10, R1, dan R2, there is reduction in grain weight of 4.94%, 4.56% and 3.76% respectively. The calculation of EILs was based on the proportion of yield loss per larvae per plant on three corn growth stages with the assumption that pesticide control reduced 67% of O. furnacalis population. The lowest EIL was 0.31 larvae per plant at V10 when the cost of control reaching Rp.125,000 per ha and crop value of Rp.12,000,000 per ha. The highest EIL of 1.24 larvae per plant was found at R2 with the cost of control of Rp.250,000 per ha and crop value of Rp.8,000,000 per ha.

  19. Energy density of zooplankton and fish larvae in the southern Catalan Sea (NW Mediterranean)

    Science.gov (United States)

    Barroeta, Ziortza; Olivar, M. Pilar; Palomera, Isabel

    2017-06-01

    In marine communities, energy of small planktonic organisms is transferred to their predators through feeding. The energy accumulated as organic substances by the different plankton organisms (Energetic Density content, ED) has been analysed in high latitudes and tropical areas, but not in the Mediterranean Sea. In this study, we approach this type of investigation for Mediterranean plankton through measures of total calorimetric content using an oxygen bomb calorimeter. We examined the spatiotemporal variation in the ED of microplankton (50-200 μm) and mesozooplankton (200-2000 μm), and two plankton-consumers, sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) larvae. The study was carried out during the winter and summer of 2013 off the Ebro River Delta (NW Mediterranean Sea). Both plankton fractions showed a more coastal distribution and higher biomasses during winter, the period of sardine larvae occurrences, in front of a wider cross-shelf distribution and lower biomasses in summer, when anchovy appeared. ED values increased with the size of each plankton component, i.e., microzooplankton < mesozooplankton < fish larvae. A tendency for higher plankton ED in the winter period was observed, although being only significant for coastal zone, associated to the more productive waters there. Sardine and anchovy larvae showed an increasing trend in the amount of energy during development, with significantly lower ED between early larvae (6-10 mm standard length) and late postflexion stages (16-20 mm standard length). Small larvae of both species departed from a similarly low ED content, but in the next two size classes sardine larvae showed higher ED values than anchovy, being significantly higher in the 16-20 mm size class. Information on larval feeding patterns and larval growth rates for each species were used to discuss differences in energy allocation strategies.

  20. Proteomic and metabolomic analysis reveals rapid and extensive nicotine detoxification ability in honey bee larvae.

    Science.gov (United States)

    du Rand, Esther E; Human, Hannelie; Smit, Salome; Beukes, Mervyn; Apostolides, Zeno; Nicolson, Susan W; Pirk, Christian W W

    2017-03-01

    Despite potential links between pesticides and bee declines, toxicology information on honey bee larvae (Apis mellifera) is scarce and detoxification mechanisms in this development stage are virtually unknown. Larvae are exposed to natural and synthetic toxins present in pollen and nectar through consumption of brood food. Due to the characteristic intensive brood care displayed by honey bees, which includes progressive feeding throughout larval development, it is generally assumed that larvae rely on adults to detoxify for them and exhibit a diminished detoxification ability. We found the opposite. We examined the proteomic and metabolomic responses of in vitro reared larvae fed nicotine (an alkaloid found in nectar and pollen) to understand how larvae cope on a metabolic level with dietary toxins. Larvae were able to effectively detoxify nicotine through an inducible detoxification mechanism. A coordinated stress response complemented the detoxification processes, and we detected significant enrichment of proteins functioning in energy and carbohydrate metabolism, as well as in development pathways, suggesting that nicotine may promote larval growth. Further exploration of the metabolic fate of nicotine using targeted mass spectrometry analysis demonstrated that, as in adult bees, formation of 4-hydroxy-4-(3-pyridyl) butanoic acid, the result of 2'C-oxidation of nicotine, is quantitatively the most significant pathway of nicotine metabolism. We provide conclusive evidence that larvae are capable of effectively catabolising a dietary toxin, suggesting that increased larval sensitivity to specific toxins is not due to diminished detoxification abilities. These findings broaden the current understanding of detoxification biochemistry at different organizational levels in the colony, bringing us closer to understanding the capacity of the colony as a superorganism to tolerate and resist toxic compounds, including pesticides, in the environment. Copyright © 2017

  1. Temperature-dependent settlement of planula larvae of two scyphozoan jellyfish from the North Sea

    Science.gov (United States)

    Gambill, Maria; McNaughton, Sadie L.; Kreus, Markus; Peck, Myron A.

    2018-02-01

    Exploring the settlement dynamics of the planula larvae is critical to understanding the establishment of polyp populations that can give rise to blooms of scyphozoan jellyfish. We conducted experiments to examine the effects of temperature on settlement of planulae of the scyphozoans Cyanea lamarckii and Chrysaora hysoscella, two jellyfish commonly encountered within the North Sea. When provided immediate access to substrate, larvae of C. lamarckii were able to settle at each of 12 temperatures between 9 and 27 °C. Most settlement occurred within the first five days and warmer temperatures were not only associated with decreased time to settlement but also increased settlement success. When not allowed access to substrate and maintained in the water column, planula larvae remained competent to settle for 21, 21 and 14 days at 11.3, 13.4 and 19.4 °C, respectively. Based on these maximum times of competency, hydrodynamic model simulations suggested that the planula larvae of C. lamarckii released in May could be transported up to 100 km before settlement. A substrate choice experiment indicated that larvae of C. hysoscella settled in similar numbers onto PET, wood and concrete. Settlement was highest at 20 °C and a 12/12 light/dark regime and lower at 10 °C and 15 °C in total darkness. The results of all three experiments suggest that projected warming of the North Sea will not impede the settlement of planula larvae of resident C. lamarckii and C. hysoscella populations. Species- and/or population-specific differences may exist in the ecophysiology of planula larvae and additional experiments are needed to understand the mechanisms promoting the establishment of new benthic populations of polyps. That information, combined with process knowledge on the productivity of benthic polyps, will be needed to better understand and predict climate-dependent changes in the production of scyphozoans and other gelatinous plankton.

  2. Description of the larva of Alampoides alychnus (Kirsch, 1873, the first known species with bioluminescent immatures in Euplinthini (Elateridae, Agrypninae

    Directory of Open Access Journals (Sweden)

    Simone Policena Rosa

    2013-01-01

    Full Text Available Mature larva of Alampoides alychnus (Kirsch is described and compared to known Pyrophorini immatures. Larvae were collected live in the soil of a region dominated by sugarcane plantation and gallery forest in Campo Novo dos Parecis, Mato Grosso, Brazil. They were maintained in laboratory and the pupal period lasted 14 days. This larva differs from other Pyrophorini larvae mainly by bioluminescent pattern: one pair of luminous spots on the mesonotum, and a longitudinal series of median spots on the metanotum and all abdominal segments. The morphology of larva and the bioluminescent pattern of larva and pupa are described for the first time to the genus and the tribe. The fact that adults show no trace of luminescence is emphasized.

  3. Egg Predation Risk Trigger Adult Hoverfly (Diptera: Syrphidae to Avoid Laying Eggs in Patches Attended by Ladybird Larvae (Coleoptera: Coccinellidae

    Directory of Open Access Journals (Sweden)

    Nugroho Susetya Putra

    2005-12-01

    Full Text Available Oviposition preference of a predatory hoverfly, Episyrphus balteatus on the presence of its potential predators, the ladybird larvae which are inflicted serious impacts on its eggs was examined in a non-choice test. Our results revealed that the biggest and the most aggressive species of ladybird, Harmonia axyridis caused the worst impact on hoverfly eggs by attacking and feeding on. The species and developmental stages of ladybird were attributed to the level of predation risk. We correlated the oviposition site selection by hoverfly females to the egg predation risk level inflicted by ladybird larvae. Hoverfly females laid the least number of eggs on the patches attended by the strongest competitor, the larva of H. axyridis, and tended to lay the highest number of eggs on colonies attended by the weakest competitor, the larva of Scymnus posticalis. In addition, the impact of the fourth instar larva of ladybirds was stronger than of the first instar larva.

  4. Some aspects in early life stage of climbing perch, Anabas testudineus larvae

    Directory of Open Access Journals (Sweden)

    Ponpanom Promkaew

    2005-02-01

    Full Text Available The sexual maturity of female climbing perch, Anabas testudineus was studied by determining fecundity and gonadosomatic index (GSI. It was found that the size at sexual maturity of female climbing perch was 15.20±1.24 cm (mean±SD in total length and 61.10±17.32 g in body weight. The eggs were floating and rounded. The fertilized eggs had a diameter of 830±39 μm. The fecundity was 24,120.5±3,328.24 ova/ fish and gonadosomatic index (GSI was 10.4±2.5%. Newly hatched larvae of climbing perch were produced by induced spawning using chemical injection (Suprefact and Motilium. The sexually mature fishes were cultured in fiber-glass tank (water volume 300 liters with the ratio of male and female brooders 2:1. The fertilization rate, hatching out and hatching rate experiments were carried out using a 15-liter glass aquarium (water volume 10 liters containing 7,000-9,000 eggs. It was found that the eggs were floating and rounded. The fertilized eggs had a diameter of 830±39 μm. The average fertilization rate was 92.67%, hatching out was 20 hr 30 min and average hatching rate was 87.44% at a water temperature of 27.0-30.5ºC. Sampling of the newly-hatched larvae was done at 2-hour intervals, when 20 of them were randomly taken and preserved in 10% buffered formalin for later deter-mination of yolk absorption time. Observation using a microscope revealed that newly hatched larvae were 2.02±0.20 mm in total length and had yolk sacs of 111.33±46.19 mm3 in volume. The yolk sacs were completely absorbed within 92 hr after hatching at a water temperature of 27.0-30.5ºC. Up until full mouth development (start of feeding, 2-hourly samplings of twenty newly hatched larvae were taken from an aquarium for observation of the size of mouth opening. All the larvae had open mouths about 28 hr after hatching (2.95±0.59 mm TL, with the mouths measuring 328.42±32.23 mm in height. The feeding experiments were carried out using a 15-liter glass aquarium (water

  5. Hepatic arginase activity in intra- and extrauterine larvae of the ovoviviparous salamander. Salamandra salamandra (L.) (Amphibia, Urodela).

    Science.gov (United States)

    Schindelmeiser, J; Schindelmeiser, I; Greven, H

    1983-01-01

    The hepatic arginase activity of Salamandra salamandra was determined at three different stages of intra- and extrauterine larval development and at fully metamorphosed juveniles. The highest enzymatic activity was found in intrauterine larvae in November, the lowest in intrauterine larvae in June of the following year. These data can be correlated with the ureotelism of intrauterine larvae previously described and are discussed with respect to the metabolism of larval and juvenile fire salamanders.

  6. The in vitro effect of prolactin on the growth, motility and expression of prolactin receptors in larvae of Toxocara canis.

    Science.gov (United States)

    Chávez-Güitrón, L E; Morales-Montor, J; Muñoz-Guzmán, M A; Nava-Castro, K E; Ramírez-Álvarez, H; Moreno-Méndoza, N A; Hernández-Cervantes, R; Alba-Hurtado, F

    2016-07-15

    The in vitro effect of prolactin (PRL) on the growth and motility of Toxocara canis larvae was assessed. Additionally, the expression and location of prolactin receptors (PRL-Rs) were determined in the larvae. Larvae of T. canis were incubated with different concentrations of PRL for different periods of time. The stimulated larvae accelerated their enlargement and increased their motility. The mean percentage of PRL-R+ cells in non-stimulated larvae, measured by flow cytometry was 7.3±0.3%. Compared with non-stimulated larvae, the mean fluorescence intensity (p<0.05) increased in larvae incubated with 40ng/mL of PRL for 10 days. A 465-bp length fragment was amplified from larvae gDNA by PCR. The sequence of this fragment showed 99% similarity with the gene fragment that codes for the PRL-R of the domestic dog. A high concentration of PRL-Rs was immune-located in the posterior region of the larval intestine; therefore, the intestinal cells in this region were most likely the targets for this hormone. Based on these results, PRL-Rs were identified in T. canis larvae, and the in vitro stimulation with PRL increased the number of these receptors, accelerated the growth and modified the activity of larvae. All of the above suggest that T. canis larvae are evolutionarily adapted to recognize the PRL of their definitive host and furthermore might explain the reactivation of tissue-arrested larvae during the gestation of bitches, which does not occur in gestating females of other species. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Rate of Parasitism of the Antlion Larvae, Myrmeleon bore (Neuroptera : Myrmeleontidae) by the Bee Fly, Villa myrmeleonostena (Diptera : Bombyliidae)

    OpenAIRE

    Toshiaki, MATSURA; Hiroki, OHNO; Megumi, SAKAMOTO; Department of Biology, Kyoto University of Education; Department of Biology, Kyoto University of Education; Department of Biology, Kyoto University of Education

    1998-01-01

    The bee fly, Villa myrmeleonostena parasitize the antlion larva, Myrmeleon bore living in seaside dune. To obtain the ecological information on the parasitism by V. myrmeleonostena, we examined rates of parasitism in the antlion larvae collected monthly from April to October in 1991. Adult bee flies emerged from cocoons, which we obtained by rearing the antlion larvae. The emergence times of parasitoids and hosts were similar. The parasitism rate based on pooled data was the highest in the th...

  8. Larvae of the pycnogonids Ammothea gigantea Gordon, 1932 and Achelia cuneatis Child, 1999 described from archived specimens

    OpenAIRE

    John A. Fornshell; Frank D. Ferrari

    2012-01-01

    The larvae of two species of Pycnogonida are described from archived collections. Achelia cuneatis Child, 1999 is an example of a typical protonymphon larva in having three pairs of three segmented appendages, cheliphores, palps and ovigerous appendages. Ammothea gigantea Gordon, 1932 is an example of a lecithotrophic protonymphon larva, having the three pair of appendages plus buds of the first walking legs. Ammothea gigantea is the third species known to have this larval type. The Achelia c...

  9. Reduction of Escherichia coli, Salmonella Enteritidis and Campylobacter jejuni in poultry manure by rearing of Musca domestica fly larvae

    DEFF Research Database (Denmark)

    Nordentoft, Steen; Fischer, C.; Bjerrum, L.

    2017-01-01

    A major barrier for using animal waste as substrate for production of insects for feed or food is the concern for safety of the end products. In this study we investigated how rearing of fly larvae of Musca domestica in poultry manure influenced the counts of three pathogenic test strains...... of the larvae stage. This study provides data for evaluation of feed safety of fly larvae reared on animal waste. Furthermore suggests a potential use for reduction of these pathogens in manure....

  10. Descriptions of the Larvae of Two Species of Paranomala and One Species of Strigoderma (Coleoptera: Melolonthidae: Rutelinae) from Puebla, Mexico

    OpenAIRE

    Víctor Alfonso Cuate Mozo; Agustin Aragon Garcia; Betzabeth Cecilia Pérez Torres; Miguel Ángel Morón; Jesús Francisco López Olguín; Vicente Santiago Marco Mancebón

    2014-01-01

    The third instar larvae of Paranomala flavilla  (Bates), P. hoepfneri  (Bates) and Strigoderma costulipennis  Bates, collected in Puebla, Mexico, in soils cultivated with amaranth are described. Illustrations of the diagnostic structures and comments on the differences with other larvae of the genera studied in Mexico are included. CARACTERIZACIÓN DE LAS LARVAS DE DOS ESPECIES DE Paranomala Y UNA ESPECIE DE Strigoderma (COLEOPTERA: MELOLONTHIDAE: RUTELINAE) DE PUEBLA, MÉXICO. Se prese...

  11. Descriptions of the larvae of two species of paranomala and one species of strigoderma (coleoptera: melolonthidae: rutelinae) from puebla, mexico

    OpenAIRE

    Cuate Mozo, Víctor Alfonso; Aragon Garcia, Agustin; Pérez Torres, Betzabeth Cecilia; Morón, Miguel Ángel; López Olguín, Jesús Francisco; Marco Mancebón, Vicente Santiago

    2014-01-01

     The third instar larvae of Paranomala flavilla  (Bates), P. hoepfneri  (Bates) and Strigoderma costulipennis  Bates, collected in Puebla, Mexico, in soils cultivated with amaranth are described. Illustrations of the diagnostic structures and comments on the differences with other larvae of the genera studied in Mexico are included.CARACTERIZACIÓN DE LAS LARVAS DE DOS ESPECIES DE Paranomala Y UNA ESPECIE DE Strigoderma (COLEOPTERA: MELOLONTHIDAE: RUTELINAE) DE PUEBLA, MÉXICO.Se presentan las ...

  12. Description of the mature larva of Austrolimnius nyctelioides (Germain, 1892) and A. elatus Hinton, 1941 (Coleoptera: Elmidae).

    Science.gov (United States)

    Román, Nicolás Martínez; Archangelsky, Miguel

    2017-01-11

    Mature larvae of two species of the riffle beetle genus Austrolimnius Carter & Zeck, 1929 are described and illustrated for the first time: Austrolimnius nyctelioides (Germain, 1892) and A. elatus Hinton, 1941. A larval diagnosis for the genus is presented and both larvae are compared with each other and with the previously described larva of A. mucubajiensis Gómez & Bello, 2006. Comments on the species' habitats are included.

  13. Hemocyte quantitative changes in Anticarsia gemmatalis (Lepidoptera: Noctuidae larvae infected by AgMNPV

    Directory of Open Access Journals (Sweden)

    Fábio Goulart de Andrade

    2010-04-01

    Full Text Available The initial effects of the infection by AgMNPV in the total and differential counts of the hemocytes in Anticarsia gemmatalis (Lepidoptera: Noctuidae larvae were studied. The total number of the hemocytes did not decrease in infected larvae, as it occurred in non infected larvae. In infected larvae, the hemocyte types showed the following frequencies: plasmatocytes - 47.8%, esferulocytes - 25.9%, granulocytes - 15.8%, oenocytoids - 7.2%, prohemocytes - 2.8%, vermicytes - 0,5%. Only the percentage of the granulocytes was different among infected and non infected larvae, indicating that these cells responded quickly to the initial viral infection. These results showed the effective role of the hemocytes in the response of the A. gemmatalis to the infection by AgMNPV. The comprehension of the immunological mechanisms of this insect is an important tool to understand its biological control.Os efeitos iniciais da infecção por AgMNPV nas contagens total e diferencial dos hemócitos em Anticarsia gemmatalis (Lepidoptera: Noctuidae foram estudados. O número total de hemócitos não diminuiu nas larvas infectadas, como ocorreu nas larvas não infectadas. Nas larvas infectadas, os tipos de hemócitos apresentaram as seguintes freqüências: plasmatócitos - 47,8%, esferulócitos - 25,9%, granulócitos - 15,8%, oenocitóides - 7,2%, prohemócitos - 2,8%, vermiformes - 0,5%. Apenas a porcentagem de granulócitos foi diferente entre larvas infectadas e não infectadas, indicando que estas células responderam rapidamente à infecção viral inicial. Estes resultados mostraram o papel efetivo que dos hemócitos na resposta de A. gemmatalis à infecção por AgMNPV. A compreensão dos mecanismos imunológicos deste inseto é uma ferramenta importante para compreender seu controle biológico.

  14. The importance of an invasive tree fruit as a resource for mosquito larvae.

    Science.gov (United States)

    Reiskind, Michael H; Zarrabi, Ali A

    2011-06-01

    Invasive plants are common and may provide resources through litter for container mosquito larvae. Invasive plant reproductive parts can make up a substantial part of litter but have mostly been ignored as a resource for mosquito larvae. We hypothesized that the reproductive fruits of the invasive eastern red cedar, Juniperus virginiana, provide high quality resources for the invasive, container mosquito Aedes albopictus at the western margin of its invasive range in North America. To test this hypothesis, we performed two laboratory experiments. The first examined the response of individual larvae of Ae. albopictus to different amounts of J. virginiana leaf (fresh and senesced) and J. virginiana fruit (ripe and unripe), as well as to a control leaf (Quercus virginiana, live oak). The second experiment examined the response of different densities of Ae. albopictus larvae to each litter type. We found significant differences in response by individual larvae to different amounts of litter and litter types. We also found J. virginiana litter components could support positive population growth rates as a function of initial larval density where the control leaf could not. We conclude that invasive plants may provide high quality resources, and that the reproductive parts (fruits, flowers, cones) may be an important and overlooked component in provisioning larval habitats. Therefore, the expansion of J. virginiana into grassland areas may contribute to the expansion of Ae. albopictus westward in North America. © 2011 The Society for Vector Ecology.

  15. Differential growth identified in salamander larvae half-sib cohorts: survival strategy?

    Science.gov (United States)

    Cohen, Miriam; Yeheskely-Hayon, Daniella; Warburg, Michael R; Davidson, Dana; Halevi, Gili; Sharon, Rakefet

    2006-10-01

    In this study we describe the growth of several different larval cohorts (i.e. half-siblings of the same mother born on the same day) of a rare, xeric-adapted salamander Salamandra s. infraimmaculata Martens, 1885, under constant density and food conditions from birth to metamorphosis. The larvae spend the critical first phase of their lives in water, mostly in temporary ponds. Age and weight at metamorphosis were highly affected by varying food conditions. We have identified six different growth modes that these larvae use, both fast growing and slow growing. Each larval cohort was found to use 2-4 different such growth modes regardless of their initial weight. Fast growing modes (I-III) will enable larvae to survive dry years, and metamorphose bigger. Slow growing modes (IV-VI), used by 8% of the larval population, will enable survival only in rainy years. These last growth modes effect differential temporal dispersal in wet years by delaying the emergence of postmetamorphs onto land. Distribution of growth modes in the larval population is affected by food but not by density conditions. Late-born, fast-growing larvae will have an advantage in dry years being able to metamorphose and disperse, whereas the slow-growing larvae will survive only in wet years.

  16. Antixenosis in maize reduces feeding by western corn rootworm larvae (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Bernklau, E J; Hibbard, B E; Bjostad, L B

    2010-12-01

    SUM2162 is the first known example of a naturally occurring maize, Zea mays L., genotype with antixenosis (nonpreference) resistance to western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), larval feeding. Behavioral responses of neonate western corn rootworm larvae were evaluated in laboratory bioassays with seven maize genotypes selected for native resistance to rootworm feeding damage. Two susceptible maize genotypes and one transgenic (Bacillus thuringiensis) maize genotype were included as controls. In soil bioassays with cut roots, no larvae entered the roots of the resistant variety SUM2162, but at least 75% of the larvae entered the roots of every other maize type. Larvae made significantly fewer feeding holes in the roots of SUM2162 than in all the other maize genotypes, except the isoline control. In feeding bioassays, larval feeding varied significantly among maize genotypes, but there was no significant difference between the resistant varieties and the susceptible controls. There were no significant differences among any of the genotypes in host recognition (search) behavior of larvae after exposure to the roots. Little variation in feeding stimulant blends was observed among maize genotypes, indicating minimal contribution to the observed antixenosis.

  17. Insecticide enhancement with feeding stimulants in corn for western corn rootworm larvae (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Bernklau, E J; Bjostad, L B

    2005-08-01

    Amounts of the insecticide thiamethoxam required for 50% mortality of western corn rootworm larvae, Diabrotica virgifera virgifera LeConte, were reduced 100-fold when extracts of germinating corn, Zea mays L., were used to entice neonate larvae to feed on it. In behavioral bioassays, neonate rootworm larvae fed vigorously on filter paper disks treated with liquid pressed from corn roots. Moreover, disks treated with an acetone extract of corn (dried and rewetted with water) also elicited strong feeding from larvae. Larvae wandered away from filter paper disks treated with distilled water without feeding. Dilutions of thiamethoxam were tested in the bioassay alone or with corn extract and the efficacy of this insecticide was improved by the addition of the corn extract. For solutions containing 10 ppm thiamethoxam, 95% larval mortality occurred after 30 min of exposure when corn extract was present, but only 38% mortality occurred when the same concentration of insecticide alone (no feeding stimulants) was tested. Larval mortality after 24 h was significantly higher for corn extract-treated disks with 0.01, 0.1, 1, or 10 ppm insecticide than for the same concentrations without corn extract. Thiamethoxam did not deter larval feeding on corn extract, even at the highest concentration of thiamethoxam tested.

  18. Methyl Anthranilate as a Repellent for Western Corn Rootworm Larvae (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Bernklau, E J; Hibbard, B E; Norton, A P; Bjostad, L B

    2016-08-01

    Methyl anthranilate was identified as the active compound in extracts of maize (Zea mays L.) roots that were shown to be repellent to neonate western corn rootworm (Diabrotica virgifera virgifera LeConte) larvae. A bioassay-driven approach was used to isolate the active material from diethyl ether extracts of roots from germinating maize seeds. Separation of the extract on a Florisil column yielded an active fraction of 90:10 hexane:diethyl ether. Analysis with gas chromatography-mass spectrometry identified two compounds in the active fraction: indole (2,3-benzopyrrole) and methyl anthranilate (methyl 2-aminobenzoate). When tested in behavioral bioassays, methyl anthranilate elicited a significant (P < 0.05) repellent response at doses of 1, 10, and 100 µg. In subsequent single-choice bioassays, 1, 10, and 100 µg of methyl anthranilate prevented larvae from approaching 10 mmol/mol concentrations of carbon dioxide, which is normally highly attractive to the larvae. Indole, the other compound identified from the active fraction, did not elicit a behavioral response by the larvae. Methyl anthranilate has potential for development as a management tool for western corn rootworm larvae and may be best suited for use in a push-pull control strategy. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Larvicidal effects of endophytic and basidiomycete fungus extracts on Aedes and Anopheles larvae (Diptera, Culicidae

    Directory of Open Access Journals (Sweden)

    Augusto Bucker

    2013-08-01

    Full Text Available Introduction In vitro bioassays were performed to access the larvicidal activity of crude extracts from the endophytic fungus Pestalotiopsis virgulata (Melanconiales, Amphisphaeriaceae and the saprophytic fungus Pycnoporus sanguineus (Basidiomycetes, Polyporaceae against the mosquitoes Aedes aegypti and Anopheles nuneztovari. Methods The extracts were tested at concentrations of 100, 200, 300, 400 and 500ppm. Ethyl acetate mycelia (EAM extracts and liquid culture media (LCM from Pe. virgulata and Py. sanguineus were tested against third instar larvae of Ae. aegypti and An. nuneztovari. Results The larvicidal activity of the EAM extracts from Pe. virgulata against Ae. aegypti had an LC50=101.8ppm, and the extract from the basidiomycete fungus Py. sanguineus had an LC50=156.8ppm against the Ae. aegypti larvae. The Pe. virgulata extract had an LC50=16.3ppm against the An. nuneztovari larvae, and the Py. sanguineus extract had an LC50=87.2ppm against these larvae. Conclusions These results highlight the larvicidal effect of EAM extracts from the endophyte Pe. virgulata against the two larval mosquitoes tested. Thus, Pe. virgulata and Py. sanguineus have the potential for the production of bioactive substances against larvae of these two tropical disease vectors, with An. nuneztovari being more susceptible to these extracts.

  20. Digestive enzymatic activity on tropical gar (Atractosteus tropicus) larvae fed different diets.

    Science.gov (United States)

    Aguilera, Carlos; Mendoza, Roberto; Iracheta, Israel; Marquez, Gabriel

    2012-06-01

    Digestive enzymatic activity and growth performance on tropical gar (Atractosteus tropicus) larvae fed Artemia nauplii (LF), frozen adult Artemia (AB), an artificial diet (AF) with 46% protein and 16% lipids and a starvation group (SG) from first feeding (5 days after hatching-5 DAH) to 34 DAH were studied. All larvae under starvation (SG) died at 15 DAH. By the end of the experimental period, morphological variables (total length, wet weight and specific growth rate) were significant in larvae fed AF compared to LF and AB. All enzymes studied in the experiment were present since the start of exogenous feeding (including pepsin) and the enzymatic activity varied with the diets. Low levels of enzymatic activity were observed until the 29 DAH; however, after this moment, there was a significant increase (eightfold), particularly for the AF treatment. In vitro protein digestibility tests performed with enzymatic extracts showed that artificial diets with 52% protein and 14% lipids were better digested by larvae before 30 DAH, while diets with 45% protein and 11% lipids were better digested after this age. Taking into account the better growth performance, higher enzymatic activity and better protein digestibility obtained, artificial diets can be used since the start of exogenous feeding on tropical gar larvae, as in other lepisosteids.