Transstadial transmission of Hepatozoon canis from larvae to nymphs of Rhipicephalus sanguineus.

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Giannelli, Alessio; Ramos, Rafael Antonio Nascimento; Di Paola, Giancarlo; Mencke, Norbert; Dantas-Torres, Filipe; Baneth, Gad; Otranto, Domenico

2013-09-01

Hepatozoon canis is an apicomplexan parasite of dogs, which is known to become infected by ingesting Rhipicephalus sanguineus adult ticks. To investigate the possibility of H. canis transovarial and transstadial transmission from larvae to nymphs, engorged adult female ticks were collected from a private animal shelter in southern Italy, where H. canis infection is highly prevalent. Female ticks (n=35) and egg batches were tested by PCR for H. canis. All eggs examined were PCR-negative whereas 88.6% of females from the environment tested positive. Additionally, fed larvae (n=120) from a dog naturally infected by H. canis were dissected at different time points post collection (i.e. 0, 10, 20 and 30 days). Molted nymphs dissected at 20 days post collection revealed immature oocysts displaying an amorphous central structure in 50% of the specimens, and oocysts containing sporocysts with sporozoites were found in 53.3% of the nymphs dissected at 30 days post collection. This study demonstrates that H. canis is not transmitted transovarially, but it is transmitted transstadially from larvae to nymphs of R. sanguineus and develops sporozoites in oocysts that may infect dogs. Copyright © 2013 Elsevier B.V. All rights reserved.

Established Population of Blacklegged Ticks with High Infection Prevalence for the Lyme Disease Bacterium, Borrelia burgdorferi Sensu Lato, on Corkscrew Island, Kenora District, Ontario

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Scott, John D.; Foley, Janet E.; Clark, Kerry L.; Anderson, John F.; Durden, Lance A.; Manord, Jodi M.; Smith, Morgan L.

2016-01-01

We document an established population of blacklegged ticks, Ixodes scapularis, on Corkscrew Island, Kenora District, Ontario, Canada. Primers of the outer surface protein A (OspA) gene, the flagellin (fla) gene, and the flagellin B (flaB) gene were used in the PCR assays to detect Borrelia burgdorferi sensu lato (s.l.), the Lyme disease bacterium. In all, 60 (73%) of 82 adult I. scapularis, were infected with B. burgdorferi s.l. As well, 6 (43%) of 14 unfed I. scapularis nymphs were positive for B. burgdorferi s.l. An I. scapularis larva was also collected from a deer mouse, and several unfed larvae were gathered by flagging leaf litter. Based on DNA sequencing of randomly selected Borrelia amplicons from six nymphal and adult I. scapularis ticks, primers for the flagellin (fla) and flagellin B (flaB) genes reveal the presence of B. burgdorferi sensu stricto (s.s.), a genospecies pathogenic to humans and certain domestic animals. We collected all 3 host-feeding life stages of I. scapularis in a single year, and report the northernmost established population of I. scapularis in Ontario. Corkscrew Island is hyperendemic for Lyme disease and has the highest prevalence of B. burgdorferi s.l. for any established population in Canada. Because of this very high infection prevalence, this population of I. scapularis has likely been established for decades. Of epidemiological significance, cottage owners, island visitors, outdoors enthusiasts, and medical professionals must be vigilant that B. burgdorferi s.l.-infected I. scapularis on Corkscrew Island pose a serious public health risk. PMID:27877080

Pathogenicity of entomopathogenic fungus Metarhizium anisopliae (Deuteromycetes) to Ixodes scapularis (Acari: Ixodidae)

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Zhioua, E.; Browning, M.; Johnson, P.W.; Ginsberg, H.S.; LeBrun, R.A.

1997-01-01

The entomopathogenic fungus Metarhizium anisopliae is highly pathogenic to the black-legged tick, Ixodes scapularis. Spore concentrations of 108/ml for engorged larvae and 107/ml for engorged females resulted in 100% tick mortality, 2 wk post-infection. The LC50 value for engorged larvae (concentration to kill 50% of ticks) was 107 spores/ml. Metarhizium anisopliae shows considerable potential as a microbial control agent for the management of Ixodes scapularis.

Do Scaphoideus titanus (Hemiptera: Cicadellidae) nymphs use vibrational communication?

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Chuche, Julien; Thiéry, Denis; Mazzoni, Valerio

2011-07-01

Small Auchenorrhyncha use substrate-borne vibrations to communicate. Although this behaviour is well known in adult leafhoppers, so far no studies have been published on nymphs. Here we checked the occurrence of vibrational communication in Scaphoideus titanus (Hemiptera: Cicadellidae) nymphs as a possible explanation of their aggregative distributions on host plants. We studied possible vibratory emissions of isolated and grouped nymphs, as well as their behavioural responses to vibration stimuli that simulated presence of conspecifics, to disturbance noise, white noise and predator spiders. None of our synthetic stimuli or pre-recorded substrate vibrations from nymphs elicited specific vibration responses and only those due to grooming or mechanical contacts of the insect with the leaf were recorded. Thus, S. titanus nymphs showed to not use species-specific vibrations neither for intra- nor interspecific communication and also did not produce alarm vibrations when facing potential predators. We conclude that their aggregative behaviour is independent from a vibrational communication.

Tomographic reconstruction of neopterous carboniferous insect nymphs.

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Russell Garwood

Full Text Available Two new polyneopteran insect nymphs from the Montceau-les-Mines Lagerstätte of France are presented. Both are preserved in three dimensions, and are imaged with the aid of X-ray micro-tomography, allowing their morphology to be recovered in unprecedented detail. One-Anebos phrixos gen. et sp. nov.-is of uncertain affinities, and preserves portions of the antennae and eyes, coupled with a heavily spined habitus. The other is a roachoid with long antennae and chewing mouthparts very similar in form to the most generalized mandibulate mouthparts of extant orthopteroid insects. Computer reconstructions reveal limbs in both specimens, allowing identification of the segments and annulation in the tarsus, while poorly developed thoracic wing pads suggest both are young instars. This work describes the morphologically best-known Palaeozoic insect nymphs, allowing a better understanding of the juveniles' palaeobiology and palaeoecology. We also consider the validity of evidence from Palaeozoic juvenile insects in wing origin theories. The study of juvenile Palaeozoic insects is currently a neglected field, yet these fossils provide direct evidence on the evolution of insect development. It is hoped this study will stimulate a renewed interest in such work.

Efficacy of plant-derived and synthetic compounds on clothing as repellents against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae).

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Jordan, Robert A; Schulze, Terry L; Dolan, Marc C

2012-01-01

We conducted field trials to compare the relative repellent activity of two natural product compounds (nootkatone and carvacrol) with commercially available plant-derived (EcoSMART organic insect repellent) and permethrin-based (Repel Permanone) repellents against adult Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae) by using treated coveralls. One day after treatment, nootkatone and carvacrol provided 100% repellency of I. scapularis adults, with nootkatone maintaining complete protection through 3 d, whereas carvacrol showed steadily declining repellency against I. scapularis during the 7-d course of the trials. Nootkatone was at least as effective against host-seeking A. americanum as against I. scapularis through 3 d. Carvacrol provided little protection against A. americanum adults. Both natural compounds performed well initially in comparison with the commercial products. After 7 d, nootkatone was the most effective against both species followed in order of activity by Permanone, EcoSMART, and carvacrol. Nootkatone seems to have offer considerable potential as a clothing repellent against both I. scapularis and A. americanum.

Key to Plecoptera nymphs from the Brazilian Amazon (Insecta).

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Ribeiro, José Moacir Ferreira; Gorayeb, Inocêncio DE Sousa

2016-12-19

Nymphs of 22 species of Plecoptera from the Brazilian Amazon are keyed and illustrated to enhance their usefulness as water quality indicator taxa. Four described species of Anacroneuria, two species of Macrogynoplax, and two species of Enderleina have been associated with adults: Anacroneuria marlieri, A. manauensis, A. minuta, A. singularis, M. delicata, M. pulchra, E. froehlichi, and E. flinti. Nymphs of 14 additional morphospecies not yet associated with adults are included. Characters of the head, pronotum, mesonotum, and metanotum are used to distinguish late instar nymphs.

Tick-Host Range Adaptation: Changes in Protein Profiles in Unfed Adult Ixodes scapularis and Amblyomma americanum Saliva Stimulated to Feed on Different Hosts

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Lucas Tirloni

2017-12-01

Full Text Available Understanding the molecular basis of how ticks adapt to feed on different animal hosts is central to understanding tick and tick-borne disease (TBD epidemiology. There is evidence that ticks differentially express specific sets of genes when stimulated to start feeding. This study was initiated to investigate if ticks such as Ixodes scapularis and Amblyomma americanum that are adapted to feed on multiple hosts utilized the same sets of proteins to prepare for feeding. We exposed I. scapularis and A. americanum to feeding stimuli of different hosts (rabbit, human, and dog by keeping unfed adult ticks enclosed in a perforated microfuge in close contact with host skin, but not allowing ticks to attach on host. Our data suggest that ticks of the same species differentially express tick saliva proteins (TSPs when stimulated to start feeding on different hosts. SDS-PAGE and silver staining analysis revealed unique electrophoretic profiles in saliva of I. scapularis and A. americanum that were stimulated to feed on different hosts: rabbit, human, and dog. LC-MS/MS sequencing and pairwise analysis demonstrated that I. scapularis and A. americanum ticks expressed unique protein profiles in their saliva when stimulated to start feeding on different hosts: rabbit, dog, or human. Specifically, our data revealed TSPs that were unique to each treatment and those that were shared between treatments. Overall, we identified a total of 276 and 340 non-redundant I. scapularis and A. americanum TSPs, which we have classified into 28 functional classes including: secreted conserved proteins (unknown functions, proteinase inhibitors, lipocalins, extracellular matrix/cell adhesion, heme/iron metabolism, signal transduction and immunity-related proteins being the most predominant in saliva of unfed ticks. With exception of research on vaccines against Rhipicephalus microplus, which its natural host, cattle, research on vaccine against other ticks relies feeding ticks

A Risk Model for the Lyme Disease Vector Ixodes scapularis (Acari: Ixodidae) in the Prairie Provinces of Canada.

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Gabriele-Rivet, Vanessa; Koffi, Jules K; Pelcat, Yann; Arsenault, Julie; Cheng, Angela; Lindsay, L Robbin; Lysyk, Timothy J; Rochon, Kateryn; Ogden, Nicholas H

2017-07-01

Lyme disease is emerging in Canada due to geographic range expansion of the tick vector Ixodes scapularis Say. Recent areas of emergence include parts of the southeastern Canadian Prairie region. We developed a map of potential risk areas for future I. scapularis establishment in the Canadian Prairie Provinces. Six I. scapularis risk algorithms were developed using different formulations of three indices for environmental suitability: temperature using annual cumulative degree-days > 0 °C (DD > 0 °C; obtained from Moderate Resolution Imaging Spectroradiometer satellite data as an index of conditions that allow I. scapularis to complete its life cycle), habitat as a combined geolayer of forest cover and agricultural land use, and rainfall. The relative performance of these risk algorithms was assessed using receiver-operating characteristic (ROC) area under the curve (AUC) analysis with data on presence-absence of I. scapularis obtained from recent field surveillance in the Prairie Provinces accumulated from a number of sources. The ROC AUC values for the risk algorithms were significantly different (P  0 °C, habitat as a simple dichotomous variable of presence or absence of forest, and normalized rainfall had the highest AUC of 0.74, representing "fair to good" performance of the risk algorithm. This algorithm had good (>80%) sensitivity in predicting positive I. scapularis surveillance sites, but low (50%) specificity as expected in this region where not all environmentally suitable habitats are expected to be occupied. Further prospective studies are needed to validate and perhaps improve the risk algorithm. © Crown copyright 2017.

Using Landscape Analysis to Test Hypotheses about Drivers of Tick Abundance and Infection Prevalence with Borrelia burgdorferi.

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Ferrell, A Michelle; Brinkerhoff, R Jory

2018-04-12

Patterns of vector-borne disease risk are changing globally in space and time and elevated disease risk of vector-borne infection can be driven by anthropogenic modification of the environment. Incidence of Lyme disease, caused by the bacterium Borrelia burgdorferi sensu stricto, has risen in a number of locations in North America and this increase may be driven by spatially or numerically expanding populations of the primary tick vector, Ixodes scapularis . We used a model selection approach to identify habitat fragmentation and land-use/land cover variables to test the hypothesis that the amount and configuration of forest cover at spatial scales relevant to deer, the primary hosts of adult ticks, would be the predominant determinants of tick abundance. We expected that land cover heterogeneity and amount of forest edge, a habitat thought to facilitate deer foraging and survival, would be the strongest driver of tick density and that larger spatial scales (5-10 km) would be more important than smaller scales (1 km). We generated metrics of deciduous and mixed forest fragmentation using Fragstats 4.4 implemented in ArcMap 10.3 and found, after adjusting for multicollinearity, that total forest edge within a 5 km buffer had a significant negative effect on tick density and that the proportion of forested land cover within a 10 km buffer was positively associated with density of I. scapularis nymphs. None of the 1 km fragmentation metrics were found to significantly improve the fit of the model. Elevation, previously associated with increased density of I. scapularis nymphs in Virginia, while significantly predictive in univariate analysis, was not an important driver of nymph density relative to fragmentation metrics. Our results suggest that amount of forest cover (i.e., lack of fragmentation) is the most important driver of I. scapularis density in our study system.

Characterization of Ixophilin, a thrombin inhibitor from the gut of Ixodes scapularis.

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Sukanya Narasimhan

Full Text Available Ixodes scapularis, the black-legged tick, vectors several human pathogens including Borrelia burgdorferi, the agent of Lyme disease in North America. Pathogen transmission to the vertebrate host occurs when infected ticks feed on the mammalian host to obtain a blood meal. Efforts to understand how the tick confronts host hemostatic mechanisms and imbibes a fluid blood meal have largely focused on the anticoagulation strategies of tick saliva. The blood meal that enters the tick gut remains in a fluid state for several days during the process of feeding, and the role of the tick gut in maintaining the blood-meal fluid is not understood. We now demonstrate that the tick gut produces a potent inhibitor of thrombin, a key enzyme in the mammalian coagulation cascade. Chromatographic fractionation of engorged tick gut proteins identified one predominant thrombin inhibitory activity associated with an approximately 18 kDa protein, henceforth referred to as Ixophilin. The ixophilin gene was preferentially transcribed in the guts of feeding nymphs. Expression began after 24 hours of feeding, coincident with the flow of host blood into the tick gut. Immunity against Ixophilin delayed tick feeding, and decreased feeding efficiency significantly. Surprisingly, immunity against Ixophilin resulted in increased Borrelia burgdorferi transmission to the host, possibly due to delayed feeding and increased transmission opportunity. These observations illuminate the potential drawbacks of targeting individual tick proteins in a functional suite. They also underscore the need to identify the "anticoagulome" of the tick gut, and to prioritize a critical subset of anticoagulants that could be targeted to efficiently thwart tick feeding, and block pathogen transmission to the vertebrate host.

Lagrangian approach to understanding the origin of the gill-kinematics switch in mayfly nymphs.

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Chabreyrie, R; Balaras, E; Abdelaziz, K; Kiger, K

2014-12-01

The mayfly nymph breathes under water through an oscillating array of plate-shaped tracheal gills. As the nymph grows, the kinematics of these gills change abruptly from rowing to flapping. The classical fluid dynamics approach to consider the mayfly nymph as a pumping device fails in giving clear reasons for this switch. In order to shed some light on this switch between the two distinct kinematics, we analyze the problem under a Lagrangian viewpoint. We consider that a good Lagrangian transport that effectively distributes and stirs water and dissolved oxygen between and around the gills is the main goal of the gill motion. Using this Lagrangian approach, we are able to provide possible reasons behind the observed switch from rowing to flapping. More precisely, we conduct a series of in silico mayfly nymph experiments, where body shape, as well as gill shapes, structures, and kinematics are matched to those from in vivo. In this paper, we show both qualitatively and quantitatively how the change of kinematics enables better attraction, confinement, and stirring of water charged of dissolved oxygen inside the gills area. We reveal the attracting barriers to transport, i.e., attracting Lagrangian coherent structures, that form the transport skeleton between and around the gills. In addition, we quantify how well the fluid particles are stirred inside the gills area, which by extension leads us to conclude that it will increase the proneness of molecules of dissolved oxygen to be close enough to the gills for extraction.

Modeling the geographic distribution of Ixodes scapularis and Ixodes pacificus (Acari: Ixodidae) in the contiguous United States

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Hahn, Micah; Jarnevich, Catherine S.; Monaghan, Andrew J.; Eisen, Rebecca J.

2016-01-01

In addition to serving as vectors of several other human pathogens, the black-legged tick, Ixodes scapularis Say, and western black-legged tick, Ixodes pacificus Cooley and Kohls, are the primary vectors of the spirochete (Borrelia burgdorferi ) that causes Lyme disease, the most common vector-borne disease in the United States. Over the past two decades, the geographic range of I. pacificus has changed modestly while, in contrast, the I. scapularis range has expanded substantially, which likely contributes to the concurrent expansion in the distribution of human Lyme disease cases in the Northeastern, North-Central and Mid-Atlantic states. Identifying counties that contain suitable habitat for these ticks that have not yet reported established vector populations can aid in targeting limited vector surveillance resources to areas where tick invasion and potential human risk are likely to occur. We used county-level vector distribution information and ensemble modeling to map the potential distribution of I. scapularis and I. pacificus in the contiguous United States as a function of climate, elevation, and forest cover. Results show that I. pacificus is currently present within much of the range classified by our model as suitable for establishment. In contrast, environmental conditions are suitable for I. scapularis to continue expanding its range into northwestern Minnesota, central and northern Michigan, within the Ohio River Valley, and inland from the southeastern and Gulf coasts. Overall, our ensemble models show suitable habitat for I. scapularis in 441 eastern counties and for I. pacificus in 11 western counties where surveillance records have not yet supported classification of the counties as established.

Nucleic acids levels in X-irradiated 5th instar nymphs of Dysdercus koenigii F

International Nuclear Information System (INIS)

Harwalkar, M.R.; Ramakrishnan, V.

1993-01-01

Irradiation of early 5th instar nymphs of Dysdercus koenigii F. with X-ray doses ranging from 10 to 70 Gy affected their metamorphosis in a dose dependent manner. At 70 Gy dose, metamorphosis of nymphs was completely inhibited although these nymphs survived for more than 10 days. In unirradiated 5th instar nymphs, DNA content doubled between 2nd and 3rd day and it remained at this level till these nymphs completed metamorphosis. However, DNA content of nymphs exposed to metamorphosis inhibition dose of 70 Gy X-rays showed only slight increase from 4th day and its profile remained at lower level throughout 5th instar nymphal period. Though the increase in RNA content in both the groups was found to be gradual upto 3rd day, the increase was more pronounced in case of unexposed insects. (author). 9 refs., 2 tabs

The neuro secretory activity in the permanent nymphs of schistocerca gregarea (Forskal) as a result of gamma irradiation of the third nymphal instar

International Nuclear Information System (INIS)

Elgammal, A.M.; Abdelsalam, K.A.; Mourad, A.K.

1986-01-01

Laboratory studies were carried out to evaluate the effect of different doses of gamma radiation on the neuro secretory activity in the permanent nymphs of schistocerca gregaria by treating them in the third nymphal instar. Treatment with 30 gray induced complete mortality for all treated nymphs. However, irradiation with a dose of 20 gray produced fourth instar nymphs which entered a state of suspended development for about 14 days. Exposure to a dose of 10 gray induced three types of response associated with the endocrine activities. Some of the treated nymphs developed to the fifth instar with soft and thin cuticle without tanning or darkening, these nymphs did not survive more than a few hours after ecdysis. Others became fifth instar with anomalous wings and normal cuticle, these survived about 18 days as permanent fifth instar nymphs before dying. The rest molted to permanent fourth instar that survived more than one month and eventually died. Corporal allata (CA) volume in the permanent nymphs were estimated by planimeter method, revealing a pronounced reduction in their size in comparison with the untreated control. This reflects a sharp inhibition in their synthetic activity of juvenile hormone (J H). It is assumed that the permanent nymphs were produced as a result of direct effect on the cerebral neuro secretory cells of the brain, the source of stimulation for J H an decdysone production. In the main time, gamma rays prevented the production of the tanning and darkening factor (Bursicon hormone) in these cells.1 fig.,3 tab

Ixodes scapularis tick serine proteinase inhibitor (serpin gene family; annotation and transcriptional analysis

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Chalaire Katelyn C

2009-05-01

Full Text Available Abstract Background Serine proteinase inhibitors (Serpins are a large superfamily of structurally related, but functionally diverse proteins that control essential proteolytic pathways in most branches of life. Given their importance in the biology of many organisms, the concept that ticks might utilize serpins to evade host defenses and immunizing against or disrupting their functions as targets for tick control is an appealing option. Results A sequence homology search strategy has allowed us to identify at least 45 tick serpin genes in the Ixodes scapularis genome that are structurally segregated into 32 intronless and 13 intron-containing genes. Nine of the intron-containing serpins occur in a cluster of 11 genes that span 170 kb of DNA sequence. Based on consensus amino acid residues in the reactive center loop (RCL and signal peptide scanning, 93% are putatively inhibitory while 82% are putatively extracellular. Among the 11 different amino acid residues that are predicted at the P1 sites, 16 sequences possess basic amino acid (R/K residues. Temporal and spatial expression analyses revealed that 40 of the 45 serpins are differentially expressed in salivary glands (SG and/or midguts (MG of unfed and partially fed ticks. Ten of the 38 serpin genes were expressed from six to 24 hrs of feeding while six and fives genes each are predominantly or exclusively expressed in either MG and SG respectively. Conclusion Given the diversity among tick species, sizes of tick serpin families are likely to be variable. However this study provides insight on the potential sizes of serpin protein families in ticks. Ticks must overcome inflammation, complement activation and blood coagulation to complete feeding. Since these pathways are regulated by serpins that have basic residues at their P1 sites, we speculate that I. scapularis may utilize some of the serpins reported in this study to manipulate host defense. We have discussed our data in the context of

Biting activity of Aedes scapularis (Rondani and Haemagogus mosquitoes in Southern Brazil (Diptera: Culicidae Atividade hematófaga de mosquitos Aedes scapularis (Rondani e Haemagogus no sul do Brasil (Diptera: Culicidae

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Oswaldo Paulo Forattini

1988-04-01

Full Text Available The biting activity of a population of Aedes scapularis (Rondani, Haemagogus capricornii Lutz and Hg. leucocelaenus (Dyar and Shannon in Southern Brazil was studied between March 1980 and April 1983. Data were obtained with 25-hour human bait catches in three areas with patchy residual forests, named "Jacaré-Pepira", "Lupo" Farm, and "Sta. Helena" Farm, in the highland region of S. Paulo State (Brazil. Data obtained on Ae. scapularis were compared with those formerly gathered in the "Ribeira'' Valley lowlands, and were similar, except in the "Lupo" Farm study area, where a precrepuscular peak was observed, not recorded at the "Jacaré-Pepira" site or in the "Ribeira" Valley. In all the areas this mosquito showed diurnal and nocturnal activity, but was most active during the evening crepuscular period. These observations support the hypothesis about the successful adaptation of Ae. scapularis to man-made environments and have epidemiological implications that arise from it. As for Haemagogus, results obtained on the "Lupo" and "Sta. Helena" regions agree with previous data obtained in several other regions and show its diurnal activity. The proximity of "Lupo" Farm, where Hg. capricornii and Hg. leucocelaenus showed considerable activity, to "Araraquara" city where Aedes aegypti was recently found, raises some epidemiological considerations about the possibility of urban yellow fever resurgence.No período de março de 1980 a abril de 1983 foi estudada a atividade hematófaga de uma população de Aedes scapularis (Rondani, Haemagogus capricornii Lutz, Hg. leucocelaenus (Dyar e Shannon, na região sul do Brasil. Os dados foram obtidos com o emprego de isca humana, mediante captura de 25 horas de duração e correspondente a três áreas, contendo manchas de floresta residual, denominadas Jacaré-Pepira, Fazenda Lupo e Fazenda Santa Helena. Os resultados relativos a Ae. scapularis foram comparados com as coletas anteriormente feitas em áreas de

Combining public participatory surveillance and occupancy modelling to predict the distributional response of Ixodes scapularis to climate change.

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Lieske, David J; Lloyd, Vett K

2018-03-01

Ixodes scapularis, a known vector of Borrelia burgdorferi sensu stricto (Bbss), is undergoing range expansion in many parts of Canada. The province of New Brunswick, which borders jurisdictions with established populations of I. scapularis, constitutes a range expansion zone for this species. To better understand the current and potential future distribution of this tick under climate change projections, this study applied occupancy modelling to distributional records of adult ticks that successfully overwintered, obtained through passive surveillance. This study indicates that I. scapularis occurs throughout the southern-most portion of the province, in close proximity to coastlines and major waterways. Milder winter conditions, as indicated by the number of degree days model with a predictive accuracy of 0.845 (range: 0.828-0.893). Both RCP 4.5 and RCP 8.5 climate projections predict that a significant proportion of the province (roughly a quarter to a third) will be highly suitable for I. scapularis by the 2080s. Comparison with cases of canine infection show good spatial agreement with baseline model predictions, but the presence of canine Borrelia infections beyond the climate envelope, defined by the highest probabilities of tick occurrence, suggest the presence of Bbss-carrying ticks distributed by long-range dispersal events. This research demonstrates that predictive statistical modelling of multi-year surveillance information is an efficient way to identify areas where I. scapularis is most likely to occur, and can be used to guide subsequent active sampling efforts in order to better understand fine scale species distributional patterns. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

Tissue-specific signatures in the transcriptional response to Anaplasma phagocytophilum infection of Ixodes scapularis and Ixodes ricinus tick cell lines

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Pilar eAlberdi

2016-02-01

Full Text Available Anaplasma phagocytophilum are transmitted by Ixodes spp. ticks and have become one of the most common and relevant tick-borne pathogens due to their impact on human and animal health. Recent results have increased our understanding of the molecular interactions between Ixodes scapularis and A. phagocytophilum through the demonstration of tissue-specific molecular pathways that ensure pathogen infection, development and transmission by ticks. However, little is known about the Ixodes ricinus genes and proteins involved in the response to A. phagocytophilum infection. The tick species I. scapularis and I. ricinus are evolutionarily closely related and therefore similar responses are expected in A. phagocytophilum-infected cells. However, differences may exist between I. scapularis ISE6 and I. ricinus IRE/CTVM20 tick cells associated with tissue-specific signatures of these cell lines. To address this hypothesis, the transcriptional response to A. phagocytophilum infection was characterized by RNA sequencing and compared between I. scapularis ISE6 and I. ricinus IRE/CTVM20 tick cell lines. The transcriptional response to infection of I. scapularis ISE6 cells resembled that of tick hemocytes while the response in I. ricinus IRE/CTVM20 cells was more closely related to that reported previously in infected tick midguts. The inhibition of cell apoptosis by A. phagocytophilum appears to be a key adaptation mechanism to facilitate infection of both vertebrate and tick cells and was used to investigate further the tissue-specific response of tick cell lines to pathogen infection. The results supported a role for the intrinsic pathway in the inhibition of cell apoptosis by A. phagocytophilum infection of I. scapularis ISE6 cells. In contrast, the results in I. ricinus IRE/CTVM20 cells were similar to those obtained in tick midguts and suggested a role for the JAK/STAT pathway in the inhibition of apoptosis in tick cells infected with A. phagocytophilum

Sexual distinction between 5th instar nymphs of six species of Triatominae (Hemiptera, Reduviidae

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João Aristeu da Rosa

1992-06-01

Full Text Available The aim of this paper is to present the analysis of sexual morphological differences observed in 5th instar nymphs of the following species: Panstrongylus megistus; Rhodnius neglectus; Triatoma brasiliensis; T. infestans; T. matogrosensis and T. tibiamaculata. Male and female nymphs were examined and photographed with a Scanning Electron Microscope. The 9th segment dimensions of dorsal and ventral faces were determined through a Profile Projector. Results and statistical analysis showed significant differences: the 9th sternite is significantly broader in male than female nymphs, while in five species; tergites in female nymphs are broad and in male are narrow.

Potential of Tenebrio molitor (Coleoptera: Tenebrionidae) as a bioassay probe for Metarhizium brunneum (Hypocreales: Clavicipitaceae) activity against Ixodes scapularis (Acari: Ixodidae).

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Bharadwaj, Anuja; Stafford, Kirby C

2011-12-01

The yellow mealworm, Tenebrio molitor L., has been used to indicate qualitatively the presence of entomopathogenic fungi in the soil or as a model for evaluating stress and other factors on fungal activity. Although this beetle appears highly susceptible to many of these fungi, little quantitative information is available on the sensitivity of T. molitor to a specific fungus and, therefore, fungal presence or as an indicator for pathogenicity to other species. The purpose of this study was to establish the suitability of T. molitor larvae as a bioassay probe for Metarhizium brunneum for comparison against the blacklegged tick, Ixodes scapularis. Nine concentrations of M. brunneum strain F52 ranging from 1.0 x 10(1) to 8.4 x 10(8) conidial/ml were simultaneously tested against T. molitor larvae and I. scapularis adults. Larvae of yellow mealworm were less sensitive to M. brunneum than I. scapularis adults (LC50's 4.4 x 10(7) and 1.7 x 10(5) conidia/ml, respectively, 4-wk post-treatment). The greater sensitivity of I. scapularis to the fungus suggests that the detection of fungal mycosis in mealworms would indicate sufficient inoculum to be pathogenic to I. scapularis and make this insect a suitable probe for evaluation of the presence and activity of M. brunneum against the blacklegged tick in field applications.

Immunity against Ixodes scapularis salivary proteins expressed within 24 hours of attachment thwarts tick feeding and impairs Borrelia transmission.

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Sukanya Narasimhan

2007-05-01

Full Text Available In North America, the black-legged tick, Ixodes scapularis, an obligate haematophagus arthropod, is a vector of several human pathogens including Borrelia burgdorferi, the Lyme disease agent. In this report, we show that the tick salivary gland transcriptome and proteome is dynamic and changes during the process of engorgement. We demonstrate, using a guinea pig model of I. scapularis feeding and B. burgdorferi transmission, that immunity directed against salivary proteins expressed in the first 24 h of tick attachment - and not later - is sufficient to evoke all the hallmarks of acquired tick-immunity, to thwart tick feeding and also to impair Borrelia transmission. Defining this subset of proteins will promote a mechanistic understanding of novel I. scapularis proteins critical for the initiation of tick feeding and for Borrelia transmission.

Expansion of the Lyme Disease Vector Ixodes scapularis in Canada inferred from CMIP5 Climate Projections

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McPherson, Michelle Yvonne; García-García, Almudena; José Cuesta-Valero, Francisco; Beltrami, Hugo; Hansen-Ketchum, Patti; MacDougall, Donna; Hume Ogden, Nicholas

2017-04-01

A number of studies have assessed possible climate change impacts on the Lyme disease vector, Ixodes scapularis. However, most have used surface air temperature from only one climate model simulation and/or one emission scenario, representing only one possible climate future. We quantified effects of different Representative Concentration Pathway (RCP) and climate model outputs on the projected future changes in the basic reproduction number (R0) of I. scapularis to explore uncertainties in future R0 estimates. We used surface air temperature generated by a complete set of General Circulation Models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to hindcast historical and forecast future effects of climate change on the R0 of I. scapularis. As in previous studies, R0 of I. scapularis increased with a warming climate under future projected climate. Increases in the multi-model mean R0 values showed significant changes over time under all RCP scenarios, however; only the estimated R0 mean values between RCP6.0 and RCP8.5 showed statistically significant differences. Our results highlight the potential for climate change to have an effect on future Lyme disease risk in Canada even if the Paris Agreement's goal to keep global warming below 2°C is achieved, although mitigation reducing emissions from RCP8.5 levels to those of RCP6.0 or less would be expected to slow tick invasion after the 2030s. On-going planning is needed to inform and guide adaptation in light of the projected range of possible futures.

Ionoregulatory and toxicological responses of stonefly nymphs (Plecoptera) to acidic and alkaline pH

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Lechleitner, R.A.; Cherry, D.S.; Cairns, J. Jr.; Stetler, D.A.

1985-03-01

The acute toxicities of acidic and alkaline pH to nymphs of the stoneflies Pteronarcys dorsata, P. proteus, and Tallaperla maria were determined in 96-hr static bioassays. The acidic and alkaline 96-hr LC/sub 50/ values were 2.8 to 3.3 and 12.1 to 10.3, respectively. Exposure to pH 3.0 for 72 hr or longer caused a significant loss of sodium from nymphs of P. proteus. Morphological changes, including distension of cuticular disk and increased number of vesicles, were observed in gill tissue from nymphs of P. dorsata exposed to pH 2.5 for 9 hr while minor changes were observed in nymphs exposed to pH 4.0 for 96 hr. Changes in gill tissue ultrastructure included an increase in number of vesicles and a decrease in number and size of mitochondria in nymphs exposed to alkaline pH of 11.75.

Reciprocal Regulation of NF-kB (Relish) and Subolesin in the Tick Vector, Ixodes scapularis

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Galindo, Ruth C.; Kocan, Katherine M.; Blouin, Edmour F.; Mitra, Ruchira; Alberdi, Pilar; Villar, Margarita; de la Fuente, José

2013-01-01

Background Tick Subolesin and its ortholog in insects and vertebrates, Akirin, have been suggested to play a role in the immune response through regulation of nuclear factor-kappa B (NF-kB)-dependent and independent gene expression via interaction with intermediate proteins that interact with NF-kB and other regulatory proteins, bind DNA or remodel chromatin to regulate gene expression. The objective of this study was to characterize the structure and regulation of subolesin in Ixodes scapularis. I. scapularis is a vector of emerging pathogens such as Borrelia burgdorferi, Anaplasma phagocytophilum and Babesia microti that cause in humans Lyme disease, anaplasmosis and babesiosis, respectively. The genome of I. scapularis was recently sequenced, and this tick serves as a model organism for the study of vector-host-pathogen interactions. However, basic biological questions such as gene organization and regulation are largely unknown in ticks and other arthropod vectors. Principal Findings The results presented here provide evidence that subolesin/akirin are evolutionarily conserved at several levels (primary sequence, gene organization and function), thus supporting their crucial biological function in metazoans. These results showed that NF-kB (Relish) is involved in the regulation of subolesin expression in ticks, suggesting that as in other organisms, different NF-kB integral subunits and/or unknown interacting proteins regulate the specificity of the NF-kB-mediated gene expression. These results suggested a regulatory network involving cross-regulation between NF-kB (Relish) and Subolesin and Subolesin auto-regulation with possible implications in tick immune response to bacterial infection. Significance These results advance our understanding of gene organization and regulation in I. scapularis and have important implications for arthropod vectors genetics and immunology highlighting the possible role of NF-kB and Subolesin/Akirin in vector

Behavioral, Ultrastructural and Chemical Studies on the Honeydew and Waxy Secretions by Nymphs and Adults of the Asian Citrus Psyllid Diaphorina citri (Hemiptera: Psyllidae)

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Ammar, El-Desouky; Alessandro, Rocco; Shatters Jr, Robert G.; Hall, David G.

2013-01-01

The Asian citrus psyllid (ACP), Diaphorina citri (Hemiptera: Psyllidae) is the primary vector of the bacterium causing citrus huanglongbing (citrus greening), the most serious disease of citrus worldwide. Psyllids and other hemipterans produce large amounts of honeydew, which has been used previously as an indicator of phloem sap composition and insect feeding or metabolism. Behavioral, ultrastructural and chemical studies on ACP, its honeydew and waxy secretions showed important differences between nymphs, males and females, and suggested some mechanisms by which the psyllids, especially nymphs and adult females, can minimize their contamination with honeydew excretions. The anal opening in ACP, near the posterior end of the abdomen, is on the ventral side in nymphs and on the dorsal side in adult males and females. Video recordings showed that adult males produce clear sticky droplets of honeydew gently deposited behind their body on the leaf surface, whereas adult females produce whitish honeydew pellets powerfully propelled away from the female body, probably to get their excretions away from eggs and newly hatched nymphs. ACP nymphs produce long ribbons or tubes of honeydew that frequently stay attached to the exuviae after molting, or drop when feeding on the lower side of citrus leaves. Furthermore, honeydew excretions of both nymphs and adult females are covered with a thin layer of whitish waxy material ultrastructurally composed of a convoluted network of long fine filaments or ribbons. This material is extruded from intricate arrays of wax pores in the circumanal ring (around the anus) that is found in nymphs and females but not in males of ACP or other psyllid species. Infrared microscopy and mass spectroscopy revealed that, in addition to various sugars, honeydew excretions of ACP nymphs and females are covered with a thin layer of wax similar in profile to ester waxes. PMID:23762268

Behavioral, ultrastructural and chemical studies on the honeydew and waxy secretions by nymphs and adults of the Asian citrus psyllid Diaphorina citri (Hemiptera: Psyllidae.

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El-Desouky Ammar

Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri (Hemiptera: Psyllidae is the primary vector of the bacterium causing citrus huanglongbing (citrus greening, the most serious disease of citrus worldwide. Psyllids and other hemipterans produce large amounts of honeydew, which has been used previously as an indicator of phloem sap composition and insect feeding or metabolism. Behavioral, ultrastructural and chemical studies on ACP, its honeydew and waxy secretions showed important differences between nymphs, males and females, and suggested some mechanisms by which the psyllids, especially nymphs and adult females, can minimize their contamination with honeydew excretions. The anal opening in ACP, near the posterior end of the abdomen, is on the ventral side in nymphs and on the dorsal side in adult males and females. Video recordings showed that adult males produce clear sticky droplets of honeydew gently deposited behind their body on the leaf surface, whereas adult females produce whitish honeydew pellets powerfully propelled away from the female body, probably to get their excretions away from eggs and newly hatched nymphs. ACP nymphs produce long ribbons or tubes of honeydew that frequently stay attached to the exuviae after molting, or drop when feeding on the lower side of citrus leaves. Furthermore, honeydew excretions of both nymphs and adult females are covered with a thin layer of whitish waxy material ultrastructurally composed of a convoluted network of long fine filaments or ribbons. This material is extruded from intricate arrays of wax pores in the circumanal ring (around the anus that is found in nymphs and females but not in males of ACP or other psyllid species. Infrared microscopy and mass spectroscopy revealed that, in addition to various sugars, honeydew excretions of ACP nymphs and females are covered with a thin layer of wax similar in profile to ester waxes.

Nymphs of the common bed bug (Cimex lectularius produce anti-aphrodisiac defence against conspecific males

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Harraca Vincent

2010-09-01

Full Text Available Abstract Background Abdominal wounding by traumatic insemination and the lack of a long distance attraction pheromone set the scene for unusual sexual signalling systems. Male bed bugs (Cimex lectularius mount any large, newly fed individual in an attempt to mate. Last instar nymphs overlap in size with mature females, which make them a potential target for interested males. However, nymphs lack the female's specific mating adaptations and may be severely injured by the abdominal wounding. We, therefore, hypothesized that nymphs emit chemical deterrents that act as an honest status signal, which prevents nymph sexual harassment and indirectly reduces energy costs for males. Results Behavioural mating assays showed that males mount nymphs significantly shorter time compared to females, although initial mounting preference was the same. In support of our hypothesis, nymphs experienced the same percentage of mating with sperm transfer as females if they were unable to emit (E-2-hexenal, (E-2-octenal 4-oxo-(E-2-hexenal and 4-oxo-(E-2-octenal, from their dorsal abdominal glands. We report that the aldehydes and 4-oxo-(E-2-hexenal are detected by olfactory receptor neurons housed in smooth and grooved peg sensilla, respectively, on the adult antennae, at biologically relevant concentrations. Behavioural experiments showed that application of 4-oxo-(E-2-hexenal or the two aldehydes at a nymph-emitted ratio, to a male/female pair during mounting initiation, decreased mating frequency to a rate comparable to that of a male/nymph pair. Conclusions By combining behavioural and sensory studies, we show that the nymph-specific alarm pheromone plays an important role in intra-specific communication in the common bed bug. Alarm pheromones are commonly looked upon as a system in predator/prey communication, but here we show that alarm pheromones may be used as multipurpose signals such as decreasing the risk of nymphal mating by males. See commentary: http

Impact of Sodium Chloride and Heat on Survival Time of Linguatula Serrata Nymphs in vitro: An Experimental Study

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B. Hajimohammadi

2012-07-01

Full Text Available Introduction: Linguatula serrata is a zoonotic parasite, belonging to the class Pentastomida. The major aim of this study was to evaluate the impact of sodium chloride (NaCl and heat on survival time of Linguatula serrata nymphs. Materials & Methods: Thirty nymphs (10 in triplicate were separately transferred to plastic tubes, containing different concentrations of NaCl solution (2%, 5% and 10%. Meanwhile, 30 nymphs in tubes containing Phosphate Buffer Saline (PBS were separately treated by +50°C, +60°C and +72°C. As control group, thirty nymphs were stored in PBS at +4°C. The effects of different conditions on survival time of the nymphs were evaluated by observing their motility in different periods of time. Results: The survival time of the nymphs stored in 10% NaCl solution was too short and all of them were dead after 3 hours. But the other ones maintained in 2% NaCl solution were significantly more resistant (p<0.05 and were survived for 2 days. All the nymphs pertaining to each +60°C and +72°C treatments were found dead after first 5-minute storage interval; the nymphs stored at +50°C died totally after 20 minutes. The nymphs maintained in PBS at +4°C (control group showed the longest survival time (p<0.05; all of them were alive until day 4 and the last ones died on day 34. Conclusion: It is concluded that salting and heating have significant parasiticidal effects on L. serrata nymphs and could be used as disinfecting methods in processing of meat products especially liver. However, refrigeration at +4°C increases the resistance of the nymphs in meat products and therefore might endanger the food safety.

Genomic insights into the Ixodes scapularis tick vector of Lyme disease

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Gulia-Nuss, Monika; Nuss, Andrew B.; Meyer, Jason M.; Sonenshine, Daniel E.; Roe, R. Michael; Waterhouse, Robert M.; Sattelle, David B.; de la Fuente, José; Ribeiro, Jose M.; Megy, Karine; Thimmapuram, Jyothi; Miller, Jason R.; Walenz, Brian P.; Koren, Sergey; Hostetler, Jessica B.; Thiagarajan, Mathangi; Joardar, Vinita S.; Hannick, Linda I.; Bidwell, Shelby; Hammond, Martin P.; Young, Sarah; Zeng, Qiandong; Abrudan, Jenica L.; Almeida, Francisca C.; Ayllón, Nieves; Bhide, Ketaki; Bissinger, Brooke W.; Bonzon-Kulichenko, Elena; Buckingham, Steven D.; Caffrey, Daniel R.; Caimano, Melissa J.; Croset, Vincent; Driscoll, Timothy; Gilbert, Don; Gillespie, Joseph J.; Giraldo-Calderón, Gloria I.; Grabowski, Jeffrey M.; Jiang, David; Khalil, Sayed M. S.; Kim, Donghun; Kocan, Katherine M.; Koči, Juraj; Kuhn, Richard J.; Kurtti, Timothy J.; Lees, Kristin; Lang, Emma G.; Kennedy, Ryan C.; Kwon, Hyeogsun; Perera, Rushika; Qi, Yumin; Radolf, Justin D.; Sakamoto, Joyce M.; Sánchez-Gracia, Alejandro; Severo, Maiara S.; Silverman, Neal; Šimo, Ladislav; Tojo, Marta; Tornador, Cristian; Van Zee, Janice P.; Vázquez, Jesús; Vieira, Filipe G.; Villar, Margarita; Wespiser, Adam R.; Yang, Yunlong; Zhu, Jiwei; Arensburger, Peter; Pietrantonio, Patricia V.; Barker, Stephen C.; Shao, Renfu; Zdobnov, Evgeny M.; Hauser, Frank; Grimmelikhuijzen, Cornelis J. P.; Park, Yoonseong; Rozas, Julio; Benton, Richard; Pedra, Joao H. F.; Nelson, David R.; Unger, Maria F.; Tubio, Jose M. C.; Tu, Zhijian; Robertson, Hugh M.; Shumway, Martin; Sutton, Granger; Wortman, Jennifer R.; Lawson, Daniel; Wikel, Stephen K.; Nene, Vishvanath M.; Fraser, Claire M.; Collins, Frank H.; Birren, Bruce; Nelson, Karen E.; Caler, Elisabet; Hill, Catherine A.

2016-01-01

Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-transposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing ∼57% of the genome, reveals 20,486 protein-coding genes and expansions of gene families associated with tick–host interactions. We report insights from genome analyses into parasitic processes unique to ticks, including host ‘questing', prolonged feeding, cuticle synthesis, blood meal concentration, novel methods of haemoglobin digestion, haem detoxification, vitellogenesis and prolonged off-host survival. We identify proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent. PMID:26856261

Field and laboratory responses of adult Ixodes scapularis (Acari: Ixodidae) to kairomones produced by white-tailed deer.

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Carroll, J F; Mills, G D; Schmidtmann, E T

1996-07-01

In a field test, adult blacklegged ticks, Ixodes scapularis Say, of both sexes exhibited an arrestant response to substances associated with external glands on the legs of white-tailed deer, Odocoileus virginianus (Zimmermann), their principal host. Substances rubbed from the pelage covering tarsal and interdigital glands were applied to artificial vantage points simulating vegetation on which I. scapularis adults wait for host contact. A combination of tarsal substances (applied to the apex of the simulated vantage point) and interdigital gland substances (applied to the horizontal base) elicited a greater response than either treatment alone. A minimal response was observed on untreated vantage points. In laboratory bioassays using glass tubing as vantage points, substances associated with preorbital glands of deer elicited a strong arrestant response among I. scapularis females, whereas samples rubbed from the forehead, back, and a nonglandular area on deer tarsi evoked weak arrestant responses. These results support the hypothesis that the kairomonal properties of host-generated residues, either in conjunction with or in lieu of the effects of carbon dioxide, help account for the prevalence of host-seeking ticks along animal trails.

Physiological and behavioral responses of stonefly nymphs to enhanced limestone treatment of acid mine drainage.

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Cole, M B; Arnold, D E; Watten, B J

2001-03-01

A new acid mine drainage (AMD) treatment system uses pulsed, fluidized beds of limestone, and carbon dioxide pretreatment of influent AMD, to enhance limestone neutralization of AMD. We conducted laboratory studies to evaluate the behavior and physiology of larval stoneflies (Pteronarcys proteus, Plecoptera) exposed to effluents produced by the treatment system. Survival, sodium balance, drift, and feeding responses by P. proteus to treated and untreated AMD were examined. P. proteus nymphs exhibited significant losses of whole body sodium in exposures to untreated AMD. Nymphs exposed to treated effluents experienced no loss of whole-body sodium. Nymphs exposed to untreated AMD showed elevated drift rates and depressed feeding rates relative to those of nymphs exposed to treated AMD, and to AMD-free controls. No significant differences in feeding or drift behavior occurred between nymphs exposed to treated effluents and those exposed to AMD-free controls. The treatment system, with and without CO2 pretreatment, provided water that was not toxic to the test animals, and that allowed normal behavioral and physiological function.

An illustrated key to nymphs of Perlidae (Insecta, Plecoptera genera in Central Amazonia, Brazil

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Hamada Neusa

2003-01-01

Full Text Available An illustrated key to nymphs of Perlidae collected in streams of Central Amazonia, Brazil is provided. Three genera are reported for this region: Macrogynoplax Enderlein, Anacroneuria Klapálek and Enderleina Jewett. Additional diagnostic characters are provided for Enderleina nymphs.

Proteome analysis of gut and salivary gland proteins of fifth-instar nymph and adults of the sunn pest, Eurygaster integriceps.

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Bezdi, Mohammad Saadati; Toorchi, Mahmoud; Pourabad, Reza Farshbaf; Zarghami, Nosratollah; Nouri, Mohammad-Zaman; Komatsu, Setsuko

2012-10-01

In the digestive system of the sunn pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae), the salivary gland has a key role in extra oral digestion and the gut is the main site for digestion of food. In this study, proteomics was used to study the role of proteins involved in digestion. The amount of feeding on wheat grain by adult insects increased by comparison to fifth-instar nymphs. Proteins of the gut and salivary gland in adults and fifth-instar nymphs were analyzed 1 day after feeding. The proteins related to digestion, metabolism, and defense against toxins were accumulated in the gut of adult insects. Three plant proteins including serpin, dehydroascorbate reductase, and β-amylase were accumulated in guts of adults. In the salivary gland, phospholipase A2 and arginine kinase were increased in adults. Heat shock protein 70 increased in the gut of fifth-instar nymphs. Proteomic analysis revealed that most of changed proteins in digestive system of sunn pest were increased in adults. This study provided more targets derived from gut and salivary gland for pest management. © 2012 Wiley Periodicals, Inc.

Ixodes scapularis saliva mitigates inflammatory cytokine secretion during Anaplasma phagocytophilum stimulation of immune cells

Czech Academy of Sciences Publication Activity Database

Chen, G.; Severo, M. S.; Sohail, M.; Sakhon, O. S.; Wikel, S. K.; Kotsyfakis, Michalis; Pedra, J. H. F.

2012-01-01

Roč. 5, č. 1 (2012), s. 229 ISSN 1756-3305 Institutional support: RVO:60077344 Keywords : Tick * Ixodes scapularis * Saliva * Anaplasma phagocytophilum * Rickettsial agent Subject RIV: EC - Immunology Impact factor: 3.246, year: 2012 http://www.parasitesandvectors.com/content/5/1/229

Stonefly (Plecoptera fauna of streams in a mountainous area of Central Brazil: abiotic factors and nymph density

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Pitágoras da Conceição Bispo

2002-07-01

Full Text Available The stonefly (Pleeoptera nymphs of streams of the Almas River basin, Pirenópolis, Goiás State, Central Brazil, and some abiotie factors that might affect their temporal distribution were studied. Nymphs were sampled monthly (June 1993 to July 1994 in five stations with a Surber sampler, and each sample consisted of 20 units totalling 2 m². In each station, stream velocity, discharge, temperature, electrical conductivity and pH were measured in order to assess their influence on the density of nymphs. Nymphs were identified to genus level. In general, the annual variation in density of nymphs, in four stations, showed that the seasonal variation was not clearly influenced by the annual rain cycle. In the case of the one of the stations, where numbers of stonefly nymphs were low and the anthropic action high, there was a density peak in the rainy season. This peak was probably related to dilution of the organie pollution in the rainy season, improving the environmental conditions for the Pleeoptera.

To beat or not to beat a tick: comparison of DNA extraction methods for ticks (Ixodes scapularis

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Alyssa D. Ammazzalorso

2015-08-01

Full Text Available Background. Blacklegged ticks (Ixodes scapularis are important disease vectors in the United States, known to transmit a variety of pathogens to humans, including bacteria, protozoa, and viruses. Their importance as a disease vector necessitates reliable and comparable methods for extracting microbial DNA from ticks. Furthermore, to explore the population genetics or genomics of this tick, appropriate DNA extraction techniques are needed for both the vector and its microbes. Although a few studies have investigated different methods of DNA isolation from ticks, they are limited in the number and types of DNA extraction and lack species-specific quantification of DNA yield.Methods. Here we determined the most efficient and consistent method of DNA extraction from two different developmental stages of I. scapularis—nymph and adult—that are the most important for disease transmission. We used various methods of physical disruption of the hard, chitinous exoskeleton, as well as commercial and non-commercial DNA isolation kits. To gauge the effectiveness of these methods, we quantified the DNA yield and confirmed the DNA quality via PCR of both tick and microbial genetic material.Results. DNA extraction using the Thermo GeneJET Genomic DNA Purification Kit resulted in the highest DNA yields and the most consistent PCR amplification when combined with either cutting or bead beating with select matrices across life stages. DNA isolation methods using ammonium hydroxide as well as the MoBio PowerSoil kit also produced strong and successful PCR amplification, but only for females.Discussion. We contrasted a variety of readily available methods of DNA extraction from single individual blacklegged ticks and presented the results through a quantitative and qualitative assessment.

Water absorption through salivary gland type I acini in the blacklegged tick, Ixodes scapularis

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Donghun Kim

2017-10-01

Full Text Available Tick salivary glands play critical roles in maintaining water balance for survival, as they eliminate excess water and ions during blood feeding on hosts. In the long duration of fasting in the off-host period, ticks secrete hygroscopic saliva into the mouth cavity to uptake atmospheric water vapor. Type I acini of tick salivary glands are speculated to be involved in secretion of hygroscopic saliva based on ultrastructure studies. However, we recently proposed that type I acini play a role in resorption of water/ions from the primary saliva produced by other salivary acini (i.e., types II and III during the tick blood feeding phase. In this study, we tested the function of type I acini in unfed female Ixodes scapularis. The route of ingested water was tracked after forced feeding of water with fluorescent dye rhodamine123. We found that type-I acini of the salivary glands, but not type II and III, are responsible for water uptake. In addition, the ingestion of water through the midgut was also observed. Injection or feeding of ouabain, a Na/K-ATPase inhibitor, suppressed water absorption in type I acini. When I. scapularis was offered a droplet of water, ticks rarely imbibed water directly (5%, while some approached the water droplet to use the high humidity formed in the vicinity of the droplet (23%. We conclude that during both on- and off-host stages, type I acini in salivary glands of female Ixodes scapularis absorb water and ions.

Anaplasma phagocytophilum Infection Subverts Carbohydrate Metabolic Pathways in the Tick Vector, Ixodes scapularis

Czech Academy of Sciences Publication Activity Database

Cabezas Cruz, Alejandro; Alberdi, P.; Valdés, James J.; Villar, M.; de la Fuente, J.

2017-01-01

Roč. 7, 7 February (2017), č. článku 23. ISSN 2235-2988 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : proteomics * transcriptomics * glucose metabolism * Ixodes scapularis * Anaplasma phagocytophilum Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 4.300, year: 2016

Prevalence of Linguatula serrata Nymph in Goat in Tabriz, North-West of Iran

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Yacob Garedaghi

2011-06-01

Full Text Available Linguatula serrata is one of well-known members of Pentastomida which infects both humans and animals. The aim of this study was to evaluate the prevalence of L. serrata in mesenteric lymph nodes, livers and lungs of goats slaughtered in Tabriz area, Iran. Mesenteric lymph nodes (MLNs, livers and lungs of 280 goats slaughtered in Tabriz, North-west of Iran were investigated for nymphs of L. serrata from September 2009 to September 2010. The organs were examined macroscopically and then a tissue digestion method was also done for investigation of liver and lung of the goats that were infected MLN. The liver and lung samples were mostly taken from the condemned and rejected part of organs. The infection rate of L. serrata nymphs in MLNs, livers and lungs was 27.1 %, 2.8 % and 2.8 % respectively. The number of isolated nymph in infected lymph nodes varied from 1 to 22 with a mean of 7. Only one nymph was isolated from each infected livers and lungs. The infection rate increased with age (P 0.05. Linguatula infection occurs as an endemic zoonosis in the study area and has an active transmission life cycle.

Experimental infection in Cavia porcellus by infected Amblyomma ovale nymphs with Rickettsia sp. (Atlantic rainforest strain).

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Brustolin, Joice Magali; da Silva Krawczak, Felipe; Alves, Marta Elena Machado; Weiller, Maria Amélia; de Souza, Camila Lopes; Rosa, Fábio Brum; Cadore, Gustavo Cauduro; Dos Anjos Lopes, Sônia Terezinha; Labruna, Marcelo Bahia; Vogel, Fernanda Silveira Flores; de Avila Botton, Sônia; Sangioni, Luís Antônio

2018-03-01

This study describes experimental infection of guinea pigs (Cavia porcellus) infested with naturally infected Amblyomma ovale nymphs with Rickettsia sp. (Atlantic rainforest strain), and the capacity of A. ovale nymphs to transmit this bacterium. Twenty-six guinea pigs were divided into the following groups: G1, 10 animals infested with uninfected A. ovale nymphs; G2, 10 animals infested with nymphs infected with Rickettsia sp. (Atlantic rainforest strain); and G3, 6 animals without tick infestation. Blood samples were taken 7, 14, 21, and 28 days post-infestation for serological and hematological tests. For histopathological analysis and rickettsial DNA detection, fragments of the spleen, lung, brain, and liver were harvested after euthanasia. The average feeding period for nymphs was 6.6 days for G1 and 6 days for G2. Hemolymph and PCR assays, performed to detect the causative agent in ticks, indicated that in G1, all ticks were negative, and in G2, all nymphs were positive by PCR and 80% (8/10) was positive by hemolymph tests. The only clinical change was skin scarring at the tick attachment site. Hematological parameters indicated leukopenia and total plasma protein (TPP) increased with decreased platelets in G1. In G2, leukocytosis, neutrophilia, monocytosis, an increase in platelets, and reduced TPP were observed. Only G2 guinea pigs were seroconverted (80%; 8/10). Histopathology tests indicated mild, diffuse hemosiderosis and mild, multifocal, follicular hyperplasia in the spleen. Molecular analysis did not detect Rickettsia sp. DNA in C. porcellus tissues. We demonstrated the capacity of A. ovale nymphs to transmit Rickettsia sp. (Atlantic rainforest strain) to guinea pigs.

Spatial Distribution and Sampling Plans for Grapevine Plant Canopy-Inhabiting Scaphoideus titanus (Hemiptera: Cicadellidae) Nymphs.

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Rigamonti, Ivo E; Brambilla, Carla; Colleoni, Emanuele; Jermini, Mauro; Trivellone, Valeria; Baumgärtner, Johann

2016-04-01

The paper deals with the study of the spatial distribution and the design of sampling plans for estimating nymph densities of the grape leafhopper Scaphoideus titanus Ball in vine plant canopies. In a reference vineyard sampled for model parameterization, leaf samples were repeatedly taken according to a multistage, stratified, random sampling procedure, and data were subjected to an ANOVA. There were no significant differences in density neither among the strata within the vineyard nor between the two strata with basal and apical leaves. The significant differences between densities on trunk and productive shoots led to the adoption of two-stage (leaves and plants) and three-stage (leaves, shoots, and plants) sampling plans for trunk shoots- and productive shoots-inhabiting individuals, respectively. The mean crowding to mean relationship used to analyze the nymphs spatial distribution revealed aggregated distributions. In both the enumerative and the sequential enumerative sampling plans, the number of leaves of trunk shoots, and of leaves and shoots of productive shoots, was kept constant while the number of plants varied. In additional vineyards data were collected and used to test the applicability of the distribution model and the sampling plans. The tests confirmed the applicability 1) of the mean crowding to mean regression model on the plant and leaf stages for representing trunk shoot-inhabiting distributions, and on the plant, shoot, and leaf stages for productive shoot-inhabiting nymphs, 2) of the enumerative sampling plan, and 3) of the sequential enumerative sampling plan. In general, sequential enumerative sampling was more cost efficient than enumerative sampling.

Genomic insights into the Ixodes scapularis tick vector of Lyme disease

DEFF Research Database (Denmark)

Gulia-Nuss, Monika; Nuss, Andrew B.; Meyer, Jason M.

2016-01-01

Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects...... proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent....

Long-Term Effects of Berberis thunbergii (Ranunculales: Berberidaceae) Management on Ixodes scapularis (Acari: Ixodidae) Abundance and Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) Prevalence in Connecticut, USA.

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Williams, Scott C; Linske, Megan A; Ward, Jeffrey S

2017-12-08

Japanese barberry (Berberis thunbergii de Candolle; Ranunculales: Berberidaceae) is an exotic invasive shrub that escaped cultivation in the United States and is now permanently established in many eastern and midwestern states. This study examined the long-term impacts of Japanese barberry management on blacklegged tick (Ixodes scapularis Say; Acari: Ixodidae) abundances and associated prevalence of Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner; Spirochaetales: Spirochaetaceae), the etiologic agent of Lyme disease. At six locations across Connecticut, adult I. scapularis were sampled for up to 10 yr. At each location, we sampled an area where barberry infestations were unmanipulated, adjacent areas where barberry was virtually nonexistent, and areas where barberry was managed utilizing a variety of techniques. Barberry management reduced B. burgdorferi-infected adult I. scapularis (BBIAIS) abundances (191/ha ± 64 SE) over 6 yr to statistically indifferent from that of no barberry areas (140/ha ± 47 SE; P = 0.080) and significantly less than intact barberry stands (458/ha ± 80 SE; P = 0.026). Over 9 yr, BBIAIS abundances in managed barberry remained lower than intact barberry stands (P = 0.037), but increased to be significantly greater than no barberry areas (P = 0.007) as cover increased over time. Longer-term data further document that Japanese barberry infestations are favorable habitat for I. scapularis. Control of Japanese barberry and other invasives should be at least on a 5-yr rotation to maintain low levels of invasive cover and eliminate humidity refugia to expose juvenile I. scapularis to more hostile environmental conditions in the interest of public health. © The Authors 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.

A formulation to encapsulate nootkatone for tick control.

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Behle, Robert W; Flor-Weiler, Lina B; Bharadwaj, Anuja; Stafford, Kirby C

2011-11-01

Nootkatone is a component of grapefruit oil that is toxic to the disease-vectoring tick, Ixodes scapularis Say, but unfortunately causes phytotoxicity to treated plants and has a short residual activity due to volatility. We prepared a lignin-encapsulated nootkatone formulation to compare with a previously used emulsifiable formulation for volatility, plant phytotoxicity, and toxicity to unfed nymphs of I. scapularis. Volatility of nootkatone was measured directly by trapping nootkatone vapor in a closed system and indirectly by measuring nootkatone residue on treated filter paper after exposure to simulated sunlight (Xenon). After 24 h in the closed system, traps collected only 15% of the nootkatone applied as the encapsulated formulation compared with 40% applied as the emulsifiable formulation. After a 1-h light exposure, the encapsulated formulation retained 92% of the nootkatone concentration compared with only 26% retained by the emulsifiable formulation. For plant phytotoxicity, cabbage, Brassica oleracea L., leaves treated with the encapsulated formulation expressed less necrosis, retaining greater leaf weight compared with leaves treated with the emusifiable formulation. The nootkatone in the emulsifiable formulation was absorbed by cabbage and oat, Avena sativa L., plants (41 and 60% recovered 2 h after application, respectively), as opposed to 100% recovery from the plants treated with encapsulated nootkatone. Using a treated vial technique, encapsulated nootkatone was significantly more toxic to I. scapularis nymphs (LC50 = 20 ng/cm2) compared with toxicity of the emulsifiable formulation (LC50 = 35 ng/cm2). Thus, the encapsulation of nootkatone improved toxicity for tick control, reduced nootkatone volatility, and reduced plant phytotoxicity.

Infestation of froghopper nymphs changes the amounts of total phenolics in sugarcane

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Silva Rafael José Navas da

2005-01-01

Full Text Available The increased rate of sugarcane harvest without previous burn has provided a very favorable environment to the froghopper Mahanarva fimbriolata (Stal, 1854, with high moisture and low temperature variation. Few works have studied the response of sugarcane to this pest, so little is known about resistant cultivars. Plant phenolics are widely studied compounds because of their known antiherbivore effect. This research aims to determine if the attack of M. fimbriolata nymphs stimulates the accumulation of total phenolics in sugarcane. The experiment was carried out in greenhouse and arranged in completely randomized design, in a 3 X 2 X 4 factorial with three replications. Second instar nymphs of M. fimbriolata were infested at the following rates: control, 2-4 and 4-8 nymphs per pot (first-second infestations, respectively. Pots were covered with nylon net and monitored daily to isolate the effect of leaf sucking adults. Leaf and root samples were collected and kept frozen in liquid nitrogen until analyses. Infested plants showed higher levels of phenolics in both root and leaf tissues. In roots, the cultivar SP80-1816 accumulated more phenolic compounds in response to the infestation of M. fimbriolata. On the other hand, higher levels were found in leaves and roots of control plants of SP86-42, which might be an indication of a non-preference mechanism. The increase of total phenolics in sugarcane infested with root-sucking froghopper nymphs does not seem to be useful to detect the resistance to this pest.

Ixodes scapularis Tick Cells Control Anaplasma phagocytophilum Infection by Increasing the Synthesis of Phosphoenolpyruvate from Tyrosine

Czech Academy of Sciences Publication Activity Database

Cabezas Cruz, Alejandro; Espinosa, P. J.; Obregon, D. A.; Alberdi, P.; de la Fuente, J.

2017-01-01

Roč. 7, AUG 17 (2017), č. článku 375. ISSN 2235-2988 Institutional support: RVO:60077344 Keywords : proteomics * transcriptomics * phosphoenolpyruvate * glycerol-3-phosphate * Ixodes scapularis * Anaplasma phagocytophilum Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.300, year: 2016

COMPARISON OF THE POPULATIONS OF COMMON WOOD-NYMPH BUTTERFLIES IN BURNED PRAIRIE, UNBURNED PRAIRIE AND OLD FIELD GRASSES

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Hahn, M.; Walton, R.

2007-01-01

Common wood-nymph butterfl ies are found throughout the United States and Canada. However, not much is known about how they overwinter or their preferences for particular grasses and habitats. In this study, the impact of prairie management plans on the abundance of the wood-nymph population was assessed, as well as the preference of these butterfl ies for areas with native or non-native grasses. The abundance of common wood-nymph butterfl ies was determined using Pollard walks; more common wood-nymph butterfl ies were found in the European grasses than were found in the burned and unburned prairie sites. The majority of the vegetation at each of the three sites was identifi ed and documented. Using a 1 X 3 ANOVA analysis, it was determined there were signifi cantly more butterfl ies in the European grasses than in the burned and unburned prairie sites (p < 0.0005). There was no signifi cant difference between the burned and unburned treatments of the prairie on the common wood-nymph population. A multiple variable linear regression model described the effect of temperature and wind speed on the number of observed common wood-nymph butterfl ies per hour (p = 0.026). These preliminary results need to be supplemented with future studies. Quadrat analysis of the vegetation from all three sites should be done to search for a correlation between common wood-nymph butterfl y abundance per hour and the specifi c types or quantity of vegetation at each site. The effect of vegetation height and density on the observer’s visual fi eld should also be assessed.

Spatial distribution of Plecoptera nymphs in streams of a mountainous area of Central Brazil

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P. C. BISPO

Full Text Available In this paper the spatial distribution of Plecoptera nymphs in the Almas' River basin, Pirenópolis, GO, was studied. Two Surber samples, each comprising 20 sampling units and totalling 2 m², were taken in each of the 13 stations, one during the rainy season (January 1994 and the second during the dry season (July 1994. In 5 of these stations, monthly samplings were made from June 1993 to July 1994; in these, temperature, velocity, discharge, electrical conductivity and pH were measured. Regional rainfall was also obtained. To ascertain the distribution of nymphs in the habitat, a separate sample was taken. Of the factors considered, the most important affecting the spatial distribution of the stonefly nymphs were altitude, stream order, and anthropic influence. Locally, the genera Anacroneuria and Kempnyia showed clumped distributions, but the data for Gripopteryx and Tupiperla were inconclusive due to low numbers.

The Titanic Origin of Humans: The Melian Nymphs and Zagreus

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Velvet Yates

2010-11-01

Full Text Available Hesiod's creation myth implies that the human race derived from the "ash tree nymphs" (meliai; the Neoplatonists, with their etymological arguments, seem to have this in mind in tracing human origins to the Titans' "limbs" (melea.

Incoordination, Paralysis and Recovery after Pyrethroid Treatment on Nymphs III of Triatoma infestans (Hemiptera: Reduviidae

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Raúl A Alzogaray

1997-05-01

Full Text Available Symptoms of poisoning for deltamethrin and cis-permethrin on nymphs III of Triatoma infestans were described. The time required for incoordination and paralysis were determined. Deltamethrin was equal or more rapid in the onset of the first effect (accordingly to dose, and cis-permethrin in the onset of the second one. There were no significant differences between incoordination doses 50% (IncD50s at different times for the two pyrethroids. They showed equivalent incoordination power, but the nymphs treated with deltamethrin recovered slightly more rapid and in greater amount than the nymphs treated with cis-permethrin. The recovery was inhibited by the simultaneus application of piperonyl butoxide. This result suggests that biotransformation by mixed-function microsomal oxidases are involved in the process of recovery

Evaluation of the United States Department of Agriculture Northeast Area-Wide Tick Control Project by Meta-Analysis

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Brei, Brandon; George, John E.; Pound, J. Mathews; Miller, J. Allen; Daniels, Thomas J.; Falco, Richard C.; Stafford, Kirby C.; Schulze, Terry L.; Mather, Thomas N.; Carroll, John F.; Fish, Durland

2009-01-01

Abstract As part of the Northeast Area-wide Tick Control Project (NEATCP), meta-analyses were performed using pooled data on the extent of tick-vector control achieved through seven concurrent studies, conducted within five states, using U.S. Department of Agriculture “4-Poster” devices to deliver targeted-acaricide to white-tailed deer. Although reductions in the abundance of all life-stages of Ixodes scapularis were the measured outcomes, this study focused on metrics associated with I. scapularis nymphal tick densities as this measure has consistently proven to directly correlate with human risk of acquiring Lyme disease. Since independent tick sampling schemes were undertaken at each of the five environmentally distinct study locations, a meta-analytic approach permitted estimation of a single true control-effect size for each treatment year of the NEATCP. The control-effect is expressed as the annual percent I. scapularis nymphal control most consistent with meta-analysis data for each treatment year. Our meta-analyses indicate that by the sixth treatment year, the NEATCP effectively reduced the relative density of I. scapularis nymphs by 71% on the 5.14 km2 treatment sites, corresponding to a 71% lower relative entomologic risk index for acquiring Lyme disease. PMID:19650737

Attraction of Male Nymphs to Adult Male Volatiles in the Bronze Bug Thaumastocoris peregrinus Carpintero & Dellape (Heteroptera: Thaumastocoridae).

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Calvo, M V; Groba, H F; Martínez, G; Sellanes, C; Rossini, C; González, A

2017-12-23

The bronze bug, Thaumastocoris peregrinus Carpintero & Dellape (Heteroptera: Thaumastocoridae), is an exotic emerging pest in Eucalyptus commercial forests in South America, Africa and southern Europe. Information on the chemical communication system and reproductive ecology of this insect is scant, and it may be relevant for designing management strategies for eucalypt plantations. Adults and nymphs usually aggregate in the field, possibly by means of chemical signals. Males emit large amounts of 3-methyl-2-butenyl butyrate, which attracts conspecific adult males but not females. The ecological role of this putative male aggregation pheromone remains unknown. Here, we report olfactometer bioassays showing that late-instar male nymphs are also attracted to synthetic 3-methyl-2-butenyl butyrate and to adult male volatile extracts, which contain this compound as the major component. As previously shown for adult females, nymphs that moulted into females were not attracted to either volatile stimulus. The intra-gender attraction of nymphs and adults may be related to the exploitation of food resources, or as a reproductive strategy for newly emerged males. Further studies on the reproductive behaviour and mating system of T. peregrinus will contribute to understanding the ecological significance of male-male, adult-nymph attraction, as well as the practical applications that may result from these findings.

Physiological and behavioral response of stonefly nymphs to enhanced limestone treatment of acid mine drainage

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Cole, M.B.; Arnold, D.E.; Watten, B.J. [ABR Inc., PO Box 249, OR (USA). Environmental Research and Services

2001-07-01

A new acid mine drainage (AMD) treatment system uses pulsed, fluidized beds of limestone, and carbon dioxide pretreatment of influent AMD to enhance limestone neutralization of AMD. Laboratory studies were carried out to evaluate the behavior and physiology of larval stoneflies (Pteronarcys proteus, Plecoptera) exposed to effluents produced by the treatment system. Survival, sodium balance, drift, and feeding responses by P. proteus to treated and untreated AMD were examined. P. proteus nymphs exhibited significant losses of whole body sodium in exposures to untreated AMD. Nymphs exposed to treated effluents experienced no loss of whole-body sodium. No significant differences in feeding or drift behavior occurred between nymphs exposed to treated effluents and those exposed to AMD-free controls. The treatment system, with and without CO{sub 2} pretreatment, provided water that was not toxic to the test animals, and that allowed normal behavioral and physiological function.

Traces and burrowing behaviors of the Cicada nymph Cicadetta calliope: Neoichnology and paleoecological significance of extant soil-dwelling insects

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Smith, J.J.; Hasiotis, S.T.

2008-01-01

This study documents the traces and burrowing behaviors of nymphs of the prairie cicada Cicadetta calliope (Hemiptera: Cicadidae), as observed in neoichnological experiments. Cicada nymphs were collected from the C horizons of sandy Fluvents along the Kansas River east of Lawrence, Kansas. The nymphs appeared to be fifth instars, 13-17 mm long and 6-7 mm wide. Nymphs were placed in plastic enclosures containing layers of colored, moist, very fine-grained sand. They burrowed immediately, excavating air-filled, sediment-enclosed cells between 20 mm and 40 mm long and averaging 9 mm wide. Burrowing was completed in three stages: (1) sediment in the forward portion of the cell was excavated and rolled into a ball with the forelimbs; (2) the nymph turned 180?? using a forward roll, and moved to the back of the cell; and (3) the sediment ball was pushed up against the back wall of the cell and kneaded with the forelimbs into a thin layer. Resulting burrow traces are sinuous and distinctly meniscate and demonstrate that insect larvae construct meniscate, backfilled burrows in well-drained terrestrial settings. Cicadetta calliope nymphs and their traces are excellent analogs for meniscate trace fossils commonly found in late Paleozoic-Cenozoic alluvial deposits and paleosols. Such meniscate trace fossils are useful for interpreting the paleoenvironment and paleohydrogeology of the units in which they are found. In addition, such backfilled burrows can be used to supplement the fossil record of cicada-like hemipterans, currently known only from the latest Permian to the Early Triassic. Copyright ?? 2008, SEPM (Society for Sedimentary Geology).

Assessing peridomestic entomological factors as predictors for Lyme disease

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Connally, N.P.; Ginsberg, H.S.; Mather, T.N.

2006-01-01

The roles of entomologic risk factors, including density of nymphal blacklegged ticks (Ixodes scapularis), prevalence of nymphal infection with the etiologic agent (Borrelia burgdorferi), and density of infected nymphs, in determining the risk of human Lyme disease were assessed at residences in the endemic community of South Kingstown, RI. Nymphs were sampled between May and July from the wooded edge around 51 and 47 residential properties in 2002 and 2003, respectively. Nymphs were collected from all residences sampled. Tick densities, infection rates, and densities of infected nymphs were all significantly higher around homes reporting Lyme disease histories in 2003, while only infection rates were significantly higher in 2002. However, densities of infected nymphs did not significantly predict the probability of Lyme disease at a residence (by logistic regression) in either year. There were no significant differences in entomologic risk factors between homes with state-confirmed Lyme disease histories and homes with self-reported cases (not reported to the state health department). Therefore, although entomologic risk factors tended to be higher at residences with cases of Lyme disease, entomological indices, in the absence of human behavior measures, were not useful predictors of Lyme disease at the scale of individual residences in a tick-endemic community.

Prevalence and morphological characterizations of Linguatula serrata nymphs in camels in Isfahan Province, Iran

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Moosa Javdani

2012-03-01

Full Text Available Linguatula serrata, well known as tongue worm; is an aberrant cosmopolitan parasite, which inhabits the canine respiratory system (final host. The discharged eggs infect many plant feeder animals including human causing visceral and nasopharyngeal linguatulosis which is known as “Marrara syndrome”. In current study, the prevalence of infection with L. serrata nymphs in mesenteric lymph nodes (MLNs of slaughtered camels was investigated in Isfahan Province, Iran. The MLNs of 232 slaughtered camels, including 115 females and 117 males, were examined for L. serrata nymphs. Camels were categorized into four age groups, namely under six months, six months to two years, two to four years and greater than four years. Also, the morphometrics of the nymphs were measured using the classic parasitology methods. Results showed that 21.12% of examined camels were infected with L. serrata. Age and sex had no significant effect on the prevalence of this parasite in camels. The size of the different parts of nymphs’ body were recorded and evaluated. The infection rate to the nymphs of parasite in hemorrhagic and black-colored lymph nodes were significantly (P ≤ 0.05 higher than the infection rate in normal-colored nodes. Also, results showed that in soft lymph nodes, the infection rate was significantly (P ≤ 0.05 more than those of normal and hard nodes. A high prevalence of infection in camels suggests possibility of similar high rate of infection in other animals, and people in the investigated area. This, in turn, emphasizes the need for more preventive measures to reduce the risk of zoonotic outbreaks.

Diaphorina citri Nymphs Are Resistant to Morphological Changes Induced by "Candidatus Liberibacter asiaticus" in Midgut Epithelial Cells.

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Mann, Marina; Fattah-Hosseini, Somayeh; Ammar, El-Desouky; Stange, Richard; Warrick, EricaRose; Sturgeon, Kasie; Shatters, Robert; Heck, Michelle

2018-04-01

" Candidatus Liberibacter asiaticus" is the causative bacterium associated with citrus greening disease. " Ca Liberibacter asiaticus" is transmitted by Diaphorina citri more efficiently when it is acquired by nymphs rather than adults. Why this occurs is not known. We compared midguts of D. citri insects reared on healthy or " Ca Liberibacter asiaticus"-infected citrus trees using quantitative PCR, confocal microscopy, and mitochondrial superoxide staining for evidence of oxidative stress. Consistent with its classification as propagative, " Ca Liberibacter asiaticus" titers were higher in adults than in nymphs. Our previous work showed that adult D. citri insects have basal levels of karyorrhexis (fragmentation of the nucleus) in midgut epithelial cells, which is increased in severity and frequency in response to " Ca Liberibacter asiaticus." Here, we show that nymphs exhibit lower levels of early-stage karyorrhexis than adults and are refractory to the induction of advanced karyorrhexis by " Ca Liberibacter asiaticus" in the midgut epithelium. MitoSox Red staining showed that guts of infected adults, particularly males, experienced oxidative stress in response to " Ca Liberibacter asiaticus." A positive correlation between the titers of " Ca Liberibacter asiaticus" and the Wolbachia endosymbiont was observed in adult and nymph midguts, suggesting an interplay between these bacteria during development. We hypothesize that the resistance of the nymph midgut to late-stage karyorrhexis through as yet unknown molecular mechanisms benefits " Ca Liberibacter asiaticus" for efficient invasion of midgut epithelial cells, which may be a factor explaining the developmental dependency of " Ca Liberibacter asiaticus" acquisition by the vector.

External vortex pumping by oscillating plate arrays of mayfly nymphs

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Sensenig, Andrew; Kiger, Ken; Shultz, Jeffrey

2009-11-01

Mayfly nymphs are aquatic insects, many of which can generate ventilation currents by beating two linear arrays of external plate-like gills. The oscillation Reynolds number associated with the gill motion changes with animal size, varying from Re ˜ 2 to 50 depending on age and species. Thus mayflies provide a novel system model for studying ontogenetic changes in pumping mechanisms associated with transitions from a more viscous- to inertia-dominated flow. Observation of the 3-D kinematics of the gill motion of the species C. triangulifer reveal that the mayfly makes a transition in stroke motion when Re>5, with a corresponding shift in mean flow from the ventral to the dorsal direction. Time-resolved PIV measurements within the inter-gill space reveal the basic elements of the flow consist of vortex rings generated by the strokes of the individual gills. For the larger Re case, the phasing of the plate motion generates a complex array of small vortices that interact to produce an intermittent dorsally directed jet. For Restroke kinematics. Thus we argue the transition in the kinematics is a reflection of a single mechanism adapted over the traversed Re range, rather than a shift to a completely new mechanism. This work is supported by the NSF under grant CBET-0730907.

Reynolds number effects on gill pumping mechanics in mayfly nymphs

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Sensenig, Andrew; Shultz, Jeffrey; Kiger, Ken

2006-11-01

Mayfly nymphs have an entirely aquatic life stage in which they frequently inhabit stagnant water. Nymphs have the capability to generate a ventilation current to compensate for the low oxygen level of the water by beating two linear arrays of plate-like gills that typically line the lateral edge of the abdomen. The characteristic Reynolds number associated with the gill motion changes with animal size, varying over a span of Re = 5 to 100 depending on age and species. The assumption that the system maintains optimal energetic efficiency leads to the prediction that animals transition from rowing to flapping mechanisms with increasing Re, while possibly utilizing a squeeze mechanism to a greater extent at lower Re. To investigate this hypothesis, we capture the motion of the gills through 3D imaging to investigate the effect of Reynolds number on the stroke patterns. PIV is utilized to assess flow rates and viscous dissipation. The effectiveness of the ventilation mechanism at each size has important consequences for the range of oxygen levels, and hence the habitat range, that can be tolerated by that size.

Morphology and identification of the final instar nymphs of three cicadas (Hemiptera, Cicadidae) in Guanzhong Plain, China based on comparative morphometrics.

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Hou, Zehai; Li, Qinglong; Wei, Cong

2014-01-01

The present investigation provides comparative morphometrics of the final instar nymphs of three dominant cicada species, i.e., Cryptotympana atrata (Fabricius), Meimuna mongolica (Distant) and Platypleura kaempferi (Fabricius), in Guanzhong Plain, China. Particularly, characters on the antennae, legs, and apex of abdomen of both males and females of these three species were investigated and analyzed. In addition, the numbers of hind tibial spines of the final instar nymphs of 21 representatives of Cicadoidea were compared. The results provide useful characteristics for nymph identification of related species and for further taxonomic and phylogenetic analysis of Cicadoidea.

RNA interference of carboxyesterases causes nymph mortality in the Asian citrus psyllid, Diaphorina citri.

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Kishk, Abdelaziz; Anber, Helmy A I; AbdEl-Raof, Tsamoh K; El-Sherbeni, AbdEl-Hakeem D; Hamed, Sobhy; Gowda, Siddarame; Killiny, Nabil

2017-03-01

Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an important pest of citrus. In addition, D. citri is the vector of Huanglongbing, a destructive disease in citrus, also known as citrus greening disease caused by Candidatus Liberibacter asiaticus. Huanglongbing causes huge losses for citrus industries. Insecticide application for D. citri is the major strategy to prevent disease spread. The heavy use of insecticides causes development of insecticide resistance. We used RNA interference (RNAi) to silence genes implicated in pesticide resistance in order to increase the susceptibility. The activity of dsRNA to reduce the expression of carboxyesterases including esterases FE4 (EstFE4) and acetylcholinesterases (AChe) in D. citri was investigated. The dsRNA was applied topically to the fourth and fifth instars of nymphs. We targeted several EstFE4 and AChe genes using dsRNA against a consensus sequence for each of them. Five concentrations (25, 50, 75, 100, 125 ng/μl) from both dsRNAs were used. The treatments with the dsRNA caused concentration dependent nymph mortality. The highest gene expression levels of both AChe and EstFE4 were found in the fourth and fifth nymphal instars. Gene expression analysis showed that AChe genes were downregulated in emerged adults from dsRNA-AChe-treated nymphs compared to controls. However, EstFE4 genes were not affected. In the same manner, treatment with dsRNA-EstFE4 reduced expression level of EstFE4 genes in emerged adults from treated nymphs, but did not affect the expression of AChe genes. In the era of environmentally friendly control strategies, RNAi is a new promising venue to reduce pesticide applications. © 2017 Wiley Periodicals, Inc.

Ecology of Meimuna mongolica (Hemiptera: Cicadidae) Nymphs: Instars, Morphological Variation, Vertical Distribution and Population Density, Host-Plant Selection, and Emergence Phenology

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Li, Qinglong; Yang, Mingsheng; Liu, Yunxiang; Wei, Cong

2015-01-01

The cicada Meimuna mongolica (Distant) (Hemiptera: Cicadidae) is one of the most important pests of economic forest in Guanzhong Plain of Shaanxi Province, China. Information about ecological characteristics and some sustainable control measures of this species is urgently required for its control. In this study, nymphal instars, morphological variation, vertical distribution, and population density in soil, and emergence phenology of nymphs of M. mongolica on three main host plants (Pinus tabuliformis Carr., Populus tomentosa Carr., and Pyrus xerophila Yü) were studied, based on combined morphological and molecular identification, investigation of the first-instar nymphs hatched from eggs and others excavated from soil, and investigation of exuviae in the adult emergence period. Five nymphal instars of M. mongolica were redetermined according to the distribution plots of the head capsule widths of the nymphs. Nymphs of third and fourth instars showed morphological variation, which is closely related to host-plant association. The mean densities of nymphs in soil under the three host plants were significantly different, indicating a distinct host preference. The nymphs could extend their distribution from the 0–10 cm soil layer to the 51–60 cm soil layer underground but not beyond 60 cm soil layer under all the three host plants. The 21–30 cm soil layer under all the three host plants has the highest nymphal population density. The sex ratio of the entire population was nearly 50:50, but males dominated in the early half of the duration of the emergence. These ecological characteristics of M. mongolica could provide important information for sustainable control measures.

Prevalence of Linguatula Serrata Nymphs in Mesenteric Lymph Nodes of Cattle and Buffaloes Slaughtered in Ahvaz Abattoir, Iran

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P Haddad Molayan

2013-06-01

Full Text Available Background: Linguatula serrata, one of the parasitic zoonoses, inhabits the canine respiratory system (final hosts. The objective of this study was to determine the prevalence rate of L. serrata nymphs in mesenteric lymph nodes (MLNs of cattle and buffaloes (intermediate hosts that were processed in the Ahvaz, Iran abattoir.Methods: During November 2010 to March 2011, 223 animals (119 cattle and 104 buffaloes, in differ­ent sex and three age groups (3 years old were sampled randomly at Ahvaz abattoir. Up to 35 grams of their mesenteric lymph nodes were examined separately for nymphal stages of L. serrata by digesting the samples with acid- pepsin method, collected the nymphs and counted under stereomicroscope.Results: Overall 37(16.6% of 223 animals were infected with L. serrata nymphs in their mesenteric lymph nodes. Prevalence of the infection in cattle and buffaloes were 16.8% and 16.3% respectively. The number of collected nymphs of MLNs was ranged from 1 to 16. No significant differences were seen in the infection rates between males and females (sexes and age groups in the cattle and buffa­loes (P <0.05.Conclusion: Linguatula serrata has an active life cycle in the studied area and a zoonotic potential for transmission between animal and human. Avoiding use of raw MLNs to dogs can help reduce the infection.

Defensins from the tick Ixodes scapularis are effective against phytopathogenic fungi and the human bacterial pathogen Listeria grayi

Czech Academy of Sciences Publication Activity Database

Tonk, Miray; Cabezas-Cruz, A.; Valdés, James J.; Rego, Ryan O. M.; Chrudimská, Tereza; Strnad, Martin; Šíma, Radek; Bell-Sakyi, L.; Franta, Z.; Vilcinskas, A.; Grubhoffer, Libor; Rahnamaeian, M.

2014-01-01

Roč. 7, DEC 3 2015 (2014), s. 554 ISSN 1756-3305 R&D Projects: GA ČR(CZ) GAP302/11/1901; GA MŠk(CZ) EE2.3.30.0032; GA ČR GP13-12816P Institutional support: RVO:60077344 Keywords : Antimicrobial peptide * Defensin * Listeria grayi * Fusarium spp * Ixodes scapularis * Tick cell line Subject RIV: EE - Microbiology, Virology Impact factor: 3.430, year: 2014

Acquisition, Replication and Inoculation of Candidatus Liberibacter asiaticus following Various Acquisition Periods on Huanglongbing-Infected Citrus by Nymphs and Adults of the Asian Citrus Psyllid.

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El-Desouky Ammar

Full Text Available The Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae, is the primary vector of Candidatus Liberibacter asiaticus (Las implicated as causative agent of citrus huanglongbing (citrus greening, currently the most serious citrus disease worldwide. Las is transmitted by D. citri in a persistent-circulative manner, but the question of replication of this bacterium in its psyllid vector has not been resolved. Thus, we studied the effects of the acquisition access period (AAP by nymphs and adults of D. citri on Las acquisition, multiplication and inoculation/transmission. D. citri nymphs or adults (previously non-exposed to Las were caged on Las-infected citrus plants for an AAP of 1, 7 or 14 days. These 'Las-exposed' psyllids were then transferred weekly to healthy citrus or orange jasmine plants, and sampled via quantitative polymerase chain reaction (qPCR analysis 1-42 days post-first access to diseased plants (padp; all tested nymphs became adults 7-14 days padp. Our results indicate that following 1 or 7 day AAP as nymphs 49-59% of Las-exposed psyllids became Las-infected (qPCR-positive, whereas only 8-29% of the psyllids were infected following 1-14 day AAP as adults. Q-PCR analysis also indicated that Las titer in the Las-exposed psyllids (relative to that of the psyllid S20 ribosomal protein gene was: 1 significantly higher, and increasing at a faster rate, following Las acquisition as nymphs compared to that following Las acquisition as adults; 2 higher as post-acquisition time of psyllids on healthy plants increased reaching a peak at 14-28 days padp for nymphs and 21-35 days padp for adults, with Las titer decreasing or fluctuating after that; 3 higher with longer AAP on infected plants, especially with acquisition as adults. Our results strongly suggest that Las multiplies in both nymphs and adults of D. citri but attains much higher levels in a shorter period of time post-acquisition when acquired by nymphs than when acquired by

Prevalence of Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) in Ixodes scapularis (Acari: Ixodidae) adults in New Jersey, 2000-2001.

Science.gov (United States)

Schulze, Terry L; Jordan, Robert A; Hung, Robert W; Puelle, Rose S; Markowski, Daniel; Chomsky, Martin S

2003-07-01

Using polymerase chain reaction, we analyzed 529 Ixodes scapularis Say adults collected from 16 of New Jersey's 21 counties for the presence of Borrelia burgdorferi, the etiological agent of Lyme disease. Overall, 261 (49.3%) were positive. B. burgdorferi was detected in ticks obtained from each county and from 53 of the 58 (93.1%) municipalities surveyed. The observed statewide prevalence in New Jersey is similar to those reported from other northeastern and mid-Atlantic states.

Morphology and identification of the final instar nymphs of three cicadas (Hemiptera, Cicadidae in Guanzhong Plain, China based on comparative morphometrics

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Zehai Hou

2014-07-01

Full Text Available The present investigation provides comparative morphometrics of the final instar nymphs of three dominant cicada species, i.e., Cryptotympana atrata (Fabricius, Meimuna mongolica (Distant and Platypleura kaempferi (Fabricius, in Guanzhong Plain, China. Particularly, characters on the antennae, legs, and apex of abdomen of both males and females of these three species were investigated and analyzed. In addition, the numbers of hind tibial spines of the final instar nymphs of 21 representatives of Cicadoidea were compared. The results provide useful characteristics for nymph identification of related species and for further taxonomic and phylogenetic analysis of Cicadoidea.

Preferências alimentares e domiciliação de mosquitos Culicidae no Vale do Ribeira, São Paulo, Brasil, com especial referência a Aedes scapularis e a Culex (Melanoconion Feeding preferences and domiciliation of Culicidae mosquitoes in the Ribeira Valley, S. Paulo State, Brazil, with particular reference to Aedes scapularis and Culex (Melanoconion

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Oswaldo Paulo Forattini

1989-02-01

Full Text Available Apresentam-se novos dados sobre a identificação do sangue ingerido por culicídeos ingurgitados e coletados em quatro localidades do Vale do Ribeira, Estado de São Paulo (Brasil, no período de fevereiro a novembro de 1986, e que já tinham sido sede de observações anteriores. São fornecidos dados sobre a distribuição de algumas espécies relacionadas ao tipo de ambiente. Focalizam-se Ae. scapularis e representantes de Culex (Melanoconion, principalmente Cx. ribeirensis e Cx. sacchettae. Foi possível a identificação de 651 repastos sangüíneos. Confirmou-se a preferência de Ae. scapularis por mamíferos de grande porte representados por bovinos, eqüinos e o próprio homem, tendo reagido a todos os anti-soros testados, com exceção do correspondente a animais de sangue frio representados por anfíbio. Cx. ribeirensis revelou resultados que sugerem possível preferência por mamíferos. As duas espécies supracitadas mostram tendência nítida para adaptação ao ambiente modificado pelo homem e capacidade de evolução de seus hábitos de possível domiciliação. Quanto aos outros culicídeos, as coletas de An. bellator, An. cruzii e Cq. chrysonotum limitaram-se à isca humana que a segunda dessas espécies rendeu 31,6% do total de fêmeas capturadas.New results on blood-meal identification and the environmental distribution of mosquitoes collected in four different Ribeira Valley (S. Paulo State, Brazil environments, during the period February to November 1986, are presented. Sources of 651 blood-meals were identified. The preference of Ae. scapularis for large mammals, chiefly cattle, horse and even man, was confirmed. Data suggests that a similar behavioral pattern is presented by Cx. ribeirensis. Both mosquitoes seem to be strongly attracted by peridomiciliar blood sources represented by domestic animals sheltered in that environment. Nevertheless, the female of Ae. scapularis females may use the extradomiciliary environment

Efficacy of essential oil of Piper aduncum against nymphs and adults of Diaphorina citri.

Science.gov (United States)

Volpe, Haroldo Xl; Fazolin, Murilo; Garcia, Rafael B; Magnani, Rodrigo F; Barbosa, José Carlos; Miranda, Marcelo P

2016-06-01

Insecticide application is the main way to control Diaphorina citri. However, it causes environmental contamination, has a negative impact on beneficial organisms and leads to psyllid resistance. The essential oil of Piper aduncum has low toxicity towards the environment and contains dillapiol, which has proven to be effective against several crop pests. Here, we studied its efficacy against nymphs and adults of D. citri under laboratory conditions. Oils with three concentrations of dillapiol (69.3, 79.9 and 85.4%) at 0.5, 0.75 and 1.0% dilutions plus 0.025% adjuvant were tested. All treatments caused 90-100% mortality in nymphs. Topical treatments with oil containing 79.9 and 85.4% dillapiol at 0.75% and 1% dilutions were effective (mortality ≥80%) in adults. However, the essential oil showed no residual activity against adults (mortality ≤30%). Dillapiol-rich oil is a promising compound for D. citri control. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Occurrence of multiple infections with different Borrelia burgdorferi genospecies in Danish Ixodes ricinus nymphs

DEFF Research Database (Denmark)

Andersen, Jean Vennestrøm; Egholm, H.; Mikkelsen, Per Jensen

2008-01-01

The pathogen Borrelia burgdorferi causes Lyme Borreliosis in human and animals world-wide. In Europe the pathogen is transmitted to the host by the vector Ixodes ricinus. The nymph is the primary instar for transmission to humans. We here study the infection rate of five Borrelia genospecies: B...

Spatial Distribution and Coexisting Patterns of Adults and Nymphs of Tibraca limbativentris (Hemiptera: Pentatomidae) in Paddy Rice Fields.

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Alves, Tavvs M; Maia, Aline H N; Barrigossi, José A F

2016-12-01

The rice stem stink bug, Tibraca limbativentris Stål (Hemiptera: Pentatomidae), is a primary insect pest of paddy rice in South America. Knowledge of its spatial distribution can support sampling plans needed for timely decisions about pest control. This study aimed to investigate the spatial distribution of adults and nymphs of T. limbativentris and determine the spatial coexistence of these stages of development. Fifteen paddy rice fields were scouted once each season to estimate insect densities. Scouting was performed on regular grids with sampling points separated by ∼50 m. Moran's I and semivariograms were used to determine spatial distribution patterns. Spatial coexistence of nymphs and adults was explored via spatial point process. Here, adults and nymphs had typically contrasting spatial distribution patterns within the same field; however, the frequency of aggregation was not different between these developmental stages. Adults and nymphs were aggregated in seven fields and randomly distributed in the other eight fields. Uniform distribution of adults or nymphs was not observed. The study-wide semivariogram ranges were ∼40 m for adults and ∼55 m for nymphs. Nymphs and adults spatially coexisted on 67% of the fields. Coexisting patterns were classified using one of the following processes: stage-independent, bidirectional attractive, unidirectional attractive, bidirectional inhibiting, or unidirectional inhibiting. The information presented herein can be important for developing sampling plans for decision-making, implementing tactics for site-specific management, and monitoring areas free of T. limbativentrisResumoO percevejo-do-colmo Tibraca limbativentris Stål (Hemiptera: Pentatomidae) é uma praga primária na cultura do arroz irrigado na América do Sul. O conhecimento de sua distribuição espacial é essencial para desenvolver planos de amostragem e para o controle desta praga. Nosso objetivo foi investigar a distribuição espacial de

Efficacy of Plant-Derived and Synthetic Compounds on Clothing as Repellents Against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae)

Science.gov (United States)

2012-01-01

efÞcacy of the repellent deet against Aedes aegypti . J. Am. Mosq. Control Assoc. 14: 178Ð182. Robbins, P. J., and M. G. Cherniack. 1986. Review of...number of reported Lyme disease cases reached an all- time high of35,000 in 2008 (CDC 2010). The blacklegged tick, Ixodes scapularis Say, the principal...Paddock 2003, Mixson et al. 2006, Apperson et al. 2008). Repellents remain the primary method of personal protection against tick bites (Piesman and

Odonate Nymphs: Generalist Predators and their Potential in the Management of Dengue Mosquito, Aedes aegypti (Diptera: Culicidae

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Waseem Akram

2016-01-01

Full Text Available Background: Dengue is amongst the most serious mosquito-borne infectious disease with hot spots in tropical and subtropical parts of the world. Unfortunately, no licensed vaccine for the disease is currently available in medicine markets. The only option available is the management of dengue vector mosquito, Aedes aegypti (Diptera: Culicidae.Method: Predatory potential of five odonate nymphs namely Anax parthenope, Bradinopyga geminate, Ischnura forcipata, Rhinocypha quadrimaculata, and Orthetrum sabina were evaluated against the 4th instar larvae of the den­gue vector mosquito, Aedes aegypti, under laboratory conditions. The consumption of the mosquito larvae was eval­uated at three water volume levels viz., 1 liter, 2 liter and 3 liter.Results: The number of Ae. aegypti larvae consumed varied significantly among the five species, and at different levels of water volume (P< 0.01. However, the interaction between odonate nymphs and the water volumes was statistically non-significant (P> 0.05. Ischnura forcipata consumed the highest number of Ae. aegypti larvae (n=56 followed by A. parthenope (n=47 and B. geminate (n=46. The number of larvae consumed was decreased with in­creasing search area or water volume, and the highest predation was observed at 1-liter water volume.Conclusion: The odonate nymphs could be a good source of biological agents for the management of the mosquitoes at larval stages. 

The Ixodes scapularis Salivary Protein, Salp15, Prevents the Association of HIV-1 gp120 and CD4

OpenAIRE

Juncadella, Ignacio J.; Garg, Renu; Bates, Tonya C.; Olivera, Elias R.; Anguita, Juan

2007-01-01

Ixodes scapularis salivary protein, Salp15, inhibits CD4+ T cell activation by binding to the most-extracellular domains of the CD4 molecule, potentially overlapping with the gp120-binding region. We now show that Salp15 inhibits the interaction of gp120 and CD4. Furthermore, Salp15 prevents syncytia formation between HL2/3 (a stable HeLa cell line expressing the envelope protein) and CD4-expressing cells. Salp15 prevented gp120-CD4 interaction at least partially through its direct interactio...

Parasitological and Pathological Investigations on Linguatula serrata nymphs in Mesenteric Lymph Nodes in Sheep In Konya Region in Turkey

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Osman Selçuk Aldemir

2014-05-01

Full Text Available In this study was aimed to investigate spread and pathological findings of Linguatula serrata nymphs in mesenteric lymph nodes (MLNs in sheep. A total of 1000 MLNs from 140 sheep (125 male and 15 female were collected from a commercial (Konet abattoir. Fourteen of 140 sheep (10% were infested with nymph stages of L. serrata.Infested lymph nodes were swollen, firm, edematous, many yellowish-white pinpoint and with congestion. In histopathological examinations, these nodules were consist of one or more nymphal stages of L. serrata and these were surrounded by infiltration mononuclear cells and neutrophyl leucocyte. Lymphoid follicules were hyperplastic and sinus catarrh was also observed in medulla.

Saliva from nymph and adult females of Haemaphysalis longicornis: a proteomic study.

Science.gov (United States)

Tirloni, Lucas; Islam, Mohammad Saiful; Kim, Tae Kwon; Diedrich, Jolene K; Yates, John R; Pinto, Antônio F M; Mulenga, Albert; You, Myung-Jo; Da Silva Vaz, Itabajara

2015-06-24

Haemaphysalis longicornis is a major vector of Theileria spp., Anaplasma phagocytophilum, Babesia spp. and Coxiella burnetti in East Asian countries. All life stages of ixodid ticks have a destructive pool-feeding style in which they create a pool-feeding site by lacerating host tissue and secreting a variety of biologically active compounds that allows the tick to evade host responses, enabling the uptake of a blood meal. The identification and functional characterization of tick saliva proteins can be useful to elucidate the molecular mechanisms involved in tick development and to conceive new anti-tick control methods. H. longicornis tick saliva was collected from fully engorged nymphs and fully engorged adults induced by dopamine or pilocarpine, respectively. Saliva was digested with trypsin for LC-MS/MS sequencing and peptides were searched against tick and rabbit sequences. A total of 275 proteins were identified, of which 135 were tick and 100 were rabbit proteins. Of the tick proteins, 30 proteins were identified exclusively in fully engorged nymph saliva, 74 in fully engorged adult females, and 31 were detected in both stages. The identified tick proteins include heme/iron metabolism-related proteins, oxidation/detoxification proteins, enzymes, proteinase inhibitors, tick-specific protein families, and cytoskeletal proteins. Proteins involved in signal transduction, transport and metabolism of carbohydrate, energy, nucleotide, amino acids and lipids were also detected. Of the rabbit proteins, 13 were present in nymph saliva, 48 in adult saliva, and 30 were present in both. The host proteins include immunoglobulins, complement system proteins, antimicrobial proteins, serum albumin, peroxiredoxin, serotransferrin, apolipoprotein, hemopexin, proteinase inhibitors, and hemoglobin/red blood cells-related products. This study allows the identification of H. longicornis saliva proteins. In spontaneously detached tick saliva various proteins were identified

Study of the infestation rate of the kidney and spleen of domestic ruminants by Linguatula serrata nymphs in Urmia slaughterhouse

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S Rasouli

2009-02-01

Full Text Available In this study, the prevalence of Linguatula serrata nymphs in kidneys and spleens of 800 domestic ruminants (cattle, buffalo, sheep and goat in different sexes, ages and seasons was investigated. First, the kidneys and spleens were examined macroscopically. Then, a digestion method was also applied. Infestation rate in the spleen of cattle, buffalo, sheep and goat were %0/5, %0, %0/5 and %1/5 respectively. No infestation was found in the kidneys. The results of this study shows that the infestation of domestic ruminants to Linguatula serrat nymphs in different sexes and ages were not significant. Also the infestation rate in different seasons was not significant.

Differential susceptibility of adults and nymphs of Blattella germanica (L.) (Blattodea: Blattellidae) to infection by Metarhizium anisopliae and assessment of delivery strategies

International Nuclear Information System (INIS)

Lopes, R.B.; Alves, S.B.

2011-01-01

Microbial insecticides for cockroach control, such as those containing entomopathogenic fungi, may be an alternative to reduce contamination by chemicals in housing and food storage environments. Virulence of isolate ESALQ1037 belonging to the Metarhizium anisopliae complex against nymphs and adults of Blattella germanica (L.), and its infectivity following exposure of insects to a contaminated surface or to M. anisopliae-bait were determined under laboratory conditions. Estimated LD50 15 d following topical inoculation was 2.69 x 105 conidia per adult, whereas for nymphs the maximum mortality was lower than 50%. Baits amended with M. anisopliae conidia had no repellent effect on targets; adult mortality was inferior to 25%, and nymphs were not susceptible. All conidia found in the digestive tract of M. anisopliae-bait fed cockroaches were unviable, and bait-treated insects that succumbed to fungal infection showed a typical mycelial growth on mouthparts and front legs, but not on the hind body parts. As opposed to baits, the use of a M. anisopliae powdery formulation for surface treatment was effective in attaining high mortality rates of B. germanica. Both nymphs and adults were infected when this delivery strategy was used, and mycelia growth occurred all over the body surface. Our results suggest that the development of powders or similar formulations of M. anisopliae to control B. germanica may provide faster and better results than some of the strategies based on baits currently available. (author)

Differential susceptibility of adults and nymphs of Blattella germanica (L.) (Blattodea: Blattellidae) to infection by Metarhizium anisopliae and assessment of delivery strategies

Energy Technology Data Exchange (ETDEWEB)

Lopes, R.B., E-mail: rblopes@cenargen.embrapa.b [EMBRAPA Recursos Geneticos e Biotecnologia, Brasilia, DF (Brazil); Alves, S.B. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Entomologia e Acarologia

2011-05-15

Microbial insecticides for cockroach control, such as those containing entomopathogenic fungi, may be an alternative to reduce contamination by chemicals in housing and food storage environments. Virulence of isolate ESALQ1037 belonging to the Metarhizium anisopliae complex against nymphs and adults of Blattella germanica (L.), and its infectivity following exposure of insects to a contaminated surface or to M. anisopliae-bait were determined under laboratory conditions. Estimated LD50 15 d following topical inoculation was 2.69 x 105 conidia per adult, whereas for nymphs the maximum mortality was lower than 50%. Baits amended with M. anisopliae conidia had no repellent effect on targets; adult mortality was inferior to 25%, and nymphs were not susceptible. All conidia found in the digestive tract of M. anisopliae-bait fed cockroaches were unviable, and bait-treated insects that succumbed to fungal infection showed a typical mycelial growth on mouthparts and front legs, but not on the hind body parts. As opposed to baits, the use of a M. anisopliae powdery formulation for surface treatment was effective in attaining high mortality rates of B. germanica. Both nymphs and adults were infected when this delivery strategy was used, and mycelia growth occurred all over the body surface. Our results suggest that the development of powders or similar formulations of M. anisopliae to control B. germanica may provide faster and better results than some of the strategies based on baits currently available. (author)

Effects of tick control by acaricide self-treatement of white-tailed deer on host-seeking tick infection prevalence and entomologic risk for Ixodes scapularis-borne pathogens

Science.gov (United States)

We evaluated the effects of tick control by acaricide self-treatment of white-tailed deer on the infection prevalence and entomologic risk for three I. scapularis-borne bacteria in host-seeking ticks. Ticks were collected from vegetation in areas treated with the ‘4-Poster’ device and from control a...

Nanocladius (Plecopteracoluthus) shigaensis sp. nov. (Chironomidae: Orthocladiinae) whose larvae are phoretic on nymphs of stoneflies (Plecoptera) from Japan.

Science.gov (United States)

Inoue, Yasue; Komori, Chiharu; Kobayashi, Tadashi; Kondo, Natsuko; Ueno, Ryuhei; Takamura, Kenzi

2015-03-16

We identified a new species, Nanocladius (Plecopteracoluthus) shigaensis, from Shiga and Gifu Prefectures, Japan, whose larvae are phoretic on nymphs of Plecoptera. Although this new species is morphologically similar to Nanocladius (Plecopteracoluthus) asiaticus Hayashi (1998), which is phoretic on Megaloptera larvae, it differs from N. (P.) asiaticus: the color of the larval head capsule is light brown in N. (P.) shigaensis and dark brown in N. (P.) asiaticus and the larval capsule index of the former is significantly larger than that of the latter. Moreover, analyses based on DNA sequence of cytochrome c oxidase subunit I (COI) supported the hypothesis that N. (P.) shigaensis and N. (P.) asiaticus are two distinct species. This is the first record of a phoretic chironomid on a plecopteran nymph in the Palaearctic region.

Adverse moisture events predict seasonal abundance of Lyme disease vector ticks (Ixodes scapularis)

Science.gov (United States)

Berger, Kathryn A.; Ginsberg, Howard S.; Dugas, Katherine D.; Hamel, Lutz H.; Mather, Thomas N.

2014-01-01

Background: Lyme borreliosis (LB) is the most commonly reported vector-borne disease in north temperate regions worldwide, affecting an estimated 300,000 people annually in the United States alone. The incidence of LB is correlated with human exposure to its vector, the blacklegged tick (Ixodes scapularis). To date, attempts to model tick encounter risk based on environmental parameters have been equivocal. Previous studies have not considered (1) the differences between relative humidity (RH) in leaf litter and at weather stations, (2) the RH threshold that affects nymphal blacklegged tick survival, and (3) the time required below the threshold to induce mortality. We clarify the association between environmental moisture and tick survival by presenting a significant relationship between the total number of tick adverse moisture events (TAMEs - calculated as microclimatic periods below a RH threshold) and tick abundance each year.Methods: We used a 14-year continuous statewide tick surveillance database and corresponding weather data from Rhode Island (RI), USA, to assess the effects of TAMEs on nymphal populations of I. scapularis. These TAMEs were defined as extended periods of time (>8 h below 82% RH in leaf litter). We fit a sigmoid curve comparing weather station data to those collected by loggers placed in tick habitats to estimate RH experienced by nymphal ticks, and compiled the number of historical TAMEs during the 14-year record.Results: The total number of TAMEs in June of each year was negatively related to total seasonal nymphal tick densities, suggesting that sub-threshold humidity episodes >8 h in duration naturally lowered nymphal blacklegged tick abundance. Furthermore, TAMEs were positively related to the ratio of tick abundance early in the season when compared to late season, suggesting that lower than average tick abundance for a given year resulted from tick mortality and not from other factors.Conclusions: Our results clarify the mechanism

Liolaemus lizards (Squamata: Liolaemidae) as hosts for the nymph of Amblyomma parvitarsum (Acari: Ixodidae), with notes on Rickettsia infection.

Science.gov (United States)

Muñoz-Leal, Sebastián; Tarragona, Evelina L; Martins, Thiago F; Martín, Claudia M; Burgos-Gallardo, Freddy; Nava, Santiago; Labruna, Marcelo B; González-Acuña, Daniel

2016-10-01

Adults of Amblyomma parvitarsum are common ectoparasites of South American camelids of the genera Lama and Vicugna, occuring in highlands of Argentina, Bolivia, Chile, Peru and also in Argentinean Patagonia. Whereas larval stages of this tick are known to feed on small lizards, host records for the nymphal instar have remained unreported. Supported by morphological and molecular analyses, herein we report A. parvitarsum nymphs parasitizing two Liolaemus species (Reptilia: Squamata) in the Andean Plateau of Argentina and Chile. Additionally, by a PCR screening targetting gltA and ompA genes, DNA of Rickettsia was detected in one of the collected nymphs. Obtained sequences of this agent were identical to a recent Rickettsia sp. described infecting adults of this tick species in Chile and Argentina.

The price of protection: a defensive endosymbiont impairs nymph growth in the bird cherry-oat aphid, Rhopalosiphum padi.

Science.gov (United States)

Leybourne, Daniel J; Bos, Jorunn I B; Valentine, Tracy A; Karley, Alison J

2018-05-24

Bacterial endosymbionts have enabled aphids to adapt to a range of stressors, but their effects in many aphid species remain to be established. The bird cherry-oat aphid, Rhopalosiphum padi (Linnaeus), is an important pest of cereals worldwide and has been reported to form symbiotic associations with Serratia symbiotica and Sitobion miscanthi L-type Symbiont endobacteria, although the resulting aphid phenotype has not been described. This study presents the first report of R. padi infection with the facultative bacterial endosymbiont Hamiltonella defensa. Individuals of R. padi were sampled from populations in Eastern Scotland, UK, and shown to represent seven R. padi genotypes based on the size of polymorphic microsatellite markers; two of these genotypes harboured H. defensa. In parasitism assays, survival of H. defensa-infected nymphs following attack by the parasitoid wasp Aphidius colemani (Viereck) was five-fold higher than for uninfected nymphs. Aphid genotype was a major determinant of aphid performance on two Hordeum species, a modern cultivar of barley H. vulgaris and a wild relative H. spontaneum, although aphids infected with H. defensa showed 16% lower nymph mass gain on the partially-resistant wild relative compared with uninfected individuals. These findings suggest that deploying resistance traits in barley will favour the fittest R. padi genotypes, but symbiont-infected individuals will be favoured when parasitoids are abundant, although these aphids will not achieve optimal performance on a poor quality host plant. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Critical Evaluation of the Linkage Between Tick-Based Risk Measures and the Occurrence of Lyme Disease Cases

Science.gov (United States)

Eisen, Lars; Eisen, Rebecca J.

2018-01-01

The nymphal stage of the blacklegged tick, Ixodes scapularis Say, is considered the primary vector to humans in the eastern United States of the Lyme disease spirochete Borrelia burgdorferi sensu stricto. The abundance of infected host-seeking nymphs is commonly used to estimate the fundamental risk of human exposure to B. burgdorferi, for the purpose of environmental risk assessment and as an outcome measure when evaluating environmentally based tick or pathogen control methods. However, as this tick-based risk measure does not consider the likelihoods of either human encounters with infected ticks or tick bites resulting in pathogen transmission, its linkage to the occurrence of Lyme disease cases is worth evaluating. In this Forum article, we describe different tick-based risk measures, discuss their strengths and weaknesses, and review the evidence for their capacity to predict the occurrence of Lyme disease cases. We conclude that: 1) the linkage between abundance of host-seeking B. burgdorferi-infected nymphs and Lyme disease occurrence is strong at community or county scales but weak at the fine spatial scale of residential properties where most human exposures to infected nymphs occur in Northeast, 2) the combined use of risk measures based on infected nymphs collected from the environment and ticks collected from humans is preferable to either one of these risk measures used singly when assessing the efficacy of environmentally based tick or pathogen control methods aiming to reduce the risk of human exposure to B. burgdorferi, 3) there is a need for improved risk assessment methodology for residential properties that accounts for both the abundance of infected nymphs and the likelihood of human–tick contact, and 4) we need to better understand how specific human activities conducted in defined residential microhabitats relate to risk for nymphal exposures and bites. PMID:27330093

Acute and chronic toxicity of neonicotinoids to nymphs of a mayfly species and some notes on seasonal differences

NARCIS (Netherlands)

Brink, Van den P.J.; Smeden, Van J.M.; Bekele, R.S.; Dierick, Wiebe; Gelder, De Daphne M.; Noteboom, Maarten; Roessink, Ivo

2016-01-01

Mayfly nymphs are among the most sensitive taxa to neonicotinoids. The present study presents the acute and chronic toxicity of 3 neonicotinoids (imidacloprid, thiacloprid, and thiamethoxam) to a mayfly species (Cloeon dipterum) and some notes on the seasonality of the toxicity of imidacloprid to

Transitions in low Re pumping by oscillating plate arrays of mayfly nymphs

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Kiger, Ken; Sensenig, Andrew; Shultz, Jeffrey

2008-11-01

Mayfly nymphs are aquatic insects which alter behavior and metabolism to accommodate changes in ambient dissolved oxygen. Many species can generate a ventilation current to compensate for low oxygen levels by beating two linear arrays of plate-like gills that line the lateral edge of the abdomen. The oscillation Reynolds number associated with the gill motion changes with animal size, varying over a span of Re = 2 to 50 depending on age and species. Thus mayflies provide a novel system model for studying ontological changes in pumping mechanisms associated with transitions from a viscous- to inertia-dominated flow. Observation of the detailed 3-D kinematics of the gill motion of the species Centroptilum triangulifer reveal that the mayfly makes a marked transition in stroke motion when Re>5, with a corresponding shift in mean flow from the ventral to the dorsal direction. Results of the time-resolved flow within the inter-gill space shows that for Re>12 the plate motion generates a complex array of bound and shed vortices, which interact to produce an intermittent dorsally directed jet. For the Re<5, distinct bound vortices are still observed, but increased diffusive effects creates vortices which simultaneously envelope several gills, forcing a new flow pattern to emerge. Details of the flow mechanism and its implications will be discussed. This work is supported by NSF under grant CBET-0730907.

Hydrodynamic pumping by serial gill arrays in the mayfly nymph Centroptilum triangulifer.

Science.gov (United States)

Sensenig, Andrew T; Kiger, Ken T; Shultz, Jeffrey W

2010-10-01

Aquatic nymphs of the mayfly Centroptilum triangulifer produce ventilatory flow using a serial array of seven abdominal gill pairs that operates across a Reynolds numbers (Re) range from 2 to 22 during ontogeny. Net flow in small animals is directed ventrally and essentially parallel to the stroke plane (i.e. rowing), but net flow in large animals is directed dorsally and essentially transverse to the stroke plane (i.e. flapping). Detailed flow measurements based on Particle Image Velocimetry (PIV) ensemble-correlation analysis revealed that the phasing of the gills produces a time-dependent array of vortices associated with a net ventilatory current, a fluid kinematic pattern, here termed a 'phased vortex pump'. Absolute size of vortices does not change with increasing animal size or Re, and thus the vortex radius (R(v)) decreases relative to inter-gill distance (L(is)) during mayfly growth. Given that effective flapping in appendage-array animals requires organized flow between adjacent appendages, we hypothesize that rowing should be favored when L(is)/R(v)1. Significantly, the rowing-to-flapping transition in Centroptilum occurs at Re∼5, when the mean dynamic inter-gill distance equals the vortex radius. This result suggests that the Re-based rowing-flapping demarcation observed in appendage-array aquatic organisms may be determined by the relative size of the propulsive mechanism and its self-generated vortices.

Diaphorina citri nymphs are resistant to morphological changes induced by “Candidatus Liberibacter asiaticus” in midgut epithelial cells

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“Candidatus Liberibacter asiaticus” is the causative bacterium associated with citrus greening disease. “Ca. L. asiaticus” is transmitted by Diaphorina citri more efficiently when it is acquired by nymphs rather than adults. Why this occurs is not known. We compared midguts of D. citri reared on hea...

Evaluation of DEET and eight essential oils for repellency against nymphs of the lone star tick, Amblyomma americanum (Acari: Ixodidae)

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Eight commercially available essential oils (oregano, clove, thyme, vetiver, sandalwood, cinnamon, cedarwood, and peppermint) were evaluated for repellency against host-seeking nymphs of the lone star tick, Amblyomma americanum. Concentration- repellency response was established using the vertical ...

Repellent activity of fractioned compounds from Chamaecyparis nootkatensis essential oil against nymphal Ixodes scapularis (Acari: Ixodidae).

Science.gov (United States)

Dietrich, Gabrielle; Dolan, Marc C; Peralta-Cruz, Javier; Schmidt, Jason; Piesman, Joseph; Eisen, Rebecca J; Karchesy, Joseph J

2006-09-01

Preliminary repellent activity of 14 natural products isolated from essential oil components extracted from the heartwood of Alaska yellow cedar, Chamaecyparis nootkatensis (D. Don) Spach., were evaluated against nymphal Ixodes scapularis Say in a laboratory bioassay and compared with technical grade N,N-diethyl-3-methylbenzamide (deet). Four hours after treatment, nootkatone and valencene-13-ol had repellent concentration (RC)50 values of 0.0458 and 0.0712% (wt:vol), respectively; two additional Alaska yellow cedar compounds, nootkatone 1 --> 10 epoxide and carvacrol had reported RC50 values of 0.0858 and 0.112%, respectively. The observed RC50 value for deet was 0.0728% (wt:vol). Although not statistically significantly more active than deet, the ability of these natural products to repel ticks at relatively low concentrations may represent a potential alternative to synthetic commercial repellents.

Essential oils of aromatic Egyptian plants repel nymphs of the tick Ixodes ricinus (Acari: Ixodidae).

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El-Seedi, Hesham R; Azeem, Muhammad; Khalil, Nasr S; Sakr, Hanem H; Khalifa, Shaden A M; Awang, Khalijah; Saeed, Aamer; Farag, Mohamed A; AlAjmi, Mohamed F; Pålsson, Katinka; Borg-Karlson, Anna-Karin

2017-09-01

Due to the role of Ixodes ricinus (L.) (Acari: Ixodidae) in the transmission of many serious pathogens, personal protection against bites of this tick is essential. In the present study the essential oils from 11 aromatic Egyptian plants were isolated and their repellent activity against I. ricinus nymphs was evaluated Three oils (i.e. Conyza dioscoridis L., Artemisia herba-alba Asso and Calendula officinalis L.) elicited high repellent activity in vitro of 94, 84.2 and 82%, respectively. The most active essential oil (C. dioscoridis) was applied in the field at a concentration of 6.5 µg/cm 2 and elicited a significant repellent activity against I. ricinus nymphs by 61.1%. The most repellent plants C. dioscoridis, C. officinalis and A. herba-alba yielded essential oils by 0.17, 0.11 and 0.14%, respectively. These oils were further investigated using gas chromatography-mass spectrometry analysis. α-Cadinol (10.7%) and hexadecanoic acid (10.5%) were the major components of C. dioscoridis whereas in C. officinalis, α-cadinol (21.2%) and carvone (18.2%) were major components. Artemisia herba-alba contained piperitone (26.5%), ethyl cinnamate (9.5%), camphor (7.7%) and hexadecanoic acid (6.9%). Essential oils of these three plants have a potential to be used for personal protection against tick bites.

Efficacy of Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae) on the leaf phylloplane over time for controlling Madeira mealybug nymphs preshipping

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The efficacy of Isaria fumosorosea (= PFR 97®) on the leaf phylloplane over time for controlling Madeira mealybug nymphs before shipping plant products was assessed under laboratory conditions. Hibiscus leaves were dipped into beakers filled with 0, 1, 2, 4, 8, and 10 g of PFR 97® / L of water and t...

Out of a digital chrysalis: NIHNMF (pronounced nymph--the National Indigenous Health and New Media Forum).

Science.gov (United States)

Cattoni, Jan; Gamble, Lucinda; Gibson, Julie; Hunter, Ernest; Jones, Anita; Mitchell, Sarah; Pelham, Steven; Smith, Rakana; Travers, Helen

2009-08-01

In conjunction with the Creating Futures conference, the inaugural meeting of the National Indigenous Health and New Media Forum (NIHNMF--pronounced as 'nymph') was held at the Tanks Gallery in Cairns, Queensland, Australia. This paper describes the background to this innovative meeting of media minds. It also explores an emerging vision for addressing Indigenous health disparities through digital inclusion to overcome the 'digital divide' between mainstream and Indigenous Australians that constrains the delivery of appropriate health promotion to this health priority population.

Irradiation effects on the duration of intermolt in nymphs of the fourth instar of Panstrongylus megistus Burmeister, 1835 (Hemiptera: Reduviidae)

International Nuclear Information System (INIS)

Barros Falcao, P.H. de.

1987-01-01

The duration of intermolt, in nymphs of the fourth instar, of P. megistus, submitted to irradiation with Cobalt 60, 24 hs after the blood meal is studied. The insects were divided in four groups of 40 and were irradiated with doses of 10, 20, 40 and 80 Gray, respectively. (M.A.C.) [pt

Unraveling the Host Plant Alternation of Cacopsylla pruni – Adults but Not Nymphs Can Survive on Conifers Due to Phloem/Xylem Composition

Science.gov (United States)

Gallinger, Jannicke; Gross, Jürgen

2018-01-01

Plant sap feeding insects like psyllids are known to be vectors of phloem dwelling bacteria (‘Candidatus Phytoplasma’ and ‘Ca. Liberibacter’), plant pathogens which cause severe diseases and economically important crop damage. Some univoltine psyllid species have a particular life cycle, within one generation they alternate two times between different host plant species. The plum psyllid Cacopsylla pruni, the vector of European Stone Fruit Yellows (ESFY), one of the most serious pests in European fruit production, migrates to stone fruit orchards (Prunus spp.) for mating and oviposition in early spring. The young adults of the new generation leave the Prunus trees in summer and emigrate to their overwintering hosts like spruce and other conifers. Very little is known about the factors responsible for the regulation of migration, reasons for host alternation, and the behavior of psyllids during their phase of life on conifers. Because insect feeding behavior and host acceptance is driven by different biotic factors, such as olfactory and gustatory cues as well as mechanical barriers, we carried out electrical penetration graph (EPG) recordings and survival bioassays with C. pruni on different conifer species as potential overwintering hosts and analyzed the chemical composition of the respective plant saps. We are the first to show that migrating psyllids do feed on overwintering hosts and that nymphs are able to ingest phloem and xylem sap of coniferous trees, but cannot develop on conifer diet. Analyses of plant saps reveal qualitative differences in the chemical composition between coniferous trees and Prunus as well as within conifer species. These differences are discussed with regard to nutritional needs of psyllid nymphs for proper development, overwintering needs of adults and restriction of ‘Ca. P. prunorum’ to Prunus phloem. PMID:29706983

Redescubrimiento de Neopentura semifusca (Plecoptera: Gripopterygidae, descripción del imago macho, redescripción de la hembra y la ninfa Rediscovery of Neopentura semifusca (Plecoptera: Gripopterygidae, description of the male imago, redescription of the female and the nymph

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Alejandro Vera

2006-12-01

Full Text Available Se describen ambos sexos y la ninfa de Neopentura semifusca Illies, 1965. El macho es descrito por primera vez. La ninfa corresponde a la «Ninfa A» descrita tentativamente por Illies para Araucanioperla . Se discute la clasificación a nivel de subfamilia y su distribución geográfica.Both sexes and the nymph of Neopentura semifusca Illies, 1965 are described. The male is described for the first time. The nymph corresponds to the «Nymph A» tentatively described by Illies for Araucanioperla . The classification to subfamily level and the geographic distribution are discussed.

The effect of indoxacarb and five other insecticides on Phytoseiulus persimilis (Acari: Phytoseiidae), Amblyseius fallacis (Acari: Phytoseiidae) and nymphs of Orius insidiosus (Hemiptera: Anthocoridae).

Science.gov (United States)

Bostanian, Noubar J; Akalach, Mohammed

2006-04-01

A laboratory study assessed the contact toxicity of indoxacarb, abamectin, endosulfan, insecticidal soap, S-kinoprene and dimethoate to Amblyseius fallacis (Garman), Phytoseiulus persimilis Athias-Henriot and nymphs of Orius insidiosus (Say). Amblyseius fallacis is a predacious phytoseiid mite and an integral part of integrated pest management (IPM) programmes in North American apple orchards. The other two beneficials are widely used in greenhouses to manage various arthropod pests infesting vegetable and ornamental crops. Indoxacarb is a slow-acting insecticide, so toxicity data were recorded 7 days post-treatment when the data had stabilised. It showed no toxicity to O. insidiosus nymphs or to A. fallacis or P. persimilis adults. The LC50 values for O. insidiosus nymphs and P. persimilis could not be estimated with their associated confidence limits, because the g values were greater than 0.5 and under such circumstances the lethal concentration would lie outside the limits. The LC50 for A. fallacis was 7.6x the label rate. The fecundity of P. persimilis was reduced by 26.7%. The eclosion of treated eggs from both species of beneficial mites was not affected adversely. Among the other pest control products, S-kinoprene and endosulfan affected adversely at least one species of the predators, whereas dimethoate, abamectin and insecticidal soap were very toxic to all three beneficials. Indoxacarb should be evaluated as a pest control product in IPM programmes. Copyright (c) 2006 Crown in the right of Canada.

Efficacy and environmental persistence of nootkatone for the control of the blacklegged tick (Acari: Ixodidae) in residential landscapes.

Science.gov (United States)

Bharadwaj, Anuja; Stafford, Kirby C; Behle, Robert W

2012-09-01

The ability of the plant-derived compound nootkatone to control nymphs of the blacklegged tick, Ixodes scapularis Say, was evaluated at lawn perimeter plots at homes in Lyme disease endemic areas of Connecticut. Three formulations of nootkatone ranging from 0.05 to 0.84% (0.06 - 1.03 g AI/m2) were applied by a hydraulic sprayer from 2008 to 2010. In 2008, the 0.84% emulsifiable nootkatone formulation provided 100% control of I. scapularis through week 1, but declined to 49 and 0% by 2 and 3 wk posttreatment, respectively. A combination of 0.05% nootkatone and entomopathogenic fungus, Metarhizium brunneum Petch F52, resulted in 50% control for the first week posttreatment and no control in subsequent weeks. The 0.84% emulsifiable nootkatone formulation was phytotoxic, although no damage was observed with the 0.05% formulation with Metarhizium. Residual analysis of nootkatone collected on filter paper disks showed that > or = 95% of the emulsified nootkatone for both formulations was lost within 7 d after application. A lignin-encapsulated nootkatone formulation (0.56 and 0.46% in 2009 and 2010, respectively) provided 100% control of I. scapularis for 8 wk in 2009 and, in 2010, 67% control at approximately 1 wk posttreatment with respect to the pretreatment counts, although there was no difference in tick abundance posttreatment. A 0.60% Maillard-reaction encapsulated nootkatone formulation in 2010 provided a similar level of control (62%). Nootkatone in the lignin and Maillard formulations were more persistent than the emulsifiable formulation. Little or no phytotoxicity was observed with the encapsulated formulations. Encapsulating nootkatone reduced phytotoxicity and appeared to reduce environmental loss. While nootkatone can provide effective tick control, further work is needed to refine formulations to address phytotoxicity, yet provide sufficient material to control ticks.

Oral delivery of double-stranded RNAs induces mortality in nymphs and adults of the Asian citrus psyllid, Diaphorina citri.

Science.gov (United States)

Galdeano, Diogo Manzano; Breton, Michèle Claire; Lopes, João Roberto Spotti; Falk, Bryce W; Machado, Marcos Antonio

2017-01-01

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is one of the most important citrus pests. ACP is the vector of the phloem-limited bacteria Candidatus Liberibacter americanus and Candidatus Liberibacter asiaticus, the causal agents of the devastating citrus disease huanglongbing (HLB). The management of HLB is based on the use of healthy young plants, eradication of infected plants and chemical control of the vector. RNA interference (RNAi) has proven to be a promising tool to control pests and explore gene functions. Recently, studies have reported that target mRNA knockdown in many insects can be induced through feeding with double-stranded RNA (dsRNA). In the current study, we targeted the cathepsin D, chitin synthase and inhibitor of apoptosis genes of adult and nymph ACP by feeding artificial diets mixed with dsRNAs and Murraya paniculata leaves placed in dsRNAs solutions, respectively. Adult ACP mortality was positively correlated with the amount of dsRNA used. Both nymphs and adult ACP fed dsRNAs exhibited significantly increased mortality over time compared with that of the controls. Moreover, qRT-PCR analysis confirmed the dsRNA-mediated RNAi effects on target mRNAs. These results showed that RNAi can be a powerful tool for gene function studies in ACP and perhaps for HLB control.

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

NARCIS (Netherlands)

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

2005-01-01

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

Two new species of Cryptoperla (Plecoptera: Peltoperlidae) from China, with description of the nymph of Cryptoperla dui Sivec.

Science.gov (United States)

Huo, Qing-Bo; Du, Yu-Zhou

2018-01-18

Two species of the peltoperlid genus Cryptoperla Needham, C. dactylina Du, sp. nov. and C. nangongshana Huo Du, sp. nov. are described as new to science from Yunnan and Shaanxi provinces of China. Cryptoperla dactylina is characterized by a finger-like sclerotized projection with small-rounded processes on the first cercal segment and C. nangongshana is characterized by clusters of long bristles on the first six cercal segments. Additionally, a description of the nymph of C. dui Sivec is provided.

Natural parasitism of Diaphorina citri Kuwayama (Hemiptera, Psyllidae nymphs by Tamarixia radiata Waterston (Hymenoptera, Eulophidae in São Paulo orange groves

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Paulo Eduardo Branco Paiva

2012-12-01

Full Text Available The psyllid Diaphorina citri Kuwayama 1908 has become the main citrus pest species in the state of São Paulo, Brazil, after the introduction of the huanglongbing or citrus greening. This study evaluated the parasitism of 3rd, 4th and 5th instar D. citri nymphs by Tamarixia radiata (Waterston, 1922 in citrus groves under a regimen of regular insecticide applications in ten producing regions: Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins and São João da Boa Vista. Sixty-nine samples of new branches infested with nymphs of D. citri were collected from 2005 to 2008 in orange groves ranging from 1 to 20 years old, of the varieties Hamlin, Pera, Valencia and Natal. The parasitoid T. radiata is widely distributed in São Paulo orange groves, and was identified in 50 (72% of the samples, showing a mean parasitism rate of 12.4%. The highest parasitism rate was observed in the "summer" (from January through March, with a mean of 25.7%. Nymphal parasitism was above 90% in two samples. The probable causes of the variations in parasitism of D. citri by T. radiata are discussed.

Oral delivery of double-stranded RNAs induces mortality in nymphs and adults of the Asian citrus psyllid, Diaphorina citri.

Directory of Open Access Journals (Sweden)

Diogo Manzano Galdeano

Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri Kuwayama, is one of the most important citrus pests. ACP is the vector of the phloem-limited bacteria Candidatus Liberibacter americanus and Candidatus Liberibacter asiaticus, the causal agents of the devastating citrus disease huanglongbing (HLB. The management of HLB is based on the use of healthy young plants, eradication of infected plants and chemical control of the vector. RNA interference (RNAi has proven to be a promising tool to control pests and explore gene functions. Recently, studies have reported that target mRNA knockdown in many insects can be induced through feeding with double-stranded RNA (dsRNA. In the current study, we targeted the cathepsin D, chitin synthase and inhibitor of apoptosis genes of adult and nymph ACP by feeding artificial diets mixed with dsRNAs and Murraya paniculata leaves placed in dsRNAs solutions, respectively. Adult ACP mortality was positively correlated with the amount of dsRNA used. Both nymphs and adult ACP fed dsRNAs exhibited significantly increased mortality over time compared with that of the controls. Moreover, qRT-PCR analysis confirmed the dsRNA-mediated RNAi effects on target mRNAs. These results showed that RNAi can be a powerful tool for gene function studies in ACP and perhaps for HLB control.

Identification of Novel Viruses in Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis Ticks

Science.gov (United States)

Sameroff, Stephen; Tagliafierro, Teresa; Jain, Komal; Williams, Simon H.; Cucura, D. Moses; Rochlin, Ilia; Monzon, Javier; Carpi, Giovanna; Tufts, Danielle; Diuk-Wasser, Maria; Brinkerhoff, Jory; Lipkin, W. Ian

2018-01-01

ABSTRACT Ticks carry a wide range of known human and animal pathogens and are postulated to carry others with the potential to cause disease. Here we report a discovery effort wherein unbiased high-throughput sequencing was used to characterize the virome of 2,021 ticks, including Ixodes scapularis (n = 1,138), Amblyomma americanum (n = 720), and Dermacentor variabilis (n = 163), collected in New York, Connecticut, and Virginia in 2015 and 2016. We identified 33 viruses, including 24 putative novel viral species. The most frequently detected viruses were phylogenetically related to members of the Bunyaviridae and Rhabdoviridae families, as well as the recently proposed Chuviridae. Our work expands our understanding of tick viromes and underscores the high viral diversity that is present in ticks. IMPORTANCE The incidence of tick-borne disease is increasing, driven by rapid geographical expansion of ticks and the discovery of new tick-associated pathogens. The examination of the tick microbiome is essential in order to understand the relationship between microbes and their tick hosts and to facilitate the identification of new tick-borne pathogens. Genomic analyses using unbiased high-throughput sequencing platforms have proven valuable for investigations of tick bacterial diversity, but the examination of tick viromes has historically not been well explored. By performing a comprehensive virome analysis of the three primary tick species associated with human disease in the United States, we gained substantial insight into tick virome diversity and can begin to assess a potential role of these viruses in the tick life cycle. PMID:29564401

Successful Feeding of Amblyomma coelebs (Acari: Ixodidae) Nymphs on Humans in Brazil: Skin Reactions to Parasitism.

Science.gov (United States)

Garcia, Marcos V; Matias, Jaqueline; Aguirre, AndrÉ De A R; Csordas, Barbara G; SzabÓ, Matias P J; Andreotti, Renato

2015-03-01

Identifying the tick species that successfully feed on humans would increase knowledge of the epidemiology of several tick-borne diseases. These species salivate into the host, increasing the risk of pathogen transmission. However, there is a lack of data in the literature regarding the ticks that prefer to feed on humans. Herein, we describe the successful feeding of Amblyomma coelebs Neumann nymphs on two of the authors after accidental tick bites occurred during field surveys in two preserved areas of Mato Grosso do Sul, Brazil. One of the host-parasite interactions was closely monitored, and the tick development, gross host skin alterations, and related sensations are presented. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America.

Comparison of Potato and Asian Citrus Psyllid Adult and Nymph Transcriptomes Identified Vector Transcripts with Potential Involvement in Circulative, Propagative Liberibacter Transmission

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Tonja W. Fisher

2014-11-01

Full Text Available The potato psyllid (PoP Bactericera cockerelli (Sulc and Asian citrus psyllid (ACP Diaphorina citri Kuwayama are the insect vectors of the fastidious plant pathogen, Candidatus Liberibacter solanacearum (CLso and Ca. L. asiaticus (CLas, respectively. CLso causes Zebra chip disease of potato and vein-greening in solanaceous species, whereas, CLas causes citrus greening disease. The reliance on insecticides for vector management to reduce pathogen transmission has increased interest in alternative approaches, including RNA interference to abate expression of genes essential for psyllid-mediated Ca. Liberibacter transmission. To identify genes with significantly altered expression at different life stages and conditions of CLso/CLas infection, cDNA libraries were constructed for CLso-infected and -uninfected PoP adults and nymphal instars. Illumina sequencing produced 199,081,451 reads that were assembled into 82,224 unique transcripts. PoP and the analogous transcripts from ACP adult and nymphs reported elsewhere were annotated, organized into functional gene groups using the Gene Ontology classification system, and analyzed for differential in silico expression. Expression profiles revealed vector life stage differences and differential gene expression associated with Liberibacter infection of the psyllid host, including invasion, immune system modulation, nutrition, and development.

The crystal structures of two salivary cystatins from the tick Ixodes scapularis and the effect of these inhibitors on the establishment of Borrelia burgdorferi infection in a murine model

Energy Technology Data Exchange (ETDEWEB)

Kotsyfakis, Michalis; Horka, Helena; Salat, Jiri; Andersen, John F. (South Bohemia); (ASCR-ICP); (NIAID)

2010-11-17

We have previously demonstrated that two salivary cysteine protease inhibitors from the Borrelia burgdorferi (Lyme disease) vector Ixodes scapularis - namely sialostatins L and L2 - play an important role in tick biology, as demonstrated by the fact that silencing of both sialostatins in tandem results in severe feeding defects. Here we show that sialostatin L2 - but not sialostatin L - facilitates the growth of B. burgdorferi in murine skin. To examine the structural basis underlying these differential effects of the two sialostatins, we have determined the crystal structures of both sialostatin L and L2. This is the first structural analysis of cystatins from an invertebrate source. Sialostatin L2 crystallizes as a monomer with an 'unusual' conformation of the N-terminus, while sialostatin L crystallizes as a domain-swapped dimer with an N-terminal conformation similar to other cystatins. Deletion of the 'unusual' N-terminal five residues of sialostatin L2 results in marked changes in its selectivity, suggesting that this region is a particularly important determinant of the biochemical activity of sialostatin L2. Collectively, our results reveal the structure of two tick salivary components that facilitate vector blood feeding and that one of them also supports pathogen transmission to the vertebrate host.

Insecticidal activity of neem oil against Gyropsylla spegazziniana (Hemiptera: Psyllidae nymphs on Paraguay tea seedlings

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M. A. Formentini

Full Text Available Abstract Gyropsylla spegazziniana (Paraguay tea ampul is one of the most important pests of Paraguay tea plants, and prohibition of synthetic insecticide use for control of this pest has led to the search for alternative methods. This laboratory study aimed to compare different control strategies for G. spegazziniana, utilizing a commercial neem seed oil product. Paraguay tea seedlings were treated with neem oil solution both pre- and post-infestation with 5th instar nymphs. The systemic action of neem oil was also evaluated by treating plant soil with the neem oil solution, followed by transfer of the insects to plants 24 h post-treatment. Spray treatments were effective against the pest, especially post-infestation (80% mortality, demonstrating the potential of neem oil for control of the Paraguay tea ampul. No significant effects were observed with respect to systemic activity.

[Effect of population density on enzymatic activity of antioxidative and phenol oxidase systems of imagoes and nymphs of the marble cockroach Nauphoeta cinerea].

Science.gov (United States)

Murzagulov, G S; Saltykova, E S; Gaĭfullina, L R; Nikolenko, A G

2013-01-01

The work deals with effect of density of population on functional activity of components pf protective system of adult individuals and nymphs of the marble cockroach. The resistance of individuals has been noted to decrease both at individual maintenance and under conditions of overpopulation. Changes in activities of enzymes of antioxidative and phenoloxidase systems are studied ion the insect hemolymph and intestine. Possible consequences of isolation and overpopulation are discussed both for stability and for individual development.

Prey Preference of the Predatory Mite, Amblyseius swirskii between First Instar Western Flower Thrips Frankliniella occidentalis and Nymphs of the Twospotted Spider Mite Tetranychus urticae

OpenAIRE

Xu, Xuenong; Enkegaard, Annie

2010-01-01

The prey preference of polyphagous predators plays an important role in suppressing different species of pest insects. In this study the prey preference of the predatory mite, Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) was examined between nymphs of the twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) and first instar larvae of the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), as well as between active and chrysa...

Efficacy of sarolaner in the prevention of Borrelia burgdorferi and Anaplasma phagocytophilum transmission from infected Ixodes scapularis to dogs.

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Honsberger, Nicole A; Six, Robert H; Heinz, Thomas J; Weber, Angela; Mahabir, Sean P; Berg, Thomas C

2016-05-30

The efficacy of sarolaner (Simparica™, Zoetis) to prevent transmission primarily of Borrelia burgdorferi and secondarily of Anaplasma phagocytophilum from infected wild-caught Ixodes scapularis to dogs was evaluated in a placebo-controlled laboratory study. Twenty-four purpose-bred laboratory Beagles seronegative for B. burgdorferi and A. phagocytophilum antibodies were allocated randomly to one of three treatment groups: placebo administered orally on Days 0 and 7, or sarolaner at 2mg/kg administered orally on Day 0 (28 days prior to tick infestation) or on Day 7 (21 days prior to tick infestation). On Day 28, each dog was infested with approximately 25 female and 25 male wild caught adult I. scapularis that were determined to have prevalence of 57% for B. burgdorferi and 6.7% for A. phagocytophilum by PCR. In situ tick counts were conducted on Days 29 and 30. On Day 33, all ticks were counted and removed. Acaricidal efficacy was calculated based on the reduction of geometric mean live tick counts in the sarolaner-treated groups compared to the placebo-treated group for each tick count. Blood samples collected from each dog on Days 27, 49, 63, 77, 91 and 104 were tested for the presence of B. burgdorferi and A. phagocytophilum antibodies using the SNAP(®) 4Dx(®) Plus Test, and quantitatively assayed for B. burgdorferi antibodies using an ELISA test. Skin biopsies collected on Day 104 were tested for the presence of B. burgdorferi by bacterial culture and PCR. Geometric mean live tick counts for placebo-treated dogs were 14.8, 12.8, and 19.1 on Days 29, 30, and 33, respectively. The percent reductions in mean live tick counts at 1, 2, and 5 days after infestation were 86.3%, 100%, and 100% for the group treated with sarolaner 21 days prior to infestation, and 90.9%, 97.1%, and 100% for the group treated with sarolaner 28 days prior to infestation. Geometric mean live tick counts for both sarolaner-treated groups were significantly lower than those for the

Prognosing the sex of adults of Amblyomma auricularium through evaluating the biological parameters of engorged nymphs Prognóstico do sexo dos adultos de Amblyomma auricularium através da avaliação de parâmetros biológicos de ninfas ingurgitadas

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Michele da Costa Pinheiro

2013-04-01

Full Text Available Maintaining tick colonies under laboratory condition, as well as carrying out experimental studies on these arthropods may be more successful with better knowledge of some basic biological parameters. In this study, we evaluated how the weight, engorgement period and premolt period of Amblyomma auricularium nymphs (N=600 correlated with the sex of the adults that subsequently emerged. The experiment was carried out in the W.O. Neitz Parasitological Research Station, Ixodology Laboratory of the Department of Animal Parasitology, Federal Rural University of Rio de Janeiro, located in Seropédica, state of Rio de Janeiro. The average weight of the nymphs was 5.1±1.51mg among those that originated males and 8.2±2.5mg among those that originated females. The engorgement period for the nymphs that originated males was 8.3±1.5days while it was longer for the nymphs that originated females, with an average of 8.8±1.8days to complete their diet. The premolt period was shorter for nymphs that originated males (17.2±0.93days than for nymphs that originated females (17.7±1.00days. Despite an area of overlapping between the weights of engorged nymphs that originated adult males and females, this is the most reliable parameter for predicting the sex of adults of A. auricularium.Para melhor gerenciamento e otimização da manutenção de colônias e experimentos com carrapatos ixodídeos, realizou-se este estudo avaliando a relação do peso, período parasitário e período de pré-ecdise de ninfas de Amblyomma auricularium (N=600 com o sexo dos adultos emergidos. O trabalho foi realizado no Laboratório de Ixodologia do Departamento de Parasitologia Animal da Universidade Federal Rural do Rio de Janeiro. O peso médio das ninfas foi de 5,1±1,51mg naquelas que originaram machos e de 8,2±2,5mg naquelas que deram origem a fêmeas. Em relação ao período de ingurgitamento, o das ninfas que originaram machos foi de 8,3±1,5dias, enquanto as ninfas que

Método para monitoramento de ninfas de cigarras e controle com inseticidas em reflorestamentos com paricá Method for monitoring nymphs of cicadas and control with insecticides in reforestations with paricá

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Alexandre Mehl Lunz

2010-07-01

Full Text Available O objetivo deste trabalho foi estabelecer um método para o monitoramento da população de cigarras (Quesada gigas e para a avaliação da eficácia de doses de thiamethoxam, carbofuran e imidaclopride no controle de ninfas, em reflorestamento com paricá (Schizolobium parahyba var. amazonicum. Foram utilizadas as seguintes dosagens de inseticidas: 2,0, 4,0 e 6,0 kg ha-1 do produto comercial Actara (250 WG, para o princípio ativo thiamethoxan; 7,15, 14,30, 21,45 L ha-1 de Furadan (350 FS, para o carbofuran; e 4,5, 9,0, 13,5 L ha-1 de Provado (200 SC, para o imidaclopride. As três dosagens de cada produto foram aplicadas em área total. Foram realizadas três avaliações quinzenais, posteriores à aplicação, em que foram contabilizados os números de buracos e de ninfas vivas, por meio da abertura, com implemento tratorizado, de trincheiras com 7 m de comprimento, 0,8 m de largura e 0,07 m de profundidade. Todos os princípios ativos testados foram eficientes na redução da população de ninfas de Q. gigas, mas não houve efeito significativo das doses avaliadas. Os princípios ativos carbofuran e thiamethoxan são os mais promissores, com controle de 75-80% da infestação de ninfas. A abertura de trincheiras com o implemento tratorizado é eficaz no monitoramento da população de ninfas de Q. gigas, em reflorestamentos com paricá.The objective of this work was to establish a method for cicad (Quesada gigas population monitoring and for the evaluation of the effectiveness of thiamethoxam, carbofuran and imidacloprid doses on the control of cicad nymphs, in reforestation with paricá (Schizolobium parahyba var. amazonicum. The following insecticide doses were used: 2.0, 4.0, and 6.0 kg ha-1 of Actara (250 WG commercial product, for thiamethoxam active principle; 7.15, 14.30, and 21.45 L ha-1 of Furadan (350 FS, for carbofuran; 4.0, 9.0, and 13.5 L ha-1 of Provado (200 SC, for imidacloprid. The three doses of each product were applied in

Tick histamine release factor is critical for Ixodes scapularis engorgement and transmission of the lyme disease agent.

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Jianfeng Dai

2010-11-01

Full Text Available Ticks are distributed worldwide and affect human and animal health by transmitting diverse infectious agents. Effective vaccines against most tick-borne pathogens are not currently available. In this study, we characterized a tick histamine release factor (tHRF from Ixodes scapularis and addressed the vaccine potential of this antigen in the context of tick engorgement and B. burgdorferi transmission. Results from western blotting and quantitative Reverse Transcription-PCR showed that tHRF is secreted in tick saliva, and upregulated in Borrelia burgdorferi-infected ticks. Further, the expression of tHRF was coincident with the rapid feeding phase of the tick, suggesting a role for tHRF in tick engorgement and concomitantly, for efficient B. burgdorferi transmission. Silencing tHRF by RNA interference (RNAi significantly impaired tick feeding and decreased B. burgdorferi burden in mice. Interfering with tHRF by actively immunizing mice with recombinant tHRF, or passively transferring tHRF antiserum, also markedly reduced the efficiency of tick feeding and B. burgdorferi burden in mice. Recombinant tHRF was able to bind to host basophils and stimulate histamine release. Therefore, we speculate that tHRF might function in vivo to modulate vascular permeability and increase blood flow to the tick bite-site, facilitating tick engorgement. These findings suggest that blocking tHRF might offer a viable strategy to complement ongoing efforts to develop vaccines to block tick feeding and transmission of tick-borne pathogens.

No Observed Effect of Landscape Fragmentation on Pathogen Infection Prevalence in Blacklegged Ticks (Ixodes scapularis in the Northeastern United States.

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Christine P Zolnik

Full Text Available Pathogen prevalence within blacklegged ticks (Ixodes scapularis Say, 1821 tends to vary across sites and geographic regions, but the underlying causes of this variation are not well understood. Efforts to understand the ecology of Lyme disease have led to the proposition that sites with higher host diversity will result in lower disease risk due to an increase in the abundance of inefficient reservoir species relative to the abundance of species that are highly competent reservoirs. Although the Lyme disease transmission cycle is often cited as a model for this "dilution effect hypothesis", little empirical evidence exists to support that claim. Here we tested the dilution effect hypothesis for two pathogens transmitted by the blacklegged tick along an urban-to-rural gradient in the northeastern United States using landscape fragmentation as a proxy for host biodiversity. Percent impervious surface and habitat fragment size around each site were determined to assess the effect of landscape fragmentation on nymphal blacklegged tick infection with Borrelia burgdorferi and Anaplasma phagocytophilum. Our results do not support the dilution effect hypothesis for either pathogen and are in agreement with the few studies to date that have tested this idea using either a landscape proxy or direct measures of host biodiversity.

Transmisión del Mal de Río Cuarto virus por ninfas de primer y tercer estadio de Delphacodes kuscheli Transmission of Mal de Río Cuarto virus by first and third-instar nymphs of Delphacodes kuscheli

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Joel Arneodo

2005-02-01

Full Text Available Se comparó la capacidad de ninfas de primer y tercer estadío de Delphacodes kuscheli Fennah (Hemiptera: Delphacidae para adquirir y posteriormente transmitir el Mal de Río Cuarto virus (MRCV, bajo condiciones controladas. Ninfas I y III avirulíferas se alimentaron separadamente de plantas de trigo infectadas durante 48 horas, para luego ser colocadas en subgrupos de tres individuos sobre plantas de trigo sanas. Se realizaron transmisiones seriales utilizando períodos de inoculación de 24 horas. Ambos estadií os lograron adquirir y transmitir el MRCV, pero se evidenció una mayor cantidad de subgrupos infectivos cuando la adquisición se efectuó como ninfas I, así como una disminución significativa en la duración del período de latencia del virus respecto de los insectos que adquirieron el MRCV durante el tercer estadio ninfal.The ability of first and third-instar Delphacodes kuscheli Fennah (Hemiptera: Delphacidae nymphs to acquire and transmit Mal de Río Cuarto virus (MRCV, under controlled conditions, was investigated. First and third-instar nymphs were allowed acquisition feeding separately on infected wheat plants for 48 hours. The insects were then placed in groups of three for serial transmissions to healthy wheat plants, using inoculation periods of 24 hours. Both instars of D. kuscheli were demonstrated to acquire and subsequently transmit the virus. Nevertheless, transmission trials showed highest transmission efficiency and shortest latent period when MRCV was acquired by first-instar nymphs.

Patogenicidade de isolados de Beauveria bassiana para ovos, larvas e ninfas ingurgitadas de Rhipicephalus sanguineus Pathogenicity of Beauveria bassiana isolates towards eggs, larvae and engorged nymphs of Rhipicephalus sanguineus

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Nancy Prette

2005-08-01

Full Text Available O presente trabalho objetivou avaliar a ação dos isolados JAB 07, CB 7 e AM 9 do fungo Beauveria bassiana para ovos, larvas e ninfas ingurgitadas de Rhipicephalus sanguineus. Padronizou-se a concentração de 109 conídios mL-1 para cada isolado e por meio de diluições seriadas, obtiveram-se as suspensões com concentrações de 10(8 e 10(7con. mL-1. Preparou-se um bioensaio para cada fase do ciclo de vida do carrapato. Cada ensaio foi composto por 10 grupos tratamentos, formados por um isolado do fungo e uma concentração de conídios, e um grupo controle contendo apenas o veículo das suspensões. Os isolados do fungo, aplicados nas diferentes concentrações de esporos, causaram redução no percentual de eclosão de larvas oriundas de ovos infectados (0,7 a 12,1% de eclosão e no percentual de ecdise de larvas (4,7 a 33,7% de ecdise e ninfas (0 a 16,7% de ecdise. Não houve diferença entre os isolados (P>0,05 quanto à infecção de ovos, mas a aplicação de 109 con./mL de JAB 07 e AM 9 promoveu redução significativa da eclosão de larvas, em relação à concentração de 10(7con. mL-1. O isolado CB 7 foi o mais eficaz na redução do número de ecdises de larvas. Os isolados e as concentrações de conídios não diferiram (P>0,05 quanto à capacidade de redução do percentual de ecdise de ninfas, mas evidenciou-se intensa atividade patogênica do fungo.The aim of the present study was to determine the action of isolates JAB 07, CB 7 and AM 9 of the fungus Beauveria bassiana on eggs, larvae and engorged nymphs of Rhipicephalus sanguineus tick. A concentration of 109 conidia mL-1 was standardized for each isolate and suspensions containing 10(8 and 10(7 conidia mL-1 were obtained by serial dilution. A bioassay was prepared for each phase of the life cycle of the tick. Each assay comprised 10 treatment groups, consisting of one fungal isolate and one conidial concentration, and one control group containing only the vehicle of

Chemical composition and repellency of essential oils from four medicinal plants against Ixodes ricinus nymphs (Acari: Ixodidae).

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El-Seedi, Hesham R; Khalil, Nasr S; Azeem, Muhammad; Taher, Eman A; Göransson, Ulf; Pålsson, Katinka; Borg-Karlson, Anna-Karin

2012-09-01

In our search for effective tick repellents from plant origin, we investigated the effect of essential oils of four medicinal and culinary plants belonging to the family Lamiaceae on nymphs of the tick Ixodes ricinus (L.). The essential oils of the dry leaves of Rosmarinus officinalis (Rosemary) (L.), Mentha spicata (Spearmint) (L.), Origanum majorana (Majoram) (L.), and Ocimum basilicum (Basil) (L.) were isolated by steam distillation and 15 microg/cm2 concentration of oils was tested against ticks in a laboratory bioassay. The oils of R. officinalis, M. spicata, and O. majorana showed strong repellency against the ticks 100, 93.2, and 84.3%, respectively, whereas O. basilicum only showed 64.5% repellency. When tested in the field, the oils of R. officinalis and M. spicata showed 68.3 and 59.4% repellency at a concentration of 6.5 microg/cm2 on the test cloths. The oils were analyzed by gas chromatography mass spectrometry and the major compounds from the most repellent oils were 1,8-cineole, camphor, linalool, 4-terpineol, borneol, and carvone.

Insecticidal effect of Canavalia ensiformis major urease on nymphs of the milkweed bug Oncopeltus fasciatus and characterization of digestive peptidases.

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Defferrari, Marina S; Demartini, Diogo R; Marcelino, Thiago B; Pinto, Paulo M; Carlini, Celia R

2011-06-01

Jackbean (Canavalia ensiformis) ureases are entomotoxic upon the release of internal peptides by insect's digestive enzymes. Here we studied the digestive peptidases of Oncopeltus fasciatus (milkweed bug) and its susceptibility to jackbean urease (JBU). O. fasciatus nymphs fed urease showed a mortality rate higher than 80% after two weeks. Homogenates of midguts dissected from fourth instars were used to perform proteolytic activity assays. The homogenates hydrolyzed JBU in vitro, yielding a fragment similar in size to known entomotoxic peptides. The major proteolytic activity at pH 4.0 upon protein substrates was blocked by specific inhibitors of aspartic and cysteine peptidases, but not significantly affected by inhibitors of metallopeptidases or serine peptidases. The optimal activity upon N-Cbz-Phe-Arg-MCA was at pH 5.0, with complete blockage by E-64 in all pH tested. Optimal activity upon Abz-AIAFFSRQ-EDDnp (a substrate for aspartic peptidases) was detected at pH 5.0, with partial inhibition by Pepstatin A in the pH range 2-8. Fluorogenic substrates corresponding to the N- and C-terminal regions flanking a known entomotoxic peptide within urease sequence were also tested. While the midgut homogenate did not hydrolyze the N-terminal peptide, it cleaved the C-terminal peptide maximally at pH 4.0-5.0, and this activity was inhibited by E-64 (10 μM). The midgut homogenate was submitted to ion-exchange chromatography followed by gel filtration. A 22 kDa active fraction was obtained, resolved in SDS-PAGE (12%), the corresponding band was in-gel digested by trypsin, the peptides were analyzed by mass spectrometry, retrieving a cathepsin L protein. The purified cathepsin L was shown to have at least two possible cleavage sites within the urease sequence, and might be able to release a known insecticidal peptide in a single or cascade event. The results suggest that susceptibility of O. fasciatus nymphs to jackbean urease is, like in other insect models, due mostly

Molecular cloning, sequencing and recombinant expression of a ...

African Journals Online (AJOL)

The 4D8 gene was recently discovered in Ixodes scapularis and identified as a tick protective antigen. Vaccination using recombinant 4D8 from I. scapularis showed a significant reduction against I. scapularis tick infestation in a sheep model. This protein is expressed in both salivary gland and gut tissues, and is thought to ...

Detection of Lyme Disease Bacterium, Borrelia burgdorferi sensu lato, in Blacklegged Ticks Collected in the Grand River Valley, Ontario, Canada

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Scott, John D.; Foley, Janet E.; Anderson, John F.; Clark, Kerry L.; Durden, Lance A.

2017-01-01

We document the presence of blacklegged ticks, Ixodes scapularis, in the Grand River valley, Centre Wellington, Ontario. Overall, 15 (36%) of 42 I. scapularis adults collected from 41 mammalian hosts (dogs, cats, humans) were positive for the Lyme disease bacterium, Borrelia burgdorferi sensu lato (s.l.). Using real-time PCR testing and DNA sequencing of the flagellin (fla) gene, we determined that Borrelia amplicons extracted from I. scapularis adults belonged to B. burgdorferi sensu stricto (s.s.), which is pathogenic to humans and certain domestic animals. Based on the distribution of I. scapularis adults within the river basin, it appears likely that migratory birds provide an annual influx of I. scapularis immatures during northward spring migration. Health-care providers need to be aware that local residents can present with Lyme disease symptoms anytime during the year. PMID:28260991

Insulin-related peptide 5 is involved in regulating embryo development and biochemical composition in pea aphid with wing polyphenism

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Shan-Shan eGuo

2016-02-01

Full Text Available In aphids there is a fecundity-dispersal trade-off between wingless and winged morphs. Recent research on the molecular mechanism of wing morphs associated with dispersal reveals that insulin receptors in the insulin signaling (IS pathway regulate alteration of wing morphs in planthoppers. However, little is known about whether genes in the IS pathway are involved in developmental regulation in aphid nymphs with different wing morphs. In this study, we show that expression of the insulin-related peptide 5 gene (Apirp5 affects biochemical composition and embryo development of wingless pea aphids, Acyrthosiphon pisum. After comparing expression levels of major genes in the IS pathway between third instar winged and wingless nymphs, we found that Apirp5 showed higher expression in head and thorax of the wingless nymphs than in the winged nymphs. Although microinjection treatment affects physical performance in aphids, nymphs with RNA interference of Apirp5 had less weight, smaller embryo size and higher carbohydrate and protein contents compared to control group. Comparison between winged and wingless nymphs showed a similar trend. These results indicate that Apirp5 is involved in embryo development and metabolic regulation in wing dimorphic pea aphid.

Stable Transmission of Borrelia burgdorferi Sensu Stricto on the Outer Banks of North Carolina.

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Levine, J F; Apperson, C S; Levin, M; Kelly, T R; Kakumanu, M L; Ponnusamy, L; Sutton, H; Salger, S A; Caldwell, J M; Szempruch, A J

2017-08-01

The spirochaete (Borrelia burgdorferi) associated with Lyme disease was detected in questing ticks and rodents during a period of 18 years, 1991-2009, at five locations on the Outer Banks of North Carolina. The black-legged tick (Ixodes scapularis) was collected at varied intervals between 1991 and 2009 and examined for B. burgdorferi. The white-footed mouse (Peromyscus leucopus), house mouse (Mus musculus) marsh rice rat (Oryzomys palustris), marsh rabbit (Sylvilagus palustris), eastern cottontail (Sylvilagus floridanus) and six-lined racerunner (Cnemidophorus sexlineatus) were live-trapped, and their tissues cultured to isolate spirochaetes. Borrelia burgdorferi isolates were obtained from questing adult I. scapularis and engorged I. scapularis removed from P. leucopus, O. palustris and S. floridanus. The prevalence of B. burgdorferi infection was variable at different times and sites ranging from 7 to 14% of examined questing I. scapularis. Mitochondrial (16S) rRNA gene phylogenetic analysis from 65 adult I. scapularis identified 12 haplotypes in two major clades. Nine haplotypes were associated with northern/Midwestern I. scapularis populations and three with southern I. scapularis populations. Sixteen isolates obtained from tick hosts in 2005 were confirmed to be B. burgdorferi by amplifying and sequencing of 16S rRNA and 5S-23S intergenic spacer fragments. The sequences had 98-99% identity to B. burgdorferi sensu stricto strains B31, JD1 and M11p. Taken together, these studies indicate that B. burgdorferi sensu stricto is endemic in questing I. scapularis and mammalian tick hosts on the Outer Banks of North Carolina. © 2016 Blackwell Verlag GmbH.

Eventos externos e internos da infecção de larvas e ninfas de Rhipicephalus sanguineus por Metarhizium anisopliae External and internal events of Rhipicephalus sanguineus larvae and nymphs infection by Metarhizium anisopliae

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M.V. Garcia

2008-08-01

Full Text Available Examinaram-se a adesão, a germinação, a penetração e a colonização de larvas e ninfas de Rhipicephalus sanguineus por Metarhizium anisopliae, assim como as lesões infringidas pelo fungo nas respectivas fases do ciclo de vida do ácaro. Realizaram-se infecções experimentais em 11 grupos contendo 250 larvas e 11 grupos contendo 75 ninfas de R. sanguineus, por meio de banho, durante três minutos sob agitação manual, em suspensão contendo 10(8 conídios/ml do fungo. Nos grupos-controles, o banho foi realizado usando o veículo da suspensão. Larvas e ninfas foram processadas para um estudo histopatológico e de microscopia eletrônica de varredura nos seguintes tempos após a infecção: uma e 18 horas, e um, dois, três, quatro, cinco, seis, sete, nove e 11 dias. A germinação dos conídios ocorreu em até 18 horas pós-inoculação, e o fungo penetrou nas larvas e ninfas através do tegumento, dois e três dias após a infecção, respectivamente. Após penetração, o fungo invadiu o corpo das larvas e ninfas, promovendo uma colonização difusa, sem preferência aparente por tecidos específicos. Lesões significativas não foram observadas. A morte das larvas e ninfas ocorreu no terceiro e quarto dias pós-infecção, e a esporulação do patógeno sobre o cadáver foi iniciada no sexto dia pós-infecção.The adhesion, germination and colonization of Rhipicephalus sanguineus larvae and nymphs by Metarhizium anisopliae as well as the lesions caused by the fungus were studied. For this purpose, 11 groups of 250 larvae each and 11 groups of 75 nymphs each were bathed during 3 minutes under manual shaking in a 10(8 conidia/ml suspension. Corresponding control groups were bathed only in the suspension vehicle. Ticks were also submitted to both conventional microscopy and scanning eletronmicrocopy analyses at several post-infection periods (1 and 18 hours and 1, 2, 3, 4, 5, 6, 7, 9, and 11 days. Conidial germination occurred in less

Effects of Japanese barberry (Ranunculales: Berberidaceae) removal and resulting microclimatic changes on Ixodes scapularis (Acari: Ixodidae) abundances in Connecticut, USA.

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Williams, Scott C; Ward, Jeffrey S

2010-12-01

Japanese barberry (Berberis thunbergii de Candolle) is a thorny, perennial, exotic, invasive shrub that is well established throughout much of the eastern United States. It can form dense thickets that limit native herbaceous and woody regeneration, alter soil structure and function, and harbor increased blacklegged tick (Ixodes scapularis Say) populations. This study examined a potential causal mechanism for the link between Japanese barberry and blacklegged ticks to determine if eliminating Japanese barberry could reduce tick abundance and associated prevalence of Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner). Japanese barberry was controlled at five study areas throughout Connecticut; adult ticks were sampled over three years. Each area had three habitat plots: areas where barberry was controlled, areas where barberry remained intact, and areas where barberry was minimal or absent. Sampled ticks were retained and tested for B. burgdorferi presence. At two study areas, temperature and relative humidity data loggers were deployed in each of the three habitat plots over two growing seasons. Intact barberry stands had 280 ± 51 B. burgdorferi-infected adult ticks/ha, which was significantly higher than for controlled (121 ± 17/ha) and no barberry (30 ± 10/ha) areas. Microclimatic conditions where Japanese barberry was controlled were similar to areas without barberry. Japanese barberry infestations are favorable habitat for ticks, as they provide a buffered microclimate that limits desiccation-induced tick mortality. Control of Japanese barberry reduced the number of ticks infected with B. burgdorferi by nearly 60% by reverting microclimatic conditions to those more typical of native northeastern forests. © 2010 Entomological Society of America

Controle químico de ovos e ninfas de Bemisia tabaci biótipo B (Hemiptera: aleyrodidae Chemical control of Bemisia tabaci B biotype (Hemiptera: aleyrodidae eggs and nymphs

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Giuliana Etore do Valle

2002-06-01

Full Text Available Moscas brancas são pragas de diversas culturas, causam redução na produção e na qualidade do produto. Inseticidas, com diferentes modos de ação vêm sendo utilizados, sem muito sucesso. Neste trabalho avaliou-se a eficiência de inseticidas sobre ovos de diferentes idades (1, 3 e 5 dias e de ninfas de 1° ínstar da mosca branca Bemisia tabaci biótipo B. Os experimentos foram realizados em condições de laboratório, sob temperatura de 25 ± 2°C e fotofase de 12 horas. Piriproxifem (75 mg L-1 atuou como excelente ovicida, sendo altamente eficiente, 3 dias de idade. Cartape (500 mg L-1 não teve efeito satisfatório, mas a 1000 mg L-1 foi eficiente em ovos com até 5 dias de idade. Quanto à ação sobre ninfas de 1° ínstar, para pulverizações na face superior das folhas, piriproxifem, a 75 mg L-1, apresentou eficiência na supressão da emergência de adultos, caracterizando presença de ação translaminar; buprofezim, cartape, acefato e fempiroximate não apresentaram eficiência no controle de ninfas. Quando aplicado na face inferior das folhas, buprofezim (375 mg L-1 apresentou eficiência comparável à de piriproxifem, impedindo a emergência de adultos.Whiteflies are pests of many crops, cause severe yield losses and reduce crop quality. Insecticides of different modes of action have been used without success. In this work, the efficiency of five insecticides on Bemisia tabaci B biotype (= B. argentifolii eggs and nymphs was evaluated under laboratory conditions (T = 25 ± 2°C; 12 h photophase. In relation to the ovicidal effect, pyriproxyfen (75 mg L-1 caused egg hatching inhibition up to three day old eggs. Cartap showed efficiency only at the concentration of 1000 mg L-1, supressing the viability of eggs up to five days. Soybean leaves with first instar nymphs were treated in the upper surface with pyriproxyfen (75 mg L-1, buprofezin (375 mg L-1, cartap (1000 mg L-1, acephate (750 mg L-1 and fenpyroximate (100 mg L-1; in

Life table analysis of the performance of aphid Sitobion avenae (Homoptera: Aphididae nymphs exposed to a static magnetic field

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He Juan

2013-01-01

Full Text Available Using the age-stage two-sex life table, this work was undertaken in order to determine the effect of static magnetic fields (SMFs at two flux densities (0.176T and 0.065T applied at increasing times of duration (0.25, 0.5, 1 and 2 h on the development, fecundity and reproduction of the aphid, Sitobion avenae. Exposed nymphs had a statistically significant shortened first instar period and adult longevity and prolonged fourth instar periods compared to controls. There were significant differences in the population parameters for two exposure combinations, 0.176T for 0.5 h and 0.065T for 1 h. The intrinsic rate of increase (r, net reproductive rate (R0 and mean generation time (T were 0.1165, 3.5 and 11.7 days, respectively, 0.176 T for 0.5 h and -0.0198, 0.7 and 11.8 days, respectively, 0.065T for 1 h. We therefore recommend using the age-stage, two-sex life table to study the effect of the static magnetic field on development and growth of the aphid, Sitobion avenae.

Identification of a sex pheromone of the chrysanthemum lace bug Corythucha marmorata (Hemiptera: Tingidae)

OpenAIRE

Watanabe, Kisaki; Shimizu, Nobuhiro

2017-01-01

Although the nymphs of Corythucha marmorata form clusters on the undersides of host plant leaves, as frequently observed for Hemiptera, the adults are scattered in the vicinity of the nymph population. By investigating the biological activities of volatile secretions from the adult, we found that the secretions activated male mounting behaviour. A chemical analysis revealed that borneol was a common component of the secretions from both sexes. The absolute configuration of the natural product...

La ondina digital: Apariciones posmodernas de la ninfa acuática en el imaginario del algoritmo digital = Digital Undine: Postmodern Appearances of the Water Nymph in the Digital Algorithm Imaginarium

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Jaime Repollés Llauradó

2014-12-01

Full Text Available Los artistas digitales recurren a los algoritmos para generar sistemas lineales y vectoriales que se conforman como paisajes y figuras que frecuentemente evocan imaginarios acuáticos. En estos escenarios virtuales se multiplican y reverberan los atributos de las ninfas clásicas. Tanto el cibernauta posmoderno como el espectador del cine de animación pueden contemplar estas aguas digitales con la misma mirada evocadora que permitió a los poetas clásicos advertir la emergencia de las nereidas de las fuentes míticas. Aquella ninfomanía que agitó el imaginario artístico fin de siècle revive cuando advertimos ondinas posmodernas surgidas de curvas algorítmicas, emanando del mismo manantial mítico que el imaginario de la ninfa moderna, desde los objetos art nouveau hasta el cine de la era digital. AbstractDigital artists use algorithms to generate linear and vector systems which take the shape of landscapes and human figures and often evoke water imaginaria. Inside this virtual setting the attributes of classic Nymphs resonate and multiply. Both the Postmodern Internet user and the audience of animation cinema can contemplate these digital waters with the same evocative gaze that allowed classic poets to notice the emergence of Nereids from the mythical springs. The same “nymphomania” that stirred the fin de siècle artistic imaginarium revives when we notice the presence of Postmodern Undines, emerged from algorithm curves, emanating from the same mythical spring as the imaginarium of the Modern Nymph, from the Art Nouveau objects to the digital age cinema.

NCBI nr-aa BLAST: CBRC-MDOM-02-0026 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-MDOM-02-0026 ref|XP_002416287.1| glycine rich secreted cement protein, putativ...e [Ixodes scapularis] gb|EEC19954.1| glycine rich secreted cement protein, putative [Ixodes scapularis] XP_002416287.1 5e-51 48% ...

NCBI nr-aa BLAST: CBRC-PVAM-01-1566 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-PVAM-01-1566 ref|XP_002416287.1| glycine rich secreted cement protein, putativ...e [Ixodes scapularis] gb|EEC19954.1| glycine rich secreted cement protein, putative [Ixodes scapularis] XP_002416287.1 4e-13 42% ...

NCBI nr-aa BLAST: CBRC-GGOR-01-1493 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-GGOR-01-1493 ref|XP_002416287.1| glycine rich secreted cement protein, putativ...e [Ixodes scapularis] gb|EEC19954.1| glycine rich secreted cement protein, putative [Ixodes scapularis] XP_002416287.1 7e-28 46% ...

Control of San Jose Scale Nymphs, Diaspidiotus perniciosus (Comstock, on Almond and Apple Orchards with Pyriproxyfen, Phenoxycarb, Chlorpyrifos, and Mineral Oil Control de Ninfas de la Escama de San José, Diaspidiotus perniciosus (Comstock, en Almendros y Manzanos con Piriproxifen, Fenoxicarb, Clorpirifos y Aceite Mineral

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Luis Sazo

2008-09-01

Full Text Available The effect of pyriproxyfen, phenoxycarb, chlorpyrifos, and mineral oil in the control of first generation nymphs of the San Jose scale (SJC, Diaspidiotus perniciosus (Comstock, in almond, Prunusdulcis (Mill. D.A. Webb, and apple, Malusdomestica Borkh. orchards was studied in the 2001-2002 season in central Chile. One and two sprays of pyriproxyfen 0.07% and phenoxycarb 0.05% were applied, the first at the beginning of the appearance of nymphs in early spring (biofix, and the other 15 days later, and were compared with one spray of chlorpyrifos 0.08% applied at the biofix. Also, one and two sprays of mineral oil 1% were evaluated, the first applied 7 days after the biofix, and the second 15 days after the first spray. Evaluations were done in the laboratory at the end of the dispersion of first generation nymphs, on December 27 and 28 for almonds and apples, respectively, counting the number of nymphs fixed per lineal meter of new twigs collected at infested sectors, percentage of infested apples, and the number of scales fixed per fruit. Results were subjected to ANOVA and Duncan multiple range tests. At low level infestation, one application of pyriproxyfen 0.07%, phenoxycarb 0.05%, or mineral oil 1% in spring reduced significantly (P≤0.05 the number of nymphs fixed per twig, at a level similar to that of a traditional treatment of chlorpyrifos 0.08%. However, at greater infestations, one spray of pyriproxyfen or mineral oil in spring was insufficient to control ESJ.En la temporada 2001-2002 se estudió el efecto de piriproxifen, fenoxicarb, clorpyrifos y aceite mineral en el control de las ninfas de la primera generación de la Escama de San José (ESJ, Diaspidiotus perniciosus (Comstock, en almendros, Prunusdulcis (Mill. D.A. Webb, y manzanos, Malusdomestica Borkh., en Chile central. Se hicieron una y dos aplicaciones de piriproxifen 0,07% y fenoxicarb 0,05%, la primera en el inicio del nacimiento de ninfas de primavera (biofix y la segunda

Redescription and resurrection from synonymy, of Aedes (Ochlerotatus Rhyacophilus Costa Lima, 1933 Redescrição e revalidação de Aedes (Ochlerotatus rhyacophilus Costa Lima, 1933

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Maria Anice Mureb Sallum

1988-03-01

Full Text Available Aedes (Ochlerotatu rhyacophilus Costa Lima i resurrected from the synonymy with Aedes (Ochlerotatus scapularis (Rondani. Lectotype and paralectotypes are designated Larval, pupal and both sexes of adult stages are redescribed and illustrated. Bionomics include a picture of a brreding place. Diagnostic characters for distinguishing rhyacophilus from other species of the Scapularis Group are provided. Some data about known distribution are presented.Aedes (Ochlerotatus rhyacophilus Costa Lima é retida da sinonímia con Aedes (Ochlerotatus scapularis (Rondani. São designados lectótipo e paralectótipos. As formas larval, pupal e adulta de ambos os sexos são redescritas e acompanhadas de ilustrações representativas desses estádios, além do aspecto de um criadouro natural. Apresentam-se caracteres diagnósticos que permitem separar rhyacophilus das outras espécies do Grupo Scapularis, e alguns dados sobre a distribuição geográfica até agora conhecida.

O virus do mixoma no coelho do mato (Sylvilagus minenses, sua transmissão pelos Aedes scapularis e aegypti

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Henrique Beaurepaire Aragão

1943-01-01

Full Text Available The brazilian wild rabbit (Sylvilagus minensis is sensible to the virus of the mixomatosis but the desease takes on it a mild character, lasts for long time and generally do not kill the animal. The tumors are generally smaller and less numerous than those of the domestic rabbit, but sometimes there were noted large and flat lesions (fig. 3. The natural infection of the wild rabbit may be quite common not only because many rabbits caught in the country were found to be immune as also because it was found among the animals caught in the country near Rio, one that was infected with mixomatosis. The experimental infection of the Sylvilagus may be easily obtained by cutan, subcutan or conjuntival way and also when a health wild rabbit is placed in the same cage with a sick domestic animal. It is also possible to obtain the infection of the wild and domestic rabbits by the bite of infected blood sucking insects as fleas and mosquitoes. The infected mosquito can transmit the disease 2 or 3 times til 17 days after an infective meal on a sick rabbit. The transmission is a mecanical one and only the proboscis of the insect contains the virus as it was shown by the inoculation of emulsions of the proboscis, thorax and abdomen of the mosquito. Though mecanical this kind of transmission acts as an important epidemiological mean of dissemination of the deseasse and splains the suddendly outbreaks of mixomatosis in rabbits breedings where no new rabbits were introduced since very long time. The transmition of mixomatosis by fleas (Slenopsylla was at first demonstrated by us, then S. Torres pointed out the capacity of Culex fatigans to transmit the desease and now we have proved that Aedes scapularis and Aedes aegypti were also able to transmit it (Foto 1 and 2. The virus of the mixomatosis (Chlamidozoon mixoma is seen on the smeavs of the tumors of the wild reabbit with the same morphology, as in the material of the domestic animal.

Ultrastructure of Wax-Producing Structures on the Integument of the Melaleuca Psyllid Boreioglycaspis melaleucae (Hemiptera: Psyllidae), with Honeydew Excretion Behavior in Males and Females

Science.gov (United States)

Ammar, El-Desouky; Hentz, Matthew; Hall, David G.; Shatters, Robert G.

2015-01-01

The melaleuca psyllid, Boreioglycaspis melaleucae (Hemiptera: Psyllidae), was introduced to Florida as a biological control agent against Melaleuca quinquenervia, an invasive evergreen tree that has invaded large areas of Florida Everglades. Colonies of B. melaleucae nymphs are normally covered by white waxy secretions, and nymphs of various instars produce long bundles of white waxy filaments extending laterally and posteriorly from their abdomen. Scanning electron microscopy of ‘naturally waxed’ and ‘dewaxed’ nymphs (cleaned from wax) revealed two types of wax pore plates located dorsally and laterally on the integument of posterior abdominal segments starting with the 4th segment. Type-1 wax pore plates, with raised rim, peripheral groove, slits and pits, produce long ribbons and filaments of waxy secretions that are wound together forming long wax bundles, whereas type-2 wax pore plates, with slits only, produce shorter wax curls. Additionally, in both nymphs and adult females, the circumanal ring contained ornate rows of wax pores that produce wax filaments covering their honeydew excretions. Video recordings with stereomicroscopy showed that adult females produce whitish honeydew balls, powerfully propelled away from their body, probably to get these sticky excretions away from their eggs and newly hatched nymphs. Adult males, however, produce clear droplets of honeydew immediately behind them, simply by bending the posterior end of the abdomen downward. The possible role(s) of waxy secretions by nymphs and adults of B. melaleucae in reducing contamination of their colonies with honeydew, among other possibilities, are discussed. PMID:25793934

Survey of ticks (Acari: Ixodidae) and tick-borne pathogens in North Dakota.

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Russart, Nathan M; Dougherty, Michael W; Vaughan, Jefferson A

2014-09-01

Ticks were sampled at nine locations throughout North Dakota during early summer of 2010, using flagging techniques and small mammals trapping. In total, 1,762 ticks were collected from eight of the nine locations. The dominant species were Dermacentor variabilis (Say) (82%), found throughout the state, and Ixodes scapularis Say (17%), found in northeastern counties. A few nymphal and adult I. scapularis tested positive for Borrelia burgdorferi (3%) and Anaplasma phagocytophilum (8%). This is the first report of I. scapularis and associated pathogens occurring in North Dakota and provides evidence for continued westward expansion of this important vector tick species in the United States.

Ticks and tick-borne pathogens and putative symbionts of black bears (Ursus americanus floridanus) from Georgia and Florida.

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Yabsley, Michael J; Nims, Todd N; Savage, Mason Y; Durden, Lance A

2009-10-01

Ticks were collected from 38 black bears (Ursus americanus floridanus) from northwestern Florida (n = 18) from 2003 to 2005 and southern Georgia (n = 20) in 2006. Five species (Amblyomma americanum, A. maculatum, Dermacentor variabilis, Ixodes scapularis, and I. affinis) were collected from Florida bears, and 4 species (A. americanum, A. maculatum, D. variabilis, I. scapularis) were collected from bears in Georgia. Ixodes scapularis was the most frequently collected tick, followed by D. variabilis, A. americanum, A. maculatum, and I. affinis. The collection of I. affinis from a Florida bear represents a new host record. A subset of ticks was screened for pathogens and putative symbionts by polymerase chain reaction (PCR). The zoonotic tick-borne pathogens Ehrlichia chaffeensis and Rickettsia parkeri were detected in 1 of 23 (4.3%) A. americanum and 1 of 12 (8.3%) A. maculatum, respectively. The putative zoonotic pathogen "Rickettsia amblyommii" was detected in 4 (17.4%) A. americanum and 1 (8.3%) A. maculatum. Other putative symbiotic rickettsiae detected included R. bellii and R. montanensis in D. variabilis, a Rickettsia cooleyi-like sp. and Rickettsia sp. Is-1 in I. scapularis, and Rickettsia TR39-like sp. in I. scapularis and A. americanum. All ticks were PCR-negative for Anaplasma phagocytophilum, Panola Mountain Ehrlichia sp., E. ewingii, Francisella tularensis, and Borrelia spp.

Datura metel-synthesized silver nanoparticles magnify predation of dragonfly nymphs against the malaria vector Anopheles stephensi.

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Murugan, Kadarkarai; Dinesh, Devakumar; Kumar, Prabhu Jenil; Panneerselvam, Chellasamy; Subramaniam, Jayapal; Madhiyazhagan, Pari; Suresh, Udaiyan; Nicoletti, Marcello; Alarfaj, Abdullah A; Munusamy, Murugan A; Higuchi, Akon; Mehlhorn, Heinz; Benelli, Giovanni

2015-12-01

Malaria is a life-threatening disease caused by parasites transmitted to people and animals through the bites of infected mosquitoes. The employ of synthetic insecticides to control Anopheles populations leads to high operational costs, non-target effects, and induced resistance. Recently, plant-borne compounds have been proposed for efficient and rapid extracellular synthesis of mosquitocidal nanoparticles. However, their impact against predators of mosquito larvae has been poorly studied. In this study, we synthesized silver nanoparticles (AgNPs) using the Datura metel leaf extract as reducing and stabilizing agent. The biosynthesis of AgNPs was confirmed analyzing the excitation of surface plasmon resonance using ultraviolet-visible (UV-vis) spectroscopy. Scanning electron microscopy (SEM) showed the clustered and irregular shapes of AgNPs, with a mean size of 40-60 nm. The presence of silver was determined by energy-dispersive X-ray (EDX) spectroscopy. Fourier transform infrared (FTIR) spectroscopy analysis investigated the identity of secondary metabolites, which may be acting as AgNP capping agents. In laboratory, LC50 of D. metel extract against Anopheles stephensi ranged from 34.693 ppm (I instar larvae) to 81.500 ppm (pupae). LC50 of AgNP ranged from 2.969 ppm (I instar larvae) to 6.755 ppm (pupae). Under standard laboratory conditions, the predation efficiency of Anax immaculifrons nymphs after 24 h was 75.5 % (II instar larvae) and 53.5 % (III instar larvae). In AgNP-contaminated environment, predation rates were boosted to 95.5 and 78 %, respectively. Our results documented that D. metel-synthesized AgNP might be employed at rather low doses to reduce larval populations of malaria vectors, without detrimental effects on behavioral traits of young instars of the dragonfly Anax immaculifrons.

Dissecting the variance-covariance structure in insect physiology: the multivariate association between metabolism and morphology in the nymphs of the sand cricket (Gryllus firmus).

Science.gov (United States)

Nespolo, Roberto F; Castañeda, Luis E; Roff, Derek A

2005-08-01

Energy metabolism in animals has been largely studied in relation to exogenous sources of variation. However, because they give insight into the relationship between whole metabolism and lower organizational levels such as organs and tissues, examination of endogenous determinants of metabolism other than body mass is itself very important. We studied the multivariate association of body parts and several aspects of energy metabolism in an insect, the nymphs of the sand cricket, Gryllus firmus. By using a variety of both univariate and multivariate techniques, we explored the resultant variance-covariance matrix to build a path diagram with latent variables. After controlling for body mass, we found a significant canonical correlation between metabolism and morphology. According to the factor loadings and path coefficients, the most important contributions of morphology to the correlation were thorax and abdomen size measures, whereas the most important metabolic contribution was resting metabolism. Activity metabolism was mostly explained by body mass rather than body parts, which could be a result of resting rates being chronic consequences of the functioning of the metabolic machinery that the insect must maintain.

Remodeling of tick cytoskeleton in response to infection with Anaplasma phagocytophilum.

Science.gov (United States)

Cabezas-Cruz, Alejandro; Alberdi, Pilar; Valdes, James J; Villar, Margarita; de la Fuente, Jose

2017-06-01

The obligate intracellular pathogen Anaplasma phagocytophilum infects vertebrate and tick hosts. In this study, a genome-wide search for cytoskeleton components was performed in the tick vector, Ixodes scapularis . The available transcriptomics and proteomics data was then used to characterize the mRNA and protein levels of I. scapularis cytoskeleton components in response to A. phagocytophilum infection. The results showed that cytoskeleton components described in other model organisms were present in the I. scapularis genome. One type of intermediate filaments (lamin), a family of septins that was recently implicated in the cellular response to intracellular pathogens, and several members of motor proteins (kinesins and dyneins) that could be implicated in the cytoplasmic movements of A. phagocytophilum were found. The results showed that levels of tubulin, actin, septin, actin-related proteins and motor proteins were affected by A. phagocytophilum , probably to facilitate infection in I. scapularis . Functional studies demonstrated a role for selected cytoskeleton components in pathogen infection. These results provided a more comprehensive view of the cytoskeletal components involved in the response to A. phagocytophilum infection in ticks.

Prevalence of Linguatula serrata nymphs and pathological lesions of infected mesenteric lymph nodes among ruminants in Kermanshah, western Iran

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M. Hashemnia

2018-03-01

Full Text Available Linguatulosis is one of the important zoonotic diseases that cause public health problems worldwide. This study was carried out from March 2014 to February 2015 to estimate the prevalence of nymphal stages of Linguatula serrata in ruminants of different sex and age slaughtered at the Kermanshah municipal abattoir, in western Iran. For this purpose, the mesenteric lymph nodes (MLNs were ex-amined grossly and three MLNs for each animal were collected for parasitological and pathological studies. Of the total of 456 sheep (252 ♂ and 204 ♀, 390 goats (215 ♂ and 175 ♀ and 412 cattle (255 ♂ and 157 ♀, 90 (19.7%, 98 (25.1% and 53 (12.8% were infected with nymph stages of L. serrata, respectively. A significant difference in the prevalence of linguatulosis was observed among studied animals (P0.05. The prevalence increased with age (P<0.05. Grossly, the infected MLNs were enlarged, and their cross-sectional areas were coarse, firm, granulated, oedematous, and red in colour. Necrosis, oedema, haemorrhages, depletion of the lymphocytes and granulomatous reactions which are charac-terised by infiltration of mononuclear inflammatory cell around the parasite were the main histopa-thological lesions. These results indicated the high prevalence of L. serrata infection in livestock animals in Kermanshah. Furthermore, this study provides a preliminary baseline data for the future monitoring of this potentially important parasitic disease. The potential importance of these findings to human health is discussed.

An Ixodes ricinus Tick Salivary Lectin Pathway Inhibitor Protects Borrelia burgdorferi sensu lato from Human Complement.

Science.gov (United States)

Wagemakers, Alex; Coumou, Jeroen; Schuijt, Tim J; Oei, Anneke; Nijhof, Ard M; van 't Veer, Cornelis; van der Poll, Tom; Bins, Adriaan D; Hovius, Joppe W R

2016-04-01

We previously identified tick salivary lectin pathway inhibitor (TSLPI) in Ixodes scapularis, a vector for Borrelia burgdorferi sensu stricto (s.s.) in North America. TSLPI is a salivary protein facilitating B. burgdorferi s.s. transmission and acquisition by inhibiting the host lectin complement pathway through interference with mannose binding lectin (MBL) activity. Since Ixodes ricinus is the predominant vector for Lyme borreliosis in Europe and transmits several complement sensitive B. burgdorferi sensu lato (s.l.) strains, we aimed to identify, describe, and characterize the I. ricinus ortholog of TSLPI. We performed (q)PCRs on I. ricinus salivary gland cDNA to identify a TSLPI ortholog. Next, we generated recombinant (r)TSLPI in a Drosophila expression system and examined inhibition of the MBL complement pathway and complement-mediated killing of B. burgdorferi s.l. in vitro. We identified a TSLPI ortholog in I. ricinus salivary glands with 93% homology at the RNA and 89% at the protein level compared to I. scapularis TSLPI, which was upregulated during tick feeding. In silico analysis revealed that TSLPI appears to be part of a larger family of Ixodes salivary proteins among which I. persulcatus basic tail salivary proteins and I. scapularis TSLPI and Salp14. I. ricinus rTSLPI inhibited the MBL complement pathway and protected B. burgdorferi s.s. and Borrelia garinii from complement-mediated killing. We have identified a TSLPI ortholog, which protects B. burgdorferi s.l. from complement-mediated killing in I. ricinus, the major vector for tick-borne diseases in Europe.

Temporal and Directional Patterns of Nymphal Halyomorpha halys (Hemiptera: Pentatomidae) Movement on the Trunk of Selected Wild and Fruit Tree Hosts in the Mid-Atlantic Region.

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Acebes-Doria, Angelita L; Leskey, Tracy C; Bergh, J Christopher

2017-04-01

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) is an invasive and polyphagous herbivore that has been problematic in Mid-Atlantic fruit orchards, many of which are adjacent to woodlands containing its wild hosts. Our tree census in woodlands bordering 15 Mid-Atlantic apple orchards revealed 47 species of deciduous trees and shrubs, 76.6% of which were recorded hosts of H. halys. Tree of heaven was most common and abundant overall. Halyomorpha halys nymphs have a substantial walking dispersal capacity, and their fitness is enhanced by feeding on multiple hosts. Directional and temporal patterns of nymphal H. halys movement on selected wild hosts and apple and peach trees at the orchard-woodland interface were monitored in 2014 and 2015 using passive traps to capture nymphs walking up and down tree trunks. Weekly captures from mid-May to late September or mid-October were compared among hosts across both seasons. Despite higher total nymphal captures in 2014 than 2015, the seasonal trends for both years were similar and indicated bivoltine H. halys populations. In both years, more nymphs were intercepted while walking up than down and captures of upward- and downward-walking nymphs varied significantly among the hosts. All instars were captured, but captures of second instars predominated. Captures reflected seasonal changes in instar distribution and consisted predominantly of younger and older nymphs, early and later in the season, respectively. Results are discussed in relation to host and seasonal effects on the movement of nymphs at the orchard-woodland interface, and the implications for H. halys management. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

High Prevalence of Porocephalus crotali Infection on a Barrier Island (Cumberland Island) off the Coast of Georgia, with Identification of Novel Intermediate Hosts.

Science.gov (United States)

Yabsley, Michael J; Ellis, Angela E; Cleveland, Christopher A; Ruckdeschel, Carol

2015-10-01

Porocephalus crotali is a pentastomid parasite that uses crotaline snakes as definitive hosts and a variety of rodents as intermediate hosts. A study of definitive and intermediate pentastome hosts on Cumberland Island, Georgia, revealed high prevalence of P. crotali infection in crotalid snakes as well as several mammalian species. Despite the presence of numerous nymphs in some animals, clinical signs of disease were not observed. In intermediate hosts, the liver, mesentery, and reproductive organs were most commonly infected. No gross evidence of tissue damage was noted in association with the numerous encysted nymphal pentastomes, and histopathology demonstrated minimal reaction to the encysted nymphs. Partial 18S rRNA gene sequences confirmed the parasites were P. crotali. In contrast to many previous reports in rodents, the prevalence on this barrier island was high, and this is the first report of Virginia opossums (Didelphis virginiana) and any insectivore species as intermediate hosts. Although generally not considered pathogenic, the long-term consequences of high nymph intensities on individuals deserve attention.

A salivary EF-hand calcium-binding protein of the brown planthopper Nilaparvata lugens functions as an effector for defense responses in rice

Science.gov (United States)

Ye, Wenfeng; Yu, Haixin; Jian, Yukun; Zeng, Jiamei; Ji, Rui; Chen, Hongdan; Lou, Yonggen

2017-01-01

The brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), a major pest of rice in Asia, is able to successfully puncture sieve tubes in rice with its piercing stylet and then to ingest phloem sap. How BPH manages to continuously feed on rice remains unclear. Here, we cloned the gene NlSEF1, which is highly expressed in the salivary glands of BPH. The NlSEF1 protein has EF-hand Ca2+-binding activity and can be secreted into rice plants when BPH feed. Infestation of rice by BPH nymphs whose NlSEF1 was knocked down elicited higher levels of Ca2+ and H2O2 but not jasmonic acid, jasmonoyl-isoleucine (JA-Ile) and SA in rice than did infestation by control nymphs; Consistently, wounding plus the recombination protein NlSEF1 suppressed the production of H2O2 in rice. Bioassays revealed that NlSEF1-knockdown BPH nymphs had a higher mortality rate and lower feeding capacity on rice than control nymphs. These results indicate that the salivary protein in BPH, NlSEF1, functions as an effector and plays important roles in interactions between BPH and rice by mediating the plant’s defense responses. PMID:28098179

Localization and dynamics of Wolbachia infection in Asian citrus psyllid Diaphorina citri, the insect vector of the causal pathogens of Huanglongbing.

Science.gov (United States)

Ren, Su-Li; Li, Yi-Han; Ou, Da; Guo, Yan-Jun; Qureshi, Jawwad A; Stansly, Philip A; Qiu, Bao-Li

2018-03-23

Wolbachia is a group of intracellular bacteria that infect a wide range of arthropods including the Asian citrus psyllid (ACP), Diaphorina citri Kuwayama. This insect is the vector of Candidatus Liberibacter asiaticus (CLas), the causal pathogen of Huanglongbing or citrus greening disease. Here, we investigated the localization pattern and infection dynamics of Wolbachia in different developmental stages of ACP. Results revealed that all developmental stages of ACP including egg, 1st-5th instar nymphs, and adults of both gender were infected with Wolbachia. FISH visualization of an ACP egg showed that Wolbachia moved from the egg stalk of newly laid eggs to a randomly distributed pattern throughout the egg prior to hatching. The infection rate varied between nymphal instars. The titers of Wolbachia in fourth and fifth instar nymphs were significantly higher than those in the first and second instar nymphs. Wolbachia were scattered in all nymphal stages, but with highest intensity in the U-shaped bacteriome located in the abdomen of the nymph. Wolbachia was confined to two symmetrical organizations in the abdomen of newly emerged female and male adults. The potential mechanisms of Wolbachia infection dynamics are discussed. © 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Silencing abnormal wing disc gene of the Asian citrus psyllid, Diaphorina citri disrupts adult wing development and increases nymph mortality.

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Ibrahim El-Shesheny

Full Text Available Huanglongbing (HLB causes considerable economic losses to citrus industries worldwide. Its management depends on controlling of the Asian citrus Psyllid (ACP, the vector of the bacterium, Candidatus Liberibacter asiaticus (CLas, the causal agent of HLB. Silencing genes by RNA interference (RNAi is a promising tool to explore gene functions as well as control pests. In the current study, abnormal wing disc (awd gene associated with wing development in insects is used to interfere with the flight of psyllids. Our study showed that transcription of awd is development-dependent and the highest level was found in the last instar (5(th of the nymphal stage. Micro-application (topical application of dsRNA to 5(th instar of nymphs caused significant nymphal mortality and adult wing-malformation. These adverse effects in ACP were positively correlated with the amounts of dsRNA used. A qRT-PCR analysis confirmed the dsRNA-mediated transcriptional down-regulation of the awd gene. Significant down-regulation was required to induce a wing-malformed phenotype. No effect was found when dsRNA-gfp was used, indicating the specific effect of dsRNA-awd. Our findings suggest a role for awd in ACP wing development and metamorphosis. awd could serve as a potential target for insect management either via direct application of dsRNA or by producing transgenic plants expressing dsRNA-awd. These strategies will help to mitigate HLB by controlling ACP.

Optimal reproduction strategies in two species of mound-building termites.

Science.gov (United States)

Cameron, David A; Ivers, David J; Evans, Theodore A; Myerscough, Mary R

2008-01-01

We formulate a mathematical model for food collection and production of workers and nymphs in 2 species of mound building termites. We maximise the number of nymphs (reproductives) produced by each colony over its lifetime with respect to the proportion of eggs that hatch as nymphs as opposed to workers. The results predict that food storage has a very important influence on the pattern of nymph and worker production. Food storage affects the part of the year that nymph production dominates, whether nymphs and workers are produced at the same time or not, and the existence of a final phase in the colony's life when a very large number of nymphs but no workers are produced.

Detection of human bacterial pathogens in ticks collected from Louisiana black bears (Ursus americanus luteolus).

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Leydet, Brian F; Liang, Fang-Ting

2013-04-01

There are 4 major human-biting tick species in the northeastern United States, which include: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. The black bear is a large mammal that has been shown to be parasitized by all the aforementioned ticks. We investigated the bacterial infections in ticks collected from Louisiana black bears (Ursus americanus subspecies luteolus). Eighty-six ticks were collected from 17 black bears in Louisiana from June 2010 to March 2011. All 4 common human-biting tick species were represented. Each tick was subjected to polymerase chain reaction (PCR) targeting select bacterial pathogens and symbionts. Bacterial DNA was detected in 62% of ticks (n=53). Rickettsia parkeri, the causative agent of an emerging spotted fever group rickettsiosis, was identified in 66% of A. maculatum, 28% of D. variabilis, and 11% of I. scapularis. The Lyme disease bacterium, Borrelia burgdorferi, was detected in 2 I. scapularis, while one A. americanum was positive for Borrelia bissettii, a putative human pathogen. The rickettsial endosymbionts Candidatus Rickettsia andeanae, rickettsial endosymbiont of I. scapularis, and Rickettsia amblyommii were detected in their common tick hosts at 21%, 39%, and 60%, respectively. All ticks were PCR-negative for Anaplasma phagocytophilum, Ehrlichia spp., and Babesia microti. This is the first reported detection of R. parkeri in vector ticks in Louisiana; we also report the novel association of R. parkeri with I. scapularis. Detection of both R. parkeri and B. burgdorferi in their respective vectors in Louisiana demands further investigation to determine potential for human exposure to these pathogens. Copyright © 2013 Elsevier GmbH. All rights reserved.

Freqüência ao ambiente humano e dispersão de mosquitos Culicidae em área adjacente à mata atlântica primitiva da planície Frequency of occurrence in the human environment dispersal of Culicidae mosquitoes in an area adjacent to a primitive Atlantic plain forest

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Oswaldo Paulo Forattini

1990-04-01

Full Text Available Apresentam-se resultados obtidos com observações em área adjacente a ambiente primitivo representado pela mata atlântica da planície. Focalizam-se as espécies Aedes scapularis, Anopheles bellator, An. cruzii e Culex sacchettae. A dispersão foi estudada com a utilização de hospedeiro único e que assim permitiu o reconhecimento dos mosquitos pela identificação do sangue ingerido. A freqüência ao ambiente humano foi observada mediante a realização de coletas com aspiração e utilização de isca humana, no peridomicílio e na mata circunjacente. Ae. scapularis revelou acentuada capacidade de dispersão apetente, bem como permanência no ambiente domiciliar. Os anofelinos Kerteszia mostraram tendência ao abandono desse meio e capacidade de retorno pós-prandial ao ambiente florestal primitivo. O Cx. sacchettae, juntamente com as outras três espécies, revelou freqüência regular "a isca humana no peridomicílio. A estimativa do índice alimentar ("feeding index" para Ae. scapularis mostrou preferência por animais de grande porte, principalmente bovinos. Considera-se que no mecanismo de domiciliação, desses mosquitos, a presença de fontes sangüíneas, representada por número significante de animais domésticos de grande porte, constitui fator de atração para populações de mosquitos silvestres existentes na mata adjacente. Destes, aqueles que tendem a permanecer no ambiente humano, após a realização do repasto sanguíneo, assumem particular significado na transmissão de agentes infecciosos, destacando Ae. scapularis e Cx. sacchettae.Results of peridomiciliar and forest environment mosquito catches are presented. By using the method single host, mosquitoes were identified according to blood-meal and thus their dispersal was observed Evidence was obtained for movements of Aedes scapularis, due apparently were appetential flights, as well as its permanence in peridomiciliar resting places. Occurrence in domestic animal

Dihydronepetalactones deter feeding activity by mosquitoes, stable flies, and deer ticks.

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Feaster, John E; Scialdone, Mark A; Todd, Robin G; Gonzalez, Yamaira I; Foster, Joseph P; Hallahan, David L

2009-07-01

The essential oil of catmint, Nepeta cataria L., contains nepetalactones, that, on hydrogenation, yield the corresponding dihydronepetalactone (DHN) diastereomers. The DHN diastereomer (4R,4aR,7S,7aS)-4,7-dimethylhexahydrocyclopenta[c]pyran-1(3H)-one, DHN 1) was evaluated as mosquito repellent, as was the mixture of diastereomers {mostly (4S,4aR,7S,7aR)-4,7-dimethylhexahydrocyclopenta[c]pyran-1(3H)-one, DHN 2} present after hydrogenation of catmint oil itself. The repellency of these materials to Aedes aegypti L. and Anopheles albimanus Wiedemann mosquitoes was tested in vitro and found to be comparable to that obtained with the well-known insect repellent active ingredient N,N-diethyl-3-methylbenzamide (DEET). DHN 1 and DHN 2 also repelled the stable fly, Stomoxys calcitrans L., in this study. DHN 1, DHN 2, and p-menthane-3,8-diol (PMD), another natural monoterpenoid repellent, gave comparable levels of repellency against An. albimanus and S. calcitrans. Laboratory testing of DHN 1 and DHN 2 using human subjects with An. albimanus mosquitoes was carried out. Both DHN 1 and DHN 2 at 10% (wt:vol) conferred complete protection from bites for significant periods of time (3.5 and 5 h, respectively), with DHN2 conferring protection statistically equivalent to DEET. The DHN 1 and DHN 2 diastereomers were also efficaceous against black-legged tick (Ixodes scapularis Say) nymphs.

Structure-activity relationship studies on the mosquito toxicity and biting deterrency of callicarpenal derivatives.

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Cantrell, Charles L; Klun, Jerome A; Pridgeon, Julia; Becnel, James; Green, Solomon; Fronczek, Frank R

2009-04-01

Callicarpenal (=13,14,15,16-tetranorclerod-3-en-12-al=[(1S,2R,4aR,8aR)-1,2,3,4,4a,7,8,8a-octahydro-1,2,4a,5-tetramethylnaphthalen-1-yl]acetaldehyde; 1) has previously demonstrated significant mosquito bite-deterring activity against Aedes aegypti and Anopheles stephensi in addition to repellent activity against host-seeking nymphs of the blacklegged tick, Ixodes scapularis. In the present study, structural modifications were performed on callicarpenal (1) in an effort to understand the functional groups necessary for maintaining and/or increasing its activity and to possibly lead to more effective insect control agents. All modifications in this study targeted the C(12) aldehyde or the C(3) alkene functionalities or combinations thereof. Mosquito biting deterrency appeared to be influenced most by C(3) alkene modification as evidenced by catalytic hydrogenation that resulted in a compound having significantly less effectiveness than 1 at a test amount of 25 nmol/cm2. Oxidation and/or reduction of the C(12) aldehyde did not diminish mosquito biting deterrency, but, at the same time, none of the modifications were more effective than 1 in deterring mosquito biting. Toxicities of synthesized compounds towards Ae. aegypti ranged from an LD50 value of 2.36 to 40.11 microg per mosquito. Similarly, LD95 values ranged from a low of 5.59 to a high of 104.9 microg.

Use of novel compounds for pest control: insecticidal and acaricidal activity of essential oil components from heartwood of Alaska yellow cedar.

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Panella, Nicholas A; Dolan, Marc C; Karchesy, Joseph J; Xiong, Yeping; Peralta-Cruz, Javier; Khasawneh, Mohammad; Montenieri, John A; Maupin, Gary O

2005-05-01

Laboratory bioassays were conducted to determine the activity of 15 natural products isolated from essential oil components extracted from the heartwood of Alaska yellow cedar, Chamaecyparis nootkatensis (D. Don) Spach., against Ixodes scapularis Say nymphs, Xenopsylla cheopis (Rothchild), and Aedes aegypti (L.) adults. Four of the compounds from the essential oil have been identified as monoterpenes, five as eremophilane sesquiterpenes, five as eremophilane sesquiterpene derivatives from valencene and nootkatone, and one as a sesquiterpene outside the eremophilane parent group. Carvacrol was the only monoterpene that demonstrated biocidal activity against ticks, fleas, and mosquitoes with LC50 values after 24 h of 0.0068, 0.0059, and 0.0051% (wt:vol), respectively. Nootkatone from Alaska yellow cedar was the most effective of the eremophilane sesquiterpenes against ticks (LC50 = 0.0029%), whereas the nootkatone grapefruit extract exhibited the greatest biocidal activity against fleas (LC50 = 0.0029%). Mosquitoes were most susceptible to one of the derivatives of valencene, valencene-13-aldehyde (LC50 = 0.0024%), after 24 h. Bioassays to determine residual activity of the most effective products were conducted at 1, 2, 4, and 6 wk after initial treatment. Residual LC50 values for nootkatone did not differ significantly at 4 wk posttreatment from the observations made at the initial 24-h treatment. The ability of these natural products to kill arthropods at relatively low concentrations represents an alternative to the use of synthetic pesticides for control of disease vectors.

Transstadial Transmission of Hepatozoon canis by Rhipicephalus sanguineus (Acari: Ixodidae) in Field Conditions.

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Aktas, M; Özübek, S

2017-07-01

This study investigated possible transovarial and transstadial transmission of Hepatozoon canis by Rhipicephalus sanguineus (Latreille) ticks collected from naturally infected dogs in a municipal dog shelter and the grounds of the shelter. Four hundred sixty-five engorged nymphs were collected from 16 stray dogs that were found to be infected with H. canis by blood smear and PCR analyses and maintained in an incubator at 28 °C for moulting. Four hundred eighteen nymphs moulted to adults 14-16 d post collection. Unfed ticks from the shelter grounds comprised 1,500 larvae, 2,100 nymphs, and 85 adults; were sorted according to origin, developmental stage, and sex into 117 pools; and screened by 18S rRNA PCR for Hepatozoon infection. Of 60 adult tick pools examined, 51 were infected with H. canis. The overall maximum likelihood estimate (MLE) of infection rate was calculated as 21.0% (CI 15.80-28.21). Hepatozoon canis was detected in 31 out of 33 female pools (MLE 26.96%, CI 17.64-44.33) and 20 out of 27 male pools (MLE 14.82%, CI 20.15-46.41). Among 42 unfed nymph pools collected from the shelter, 26 were infected with H. canis, and MLE of infection was calculated as 1.9% (CI 1.25-2.77). No H. canis DNA was detected in any of the gDNA pools consisting of larva specimens. Partial sequences of the 18S rRNA gene shared 99-100% similarity with the corresponding H. canis isolates. Our results revealed the transstadial transmission of H. canis by R. sanguineus, both from larva to nymph and from nymph to adult, in field conditions. However, there were no evidence of transovarial transmission. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Maternal care, mother-offspring aggregation and age-dependent coadaptation in the European earwig.

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Gómez, Y; Kölliker, M

2013-09-01

Benefits and costs of parental care are expected to change with offspring development and lead to age-dependent coadaptation expressed as phenotypic (behavioural) matches between offspring age and parental reproductive stage. Parents and offspring interact repeatedly over time for the provision of parental care. Their behaviours should be accordingly adjusted to each other dynamically and adaptively, and the phenotypic match between offspring age and parental stage should stabilize the repeated behavioural interactions. In the European earwig (Forficula auricularia), maternal care is beneficial for offspring survival, but not vital, allowing us to investigate the extent to which the stability of mother-offspring aggregation is shaped by age-dependent coadaptation. In this study, we experimentally cross-fostered nymphs of different age classes (younger or older) between females in early or late reproductive stage to disrupt age-dependent coadaptation, thereby generating female-nymph dyads that were phenotypically matched or mismatched. The results revealed a higher stability in aggregation during the first larval instar when care is most intense, a steeper decline in aggregation tendency over developmental time and a reduced developmental rate in matched compared with mismatched families. Furthermore, nymph survival was positively correlated with female-nymph aggregation stability during the early stages when maternal care is most prevalent. These results support the hypothesis that age-related phenotypically plastic coadaptation affects family dynamics and offspring developmental rate. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

Silencing of Iron and Heme-Related Genes Revealed a Paramount Role of Iron in the Physiology of the Hematophagous Vector Rhodnius prolixus

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Ana B. Walter-Nuno

2018-02-01

Full Text Available Iron is an essential element for most organisms However, free iron and heme, its complex with protoporphyrin IX, can be extremely cytotoxic, due to the production of reactive oxygen species, eventually leading to oxidative stress. Thus, eukaryotic cells control iron availability by regulating its transport, storage and excretion as well as the biosynthesis and degradation of heme. In the genome of Rhodnius prolixus, the vector of Chagas disease, we identified 36 genes related to iron and heme metabolism We performed a comprehensive analysis of these genes, including identification of homologous genes described in other insect genomes. We observed that blood-meal modulates the expression of ferritin, Iron Responsive protein (IRP, Heme Oxygenase (HO and the heme exporter Feline Leukemia Virus C Receptor (FLVCR, components of major pathways involved in the regulation of iron and heme metabolism, particularly in the posterior midgut (PM, where an intense release of free heme occurs during the course of digestion. Knockdown of these genes impacted the survival of nymphs and adults, as well as molting, oogenesis and embryogenesis at different rates and time-courses. The silencing of FLVCR caused the highest levels of mortality in nymphs and adults and reduced nymph molting. The oogenesis was mildly affected by the diminished expression of all of the genes whereas embryogenesis was dramatically impaired by the knockdown of ferritin expression. Furthermore, an intense production of ROS in the midgut of blood-fed insects occurs when the expression of ferritin, but not HO, was inhibited. In this manner, the degradation of dietary heme inside the enterocytes may represent an oxidative challenge that is counteracted by ferritins, conferring to this protein a major antioxidant role. Taken together these results demonstrate that the regulation of iron and heme metabolism is of paramount importance for R. prolixus physiology and imbalances in the levels of

Seasonal Changes in the Caste Distribution of Foraging Populations of Formosan Subterranean Termite in New Orleans, Louisiana.

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Cornelius, Mary L; Osbrink, Weste L A; Gallatin, Erin M

2015-01-01

This study examined the relationship between temperature, precipitation, soil composition, levels of feeding damage, and the caste distribution (workers, soldiers, nymphs) of the Formosan subterranean termite, Coptotermes formosanus Shiraki, collected in underground monitoring stations over a 12 mo period. Because nymphs are the caste that develops into alates, the seasonal abundance of nymphs was examined over a 5 yr period. Numbers of workers, soldiers, and soldier/worker ratio were significantly affected by month. Recruitment and retention of foraging termites in stations was significantly affected by the level of feeding damage. The number of nymphs collected in monitoring stations was highly variable. In the 12 mo test, there was a significant correlation between numbers of nymphs and level of feeding damage, temperature, precipitation, and soil composition. Over a 5 yr period, significantly more nymphs were collected in 2011 than in 2007 and 2008. Peak nymph collections varied from year to year. Overall, peak nymph collections were more likely to occur in Mar., Sept., and Oct. Increasing our knowledge of the environmental factors that influence recruitment and retention of foraging termites in monitoring stations could influence termite bait placement and improve baiting strategies for termite control. Identifying the key factors that cause aggregations of nymphs in underground stations could increase our ability to predict the intensity and location of alate swarms. © Crown copyright 2015.

RNA-Seq and molecular docking reveal multi-level pesticide resistance in the bed bug

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Mamidala Praveen

2012-01-01

Full Text Available Abstract Background Bed bugs (Cimex lectularius are hematophagous nocturnal parasites of humans that have attained high impact status due to their worldwide resurgence. The sudden and rampant resurgence of C. lectularius has been attributed to numerous factors including frequent international travel, narrower pest management practices, and insecticide resistance. Results We performed a next-generation RNA sequencing (RNA-Seq experiment to find differentially expressed genes between pesticide-resistant (PR and pesticide-susceptible (PS strains of C. lectularius. A reference transcriptome database of 51,492 expressed sequence tags (ESTs was created by combining the databases derived from de novo assembled mRNA-Seq tags (30,404 ESTs and our previous 454 pyrosequenced database (21,088 ESTs. The two-way GLMseq analysis revealed ~15,000 highly significant differentially expressed ESTs between the PR and PS strains. Among the top 5,000 differentially expressed ESTs, 109 putative defense genes (cuticular proteins, cytochrome P450s, antioxidant genes, ABC transporters, glutathione S-transferases, carboxylesterases and acetyl cholinesterase involved in penetration resistance and metabolic resistance were identified. Tissue and development-specific expression of P450 CYP3 clan members showed high mRNA levels in the cuticle, Malpighian tubules, and midgut; and in early instar nymphs, respectively. Lastly, molecular modeling and docking of a candidate cytochrome P450 (CYP397A1V2 revealed the flexibility of the deduced protein to metabolize a broad range of insecticide substrates including DDT, deltamethrin, permethrin, and imidacloprid. Conclusions We developed significant molecular resources for C. lectularius putatively involved in metabolic resistance as well as those participating in other modes of insecticide resistance. RNA-Seq profiles of PR strains combined with tissue-specific profiles and molecular docking revealed multi-level insecticide

Economic injury level of the psyllid, Agonoscena pistaciae, on Pistachio, Pistacia vera cv. Ohadi.

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Reza Hassani, Mohammad; Nouri-Ganbalani, Gadir; Izadi, Hamzeh; Shojai, Mahmoud; Basirat, Mehdi

2009-01-01

The pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae) is a major pest of pistachio trees, Pistacia vera L. (Sapindalis: Anacardiaceae) throughout pistachio-producing regions in Iran. Different density levels of A. pistaciae nymphs were maintained on pistachio trees by different insecticide dosages to evaluate the relationship between nymph density and yield loss (weight of 1000 nuts). Psylla nymph densities were monitored weekly by counting nymphs on pistachio terminal leaflets. There was a significant reduction in weight of 1000 nuts as seasonal averages of nymphs increased. Regression analysis was used to determine the relationship between nymph density and weight of 1000 nuts. The economic injury levels varied as a function of market values, management costs, insecticide efficiency and yield loss rate and ranged from 7.7 to 30.7 nymphal days per terminal leaflet, based on weight of 1000 nuts.

Evaluating the Effect of Electron-Beam Irradiation on Linguatula serrata Destroy Isolated from Animal Products and Determining its Effective Dose

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S Khalatbari-limaki

2015-11-01

Full Text Available Abstract Introduction: Foodborne parasitic diseases are considered common in most parts of the world, which can cause significant health problems. Linguatula serrata is a zoonotic parasite causing human linguatulosis due to consumption of raw and semi-cooked animal offal infected with nymphs of this parasite. Therefore, the main objective of this study was to determine the effect of Electron beam irradiation on death of the Linguatula serrata nymphs isolated from animal products. Methods: Linguatula serrata nymphs were irradiated with E-beam irradiation of 1, 2, 3 and 5 kGy doses 15 nymphs were classified into three groups of 5 for each dose. Death time of the nymphs was recorded by examining their movement under a stereomicroscope and then was compared with that of the control group stored at 4 °C. In order to analyze the study data, T-test and ANOVA were utilized setting the significance level at 0.05. Results: The comparison between treatment and control groups demonstrated a statistically significant difference in death time of the nymphs (P 0.05. Moreover, there was a statistically significant difference between the doses of 1, 2 and 3 kGy with dose of 5 kGy (P 0.05 in regard with their lethality speed. The results showed that minimum destruction dose of Linguatula serrata nymphs was 1 kGy and 5 KGy , resulted in a more rapidly death within the nymphs. Conclusion: Regarding the high sensitivity of Linguatula serrata nymphs to E-beam irradiation, this method can be used to enhance the safety of animal products in future.

Evaluating the utility of companion animal tick surveillance practices for monitoring spread and occurrence of human Lyme disease in West Virginia, 2014-2016.

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Hendricks, Brian; Mark-Carew, Miguella; Conley, Jamison

2017-11-13

Domestic dogs and cats are potentially effective sentinel populations for monitoring occurrence and spread of Lyme disease. Few studies have evaluated the public health utility of sentinel programmes using geo-analytic approaches. Confirmed Lyme disease cases diagnosed by physicians and ticks submitted by veterinarians to the West Virginia State Health Department were obtained for 2014-2016. Ticks were identified to species, and only Ixodes scapularis were incorporated in the analysis. Separate ordinary least squares (OLS) and spatial lag regression models were conducted to estimate the association between average numbers of Ix. scapularis collected on pets and human Lyme disease incidence. Regression residuals were visualised using Local Moran's I as a diagnostic tool to identify spatial dependence. Statistically significant associations were identified between average numbers of Ix. scapularis collected from dogs and human Lyme disease in the OLS (β=20.7, PLyme disease. Findings reinforce the utility of spatial analysis of surveillance data, and highlight West Virginia's unique position within the eastern United States in regards to Lyme disease occurrence.

Variation in the Microbiota of Ixodes Ticks with Regard to Geography, Species, and Sex.

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Van Treuren, Will; Ponnusamy, Loganathan; Brinkerhoff, R Jory; Gonzalez, Antonio; Parobek, Christian M; Juliano, Jonathan J; Andreadis, Theodore G; Falco, Richard C; Ziegler, Lorenza Beati; Hathaway, Nicholas; Keeler, Corinna; Emch, Michael; Bailey, Jeffrey A; Roe, R Michael; Apperson, Charles S; Knight, Rob; Meshnick, Steven R

2015-09-01

Ixodes scapularis is the principal vector of Lyme disease on the East Coast and in the upper Midwest regions of the United States, yet the tick is also present in the Southeast, where Lyme disease is absent or rare. A closely related species, I. affinis, also carries the pathogen in the South but does not seem to transmit it to humans. In order to better understand the geographic diversity of the tick, we analyzed the microbiota of 104 adult I. scapularis and 13 adult I. affinis ticks captured in 19 locations in South Carolina, North Carolina, Virginia, Connecticut, and New York. Initially, ticks from 4 sites were analyzed by 454 pyrosequencing. Subsequently, ticks from these sites plus 15 others were analyzed by sequencing with an Illumina MiSeq machine. By both analyses, the microbiomes of female ticks were significantly less diverse than those of male ticks. The dissimilarity between tick microbiomes increased with distance between sites, and the state in which a tick was collected could be inferred from its microbiota. The genus Rickettsia was prominent in all locations. Borrelia was also present in most locations and was present at especially high levels in one site in western Virginia. In contrast, members of the family Enterobacteriaceae were very common in North Carolina I. scapularis ticks but uncommon in I. scapularis ticks from other sites and in North Carolina I. affinis ticks. These data suggest substantial variations in the Ixodes microbiota in association with geography, species, and sex. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Variation in the Microbiota of Ixodes Ticks with Regard to Geography, Species, and Sex

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Van Treuren, Will; Ponnusamy, Loganathan; Brinkerhoff, R. Jory; Gonzalez, Antonio; Parobek, Christian M.; Juliano, Jonathan J.; Andreadis, Theodore G.; Falco, Richard C.; Ziegler, Lorenza Beati; Hathaway, Nicholas; Keeler, Corinna; Emch, Michael; Bailey, Jeffrey A.; Roe, R. Michael; Apperson, Charles S.; Knight, Rob

2015-01-01

Ixodes scapularis is the principal vector of Lyme disease on the East Coast and in the upper Midwest regions of the United States, yet the tick is also present in the Southeast, where Lyme disease is absent or rare. A closely related species, I. affinis, also carries the pathogen in the South but does not seem to transmit it to humans. In order to better understand the geographic diversity of the tick, we analyzed the microbiota of 104 adult I. scapularis and 13 adult I. affinis ticks captured in 19 locations in South Carolina, North Carolina, Virginia, Connecticut, and New York. Initially, ticks from 4 sites were analyzed by 454 pyrosequencing. Subsequently, ticks from these sites plus 15 others were analyzed by sequencing with an Illumina MiSeq machine. By both analyses, the microbiomes of female ticks were significantly less diverse than those of male ticks. The dissimilarity between tick microbiomes increased with distance between sites, and the state in which a tick was collected could be inferred from its microbiota. The genus Rickettsia was prominent in all locations. Borrelia was also present in most locations and was present at especially high levels in one site in western Virginia. In contrast, members of the family Enterobacteriaceae were very common in North Carolina I. scapularis ticks but uncommon in I. scapularis ticks from other sites and in North Carolina I. affinis ticks. These data suggest substantial variations in the Ixodes microbiota in association with geography, species, and sex. PMID:26150449

Cues of maternal condition influence offspring selfishness.

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Wong, Janine W Y; Lucas, Christophe; Kölliker, Mathias

2014-01-01

The evolution of parent-offspring communication was mostly studied from the perspective of parents responding to begging signals conveying information about offspring condition. Parents should respond to begging because of the differential fitness returns obtained from their investment in offspring that differ in condition. For analogous reasons, offspring should adjust their behavior to cues/signals of parental condition: parents that differ in condition pay differential costs of care and, hence, should provide different amounts of food. In this study, we experimentally tested in the European earwig (Forficula auricularia) if cues of maternal condition affect offspring behavior in terms of sibling cannibalism. We experimentally manipulated female condition by providing them with different amounts of food, kept nymph condition constant, allowed for nymph exposure to chemical maternal cues over extended time, quantified nymph survival (deaths being due to cannibalism) and extracted and analyzed the females' cuticular hydrocarbons (CHC). Nymph survival was significantly affected by chemical cues of maternal condition, and this effect depended on the timing of breeding. Cues of poor maternal condition enhanced nymph survival in early broods, but reduced nymph survival in late broods, and vice versa for cues of good condition. Furthermore, female condition affected the quantitative composition of their CHC profile which in turn predicted nymph survival patterns. Thus, earwig offspring are sensitive to chemical cues of maternal condition and nymphs from early and late broods show opposite reactions to the same chemical cues. Together with former evidence on maternal sensitivities to condition-dependent nymph chemical cues, our study shows context-dependent reciprocal information exchange about condition between earwig mothers and their offspring, potentially mediated by cuticular hydrocarbons.

Cues of maternal condition influence offspring selfishness.

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Janine W Y Wong

Full Text Available The evolution of parent-offspring communication was mostly studied from the perspective of parents responding to begging signals conveying information about offspring condition. Parents should respond to begging because of the differential fitness returns obtained from their investment in offspring that differ in condition. For analogous reasons, offspring should adjust their behavior to cues/signals of parental condition: parents that differ in condition pay differential costs of care and, hence, should provide different amounts of food. In this study, we experimentally tested in the European earwig (Forficula auricularia if cues of maternal condition affect offspring behavior in terms of sibling cannibalism. We experimentally manipulated female condition by providing them with different amounts of food, kept nymph condition constant, allowed for nymph exposure to chemical maternal cues over extended time, quantified nymph survival (deaths being due to cannibalism and extracted and analyzed the females' cuticular hydrocarbons (CHC. Nymph survival was significantly affected by chemical cues of maternal condition, and this effect depended on the timing of breeding. Cues of poor maternal condition enhanced nymph survival in early broods, but reduced nymph survival in late broods, and vice versa for cues of good condition. Furthermore, female condition affected the quantitative composition of their CHC profile which in turn predicted nymph survival patterns. Thus, earwig offspring are sensitive to chemical cues of maternal condition and nymphs from early and late broods show opposite reactions to the same chemical cues. Together with former evidence on maternal sensitivities to condition-dependent nymph chemical cues, our study shows context-dependent reciprocal information exchange about condition between earwig mothers and their offspring, potentially mediated by cuticular hydrocarbons.

Review of the leafhopper genus Penthimia Germar (Hemiptera: Cicadellidae: Deltocephalinae) from the Indian subcontinent with description of seven new species.

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Shobharani, M; Viraktamath, C A; Webb, M D

2018-01-02

Species of the leafhopper genus Penthimia Germar known from the Indian subcontinent are reviewed based on the examination of type specimens. Seven new species of the genus, Penthimia curvata sp. nov. (Karnataka: Bandipur), P. meghalayensis sp. nov. (Meghalaya: Nangpoh), P. neoattenuata sp. nov. (India: Tamil Nadu), P. ribhoi sp. nov. (India: Meghalaya), P. sahyadrica sp. nov. (Karnataka: Dharmasthala, Agumbe; Kerala: Thekkady), P. spiculata sp. nov. (Karnataka: Nagarahole) and P. tumida sp. nov. (Tamil Nadu: Ootacamund; Kerala: Munnar) are described. The following nomenclatorial changes are proposed: Penthimia alba Zahniser, McKamey Dmitriev, 2012 (replacement name for P. thoracica Distant, 1918, nec Panzer, 1799), syn. nov. of P. quadrinotata Distant, 1918; Neodartus scutellatus Distant, 1908 syn. nov. of Penthimia ereba Distant 1908; P. nilgiriensis Distant, 1918 syn. nov. of P. montana Distant, 1918; P. scutellata (Distant) comb. nov. (from genus Neodartus); a lectotype is designated for P. maculosa Distant, stat. revived, thereby removing its synonymy with P. scapularis Distant. The following other lectotypes are designated: P. attenuata Distant, P. subniger Distant, P. scapularis Distant, P. distanti Baker, P. ereba Distant, N. scutellatus Distant, P. fraterna Distant, P. funebris Distant, P. juno Distant, P. maculosa Distant, P. montana Distant, P. noctua Distant, P. quadrinotata Distant, P. alba Zahniser, McKamey Dmitriev. Examination of types of Penthimia rufopunctata Motschulsky revealed that it belongs to Penthimia and hence it is transferred back to that genus from Neodartus, revised placement. The following species previously included in the genus Penthimia are transferred to the genera Tambila Distant and Vulturnus Kirkaldy: Tambila badia (Distant) comb. nov., T. majuscula (Distant) comb. nov., T. vittatifrons (Distant) comb. nov., T. variabilis (Distant) comb. nov. and Vulturnus flavocapitata (Distant) comb. nov. Three species are treated in a new

Descrição de ovos e ninfas de Triatoma klugi (Hemiptera, Reduviidae, Triatominae Description of eggs and nymphs of Triatoma klugi (Hemiptera, Reduviidae, Triatominae

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José Jurberg

Full Text Available Os autores descreveram as características morfológicas de Triatoma klugi Carcavallo, Jurberg, Lent & Galvão, 2001 pertencente ao grupo de espécies que compõem o "complexo T. oliveirai". Até o presente tem sido difícil separar essas espécies com base nas características ninfais, o que justifica o desenvolvimento deste trabalho. Os espécimes foram coletados em frestas de rochas no morro Malavok na localidade de Linha Brasil, município de Nova Petrópolis, no Estado do Rio Grande do Sul. O local de captura dos triatomíneos situa-se entre 700 e 800 m de altitude (29º18'38''S, 51º04'57''W. Juntamente com T. oliveirai (Neiva, Pinto & Lent, 1939, espécie morfologicamente mais próxima, são as únicas do complexo que não foram encontradas, até o momento, no Estado do Mato Grosso, Mato Grosso do Sul e Goiás, Brasil. Em condições experimentais, já foi testada e comprovada a sua susceptibilidade à infecção pelo Trypanosoma cruzi (Chagas, 1909 e Trypanosoma rangeli (Tejera, 1920. A análise comparativa das ornamentações do exocório dos ovos e de três estádios ninfais de T. klugi por microscopia óptica e microscopia eletrônica de varredura mostrou algumas particularidades morfológicas, com destaque para: a face ventral da cabeça, o sulco estridulatório e os últimos segmentos abdominais (IX, X - futura genitália e XI - tubo anal. Esses dados contribuem para a ampliação dos parâmetros diferenciais visando à diagnose de T. klugi durante o seu desenvolvimento ninfal.The authors had described the morphologic characteristics of Triatoma klugi Carcavallo, Jurberg, Lent & Galvão, 2001 to the group of species belonging to "T. oliveirai complex". Until the moment it has been difficult to separate on the nymphs characteristics basis these species, what it justifies the development of this work. The specimens had been collected in openings of rocks in the Malavok mount in the locality of Linha Brazil, city of Nova Petr

Culicídeos do lago de Itaipu, no rio Paraná, Sul do Brasil Culicidae of Itaipu lake, Paraná River, southern Brazil

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Ueslei Teodoro

1995-02-01

Full Text Available De janeiro a dezembro de 1991 foram realizadas capturas mensais de culicídeos, no Município de Guaíra, Estado do Paraná (Brasil, na margem esquerda do lago de Itaipu, ao lado da via de acesso que conduzia aos Saltos das Sete Quedas, usando-se armadilha luminosa de Shannon, e isca humana em área urbanizada. Obtiveram-se informações sobre a fauna culicidiana, as espécies prevalentes, a variação sazonal, o horário de maior densidade e a afinidade dos mosquitos em relação ao hospedeiro humano. Foram identificadas 41 espécies de culicídeos dos gêneros Anopheles, Aedes, Aedomyia, Coquillettidia, Culex, Mansonia, Psorophora e Uranotaenia. Capturaram-se 21.280 mosquitos em armadilha de Shannon e 1.010 em isca humana. As espécies mais freqüentes em armadilha de Shannon - Coquillettidia shannoni, Mansonia humeralis, Anopheles triannulatus, Aedes scapularis e Anopheles albitarsis - perfizeram 82,78% dos mosquitos capturados. Em isca humana Aedes scapularís, Mansonia humeralis e Anopheles albitarsis, somaram 91,21% dos insetos capturados. Em armadilha de Shannon o horário de maior atividade das espécies prevalentes foi entre 19 e 22 h. Em isca humana Aedes scapularis teve maior densidade das 20 às 21 h, enquanto Mansonia humeralis e Anopheles albitarsis prevaleceram das 18 às 19 h. Dentre as espécies prevalentes em armadilha de Shannon, Coquillettidia shannoni, Mansonia humeralis e Anopheles albitarsis tiveram pico de atividade no mês de abril, Anopheles triannulatus em janeiro e Aedes scapularis em fevereiro.Mosquito catches were made in Guaíra county, Paraná State, southern Brazil, in the vicinity of Itaipu dam, from January to December 1991. The catches were made with a Shannon light trap and human bait. The Shannon light trap was installed beside the highway that used, formerly, to lead to the Sete Quedas cataracts and the human bait was used in the urban area. Data about the Culicidae fauna were obtained as to predominant

Repellent activity of DEET against Amblyomma cajennense (Acari: Ixodidae nymphs submitted to different laboratory bioassays Atividade repelente do DEET contra ninfas de Amblyomma cajennense (Acari: Ixodidae em bioensaio laboratorial

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Sara Fernandes Soares

2010-03-01

Full Text Available This study was developed to evaluate the repellent activity of N,N-diethyl-3-methylbenzamide (DEET against Amblyomma cajennense nymphs. Two repellent bioassays were compared and the effective concentration and repellent time were calculated. The fingertip test was accomplished to evaluate in vivo four concentrations of the compound (0.200; 0.100; 0.050 and 0.025 mg.cm-2 and the filter-paper bioassay to evaluate in vitro the two highest concentrations. The compound provided repellence higher than 90% in all concentrations and at least 95% repellency in the highest concentration over 5 hours. The effective concentration against 50% of tested nymphs (EC50 was 0.006 mg.cm-2 and the EC99 was 0.036 mg.cm-2. Those concentrations were lower than the ones obtained against other tick species, denoting the effectiveness of DEET against A. cajennense. The repellency time against 50% of the ticks (RT50 was 4.8 hours and the RT90 was 2.7 hours. Both bioassays were adequate to evaluate A. cajennense repellency and provided similar results; however the in vivo test is more appropriate to estimate the effective concentration and repellency time.Este estudo foi conduzido com o objetivo de avaliar a atividade repelente do N,N-diethyl-3-methylbenzamide (DEET sobre ninfas de Amblyomma cajennense. Dois bioensaios para a avaliação de repelência foram comparados e cálculos da concentração eficaz e do tempo de repelência foram realizados. Foram empregados o bioensaio da ponta do dedo, para avaliação in vivo de quatro concentações do químico (0,200; 0,100; 0,050 e 0,025 mg.cm-2 e o bioensaio do papel filtro, para a avaliação in vitro das duas concentrações mais altas. O composto conferiu mais de 90% de repelência em todas as concentrações utilizadas e 95% de repelência por mais de cinco horas na maior concentração. A concentração do composto efetiva contra 50% das ninfas testadas (CE50 foi de 0,006 mg.cm-2 e a CE99 foi de 0,036 mg.cm-2. Estas

The Toxicity and Detoxifying Mechanism of Cycloxaprid and Buprofezin in Controlling Sogatella furcifera (Homoptera: Delphacidae)

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Chang, Xiaoli; Yuan, Yongda; Zhang, Tianshu; Wang, Dongsheng; Du, Xingbin; Wu, Xiangwen; Chen, Haixia; Chen, Yaozhong; Jiao, Yuetong; Teng, Haiyuan

2015-01-01

The effects of cycloxaprid (a modified neonicotinoid insecticide) and buprofezin (a thiadiazine insecticide) on mortality of the white-backed planthopper (WBPH), Sogatella furcifera, were determined in laboratory assays. Cycloxaprid killed WBPH nymphs and adults but buprofezin killed only nymphs, and cycloxaprid acted faster than buprofezin. One day after infestation, mortality of third-instar nymphs was >65% with cycloxaprid at 125?mg liter?1 but was

MicroRNA and dsRNA targeting chitin synthase A reveal a great potential for pest management of the hemipteran insect Nilaparvata lugens.

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Li, Tengchao; Chen, Jie; Fan, Xiaobin; Chen, Weiwen; Zhang, Wenqing

2017-07-01

Two RNA silencing pathways in insects are known to exist that are mediated by short interfering RNAs (siRNAs) and microRNAs (miRNAs), which have been hypothesised to be promising methods for insect pest control. However, a comparison between miRNA and siRNA in pest control is still unavailable, particularly in targeting chitin synthase gene A (CHSA). The dsRNA for Nilaparvata lugens CHSA (dsNlCHSA) and the microR-2703 (miR-2703) mimic targeting NlCHSA delivered via feeding affected the development of nymphs, reduced their chitin content and led to lethal phenotypes. The protein level of NlCHSA was downregulated after female adults were injected with dsNlCHSA or the miR-2703 mimic, but there were no significant differences in vitellogenin (NlVg) expression or in total oviposition relative to the control group. However, 90.68 and 46.13% of the eggs laid by the females injected with dsNlCHSA and miR-2703 mimic were unable to hatch, respectively. In addition, a second-generation miRNA and RNAi effect on N. lugens was observed. Ingested miR-2703 seems to be a good option for killing N. lugens nymphs, while NlCHSA may be a promising target for RNAi-based pest management. These findings provide important evidence for applications of small non-coding RNAs (snRNAs) in insect pest management. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Lethal concentration of carbofuran to brown planthopper (Nilaparvata lugens) and green leaf-hopper (Nephotettix virecence)

International Nuclear Information System (INIS)

Kuswadi, A.N.; Sumatra, M.; Anwar, E.; Soekarna, D.

1988-01-01

An oral toxicity test of carbofuran to brown planthopper and green leaf-hopper using sucrose solution as feed given to the hopper through a membrane feeding system was conducted in the laboratory, pure carbofuran was dilute in the feeding solution. The 50 percent lethal concentration (LC-50) of this insecticide to adult and nymph of brown planthopper were 0.21 and 0.43 ppm, respectively, while those to adult and nymph of green leaf-hopper were 0.43 and 0.58 ppm. The LC 90 were 0.56 an 0.90 ppm to adult and nymph of brown planthopper, and 1.20 and 1.60 ppm to adult and nymph of green leaf-hopper, respectively. The brown planthopper was found to be more susceptible than the nymph. When carbofuran was applied to rice plant, this insecticide was accumulated more in the leaf than in the stem, so that green leaf-hopper got more toxicity than the brown planthopper. (authors). 5 refs, 7 figs

Feeding of Whitefly on Tobacco Decreases Aphid Performance via Increased Salicylate Signaling.

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Haipeng Zhao

Full Text Available The feeding of Bemisia tabaci nymphs trigger the SA pathway in some plant species. A previous study showed that B. tabaci nymphs induced defense against aphids (Myzus persicae in tobacco. However, the mechanism underlying this defense response is not well understood.Here, the effect of activating the SA signaling pathway in tobacco plants through B. tabaci nymph infestation on subsequent M. persicae colonization is investigated. Performance assays showed that B. tabaci nymphs pre-infestation significantly reduced M. persicae survival and fecundity systemically in wild-type (WT but not salicylate-deficient (NahG plants compared with respective control. However, pre-infestation had no obvious local effects on subsequent M. persicae in either WT or NahG tobacco. SA quantification results indicated that the highest accumulation of SA was induced by B. tabaci nymphs in WT plants after 15 days of infestation. These levels were 8.45- and 6.14-fold higher in the local and systemic leaves, respectively, than in controls. Meanwhile, no significant changes of SA levels were detected in NahG plants. Further, biochemical analysis of defense enzymes polyphenol oxidase (PPO, peroxidase (POD, β-1,3-glucanase, and chitinase demonstrated that B. tabaci nymph infestation increased these enzymes' activity locally and systemically in WT plants, and there was more chitinase and β-1, 3-glucanase activity systemically than locally, which was opposite to the changing trends of PPO. However, B. tabaci nymph infestation caused no obvious increase in enzyme activity in any NahG plants except POD.In conclusion, these results underscore the important role that induction of the SA signaling pathway by B. tabaci nymphs plays in defeating aphids. It also indicates that the activity of β-1, 3-glucanase and chitinase may be positively correlated with resistance to aphids.

Molecular analyses reveal an abundant diversity of ticks and rickettsial agents associated with wild birds in two regions of primary Brazilian Atlantic Rainforest.

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Luz, Hermes Ribeiro; Faccini, João Luiz Horacio; McIntosh, Douglas

2017-06-01

Brazilian wild birds are recognized as frequent and important hosts for immature stages of more than half of the 32 recognized species of Amblyomma ticks recorded in that country. Several species of Amblyomma harbor rickettsial agents, including members of the spotted fever group (SFG). Most studies on this topic relied primarily on morphological characterization and reported large portions of the collected ticks at the genus rather than species level. Clearly, this factor may have contributed to an underestimation of tick diversity and distribution and makes comparisons between studies difficult. The current investigation combined morphological and molecular analyses to assess the diversity of ticks and rickettsial agents associated with wild birds, captured in two regions of native Atlantic rainforest, in the state of Rio de Janeiro, Brazil. A total of 910 birds were captured, representing two orders, 34 families and 106 species, among which 93 specimens (10.2%), were parasitized by 138 immature ticks (60 larvae and 78 nymphs), representing 10 recognized species of the genus Amblyomma; together with two reasonably well classified haplotypes (Amblyomma sp. haplotype Nazaré and Amblyomma sp. strain USNTC 6792). Amplification by PCR and sequencing of rickettsial genes (htrA, gltA, ompA and ompB), demonstrated the presence of Rickettsia DNA in 48 (34%) of the ticks. Specifically, Rickettsia bellii was detected in a single larva and a single nymph of A. aureolatum; R. amblyomatis was found in 16 of 37 A. longirostre and was recorded for the first time in three nymphs of A. calcaratum; R. rhipicephali was detected in 9 (47%) of 19 Amblyomma sp. haplotype Nazaré ticks. The remaining ticks were infected with genetic variants of R. parkeri, namely strain ApPR in 12 A. parkeri and seven Amblyomma sp. haplotype Nazaré ticks, with the strain NOD found in two specimens of A. nodosum. Interestingly, a single larvae of A. ovale was shown to be infected with the emerging

Relaciones tróficas de cinco peces costeros comunes en el área submareal del norte de Chile (20°11'-20°20'S

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Mauricio Vargas

1999-09-01

Full Text Available The trophic relations of five coastal Perciformes at northern Chile were analyzed on the basis of 151 specimens of Acanthistius pictus, Paralabrax humeralis, Pinguipes chilensis, Anisotremus scapularis and Cheilodactylus variegatus collected off Iquique, in April 1996, as a preliminary way to identify trophic guilds of subtidal fishes; A. pictus, P. humeralis and C. variegatus, had the crustaceans Rhynchocynetes typus, Pseudosquillopsis lessoni and Allopetrolisthes angulosus, respectively, as the best represented items. In A. scapularis and P. chilensis the best represented items were the mollusks; however for the last species, the main food was the crustacean Cancer setosus. These fish are essentially benthophagous carnivores with a variable trophic spectrum(8 to 36 items.

Recolonization and possible recovery of burrowing mayflies (Ephemeroptera: Ephemeridae: Hexagenia spp.) in Lake Erie of the Laurentian Great Lakes

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Schloesser, Don W.; Krieger, Kenneth A.; Ciborowski, Jan J.H.; Corkum, Lynda D.

2000-01-01

Burrowing mayflies of the genus Hexagenia spp. were widely distributed (ca. 80% of sites) and abundant (ca. 160 nymphs/m2) in the western basin of Lake Erie of the Laurentian Great Lakes in 1929–1930, prior to a period of anoxia in the mid 1950s. Nymphs were absent or rare in the basin between 1961 and 1973–1975. In 1979–1991, nymphs were infrequently found (13–46% of sites) in low abundance (3–40 nymphs/m2) near shore (recolonized sediments of western Lake Erie and that their abundance may be similar to levels observed before their disappearance in the mid 1950s. However, prior to the mid 1950s, densities were greater in offshore than nearshore waters, but between 1979 and 1998 greater densities occurred near shore than offshore. In addition, there were two areas in the 1990s where low densities consistently occurred. Therefore, recovery of nymphs in western Lake Erie may not have been complete in 1998. At present we do not know the cause for the sudden recolonization of nymphs in large portions of western Lake Erie. Undoubtedly, pollution-abatement programs contributed to improved conditions that would have ultimately led to mayfly recovery in the future. However, the explosive growth of the exotic zebra mussel, Dreissena polymorpha, undoubtedly diverted plankton foods to bottom substrates which could have increased the speed at which Hexagenia spp. nymphs recolonized sediments in western Lake Erie in the 1990s.

Ticks (Acari: Ixodidae) infesting some small mammals from Northern Turkey with new tick-host associations and locality records.

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Keskin, Adem; Selçuk, Ahmet Yesari; Kefelioğlu, Haluk

2017-12-01

Ticks are obligate ectoparasites of a vast range of terrestrial vertebrates which may play an important role in the transmission of many zoonotic pathogens to humans and animals. In the current study, we performed an investigation on ticks infesting some small mammals captured from Samsun and Tokat provinces, Northern Turkey. One hundred forty-five mammalian samples belonging to four species, namely Cricetulus migratorius (n = 1), Apodemus flavicollis (n = 17), Crocidura suaveolens (n = 102) and Sorex volnuchini (n = 25), were examined for the presence of tick infestations. A total of 273 (74 larvae, 194 nymphs, 5 females) hard ticks were collected from 88 mammalian samples. Ticks were identified as Ixodes laguri (1 nymph), I. redikorzevi (22 larvae, 186 nymphs, 5 females), I. ricinus (52 larvae, 4 nymphs) and Rhipicephalus turanicus (3 nymphs). Here, we also provided new tick mammalian host associations for Turkey. In addition, I. laguri and I. redikorzevi ticks were recorded for the first time in Samsun province of Turkey.

Bad little girls.

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Maggini, Carlo

2008-04-01

The characters, in little girl style, who more and more often appear in advertisements, glossy magazines, television programs and megastores, and who can be encountered in the streets of many cities, are not the product of an ephimerous fashion dictated by the logic of the market. They come from far away, disquieting and erotic, and have crossed all the cultures of the western world, fascinating and disconcerting the soul with their power of seduction. They are the nymphs of Greek mythology, and not even the gods were able to resist them, knowing very well that their bodies are a place of knowledge that could lead to insanity. The paradox of the nymph is that possessing her means being possessed. After an overview of the myth of possession by nymphs, the author discusses certain illustrious figures of western culture of the 19th and 20th century possessed by a nymph: Aby Warburg, Martin Heidegger, Carl Gustav Jung, Henrik Ibsen and Emil Cioran. In all of them the possession by a nymph unfolded in keeping with the myth: intellectual fervor was common to all, insanity in Warburg, rapacious egotism in Heidegger and Jung, and a metamorphosis of Weltanshaung in Ibsen and Cioran. Nonetheless, they all, in their encounter with a nymph, laid bare their multifaceted identities, the muddy depths and the "heart of darkness" of their souls.

Systems Biology of Tissue-Specific Response to Anaplasma phagocytophilum Reveals Differentiated Apoptosis in the Tick Vector Ixodes scapularis

Czech Academy of Sciences Publication Activity Database

Ayllón, N.; Villar, M.; Galindo, R. C.; Kocan, K.M.; Šíma, Radek; López, J.A.; Vázquez, J.; Alberdi, P.; Cabezas-Cruz, A.; Kopáček, Petr; de la Fuente, J.

2015-01-01

Roč. 11, č. 3 (2015), e1005120 ISSN 1553-7404 R&D Projects: GA MŠk(CZ) EE2.3.30.0032; GA ČR GP13-12816P Institutional support: RVO:60077344 Keywords : gene expression * human neutrophils * cancer cells Subject RIV: EC - Immunology Impact factor: 6.661, year: 2015

RNAi-mediated knockdown of SPOOK reduces ecdysteroid titers and causes precocious metamorphosis in the desert locust Schistocerca gregaria.

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Sugahara, Ryohei; Tanaka, Seiji; Shiotsuki, Takahiro

2017-09-01

The Halloween gene SPOOK (SPO) is involved in the production of the active metabolite of ecdysteroid, 20-hydroxyecdysone (20E), in insects. A previous study showed that RNAi-mediated knockdown of SPO in Schistocerca gregaria last instar nymphs markedly reduced the hemolymph 20E titer, but did not affect metamorphosis. In the present study, the effects of SPO interference on development were re-examined in this locust. Injections of SPO double-stranded RNA (dsSPO) into nymphs at mid and late instars significantly delayed nymphal development and interfered with molting. The 20E levels of dsSPO-treated nymphs were generally low, with a delayed, small peak, suggesting that disturbance of the 20E levels caused the above developmental abnormalities. A small proportion of the dsSPO-injected nymphs metamorphosed precociously, producing adults and adultoids. Precocious adults were characterized by small body size, short wings with abbreviated venation, and normal reproductive activity. Fourth instar nymphs that precociously metamorphosed at the following instar exhibited temporal expression patterns of ecdysone-induced protein 93F and the juvenile hormone (JH) early-inducible gene Krüppel homolog 1 similar to those observed at the last instar in normal nymphs. Adultoids displayed mating behavior and adultoid females developed eggs, but never laid eggs. JH injection around the expected time of the 20E peak in the dsSPO-injected nymphs completely inhibited the appearance of adultoids, suggesting that appearance of adultoids might be due to a reduced titer of JH rather than of 20E. These results suggest that SPO plays an important role in controlling morphogenesis, metamorphosis, and reproduction in S. gregaria. Copyright © 2017 Elsevier Inc. All rights reserved.

Egg Hatch Rate and Nymphal Survival of the Bed Bug (Hemiptera: Cimicidae) After Exposure to Insecticide Sprays.

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Hinson, K R; Benson, E P; Zungoli, P A; Bridges, W C; Ellis, B R

2016-12-01

Few studies have addressed the efficacy of insecticides used against eggs and first-instar nymphs of the bed bug, Cimex lectularius L. (Hemiptera: Cimicidae). Insect eggs are often resistant to insecticides; therefore, information on which products are effective is important. We evaluated the efficacy of four commonly used insecticide sprays applied directly to bed bug eggs. We also evaluated the efficacy of these insecticides to first-instar nymphs exposed to residuals resulting from directly spraying eggs. Temprid SC (beta-cyfluthrin, imidacloprid) was the most effective insecticide at preventing egg hatch (13% hatch rate) for pyrethroid-resistant, field-strain (Jersey City) bed bugs compared with a control (water [99% hatch rate]), Bedlam (MGK-264, sumithrin [84% hatch rate]), Demand CS (lambda-cyhalothrin [91% hatch rate]), and Phantom SC (chlorfenapyr [95% hatch rate]). Demand CS and Temprid SC were most effective at preventing egg hatch (0%) for an insecticide-susceptible (Harold Harlan) strain, followed by Bedlam (28%). Phantom SC produced a hatch rate similar to the control (97% and 96%, respectively). Harold Harlan-strain nymphs showed 100% survival for the control but 0% survival for Bedlam and Phantom SC. Jersey City-strain nymphs showed 100% survival for the control, 99% survival for Bedlam, 0% survival for Demand CS, 4% survival for Phantom SC, and 38% survival for Temprid SC. Demand CS was less effective at preventing hatch (91% hatch rate) of Jersey City-strain nymphs but was the only product to kill all nymphs (0% survival). One of the least effective products for preventing Jersey City-strain egg hatch (Phantom SC, 95% hatch rate) was the second most effective at killing nymphs, leaving only six of 141 alive. These findings indicate that survival of directly sprayed eggs and residually exposed, first-instar nymphs varies by strain, life stage, and product used. © The Authors 2016. Published by Oxford University Press on behalf of Entomological

EFICIÊNCIA DO CONTROLE QUÍMICO SOBRE A MOSCA BRANCA Bemisia tabaci biótipo B (HEMIPTERA: ALEYRODIDAE EM MELOEIRO

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Antônio Lindemberg Martins Mesquita

2007-01-01

efficient to control eggs, nymphs and adults of the whitefly, while the insect growth regulators buprofezin and pyriproxyfen did not control eggs and adults, but they controled nymphs, being pyriproxyfen more efficient than buprofezin.

Studies on the Susceptibility of Different Developmental Stages of [Bemisia tabaci (Gennadius] to Pyriproxyfen and Citowett Oil

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sedighe ashtari

2018-02-01

for the adult, egg, nymph along with pupa stages were 2243.888, 884.5782 and 623.9682 ppm in the same order. When the basic equation y=a+bx was dotained for each life stage including adult, egg, nymph, pupa, LC25 of pyriproxyfen was counted up with LC25 of citowett oil for each life stage separately, then the pyriproxyfen with citowett oil mixture experiment was performed.The results of this experiment showed a 52.36% mortality rate for the adult, 62.32% response for the egg and 69.19% response for the nymph and pupa stages. These experiments revealed that the enhacement of pyriproxyfen toxicity when mixed with citowett oil. It can be argued that citowett oil has a synergistic effect on pyriproxyfen.In similar research the rate of LC50 pyriproxyfen for egg was 51 ppm and for the first instar nymphs was 18 ppm. This researchres also elucidated that first instar nymphs is the most sensitive of development stages and pupae have more tolerance in contrast of nymphs. Egg sensitivity is less than the other stages due to chorion layer. In a similar study Bemisia tabaci immature stages were more sensitive to pyriproxyfen than the other stages and it was concluded that the enfulence of pyriproxyfen even at low levels was effective on the immature stages.The LC50 of Citowett oil for adult, egg and immature stages of whitefly were reported 2580, 1310 and 250 ppm, respectively, that results of this study were different to the current researchdue to differences in insect biotype and historyof pest. To evaluate the effect of pyriproxyfen and oil mixture, LC25 of these compounds in the different stages were mixed.The mortality rate caused by mixing pyriproxyfen and citowett oil was further Conclusions: These experiments demonstrated that because of the cheap price of citowett oil, in contrast to that of pyriproxyfen, a mixture of these compounds led to better control of Bemisia tabaci and is more economical.

Stylet morphometrics and citrus leaf vein structure in relation to feeding behavior of the Asian citrus psyllid Diaphorina citri, vector of citrus huanglongbing bacterium.

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El-Desouky Ammar

Full Text Available The Asian citrus psyllid (ACP, Diaphorina citri (Hemiptera: Psyllidae, is the primary vector of the phloem-limited bacterium Candidatus Liberibacter asiaticus (LAS associated with huanglongbing (HLB, citrus greening, considered the world's most serious disease of citrus. Stylet morphometrics of ACP nymphs and adults were studied in relation to citrus vein structure and to their putative (histologically verified feeding sites on Valencia orange leaves. ACP nymphs preferred to settle and feed on the lower (abaxial side of young leaves either on secondary veins or on the sides of the midrib, whereas adults preferred to settle and feed on the upper (adaxial or lower secondary veins of young or old leaves. Early instar nymphs can reach and probe the phloem probably because the distance to the phloem is considerably shorter in younger than in mature leaves, and is shorter from the sides of the midrib compared to that from the center. Additionally, the thick-walled 'fibrous ring' (sclerenchyma around the phloem, which may act as a barrier to ACP stylet penetration into the phloem, is more prominent in older than in younger leaves and in the center than on the sides of the midrib. The majority (80-90% of the salivary sheath termini produced by ACP nymphs and adults that reached a vascular bundle were associated with the phloem, whereas only 10-20% were associated with xylem vessels. Ultrastructural studies on ACP stylets and LAS-infected leaves suggested that the width of the maxillary food canal in first instar nymphs is wide enough for LAS bacteria to traverse during food ingestion (and LAS acquisition. However, the width of the maxillary salivary canal in these nymphs may not be wide enough to accommodate LAS bacteria during salivation (and LAS inoculation into host plants. This may explain the inability of early instar nymphs to transmit LAS/HLB in earlier reports.

Réduction des doses efficaces d'insecticides contre les larves de criquet pèlerin (Schistocerca gregaria Forskål, 1775 : Orthoptera, Acrididae par utilisation de quantités réduites de phénylacétonitrile

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Bocar Bal, A.

2013-01-01

Full Text Available Reduction of effective doses of insecticide against desert locust (Schistocerca gregaria Forskål, 1775: Orthoptera, Acrididae nymphs using phenylacetonitrile. In order to reduce the amount of insecticides used during a locust upsurge, phenylacetonitrile (PAN was tested in 2007 and 2008, in the Niamey area (Niger. PAN was used, on the one hand, in topical applications on third stage nymphs (L3 of the desert locust, alone or in combination with reduced amounts of various insecticides (lambda-cyhalothrin, malathion, chlorpyrifos-ethyl. In addition, experiments were carried out in semi-natural conditions, in field enclosures, and also on third stage nymphs of the desert locust. Insecticides were each applied at the recommended dose and at half of that dose with the addition or not of phenylacetonitrile. All topical applications of insecticides led to the total mortality of the nymphs within 1 to 24 h; the use of PAN alone caused a mortality rate of no higher than 18% within 120 h. In the field enclosures, mortality rates for the desert locust nymphs were the same both with the recommended doses and with half of the dose with the addition of 10 ml of PAN·ha-1. Results indicate that the addition of small quantities of phenylacetonitrile could make it possible to decrease by half the quantities of insecticides used in the control of desert locust nymphs, while preserving the same effectiveness.

Indirect effect of neem oil on Podisus nigrispinus (Hemiptera, Pentatomidae: biology and predatory capacity

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Aniele Pianoscki de Campos

2014-10-01

Full Text Available This study evaluated the effects on the development and predatory capacity of Podisus nigrispinus fed on Spodoptera frugiperda that have ingested different concentrations of neem oil. The predatory capacity of Podisus nigrispinus was assessed, separating nymphs (fourth instar and adults (males and females. The treatments consisted of S. frugiperda larvae reared in neem oil aqueous solutions (0.077, 0.359 and 0.599%, deltamethrin EC 25 (0.100% and control arranged in a completely randomized design, with ten replicates. Insects were offered three larval densities (one, three and six, in the third or fourth instars. The predated larvae were examined at 24 and 48 hours after the beginning of the experiment. Biological parameters of Podisus nigrispinus were evaluated in groups of ten second-instar nymphs transferred to pots, in five replicates. Insects were offered 2-6 third and/or fourth-instar larvae reared in the same neem oil concentrations in a completely randomized design. The following parameters were evaluated: duration of each nymph stage (days, nymph mortality (%, weight of fifth-instar nymphs (mg, sex ratio, weight of males and females (mg and longevity of unfed adults (days. The predatory capacity of nymphs and adults of Podisus nigrispinus was influenced by the neem oil at the concentrations of 0.359% and 0.599% in the highest density. The concentration of 0.359% lengthened the nymphal stage and the concentration of 0.599% reduced the weight of males.

Bacteria of the genus Rickettsia in ticks (Acari: Ixodidae) collected from birds in Costa Rica.

Science.gov (United States)

Ogrzewalska, Maria; Literák, Ivan; Capek, Miroslav; Sychra, Oldřich; Calderón, Víctor Álvarez; Rodríguez, Bernardo Calvo; Prudencio, Carlos; Martins, Thiago F; Labruna, Marcelo B

2015-06-01

The aim of this study was to document the presence of Rickettsia spp. in ticks parasitizing wild birds in Costa Rica. Birds were trapped at seven locations in Costa Rica during 2004, 2009, and 2010; then visually examined for the presence of ticks. Ticks were identified, and part of them was tested individually for the presence of Rickettsia spp. by polymerase chain reaction (PCR) using primers targeting fragments of the rickettsial genes gltA and ompA. PCR products were DNA-sequenced and analyzed in BLAST to determine similarities with previously reported rickettsial agents. A total of 1878 birds were examined, from which 163 birds (9%) were infested with 388 ticks of the genera Amblyomma and Ixodes. The following Amblyomma (in decreasing order of abundance) were found in immature stages (larvae and nymphs): Amblyomma longirostre, Amblyomma calcaratum, Amblyomma coelebs, Amblyomma sabanerae, Amblyomma varium, Amblyomma maculatum, and Amblyomma ovale. Ixodes ticks were represented by Ixodes minor and two unclassified species, designated here as Ixodes sp. genotype I, and Ixodes sp. genotype II. Twelve of 24 tested A. longirostre ticks were found to be infected with 'Candidatus Rickettsia amblyommii', and 2 of 4 A. sabanerae were found to be infected with Rickettsia bellii. Eight of 10 larval Ixodes minor were infected with an endosymbiont (a novel Rickettsia sp. agent) genetically related to the Ixodes scapularis endosymbiont. No rickettsial DNA was found in A. calcaratum, A. coelebs, A. maculatum, A. ovale, A. varium, Ixodes sp. I, and Ixodes sp. II. We report the occurrence of I. minor in Costa Rica for the first time and a number of new bird host-tick associations. Moreover, 'Candidatus R. amblyommii' and R. bellii were found in A. longirostre and A. sabanerae, respectively, in Costa Rica for the first time. Copyright © 2015 Elsevier GmbH. All rights reserved.

Closely-related Borrelia burgdorferi (sensu stricto) strains exhibit similar fitness in single infections and asymmetric competition in multiple infections.

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Rynkiewicz, Evelyn C; Brown, Julia; Tufts, Danielle M; Huang, Ching-I; Kampen, Helge; Bent, Stephen J; Fish, Durland; Diuk-Wasser, Maria A

2017-02-06

Wild hosts are commonly co-infected with complex, genetically diverse, pathogen communities. Competition is expected between genetically or ecologically similar pathogen strains which may influence patterns of coexistence. However, there is little data on how specific strains of these diverse pathogen species interact within the host and how this impacts pathogen persistence in nature. Ticks are the most common disease vector in temperate regions with Borrelia burgdorferi, the causative agent of Lyme disease, being the most common vector-borne pathogen in North America. Borrelia burgdorferi is a pathogen of high public health concern and there is significant variation in infection phenotype between strains, which influences predictions of pathogen dynamics and spread. In a laboratory experiment, we investigated whether two closely-related strains of B. burgdorferi (sensu stricto) showed similar transmission phenotypes, how the transmission of these strains changed when a host was infected with one strain, re-infected with the same strain, or co-infected with two strains. Ixodes scapularis, the black-legged tick, nymphs were used to sequentially infect laboratory-bred Peromyscus leucopus, white-footed mice, with one strain only, homologous infection with the same stain, or heterologous infection with both strains. We used the results of this laboratory experiment to simulate long-term persistence and maintenance of each strain in a simple simulation model. Strain LG734 was more competitive than BL206, showing no difference in transmission between the heterologous infection groups and single-infection controls, while strain BL206 transmission was significantly reduced when strain LG734 infected first. The results of the model show that this asymmetry in competition could lead to extinction of strain BL206 unless there was a tick-to-host transmission advantage to this less competitive strain. This asymmetric competitive interaction suggests that strain identity and

Geographical distribution of Amblyomma cajennense (sensu lato) ticks (Parasitiformes: Ixodidae) in Brazil, with description of the nymph of A. cajennense (sensu stricto).

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Martins, Thiago F; Barbieri, Amália R M; Costa, Francisco B; Terassini, Flávio A; Camargo, Luís M A; Peterka, Cássio R L; de C Pacheco, Richard; Dias, Ricardo A; Nunes, Pablo H; Marcili, Arlei; Scofield, Alessandra; Campos, Artur K; Horta, Mauricio C; Guilloux, Aline G A; Benatti, Hector R; Ramirez, Diego G; Barros-Battesti, Darci M; Labruna, Marcelo B

2016-03-31

Until recently, Amblyomma cajennense (Fabricius, 1787) was considered to represent a single tick species in the New World. Recent studies have split this taxon into six species. While the A. cajennense species complex or A. cajennense (sensu lato) (s.l.) is currently represented by two species in Brazil, A. cajennense (sensu stricto) (s.s.) and Amblyomma sculptum Berlese, 1888, their geographical distribution is poorly known. The distribution of the A. cajennense (s.l.) in Brazil was determined by morphological examination of all lots of A. cajennense (s.l.) in two large tick collections of Brazil, and by collecting new material during three field expeditions in the possible transition areas between the distribution ranges of A. cajennense (s.s.) and A. sculptum. Phylogenetic analysis inferred from the ITS2 rRNA gene was used to validate morphological results. Morphological description of the nymphal stage of A. cajennense (s.s.) is provided based on laboratory-reared specimens. From the tick collections, a total 12,512 adult ticks were examined and identified as 312 A. cajennense (s.s.), 6,252 A. sculptum and 5,948 A. cajennense (s.l.). A total of 1,746 ticks from 77 localities were collected during field expeditions, and were identified as 249 A. cajennense (s.s.), 443 A. sculptum, and 1,054 A. cajennense (s.l.) [these A. cajennense (s.l.) ticks were considered to be males of either A. cajennense (s.s.) or A. sculptum]. At least 23 localities contained the presence of both A. cajennense (s.s.) and A. sculptum in sympatry. DNA sequences of the ITS2 gene of 50 ticks from 30 localities confirmed the results of the morphological analyses. The nymph of A. cajennense (s.s.) is morphologically very similar to A. sculptum. Our results confirmed that A. cajennense (s.l.) is currently represented in Brazil by only two species, A. cajennense (s.s.) and A. sculptum. While these species have distinct distribution areas in the country, they are found in sympatry in some

Ehrlichiosis

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... Ehrlichia bacteria can be carried by the: American dog tick Deer tick ( Ixodes scapularis ), which can also ... your vital signs, including: Blood pressure Heart rate Temperature Other tests include: Complete blood count ( CBC ) Granulocyte ...

Preferências alimentares de mosquitos Culicidae no Vale do Ribeira, São Paulo, Brasil Feeding preferences of Culicidae mosquitoes in the Ribeira Valley, S.Paulo State, Brazil

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Oswaldo Paulo Forattini

1987-06-01

Full Text Available São apresentados os resultados obtidos na identificação do sangue ingerido por culicídeos ingurgitados coletados em vários ambientes rurais de cinco localidades do Vale do Ribeira, Estado de São Paulo (Brasil. O maior rendimento, que representou a quase totalidade dos espécimens coletados, foi obtido mediante o emprego da aspiração e das redes manuais. Foi possível identificar a origem de 1.444 repastos sangüíneos. Os Aedes apresentaram predominância de positividade para mamíferos. Ae. scapularis mostrou preferência por hospedeiros de grande porte representados por bovinos e eqüinos. Ae. serratus alimentou-se também em aves. Com exceção da elevada antropofilia de Cx. quinquefasciatus, os demais representantes de Cx. (Culex revelaram-se apreciavelmente ornitófilos. Em conjunto, Cx. (Melanoconion mostrou o mais amplo espectro de hematofagia, que incluiu anfíbio, ave, mamíferos e réptil. Cx. ribeirensis e Cx. sacchettae apresentaram resultados que sugerem alguma preferência por mamíferos. A antropofilia distribuiu-se por várias espécies destacando-se Ae. scapularis, Cx. sacchettae e Cx. ribeirensis que a apresentaram nas coletas efetuadas no intradomicílio. A influência da densidade de hospedeiros no ambiente modificado fez-se sentir em relação à primeira dessas três espécies, para as quais as evidências obtidas sugerem que estejam evoluindo no sentido da domiciliação.Results of blood-meal identification for mosquitoes collected in 5 different Ribeira Valley (S.Paulo State, Brazil environments are presented. Precipitin tests identified the sources of 1444 blood-meals. Aedes mosquitoes fed chiefly on mammals. Ae. scapularis showed a preference for cattle and horses. Ae. serratus also obtained meals from avian hosts. Leaving aside the anthropophilic Cx.quinquefasciatus, the other Culex (Culex mosquitoes showed feeding pattern directed to avian hosts. On the whole Culex (Melanoconion showed a largely eclectic

Survey of Borreliae in ticks, canines, and white-tailed deer from Arkansas, U.S.A.

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Fryxell Rebecca T

2012-07-01

Full Text Available Abstract Background In the Eastern and Upper Midwestern regions of North America, Ixodes scapularis (L. is the most abundant tick species encountered by humans and the primary vector of B. burgdorferi, whereas in the southeastern region Amblyomma americanum (Say is the most abundant tick species encountered by humans but cannot transmit B. burgdorferi. Surveys of Borreliae in ticks have been conducted in the southeastern United States and often these surveys identify B. lonestari as the primary Borrelia species, surveys have not included Arkansas ticks, canines, or white-tailed deer and B. lonestari is not considered pathogenic. The objective of this study was to identify Borrelia species within Arkansas by screening ticks (n = 2123, canines (n = 173, and white-tailed deer (n = 228 to determine the identity and locations of Borreliae endemic to Arkansas using PCR amplification of the flagellin (flaB gene. Methods Field collected ticks from canines and from hunter-killed white-tailed were identified to species and life stage. After which, ticks and their hosts were screened for the presence of Borrelia using PCR to amplify the flaB gene. A subset of the positive samples was confirmed with bidirectional sequencing. Results In total 53 (21.2% white-tailed deer, ten (6% canines, and 583 (27.5% Ixodid ticks (252 Ixodes scapularis, 161 A. americanum, 88 Rhipicephalus sanguineus, 50 Amblyomma maculatum, 19 Dermacentor variabilis, and 13 unidentified Amblyomma species produced a Borrelia flaB amplicon. Of the positive ticks, 324 (22.7% were collected from canines (151 A. americanum, 78 R. sanguineus, 43 I. scapularis, 26 A. maculatum, 18 D. variabilis, and 8 Amblyomma species and 259 (37.2% were collected from white-tailed deer (209 I. scapularis, 24 A. maculatum, 10 A. americanum, 10 R. sanguineus, 1 D. variabilis, and 5 Amblyomma species. None of the larvae were PCR positive. A majority of the flaB amplicons were homologous with B

[Changes in the expression of salivary gland genes in Ixodes persulcatus (Ixodidae) depending on the stage of tick feeding].

Science.gov (United States)

Shtannikov, A V; Perovskaia, O N; Reshetniak, T V; Repolovskaia, T V; Panfertsev, E A; Sergeeva, E E; Gutova, V P; Vasil'eva, I S; Ershova, A S; Prilipov, A G; Biketov, S F; Zeidner, N

2009-01-01

By using the guanidine-isothiocyanate test, the authors isolated a summary RNA preparation from Ixodes persulcatus salivary gland extracts. Activity products of the genes responsible for the expression of some salivary proteins were first identified using the RT-PCR. It has been shown that, firstly, I. persulcatus synthesizes at least 3 transcripts homologous to the respective salivary components of the related species I. scapularis, the translation product of which is likely to be immunodominant antigens; secondly, the number of each of these transcripts, as in I. scapularis, depends on the stage of tick feeding. The changes in the expression of each transcript are specific: monotonously increasing changes in Salp 17 and cyclic ones in Salp 16, and synthesis, only when the ticks are fully ingested, in Salp 25.

The Tick Salivary Protein Sialostatin L2 Inhibits Caspase-1-Mediated Inflammation during Anaplasma phagocytophilum Infection

Czech Academy of Sciences Publication Activity Database

Chen, G.; Wang, X.; Sakhon, O. S.; Sohail, M.; Brown, L.J.; Sircar, M.; Snyder, G.A.; Sundberg, E.J.; Ulland, T.K.; Olivier, A.K.; Andersen, J. F.; Zhou, Y.; Shi, G.-P.; Sutterwala, F.S.; Kotsyfakis, Michalis; Pedra, J. H. F.

2014-01-01

Roč. 82, č. 6 (2014), s. 2553-2564 ISSN 0019-9567 Institutional support: RVO:60077344 Keywords : granulocytic ehrlichiosis agent * Ixodes scapularis * tumor necrosis factor Subject RIV: EC - Immunology Impact factor: 3.731, year: 2014

Identification, expression profiling and fluorescence-based binding assays of a chemosensory protein gene from the Western flower thrips, Frankliniella occidentalis.

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Zhi-Ke Zhang

Full Text Available Using RT-PCR and RACE-PCR strategies, we cloned and identified a new chemosensory protein (FoccCSP from the Western flower thrips, Frankliniella occidentalis, a species for which no chemosensory protein (CSP has yet been identified. The FoccCSP gene contains a 387 bp open-reading frame encoding a putative protein of 128 amino acids with a molecular weight of 14.51 kDa and an isoelectric point of 5.41. The deduced amino acid sequence contains a putative signal peptide of 19 amino acid residues at the N-terminus, as well as the typical four-cysteine signature found in other insect CSPs. As FoccCSP is from a different order of insect than other known CSPs, the GenBank FoccCSP homolog showed only 31-50% sequence identity with them. A neighbor-joining tree was constructed and revealed that FoccCSP is in a group with CSPs from Homopteran insects (e.g., AgosCSP4, AgosCSP10, ApisCSP, and NlugCSP9, suggesting that these genes likely developed from a common ancestral gene. The FoccCSP gene expression profile of different tissues and development stages was measured by quantitative real-time PCR. The results of this analysis revealed this gene is predominantly expressed in the antennae and also highly expressed in the first instar nymph, suggesting a function for FoccCSP in olfactory reception and in particular life activities during the first instar nymph stage. We expressed recombinant FoccCSP protein in a prokaryotic expression system and purified FoccCSP protein by affinity chromatography using a Ni-NTA-Sepharose column. Using N-phenyl-1-naphthylamine (1-NPN as a fluorescent probe in fluorescence-based competitive binding assay, we determined the binding affinities of 19 volatile substances for FoccCSP protein. This analysis revealed that anisic aldehyde, geraniol and methyl salicylate have high binding affinities for FoccCSP, with KD values of 10.50, 15.35 and 35.24 μM, respectively. Thus, our study indicates that FoccCSP may play an important role in

Comparative efficacy of some insecticides against cotton whitefly, bemisia tabaci (gennadius) (homoptera: aleyrodidae) under natural field conditions

International Nuclear Information System (INIS)

Nadeem, M.K.; Hasnain, M.; Ahmed, S.; Ashfaq, M.

2011-01-01

Comparative efficacy of five commonly used insecticides viz., acetamiprid, buprofezin, diafenthiuron, imidacloprid and endosulfan against nymph and adult population of cotton whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) under natural field conditions has been studied. Results showed that buprofezin was the most effective insecticide against nymph population of whitefly among the tested insecticides where nymphal population of B. tabaci was 0.2/leaf after 24h spray as compared to 1.9/leaf in control. Acetamiprid was the most effective against adult population of whitefly (0.3 to 1.3/leaf post 72 h spray, as compared to control with 6.9 to 8.2/leaf) followed by diafenthiuron and imidaclopirid. whereas, endosulfan was found to be the least effective on both populations as adult and nymph of whitefly. From the tested insecticides, acetamaprid gave effective control of both nymph and adult population of B. tabaci. (author)

Novel Immunomodulators from Hard Ticks Selectively Reprogramme Human Dendritic Cell Responses

Czech Academy of Sciences Publication Activity Database

Preston, S. G.; Majtán, J.; Kouremenou, C.; Rysnik, O.; Burger, L.F.; Cabezas Cruz, Alejandro; Guzman, M.C.; Nunn, M. A.; Paesen, G.C.; Nuttall, P.A.; Austyn, J.M.

2013-01-01

Roč. 9, č. 6 (2013), e1003450 E-ISSN 1553-7374 Institutional support: RVO:60077344 Keywords : scapularis salivary protein * histamine-binding proteins * tumor necrosis factor Subject RIV: EC - Immunology Impact factor: 8.057, year: 2013

The Toxicity and Detoxifying Mechanism of Cycloxaprid and Buprofezin in Controlling Sogatella furcifera (Homoptera: Delphacidae).

Science.gov (United States)

Chang, Xiaoli; Yuan, Yongda; Zhang, Tianshu; Wang, Dongsheng; Du, Xingbin; Wu, Xiangwen; Chen, Haixia; Chen, Yaozhong; Jiao, Yuetong; Teng, Haiyuan

2015-01-01

The effects of cycloxaprid (a modified neonicotinoid insecticide) and buprofezin (a thiadiazine insecticide) on mortality of the white-backed planthopper (WBPH), Sogatella furcifera, were determined in laboratory assays. Cycloxaprid killed WBPH nymphs and adults but buprofezin killed only nymphs, and cycloxaprid acted faster than buprofezin. One day after infestation, mortality of third-instar nymphs was >65% with cycloxaprid at 125 mg liter(-1) but was buprofezin at 148 mg liter(-1). By the 4th day after infestation, however, control of nymphs by the two insecticides was similar, and cycloxaprid at 125 mg liter(-1) caused ≥ 80% mortality of adults but buprofezin at 148 mg liter(-1) (the highest rate tested) caused almost no adult mortality. LC50 values for cycloxaprid were lowest with nymphs, intermediate with adult males, and highest with adult females. Although buprofezin was slower acting than cycloxaprid, its LC50 for nymphs 5 d after infestation was 3.79-fold lower than that of cycloxaprid. Mean carboxylesterase (CarE) specific activity of nymphal WBPH treated with cycloxaprid and buprofezin was higher than that of control, but there was no significant difference between cycloxaprid and control (no insecticide), and it was significantly higher for buprofezin than those of cycloxaprid and control. For glutathione S-transferase and mixed function oxygenase, the specific activity of nymphal WBPH treated with buprofezin was significantly higher than those of cycloxaprid and control, too. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Laboratory bioassays to estimate the lethal and sublethal effects of various insecticides and fungicides on Deraeocoris brevis (Hemiptera: Miridae).

Science.gov (United States)

Amarasekare, K G; Shearer, P W

2013-04-01

This laboratory bioassay focused on lethal and sublethal effects of five insecticides (chlorantraniliprole, cyantraniliprole, spinetoram, novaluron, and lambda-cyhalothrin) and two fungicide treatments (sulfur and a mixture of copper hydroxide and mancozeb) on the predatory mired bug, Deraeocoris brevis (Uhler) (Hemiptera: Miridae) using second instars and adult males and females. Formulated pesticides were tested using concentrations that were equivalent to the high label rate (1x) (high rate) and 1/10th of that amount (0.1x) (low rate) dissolved in 378.5 liters of water. Lambda-cyhalothrin was highly toxic to D. brevis nymphs and adults at both rates, whereas both rates of novaluron were highly toxic to nymphs. Cyantraniliprole, chlorantraniliprole, and novaluron were less toxic to adults, and chlorantraniliprole and spinetoram were less toxic to nymphs. Both rates of spinetoram caused significant mortality to adults. Fecundity of adult females was affected negatively by the high rates of either novaluron or spinetoram, whereas the fertility was affected only by the high rate of novaluron. The high rate of spinetoram reduced survival of nymphs. Adults treated with spinetoram had reduced longevity. Cyantraniliprole caused some mortality to nymphs and affected their survival. Both rates of sulfur were toxic to nymphs and affected emergence to adults. The mixture of copper hydroxide and mancozeb was less toxic to D. brevis. Neither adult longevity nor sex ratio was affected by the fungicides. The r values for D. brecis treated with lambda-cyhalothrin, novaluron, spinetoram, and sulfur were low, indicating that these products may have negative impact on population growth.

Toxicity of neem oil to Bemisia tabaci biotype B nymphs reared on dry bean Toxicidade de óleo de nim para ninfas de Bemisia tabaci biótipo B criadas em feijoeiro

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Patricia Valle Pinheiro

2009-04-01

Full Text Available The objective of this work was to determine the most susceptible nymphal stage of Bemisia tabaci biotype B to neem (Azadirachta indica A. Juss. oil applied to dry bean (Phaseolus vulgaris L. in a screenhouse. A solution of commercial oil (Dalneem extracted from neem seeds was sprayed directly on each nymphal instar at 0, 0.1, 0.25, 0.5, 1 and 2% concentrations for lethal concentration (LC determination, and at 0, 0.5 and 1% concentrations for lethal time (LT determination. The number of living and dead nymphs was recorded five days after spraying for LC determination, and daily during six days for LT determination. The LC50 estimated for fourth instar nymphs occurred at 0.56% concentration. For all instars, LC50 and LC95 were estimated at 0.32 and 2.78% concentrations, respectively. The estimated values of LT50 at 1% concentration were 2.46, 4.45, 3.02 and 6.98 days for the first to fourth instars, respectively. The LT50 occurred at five days for 0.5% and at four days for 1% concentration in all instars. A mortality rate of over 80% was observed on the 6th day for the first to third instars at 1% concentration. The first three nymphal stages were more susceptible to neem oil when compared to the fourth nymphal stage.O objetivo deste trabalho foi determinar o estágio ninfal de Bemisia tabaci biótipo B mais suscetível ao óleo de nim (Azadirachta indica A. Juss. aplicado em feijoeiro (Phaseolus vulgaris L., em casa telada. Foram avaliados o tempo letal (TL e concentração letal (CL do óleo comercial de sementes de nim Dalneem. Para CL, concentrações de 0, 0,1, 0,25, 0,5, 1 e 2% do produto foram pulverizadas diretamente sobre as ninfas em cada ínstar. Para TL, o produto foi avaliado a 0, 0,5 e 1% de óleo de nim em cada ínstar. Ninfas vivas e mortas foram contadas cinco dias após a pulverização para CL e diariamente para TL durante seis dias. Para o quarto ínstar, a CL50 foi de 0,56% de óleo de nim. Considerando todos os ínstares, CL

REPELLENCY AND FUMIGANT TOXICITY OF CLOVE AND

African Journals Online (AJOL)

DELL

2013-02-27

Feb 27, 2013 ... First nymph was the most sensitive to clove oil by LC50 value 1.06 µl followed by 3.12 µl for fourth nymph and ... cockroach species (3500) existing in the world; they are ... common in restaurant, grocery stores and bakeries as.

Bed Bugs Appearance and Life Cycle

Science.gov (United States)

Identify these bugs accurately, from egg to nymph to adult. Adults are about the size of an apple seed, brown and oval-shaped, and either flat or balloon-like depending on how recently fed. Nymphs are a bit smaller and translucent or whitish yellow.

Hydration benefits to courtship feeding in crickets

Science.gov (United States)

Ivy, T. M.; Johnson, J. C.; Sakaluk, S. K.

1999-01-01

The spermatophore transferred by male decorated crickets (Gryllodes sigillatus) at mating includes a large gelatinous spermatophylax that the female consumes after copulation. Although previous studies have shown that G. sigillatus females gain no nutritional benefits from consuming food gifts, there may be other benefits to their consumption. We examined potential hydration benefits to females by experimentally manipulating both the availability of water and the number of food gifts that females consumed, and by measuring their effect on female fitness. Analysis of the number of nymphs produced by females revealed a significant interaction between the number of spermatophylaxes consumed and water availability. When spermatophylaxes were not provided, females given water ad libitum produced significantly more nymphs than females subjected to water stress. Female longevity was significantly affected by water availability, with an increase in the availability of water corresponding to a significant increase in female longevity. These data suggest that female G. sigillatus accrue fitness benefits by consuming spermatophylaxes when alternative sources of water are unavailable. In addition, females appear to allocate water contained in spermatophylaxes towards reproduction as opposed to survival.

An Architect Cicada in Brazilian Rainforest: Guyalna chlorogena (Walker).

Science.gov (United States)

Béguin, C F

2017-04-01

To study the noteworthy nest building behavior of the nymph of the Brazilian Rainforest cicada Guyalna chlorogena (Walker) during the last year of its underground life, we monitored a large number of edifices, consisting of a vertical well (up to 1 m deep) with a turret (20 to 40 cm tall) on top, and we also performed experiments. We have shown that the buildings are occupied by a single nymph, male or female, which increases the height of its turret each night by about 3 cm, during a short active growing phase. The nymph softens and reshapes the apex by pushing upwards a lump of freshly mixed soaked clay, without any opening present, i. e., without ever exposing itself to the outside. We also established that the nymph is very active once its building is achieved. For example, it restores the height of the turret to its original value when shortening and opens the top of its building in case of variation of environmental parameters. Finally, we have shown how the nymph opens its edifice to reach the outside for molting into an adult stage (imago). With this work, we contributed to a better understanding of the nesting behavior of Amazon cicadas.

Aspectos do Comportamento da Cigarrinha-das-Pastagens Mahanarva spectabilis (Distant, 1909 (Hemiptera: Cercopidae na Produção de Espuma

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Elder Batista

2010-07-01

Abstract. The spittlebug Mahanarva spectabilis (Distant synthesizes a protective froth against natural enemies and dry along the immature stage. This study aimed to evaluate the effect of grouping and forage type in the production of the froth made by the spittlebug, and the behavior exhibited during this period. Tests with individual nymphs were performed in which the average time to complete cover by the froth was 38’55’’ and 40’00’’ in elephant grass (Pennisetum purpureum, Schumach. and signal grass (Brachiaria ruziziensis Germain e Evrard, respectively; as well as tests with groups of nymphs where the average time to complete cover was 48’00’’ in elephant grass and in signal grass 41’06’’. The correlation analysis showed that the nymphs who later initiated the production of froth were those that took the most time to complete the cover within the two forage. The behavioral sequence exhibited by the nymphs was presented, since its release in the pot until the complete cover of the froth. The total time of coverage does not suffer significant change whether the nymphs feed on elephant grass or signal grass, or feeding in solitary or aggregated way.

Genomic Resources Notes accepted 1 April 2014 – 31 May 2014

Czech Academy of Sciences Publication Activity Database

Contreras, M.; de la Fuente, J.; Estrada-Pena, A.; Grubhoffer, Libor; Tobes, R.

2014-01-01

Roč. 14, č. 5 (2014), s. 1095-1095 ISSN 1755-098X Institutional support: RVO:60077344 Keywords : global transcriptome comparison * Ixodes scapularis * Ixodes ricinus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.712, year: 2014

Sequencing and Characterization of the Invasive Sycamore Lace Bug Corythucha ciliata (Hemiptera: Tingidae) Transcriptome

Science.gov (United States)

Qu, Cheng; Fu, Ningning; Xu, Yihua

2016-01-01

The sycamore lace bug, Corythucha ciliata (Hemiptera: Tingidae), is an invasive forestry pest rapidly expanding in many countries. This pest poses a considerable threat to the urban forestry ecosystem, especially to Platanus spp. However, its molecular biology and biochemistry are poorly understood. This study reports the first C. ciliata transcriptome, encompassing three different life stages (Nymphs, adults female (AF) and adults male (AM)). In total, 26.53 GB of clean data and 60,879 unigenes were obtained from three RNA-seq libraries. These unigenes were annotated and classified by Nr (NCBI non-redundant protein sequences), Nt (NCBI non-redundant nucleotide sequences), Pfam (Protein family), KOG/COG (Clusters of Orthologous Groups of proteins), Swiss-Prot (A manually annotated and reviewed protein sequence database), and KO (KEGG Ortholog database). After all pairwise comparisons between these three different samples, a large number of differentially expressed genes were revealed. The dramatic differences in global gene expression profiles were found between distinct life stages (nymphs and AF, nymphs and AM) and sex difference (AF and AM), with some of the significantly differentially expressed genes (DEGs) being related to metamorphosis, digestion, immune and sex difference. The different express of unigenes were validated through quantitative Real-Time PCR (qRT-PCR) for 16 randomly selected unigenes. In addition, 17,462 potential simple sequence repeat molecular markers were identified in these transcriptome resources. These comprehensive C. ciliata transcriptomic information can be utilized to promote the development of environmentally friendly methodologies to disrupt the processes of metamorphosis, digestion, immune and sex differences. PMID:27494615

Toxicity of the herbicide glufosinate-ammonium to predatory insects and mites of Tetranychus urticae (Acari: Tetranychidae) under laboratory conditions.

Science.gov (United States)

Ahn, Y J; Kim, Y J; Yoo, J K

2001-02-01

The toxicities of the herbicide glufosinate-ammonium to three predatory insect and two predatory mite species of Tetranychus urticae Koch were determined in the laboratory by the direct contact application. At a concentration of 540 ppm (a field application rate for weed control in apple orchards), glufosinate-ammonium was almost nontoxic to eggs of Amblyseius womersleyi Schicha, Phytoseiulus persimilis Athias-Henriot, and T. urticae but highly toxic to nymphs and adults of these three mite species, indicating that a common mode of action between predatory and phytophagous mites might be involved. In tests with predatory insects using 540 ppm, glufosinate-ammonium revealed little or no harm to larvae and pupae of Chrysopa pallens Rambur but was slightly harmful to eggs (71.2% mortality), nymphs (65.0% mortality), and adults (57.7% mortality) of Orius strigicollis Poppius. The herbicide showed no direct effect on eggs and adults of Harmonia axyridis (Pallas) but was harmful, slightly harmful, and harmless to first instars (100% mortality), fourth instars (51.1% mortality), and pupae (24.5% mortality), respectively. The larvae and nymphs of predators died within 12 h after treatment, suggesting that the larvicidal and nymphicidal action may be attributable to a direct effect rather than an inhibitory action of chitin synthesis. On the basis of our data, glufosinate-ammonium caused smaller effects on test predators than on T. urticae with the exception of P. persimilis, although the mechanism or cause of selectivity remains unknown. Glufosinate-ammonium merits further study as a key component of integrated pest management.

Within-field spatial distribution of Megacopta cribraria (Hemiptera: Plataspidae) in soybean (Fabales: Fabaceae).

Science.gov (United States)

Seiter, Nicholas J; Reay-Jones, Francis P F; Greene, Jeremy K

2013-12-01

The recently introduced plataspid Megacopta cribraria (F.) can infest fields of soybean (Glycine max (L.) Merrill) in the southeastern United States. Grid sampling in four soybean fields was conducted in 2011 and 2012 to study the spatial distribution of M. cribraria adults, nymphs, and egg masses. Peak oviposition typically occurred in early August, while peak levels of adults occurred in mid-late September. The overall sex ratio was slightly biased at 53.1 ± 0.2% (SEM) male. Sweep samples of nymphs were biased toward late instars. All three life stages exhibited a generally aggregated spatial distribution based on Taylor's power law, Iwao's patchiness regression, and spatial analysis by distance indices (SADIE). Interpolation maps of local SADIE aggregation indices showed clusters of adults and nymphs located at field edges, and mean densities of adults were higher in samples taken from field edges than in those taken from field interiors. Adults and nymphs were often spatially associated based on SADIE, indicating spatial stability across life stages.

Infection of Ixodes ricinus by Borrelia burgdorferi sensu lato in peri-urban forests of France.

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Axelle Marchant

Full Text Available Lyme borreliosis is the most common tick-borne disease in the northern hemisphere. In Europe, it is transmitted by Ixodes ticks that carry bacteria belonging to the Borrelia burgdorferi sensu lato complex. The objective of this work was to explore eco-epidemiological factors of Lyme borreliosis in peri-urban forests of France (Sénart, Notre-Dame and Rambouillet. We investigated whether the introduction of Tamias sibiricus in Sénart could alter the density of infected ticks. Moreover, the density and tick infection were investigated according to the tree species found in various patches of Sénart forest. For this purpose, ticks were sampled during 3 years. In the Sénart forest, the density of nymph and adult ticks showed no significant difference between 2008, 2009 and 2011. The nymph density varied significantly as a function of the month of collection. Regarding the nymphs, a higher rate of infection and infected density were found in 2009. Plots with chipmunks (C presented a lower density of both nymphs and adult ticks than plots without chipmunks (NC did. A higher rate of infection of nymphs with Borrelia was seen in C plots. The prevalence of the various species of Borrelia was also found to vary between C and NC plots with the year of the collect. The presence of chestnut trees positively influenced the density of both nymphs and adults. The infected nymph density showed a significant difference depending on the peri-urban forest studied, Sénart being higher than Rambouillet. The prevalence of Borrelia species also differed between the various forests studied. Concerning the putative role that Tamias sibiricus may play in the transmission of Borrelia, our results suggest that its presence is correlated with a higher rate of infection of questing ticks by Borrelia genospecies and if its population increases, it could play a significant role in the risk of transmission of Lyme borreliosis.

Identification and characterization of histidine-rich peptides from hard ticks Ixodes ricinus and Ixodes scapularis.

OpenAIRE

DORŇÁKOVÁ, Veronika

2011-01-01

Antimicrobial (cationic) proteins play an important role in innate imunity. Such proteins can possess antibacterial, antiendotoxic or fungicidal abilities. The rising resistence of microbes to common antibiotics evokes acute need of studying more endogenous proteins to reveal new potential antibiotics. Ticks, the blood-feeding ectoparasites with effectual defense system, present an endless source of newly described and unknown antimicrobial peptides/proteins with significant theurapeutic pote...

New Thai herbal shampoos as pediculicides for killing head louse, Pediculus humanus capitis De Geer (Phthiraptera

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Sirawut Sittichok

2018-01-01

Full Text Available Objective: To evaluate the efficacy of Thai herbal shampoos [Cartoxylum formosum (C. formosum + eucalyptus essential oil (EO, C. formosum + citrus EO, Solanum trilobatum + eucalyptus EO, Solanum trilobatum + citrus EO, Moringa oleifera + eucalyptus EO and Moringa oleifera + citrus EO] for killing all stages of Pediculus humanus capitis (Phthiraptera. Methods: A filter paper contact method was applied with three concentrations (0.05, 0.10 and 0.20 mL/cm2 of each Thai herbal shampoo as well as permethrin pediculicide (positive control and drinking water (negative control against eggs, nymphs and adults of Pediculus humanus capitis. Mortality rates of the eggs were recorded after 7 days of incubation while those of nymphs and adults were recorded after 5 minutes of contact. Results: All herbal shampoos at the high concentration were highly effective against nymphs and adults, but not effective against the eggs. C. formosum + eucalyptus EO and C. formosum + citrus EO shampoos at all concentrations exhibited the highest efficacy against nymphs and adults with 100% mortality rate at 5 min and LC50 values of 0.004 and 0.005 mL/cm2, respectively. All formulation of Solanum trilobatum and Moringa oleifera shampoos added with eucalyptus EO showed mortality rates against nymphs at 92.0%-100.0% and 76.0%-100.0% and against adults at 84.0%-100.0% and 20.0%-32.0%, respectively. Permethrin pediculicide was not effective against the eggs, but showed 68.0%-92.0% and 28.0%-60.0% mortality rates against nymphs and adults. Conclusions: These results indicate that C. formosum + eucalyptus EO shampoo can be used as an effective nymphicide and adulticide against Pediculus humanus capitis.

Refractoriness of the western fence lizard (Sceloporus occidentalis) to the Lyme disease group spirochete Borrelia bissettii.

Science.gov (United States)

Lane, R S; Mun, J; Eisen, L; Eisen, R J

2006-08-01

The western fence lizard, Sceloporus occidentalis, is refractory to experimental infection with Borrelia burgdorferi sensu stricto, one of several Lyme disease spirochetes pathogenic for humans. Another member of the Lyme disease spirochete complex, Borrelia bissettii, is distributed widely throughout North America and a similar, if not identical, spirochete has been implicated as a human pathogen in southern Europe. To determine the susceptibility of S. occidentalis to B. bissettii, 6 naïve lizards were exposed to the feeding activities of Ixodes pacificus nymphs experimentally infected with this spirochete. None of the lizards developed spirochetemias detectable by polymerase chain reaction for up to 8 wk post-tick feeding, infected nymphs apparently lost their B. bissettii infections within 1-2 wk after engorgement, and xenodiagnostic L. pacificus larvae that co-fed alongside infected nymphs did not acquire and maintain spirochetes. In contrast, 3 of 4 naïve deer mice (Peromyscus maniculatus) exposed similarly to feeding by 1 or more B. bissettii-infected nymphs developed patent infections within 4 wk. These and previous findings suggest that the complement system of S. occidentalis typically destroys B. burgdorferi sensu lato spirochetes present in tissues of attached and feeding I. pacificus nymphs, thereby potentially reducing the probability of transmission of these bacteria to humans or other animals by the resultant adult ticks.

Delivery of dsRNA through topical feeding for RNA interference in the citrus sap piercing-sucking hemipteran, Diaphorina citri.

Science.gov (United States)

Killiny, Nabil; Kishk, Abdelaziz

2017-06-01

RNA interference (RNAi) is a powerful means to study functional genomics in insects. The delivery of dsRNA is a challenging step in the development of RNAi assay. Here, we describe a new delivery method to increase the effectiveness of RNAi in the Asian citrus psyllid Diaphorina citri. Bromophenol blue droplets were topically applied to fifth instar nymphs and adults on the ventral side of the thorax between the three pairs of legs. In addition to video recordings that showed sucking of the bromophenol blue by the stylets, dissected guts turned blue indicating that the uptake was through feeding. Thus, we called the method topical feeding. We targeted the abnormal wing disc gene (awd), also called nucleoside diphosphate kinase (NDPK), as a reporter gene to prove the uptake of dsRNA via this method of delivery. Our results showed that dsRNA-awd caused reduction of awd expression and nymph mortality. Survival and lifespan of adults emerged from treated nymphs and treated adults were affected. Silencing awd caused wing malformation in the adults emerged from treated nymphs. Topical feeding as a delivery of dsRNA is highly efficient for both nymphs and adults. The described method could be used to increase the efficiency of RNAi in D. citri and other sap piercing-sucking hemipterans. © 2017 Wiley Periodicals, Inc.

Latency and Persistence of 'Candidatus Liberibacter asiaticus' in Its Psyllid Vector, Diaphorina citri (Hemiptera: Liviidae).

Science.gov (United States)

Canale, Maria Cristina; Tomaseto, Arthur Fernando; Haddad, Marineia de Lara; Della Coletta-Filho, Helvécio; Lopes, João Roberto Spotti

2017-03-01

Although 'Candidatus Liberibacter asiaticus' (Las) is a major pathogen associated with citrus huanglongbing (HLB), some characteristics of transmission by the psyllid vector Diaphorina citri are not fully understood. We examined the latent period and persistence of transmission of Las by D. citri in a series of experiments at 25°C, in which third-instar psyllid nymphs and 1-week-old adults were confined on infected citrus for an acquisition access period (AAP), and submitted to sequential inoculation access periods (IAPs) on healthy citrus seedlings. The median latent period (LP 50 , i.e., acquisition time after which 50% of the individuals can inoculate) of 16.8 and 17.8 days for psyllids that acquired Las as nymphs and adults, respectively, was determined by transferring single individuals in 48-h IAPs. Inoculation events were intermittent and randomly distributed over the IAPs, but were more frequent after acquisition by nymphs. A minimum latent period of 7 to 10 days was observed by transferring groups of 10 psyllids in 48-h IAPs, after a 96-h AAP by nymphs. Psyllids transmitted for up to 5 weeks, when submitted to sequential 1-week IAPs after a 14-day AAP as nymphs. The long latent period and persistence of transmission are indirect evidences of circulative propagation of Las in D. citri.

Vaccinomics Approach to the Identification of Candidate Protective Antigens for the Control of Tick Vector Infestations and Anaplasma phagocytophilum Infection

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Marinela Contreras

2017-08-01

Full Text Available Anaplasma phagocytophilum is an emerging tick-borne pathogen causing human granulocytic anaplasmosis (HGA, tick-borne fever (TBF in small ruminants, and other forms of anaplasmosis in different domestic and wild animals. The main vectors of this pathogen are Ixodes tick species, particularly I. scapularis in the United States and I. ricinus in Europe. One of the main limitations for the development of effective vaccines for the prevention and control of A. phagocytophilum infection and transmission is the identification of effective tick protective antigens. The objective of this study was to apply a vaccinomics approach to I. scapularis-A. phagocytophilum interactions for the identification and characterization of candidate tick protective antigens for the control of vector infestations and A. phagocytophilum infection. The vaccinomics pipeline included the use of quantitative transcriptomics and proteomics data from uninfected and A. phagocytophilum-infected I. scapularis ticks for the selection of candidate protective antigens based on the variation in tick mRNA and protein levels in response to infection, their putative biological function, and the effect of antibodies against these proteins on tick cell apoptosis and pathogen infection. The characterization of selected candidate tick protective antigens included the identification and characterization of I. ricinus homologs, functional characterization by different methodologies including RNA interference, immunofluorescence, gene expression profiling, and artificial tick feeding on rabbit antibodies against the recombinant antigens to select the candidates for vaccination trials. The vaccinomics pipeline developed in this study resulted in the identification of two candidate tick protective antigens that could be selected for future vaccination trials. The results showed that I. scapularis lipocalin (ISCW005600 and lectin pathway inhibitor (AAY66632 and I. ricinus homologs constitute

EST Table: DC572689 [KAIKOcDNA[Archive

Lifescience Database Archive (English)

Full Text Available DC572689 E_FL_wd--_27G20_R_0 10/09/28 53 %/126 aa ref|XP_002400269.1| DNA mismatch repair protein mlh1..., putative [Ixodes scapularis] gb|EEC09245.1| DNA mismatch repair protein mlh1, putative

EST Table: DC572641 [KAIKOcDNA[Archive

Lifescience Database Archive (English)

Full Text Available DC572641 E_FL_wd--_27E09_R_0 10/09/28 52 %/145 aa ref|XP_002400269.1| DNA mismatch repair protein mlh1..., putative [Ixodes scapularis] gb|EEC09245.1| DNA mismatch repair protein mlh1, putative

EST Table: DC563666 [KAIKOcDNA[Archive

Lifescience Database Archive (English)

Full Text Available DC563666 E_FL_wd--_01A16_R_0 10/09/28 53 %/141 aa ref|XP_002400269.1| DNA mismatch repair protein mlh1..., putative [Ixodes scapularis] gb|EEC09245.1| DNA mismatch repair protein mlh1, putative

EST Table: DC566703 [KAIKOcDNA[Archive

Lifescience Database Archive (English)

Full Text Available DC566703 E_FL_wd--_09O22_R_0 10/09/28 52 %/145 aa ref|XP_002400269.1| DNA mismatch repair protein mlh1..., putative [Ixodes scapularis] gb|EEC09245.1| DNA mismatch repair protein mlh1, putative

[Entomologic situation regarding arbovirus circulation in the Guajaibon area].

Science.gov (United States)

Fuentes González, O; Fernández Martínez, A; Castex Rodríguez, M; Pelegrino Martínez, J L

1989-01-01

The collections of culicidae made in the Guajaibón area, North coast of Havana province, are analyzed with arbovirologic purposes. The predominance of Aedes scapularis in the human bait collections is confirmed. The possibility of arbovirus circulation in the area is suggested.

Remodeling of tick cytoskeleton in response to infection with Anaplasma phagocytophilum

Czech Academy of Sciences Publication Activity Database

Cabezas Cruz, Alejandro; Alberdi, P.; Valdés, James J.; Villar, M.; de la Fuente, J.

2017-01-01

Roč. 22, Jun 1 (2017), s. 1830-1844 ISSN 1093-4715 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : cytoskeleton * proteomics * transcriptomics * Ixodes scapularis * Anaplasma phagocytophilum Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology

An Ixodes ricinus Tick Salivary Lectin Pathway Inhibitor Protects Borrelia burgdorferi sensu lato from Human Complement

NARCIS (Netherlands)

Wagemakers, Alex; Coumou, Jeroen; Schuijt, Tim J.; Oei, Anneke; Nijhof, Ard M.; van 't Veer, Cornelis; van der Poll, Tom; Bins, Adriaan D.; Hovius, Joppe W. R.

2016-01-01

We previously identified tick salivary lectin pathway inhibitor (TSLPI) in Ixodes scapularis, a vector for Borrelia burgdorferi sensu stricto (s.s.) in North America. TSLPI is a salivary protein facilitating B. burgdorferi s.s. transmission and acquisition by inhibiting the host lectin complement

Evaluating the utility of companion animal tick surveillance practices for monitoring spread and occurrence of human Lyme disease in West Virginia, 2014-2016

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Brian Hendricks

2017-11-01

Full Text Available Domestic dogs and cats are potentially effective sentinel populations for monitoring occurrence and spread of Lyme disease. Few studies have evaluated the public health utility of sentinel programmes using geo-analytic approaches. Confirmed Lyme disease cases diagnosed by physicians and ticks submitted by veterinarians to the West Virginia State Health Department were obtained for 2014-2016. Ticks were identified to species, and only Ixodes scapularis were incorporated in the analysis. Separate ordinary least squares (OLS and spatial lag regression models were conducted to estimate the association between average numbers of Ix. scapularis collected on pets and human Lyme disease incidence. Regression residuals were visualised using Local Moran’s I as a diagnostic tool to identify spatial dependence. Statistically significant associations were identified between average numbers of Ix. scapularis collected from dogs and human Lyme disease in the OLS (β=20.7, P<0.001 and spatial lag (β=12.0, P=0.002 regression. No significant associations were identified for cats in either regression model. Statistically significant (P≤0.05 spatial dependence was identified in all regression models. Local Moran’s I maps produced for spatial lag regression residuals indicated a decrease in model over- and under-estimation, but identified a higher number of statistically significant outliers than OLS regression. Results support previous conclusions that dogs are effective sentinel populations for monitoring risk of human exposure to Lyme disease. Findings reinforce the utility of spatial analysis of surveillance data, and highlight West Virginia’s unique position within the eastern United States in regards to Lyme disease occurrence.

Revealing the diversity of a once small taxon: the genus Selenoribates (Acari, Oribatida, Selenoribatidae

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Tobias Pfingstl

2013-06-01

Full Text Available Three new intertidal oribatid species, Selenoribates elegans sp. n., Selenoribates quasimodo sp. n. and Selenoribates satanicus sp. n. are described from the archipelago of Bermuda. Selenoribates elegans sp. n. is characterized by its slender body shape, S. quasimodo sp. n. possesses a hunchback in lateral view and S. satanicus sp. n. exhibits two horn-like projections on its anterior gastronotic region. Based on these new findings, the number of Selenoribates species doubled at once and the distribution of this genus, formerly limited to the Mediterranean and the Red Sea, includes now occurrences in the Atlantic and Indo-pacific Ocean as well. The morphology of S. quasimodo sp. n. and S. satanicus sp. n. deviates conspicuously from the other known members of Selenoribates, thus indicating that not only the number of species but also the anatomy of this genus is more diverse than formerly supposed. Nymphs of S. quasimodo sp. n. show an interesting case of ontogenetic neotrichy, with gastronotic setae being duplicated with each moult.

A formulation to encapusulate nootkatone oil for tick control

Science.gov (United States)

Nootkatone is a component of grapefruit oil that is toxic to the disease vectoring tick, Ixodes scapularis Say, but unfortunately causes phytotoxicity to treated plants and has a short residual activity due to volatility. We prepared an encapsulated formulation of nootkatone using lignin to compare...

Evaluation of four commercial natural products for repellency and toxicity against the lone star tick, Amblyomma americanum (Acari: Ixodidae).

Science.gov (United States)

Machtinger, Erika T; Li, Andrew Y

2017-12-01

Lone star ticks are aggressive ectoparasites of domestic and wild animals, as well as humans. These ticks can transmit many pathogens that cause disease including Erhlichia and tularemia. Common compounds used for personal protection and area sprays are N-diethyl-3-methyl benzamide (DEET) and permethrin, but public concern over personal and environmental safety require the development of new, safer products. In the current study, four commercially available products (Wondercide, Essentria IC 3 , Vet's Best, and Mosquito Barrier) were tested for both repellent and toxic effects against lone star tick nymphs and adults. Overall, all four products were more effective against nymphs than against adults. Wondercide and Essentria IC 3 were as toxic to nymphs as permethrin at concentrations of 3.13% and higher, and as repellent as DEET at all concentrations. Nymphs were also repelled by Mosquito Barrier and Vet's Best, but these products had about half or less of the repellent effects of Wondercide and Essentria IC 3 at most of the concentrations. Adult ticks were repelled similarly by all products at all tested concentrations, but at lower levels than nymphs. Toxicity of the four tested products on adults was similar at concentrations of 12.5% and below, less than half of what was observed with permethrin with declining effectiveness as concentrations decreased. Overall, these four products may offer a natural way to repel lone star ticks, but further field testing is needed to determine rates of application and residual activity.

The Enchanted Hunters in Nabokov’s Lolita

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Justine Shu- Ting Kao

2017-06-01

Full Text Available In Nabokov’s Lolita, Humbert Humbert’s The Enchanted Hunters, as a quest for love, aims to reconstruct a felicitous world or integrate various fragmentary details into an organic unity that revives a lost love, experiencing it on the basis of irony, and revealing a simulation of the desire, violence, and despondency which have been expressed in myths of nymphs and Persephone. The protagonist never reaches this unity, but his narrative of erotic and romantic love reveals him as a pathetic addict engaged in mechanical reproduction related to the phenomena of desire, seduction, violence, and sex. His The Enchanted Hunters does not simulate what he expects of his childhood love with Annabel; rather, it simulates the erotic imagination suggested in Mary D. Sheriff’s term “nymphomania,” in which artists fall degenerately to a model of tragedy. Keywords: simulation, nymph, nymphomania, The Enchanted Hunters The Enchanted Hunters in Nabokov’s Lolita refers to the name of a hotel and the title of a play. This seeming coincidence is actually not coincidental: Nabokov weaves a story concerning a pedophile’s seduction of a prepubescent child into a “story within a story,” in which the girl is imagined as a seducer who bewitches a number of hunters. Just as the girl in the play is a figment of a poet’s imagination, so Lolita in the novel Lolita is an imaginary production of a middle-aged pedophile. Yet Lolita is not so much a novel revealing guilt and mental disorder, but a mélange of art and reality, or more specifically, it is about a coinage in which the author fabricates art and myth in real life. Parallel to the protagonist who simulates what he expects of his childhood love, Annabel, in the form of the nymphet, Lolita, Nabokov replicates the beauty of butterflies in the pursuit of beauty and immortality, and develops the world of art with a pathetic tone whereby we gradually perceive a simulation of the desire, violence, and

Identification of a sex pheromone of the chrysanthemum lace bug Corythucha marmorata (Hemiptera: Tingidae).

Science.gov (United States)

Watanabe, Kisaki; Shimizu, Nobuhiro

2017-08-04

Although the nymphs of Corythucha marmorata form clusters on the undersides of host plant leaves, as frequently observed for Hemiptera, the adults are scattered in the vicinity of the nymph population. By investigating the biological activities of volatile secretions from the adult, we found that the secretions activated male mounting behaviour. A chemical analysis revealed that borneol was a common component of the secretions from both sexes. The absolute configuration of the natural product was the (+)-enantiomer of borneol and the optical isomer was undetectable. Although (+)-borneol showed significant sex pheromone activity against males, the antipode (-)-borneol also induced sex pheromone activity, albeit only slightly. Males may not have a strict identification mechanism based on stereochemistry. To verify the origin of this sex pheromone, we analysed the components of the essential oil of the leaves of Solidago canadensis L. (Compositae: Asteraceae), a host plant; bornyl acetate was detected to be a major component. The plant-produced bornyl acetate had different stereochemistry from the sex pheromone. The results suggested that the adults do not utilise the secondary metabolites of plants but biosynthesise this sex pheromone themselves. This is the first report on sex pheromone identification in Tingidae.

Search for Borrelia sp. in ticks collected from potential reservoirs in an urban forest reserve in the State of Mato Grosso do Sul, Brazil: a short report

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IP da Costa

2002-07-01

Full Text Available A total of 128 ticks of the genus Amblyomma were recovered from 5 marsupials (Didelphis albiventris - with 4 recaptures - and 17 rodents (16 Bolomys lasiurus and 1 Rattus norvegicus captured in an urban forest reserve in Campo Grande, State of Mato Grosso do Sul, Brazil. Of the ticks collected, 95 (78.9% were in larval form and 22 (21.1% were nymphs; the only adult (0.8% was identified as A. cajennense. Viewed under dark-field microscopy in the fourth month after seeding, 9 cultures prepared from spleens and livers of the rodents, blood of the marsupials, and macerates of Amblyomma sp. nymphs revealed spiral-shaped, spirochete-like structures resembling those of Borrelia sp. Some of them showed little motility, while others were non-motile. No such structures could be found either in positive Giemsa-stained culture smears or under electron microscopy. No PCR amplification of DNA from those cultures could be obtained by employing Leptospira sp., B. burgdorferi, and Borrelia sp. primers. These aspects suggest that the spirochete-like structures found in this study do not fit into the genera Borrelia or Leptospira, requiring instead to be isolated for proper identification.

Particle film affects black pecan aphid (Homoptera: Aphididae) on pecan.

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Cottrell, Ted E; Wood, Bruce W; Reilly, Charles C

2002-08-01

Three species of aphids attack pecan foliage, Carya illinoensis (Wang.) K. Koch, and cause economic damage. We tested a kaolin-based particle film against one of these aphid species, black pecan aphid, Melanocallis caryaefoliae (Davis). Effect of particle film on host selection, adult mortality, and production of nymphs by M. caryaefoliae was tested on seedling pecans in the laboratory. Fewer M. caryaefoliae adults selected treated foliage compared with untreated foliage. A higher percentage of adults that did select treated foliage were recovered from upper leaf surfaces compared with the percentage of adults recovered from upper leaf surfaces of untreated leaves. Observations with a microscope revealed an accumulation of particle film on aphid body parts, especially on tarsi, and strongly suggests that aphid mobility was restricted. Adult mortality was higher on treated foliage and led to an overall decrease in production of nymphs on those seedlings. In addition, we measured spectral properties of treated seedling pecan foliage. Light reflectance by treated foliage was increased and absorptance decreased compared with control foliage whereas transmittance of light through control and particle film-treated leaves was similar. We did not detect any phytotoxic effect on pecan due to application of particle film.

Natural parasitism of Diaphorina citri Kuwayama (Hemiptera, Psyllidae nymphs by Tamarixia radiata Waterston (Hymenoptera, Eulophidae in São Paulo orange groves Parasitismo natural de ninfas de Diaphorina citri Kuwayama (Hemiptera, Psyllidae por Tamarixia radiata Waterston (Hymenoptera, Eulophidae em pomares de laranja em São Paulo

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Paulo Eduardo Branco Paiva

2012-12-01

Full Text Available The psyllid Diaphorina citri Kuwayama 1908 has become the main citrus pest species in the state of São Paulo, Brazil, after the introduction of the huanglongbing or citrus greening. This study evaluated the parasitism of 3rd, 4th and 5th instar D. citri nymphs by Tamarixia radiata (Waterston, 1922 in citrus groves under a regimen of regular insecticide applications in ten producing regions: Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins and São João da Boa Vista. Sixty-nine samples of new branches infested with nymphs of D. citri were collected from 2005 to 2008 in orange groves ranging from 1 to 20 years old, of the varieties Hamlin, Pera, Valencia and Natal. The parasitoid T. radiata is widely distributed in São Paulo orange groves, and was identified in 50 (72% of the samples, showing a mean parasitism rate of 12.4%. The highest parasitism rate was observed in the "summer" (from January through March, with a mean of 25.7%. Nymphal parasitism was above 90% in two samples. The probable causes of the variations in parasitism of D. citri by T. radiata are discussed.O psilídeo Diaphorina citri Kuwayama 1908 tornou-se a principal praga dos citros no estado de São Paulo após a introdução do huanglongbing ou grenning dos citros. Este estudo avaliou as proporções de ninfas de terceiro a quinto ínstares de D. citri parasitadas por Tamarixia radiata (Waterston, 1922 em pomares de laranja submetidos a pulverizações constantes de inseticidas em dez regiões produtoras, Araraquara, Barretos, Bauru, Botucatu, Franca, Itapetininga, Jaú, Limeira, Lins e São João da Boa Vista. Foram coletadas 69 amostras de ramos jovens infestados com ninfas de D. citri obtidas entre 2005 e 2008 em pomares de 1 a 20 anos de idade, das cultivares Hamilin, Pera, Valencia e Natal. O parasitóide T. radiata encontra-se amplamente distribuído em pomares de São Paulo, tendo sido observado em 50 amostras (72%, com taxa média de

Molecular biology of tick Acetylcholinesterases – a minireview

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Ticks are important hematophagous arthropod ectoparasites and like mosquitoes, are vectors for a wide variety of human and animal pathogens. Ticks have significant world-wide health and economic impacts. In the U.S., major impacts include the ability of the blacklegged tick, Ixodes scapularis, to tr...

Identification of Salp15 homologues in Ixodes ricinus ticks

NARCIS (Netherlands)

Hovius, J. W. R.; Ramamoorthi, N.; van't Veer, C.; de Groot, K. A.; Nijhof, A. M.; Jongejan, F.; van Dam, A. P.; Fikrig, E.

2007-01-01

The 15-kDa Ixodes scapularis salivary gland protein Salp15 protects Borrelia burgdorferi sensu stricto from antibody-mediated killing and facilitates infection of the mammalian host. In addition, Salp 15 has been shown to inhibit T-cell activation. We determined whether Ixodes ricinus, the major

Preferential protection of Borrelia burgdorferi sensu stricto by a Salp15 homologue in Ixodes ricinus saliva

NARCIS (Netherlands)

Hovius, J. W.; Schuijt, T. J.; de Groot, K. A.; Roelofs, J. J. T. H.; Oei, G. A.; Marquart, J. A.; de Beer, R.; van 't Veer, C.; van der Poll, T.; Ramamoorthi, N.; Fikrig, E.; van Dam, A. P.

2008-01-01

BACKGROUND: Ixodes ticks are the main vectors for Borrelia burgdorferi sensu lato. In the United States, B. burgdorferi is the sole causative agent of Lyme borreliosis and is transmitted by Ixodes scapularis. In Europe, 3 Borrelia species-B. burgdorferi, B. garinii, and B. afzelii-are prevalent,

Evaluation of electrical conductivity of the fertiliser solution on ...

African Journals Online (AJOL)

The effects of three fertiliser solutions (20:20:20, 15:5:25 and 12:30:10 NPK) with electrical conductivity (EC) of 1, 1.5 or 2 mS cm-1 on growth and flowering of Cymbidium 'Sleeping Nymph' were investigated over three years. One-year-old tissue-cultured propagules of 'Sleeping Nymph' were planted singly in plastic pots in ...

Histopathology of nymphal pentastomid infections (Sebekia mississippiensis) in paratenic hosts.

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Boyce, W M; Kazacos, E A

1991-02-01

The histopathologic alterations occurring in mice, hamsters, turtles, and a frog were described following experimental infection with nymphs of Sebekia mississippiensis. Initially, nymphal migration caused traumatic tissue damage and hemorrhage characteristic of larva migrans. Subsequent inflammatory responses included cellular infiltration with eosinophils, macrophages, and lymphocytes, and fibrotic encapsulation of the nymphs. Dead nymphs were surrounded by a necrotic granulomatous response similar to that reported previously in humans and other animals. Differences were not seen in animals given single or multiple infections, but mice and hamsters exhibited a more marked inflammatory response than turtles. Overall, the histopathologic response to nymphal infections resembled those seen in infections resulting from ingestion of eggs, and both sources of infection should be considered in epidemiologic investigations of naturally occurring pentastomiasis.

Population structure of Argas arboreus (Acari : Argasidae ticks associated with seasonally abandoned mixed heronries, dominated by cattle egrets (Bubulcus ibis, in South Africa

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V.N. Belozerov

2003-11-01

Full Text Available During winter populations of Argas arboreus from heronries of the cattle egret, Bubulcus ibis, in South Africa are composed of adults, with some predominance of males, and II-IV instar nymphs, in a state of diapause. The period of tick activity, including reproduction and development of eggs, larvae and N1 nymphs, is synchronized with the nesting and breeding season of their avian hosts. It begins during spring with the return of birds to the heronry, and ceases in autumn through induction of reproductive diapause in engorged females, and behavioural diapause in unfed nymphs and adult ticks. Many ticks showed morphological anomalies and malformations, the study of which could possibly be used for monitoring of environmental pollution.

EFFECTS OF AZADIRACHTIN ON THE SUNN PEST, EURYGASTER INTEGRICEPS PUT. (HETEROPTERA, SCUTELLERIDAE IN THE LABORATORY

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Müjgan KIVAN

2006-02-01

Full Text Available To investigate the effect of azadirachtin on different stages of the sunn pest, Eurygaster integriceps Put. (Het., Scutelleridae in the laboratory, a commercial neem insecticide (NeemAzal T/S was applied at dose of 0.5 % by dipping insects. No effect was observed for 1. instar nymphs at 1 day after application, although adults had slightly effect (20 %. Adults and nymphs were infl uenced 7 days after the treatment and mortality rates for adults and nymphs were recorded 44.0 and 51.9 %, respectively. The hatching of treated eggs was reduced than control. These results indicate that NeemAzal T/S may be used in integrated sunn pest management, but should be evaluated for fi eld efficacy.

Ticks on birds from Cerrado forest patches along the Uberabinha river in the Triângulo Mineiro region of Minas Gerais, Brazil

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Khelma Torga

2013-10-01

Full Text Available We herein describe ticks parasitizing birds in forest fragments along the Uberabinha River, a major watercourse that cuts through patches of remnants of Brazilian savannah in Uberlândia, Minas Gerais, Brazil. Overall 352 birds from 62 species, overwhelmingly, Passeriformes, were captured with mist-nets. The most abundant bird species was Basileuterus hypoleucus (n=36, followed by Lanio penicillata (n=24 and Thalurania furcata (n=23. Thirty one birds, all Passeriformes, were found infested with 56 ticks from which 12 were larvae and 44 nymphs, all from the Amblyomma genus. Highest infestation prevalence was found on Taraba major (66.6%, Thamnophilus pelzeni (60% and Saltator maximus (50%. The mean intensity of tick infestation was low (1.8 tick per infested bird with most of the parasites located on the neck (60% of birds, followed by the head (20%. All larvae were attached to the skin around the eyes of birds. Amblyomma nodosum was the most numerous tick species found attached to birds (n=23 nymphs, 52.3% of nymphs followed by Amblyomma longirostre (n=5, 11.4% of nymphs. Ecological relationships are discussed.

The Rare ospC Allele L of Borrelia burgdorferi Sensu Stricto, Commonly Found among Samples Collected in a Coastal Plain Area of the Southeastern United States, Is Associated with Ixodes affinis Ticks and Local Rodent Hosts Peromyscus gossypinus and Sigmodon hispidus

Czech Academy of Sciences Publication Activity Database

Rudenko, Natalia; Golovchenko, Maryna; Grubhoffer, Libor; Oliver, J. H., Jr.

2013-01-01

Roč. 79, č. 4 (2013), s. 1403-1406 ISSN 0099-2240 Grant - others:NIH(US) R37AI-24899 Institutional support: RVO:60077344 Keywords : lyme disease * genetic diversity * scapularis tick * Acari * North Carolina * heterogenity * polymorphism * cultivation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.952, year: 2013

Life cycle, feeding and defecation patterns of Rhodnius ecuadoriensis (Lent & León 1958 (Hemiptera: Reduviidae: Triatominae under laboratory conditions

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Anita G Villacís

2008-11-01

Full Text Available Rhodnius ecuadoriensis is the second most important vector of Chagas Disease (CD in Ecuador. The objective of this study was to describe (and compare the life cycle, the feeding and defecation patterns under laboratory conditions of two populations of this specie [from the provinces of Manabí (Coastal region and Loja (Andean region]. Egg-to-adult (n = 57 development took an average of 189.9 ± 20 (Manabí and 181.3 ± 6.4 days (Loja. Mortality rates were high among Lojan nymphs. Pre-feeding time (from contact with host to feeding initiation ranged from 4 min 42 s [nymph I (NI] to 8 min 30 s (male; feeding time ranged from 14 min 45 s (NI-28 min 25 s (male (Manabí and from 15 min 25 s (NI-28 min 57 s (nymph V (Loja. The amount of blood ingested increased significantly with instar and was larger for Manabí specimens (p < 0.001. Defecation while feeding was observed in Manabí specimens from stage nymph III and in Lojan bugs from stage nymph IV. There was a gradual, age-related increase in the frequency of this behaviour in both populations. Our results suggest that R. ecuadoriensis has the bionomic traits of an efficient vector of Trypanosoma cruzi. Together with previous data on the capacity of this species to infest rural households, these results indicate that control of synanthropic R. ecuadoriensis populations in the coastal and Andean regions may have a significant impact for CD control in Ecuador and Northern Peru.

Utilization of early soybeans for food and reproduction by the tarnished plant bug (Hemiptera: Miridae) in the delta of Mississippi.

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Snodgrass, G L; Jackson, R E; Abel, C A; Perera, O P

2010-08-01

Commercially produced maturity group (MG) IV soybeans, Glycine max L., were sampled during bloom for tarnished plant bugs, Lygus lineolaris (Palisot de Beauvois), during May and June 1999 (3 fields) and 2001 (18 fields). The adults and nymphs were found primarily in single population peaks in both years, indicating a single new generation was produced during each year. The peak mean numbers of nymphs were 0.61 and 0.84 per drop cloth sample in 1999 and 2001, respectively. Adults peaked at 3.96 (1999) and 3.76 (2001) per sweep net sample (25 sweeps). Tests using laboratory-reared and field-collected tarnished plant bugs resulted in very poor survival of nymphs on 16 different soybean varieties (MG III, one; IV, four; V, nine; VI, two). A large cage (0.06 ha) field test found that the number of nymphs produced on eight soybean varieties after mated adults were released into the cages was lower than could be expected on a suitable host. These results indicated that soybean was a marginal host for tarnished plant bugs. However, the numbers of adults and nymphs found in the commercially produced fields sampled in the study may have been high enough to cause feeding damage to the flowering soybeans. The nature of the damage and its possible economic importance were not determined. Reproduction of tarnished plant bugs in the commercially produced early soybean fields showed that the early soybeans provided tarnished plant bugs with a very abundant host at a time when only wild hosts were previously available.

Variable strength of forest stand attributes and weather conditions on the questing activity of Ixodes ricinus ticks over years in managed forests.

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Ralf Lauterbach

Full Text Available Given the ever-increasing human impact through land use and climate change on the environment, we crucially need to achieve a better understanding of those factors that influence the questing activity of ixodid ticks, a major disease-transmitting vector in temperate forests. We investigated variation in the relative questing nymph densities of Ixodes ricinus in differently managed forest types for three years (2008-2010 in SW Germany by drag sampling. We used a hierarchical Bayesian modeling approach to examine the relative effects of habitat and weather and to consider possible nested structures of habitat and climate forces. The questing activity of nymphs was considerably larger in young forest successional stages of thicket compared with pole wood and timber stages. Questing nymph density increased markedly with milder winter temperatures. Generally, the relative strength of the various environmental forces on questing nymph density differed across years. In particular, winter temperature had a negative effect on tick activity across sites in 2008 in contrast to the overall effect of temperature across years. Our results suggest that forest management practices have important impacts on questing nymph density. Variable weather conditions, however, might override the effects of forest management practices on the fluctuations and dynamics of tick populations and activity over years, in particular, the preceding winter temperatures. Therefore, robust predictions and the detection of possible interactions and nested structures of habitat and climate forces can only be quantified through the collection of long-term data. Such data are particularly important with regard to future scenarios of forest management and climate warming.

Potential for entomopathogenic fungi to control Triatoma dimidiata (Hemiptera: Reduviidae, a vector of Chagas disease in Mexico

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María Guadalupe Vázquez-Martínez

2014-12-01

Full Text Available Introduction The use of entomopathogenic fungi to control disease vectors has become relevant because traditional chemical control methods have caused damage to the environment and led to the development of resistance among vectors. Thus, this study assessed the pathogenicity of entomopathogenic fungi in Triatoma dimidiata. Methods Preparations of 108 conidia/ml of Gliocladium virens, Talaromyces flavus, Beauveria bassiana and Metarhizium anisopliae were applied topically on T. dimidiata nymphs and adults. Controls were treated with the 0.0001% Tween-80 vehicle. Mortality was evaluated and recorded daily for 30 days. The concentration required to kill 50% of T. dimidiata (LC50 was then calculated for the most pathogenic isolate. Results Pathogenicity in adults was similar among B. bassiana, G. virens and T. flavus (p>0.05 and differed from that in triatomine nymphs (p=0.009. The most entomopathogenic strains in adult triatomines were B. bassiana and G. virens, which both caused 100% mortality. In nymphs, the most entomopathogenic strain was B. bassiana, followed by G. virens. The native strain with the highest pathogenicity was G. virens, for which the LC50 for T. dimidiata nymphs was 1.98 x108 conidia/ml at 13 days after inoculation. Conclusions Beauveria bassiana and G. virens showed entomopathogenic potential in T. dimidiata nymphs and adults. However, the native G. virens strain presents a higher probability of success in the field, and G. virens should thus be considered a potential candidate for the biological control of triatomine Chagas disease vectors.

The 9-lipoxygenase Osr9-LOX1 interacts with the 13-lipoxygenase-mediated pathway to regulate resistance to chewing and piercing-sucking herbivores in rice.

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Zhou, Guoxin; Ren, Nan; Qi, Jingfeng; Lu, Jing; Xiang, Caiyu; Ju, Hongping; Cheng, Jiaan; Lou, Yonggen

2014-09-01

Oxylipins produced by the 13-lipoxygenase (LOX) have been reported to play an important role in plant defense responses to herbivores. Yet, the role of oxylipins produced by the 9-LOX pathway in this process remains largely unknown. Here we cloned a gene encoding a chloroplast-localized 9-LOX, Osr9-LOX1, from rice. Transcriptional analysis revealed that herbivore infestation, mechanical wounding and jasmonic acid (JA) treatment either repressed or did not enhance the level of Osr9-LOX1 transcripts at early stages but did at later stages, whereas salicylic acid (SA) treatment quickly increased the transcript level of Osr9-LOX1. Antisense expression of Osr9-lox1 (as-r9lox1) decreased the amount of wound-induced (Z)-3-hexenal but increased levels of striped stem borer (SSB)-induced linolenic acid, JA, SA and trypsin protease inhibitors. These changes were associated with increased resistance in rice to the larvae of the SSB Chilo suppressalis. In contrast, although no significant differences were observed in the duration of the nymph stage or the number of eggs laid by female adults between the brown planthopper (BPH) Nilaparvata lugens that fed on as-r9lox1 lines and BPH that fed on wild-type (WT) rice plants, the survival rate of BPH nymphs that fed on as-r9lox1 lines was higher than that of nymphs that fed on WT plants, possibly because of a higher JA level. The results demonstrate that Osr9-LOX1 plays an important role in regulating an herbivore-induced JA burst and cross-talk between JA and SA, and in controlling resistance in rice to chewing and phloem-feeding herbivores. © 2014 Scandinavian Plant Physiology Society.

Biocide activity of Annona coriacea seeds extract on Rhodnius neglectus (Hemiptera: Reduviidae

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Ângela Pinheiro Carneiro

2013-03-01

Full Text Available The use of synthetic insecticides for insect control may lead to different kind of problems, such as vector resistance to insecticides. To avoid these problems, a new research area to study botanical products as possible disease vectors controls, has become a feasible alternative. The purpose of this research was to evaluate the biocide activity of the ethanol extract of seeds of Annona coriacea on Rhodnius neglectus (Chagas disease vector nymphs and adults. For this, different concentrations extracts were evaluated: 25, 50, 100 and 200mg/ mL, and water in DMSO (20% was used as control. The experimental design was completely randomized and we conducted the bioassay with nymphs and adults, with 10 nymphs and 10 adults (five males and five females per treatment. Extract action was evaluated in both bioassays, in order to identify possible effects of mortality and life cycle interruption of nymphs and adults during a 28-day-period. The results obtained showed that the extract of A. coriacea was able to disrupt the development of nymphs and adults of R. neglectus, with a mortality rate of more than 90%, 36% and 100%, at the highest concentrations, respectively. There was also molting inhibition in nymphs, lower reproductive capacity in females, feeding deterrence and morphological changes in nymphs and adults. We concluded that the extract of A. coriacea has insecticide action on nymphs and adults of R. neglectus.La enfermedad de Chagas se convirtió en un problema de salud debido a su importancia epidemiológica, es producida por el protista Trypanosoma cruzi, cuyos insectos vectores son del género Triatoma y Panstrongylus. El objetivo de este estudio fue evaluar la actividad biocida del extracto de Annona coriacea en las ninfas de Rhodnius neglectus y en sus adultos. Se evaluaron 14 concentraciones de 25, 50, 100 y 200mg/ml del extracto etanólico, así como el control, en este caso agua de DMSO (20%. Se utilizo un diseño completamente

The Rickettsia Endosymbiont of Ixodes pacificus Contains All the Genes of De Novo Folate Biosynthesis

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Bodnar, James; Mortazavi, Bobak; Laurent, Timothy; Deason, Jeff; Thephavongsa, Khanhkeo; Zhong, Jianmin

2015-01-01

Ticks and other arthropods often are hosts to nutrient providing bacterial endosymbionts, which contribute to their host’s fitness by supplying nutrients such as vitamins and amino acids. It has been detected, in our lab, that Ixodes pacificus is host to Rickettsia species phylotype G021. This endosymbiont is predominantly present, and 100% maternally transmitted in I. pacificus. To study roles of phylotype G021 in I. pacificus, bioinformatic and molecular approaches were carried out. MUMmer genome alignments of whole genome sequence of I. scapularis, a close relative to I. pacificus, against completely sequenced genomes of R. bellii OSU85-389, R. conorii, and R. felis, identified 8,190 unique sequences that are homologous to Rickettsia sequences in the NCBI Trace Archive. MetaCyc metabolic reconstructions revealed that all folate gene orthologues (folA, folC, folE, folKP, ptpS) required for de novo folate biosynthesis are present in the genome of Rickettsia buchneri in I. scapularis. To examine the metabolic capability of phylotype G021 in I. pacificus, genes of the folate biosynthesis pathway of the bacterium were PCR amplified using degenerate primers. BLAST searches identified that nucleotide sequences of the folA, folC, folE, folKP, and ptpS genes possess 98.6%, 98.8%, 98.9%, 98.5% and 99.0% identity respectively to the corresponding genes of Rickettsia buchneri. Phylogenetic tree constructions show that the folate genes of phylotype G021 and homologous genes from various Rickettsia species are monophyletic. This study has shown that all folate genes exist in the genome of Rickettsia species phylotype G021 and that this bacterium has the genetic capability for de novo folate synthesis. PMID:26650541

Protein interaction networks at the host-microbe interface in Diaphorina citri, the insect vector of the citrus greening pathogen.

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Ramsey, J S; Chavez, J D; Johnson, R; Hosseinzadeh, S; Mahoney, J E; Mohr, J P; Robison, F; Zhong, X; Hall, D G; MacCoss, M; Bruce, J; Cilia, M

2017-02-01

The Asian citrus psyllid ( Diaphorina citri) is the insect vector responsible for the worldwide spread of ' Candidatus Liberibacter asiaticus' (CLas), the bacterial pathogen associated with citrus greening disease. Developmental changes in the insect vector impact pathogen transmission, such that D. citri transmission of CLas is more efficient when bacteria are acquired by nymphs when compared with adults. We hypothesize that expression changes in the D. citri immune system and commensal microbiota occur during development and regulate vector competency. In support of this hypothesis, more proteins, with greater fold changes, were differentially expressed in response to CLas in adults when compared with nymphs, including insect proteins involved in bacterial adhesion and immunity. Compared with nymphs, adult insects had a higher titre of CLas and the bacterial endosymbionts Wolbachia, Profftella and Carsonella. All Wolbachia and Profftella proteins differentially expressed between nymphs and adults are upregulated in adults, while most differentially expressed Carsonella proteins are upregulated in nymphs. Discovery of protein interaction networks has broad applicability to the study of host-microbe relationships. Using protein interaction reporter technology, a D. citri haemocyanin protein highly upregulated in response to CLas was found to physically interact with the CLas coenzyme A (CoA) biosynthesis enzyme phosphopantothenoylcysteine synthetase/decarboxylase. CLas pantothenate kinase, which catalyses the rate-limiting step of CoA biosynthesis, was found to interact with a D. citri myosin protein. Two Carsonella enzymes involved in histidine and tryptophan biosynthesis were found to physically interact with D. citri proteins. These co-evolved protein interaction networks at the host-microbe interface are highly specific targets for controlling the insect vector responsible for the spread of citrus greening.

Detection of Borrelia burgdorferi sensu stricto in Amblyomma americanum ticks in the southeastern United States: the case of selective compatibility

Czech Academy of Sciences Publication Activity Database

Rudenko, Natalia; Golovchenko, Maryna; Clark, K.; Oliver, J.; Grubhoffer, Libor

2016-01-01

Roč. 5, MAY 25 (2016), č. článku e48. ISSN 2222-1751 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : lyme disease spirochete * Dermacentor variabilis * Ixodes scapularis * Ixodidae * Acari * strain Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 5.605, year: 2016

Phytophagy of the predator Podisus nigrispinus (Dallas, 1851 (Hemiptera: Pentatomidae fed on prey and Brassicaceae

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J. F. J. Grigolli

2017-03-01

Full Text Available Abstract The purpose of this study was to investigate the development and reproduction of the zoophytophagous predator Podisus nigrispinus (Dallas (Heteroptera: Pentatomidae fed kale, broccoli and cabbage affects its. Nymphs and adults of this predator were fed on larvae of Plutella xylostella (L. (Lepidoptera: Plutellidae as prey with kale, cabbage, or broccoli. In the nymph period, the duration and prey consumption were similar with all the Brassicacea cultivar. However, nymph viability was higher for predators with broccoli leaves. The mean weight of 5th-instar nymphs, newly emerged females and the sex ratio were similar among the Brassicacea cultivars, while newly emerged males were heavier with kale and broccoli leaves. The supply of broccoli leaves resulted in greater oviposition, higher number of eggs per egg mass and longer longevity of P. nigrispinus males and females. Furthermore, the consumption of P. xylostella larvae by adult predators was higher with these cultivars. The net reproductive rate (R0 and mean generation time (T were highest for predators with prey and broccoli leaves. The reproductive parameters of P. nigrispinus were enhanced when fed on P. xylostella larvae with and broccoli leaves, which can be an alternative diet in laboratory rearing of this predator.

Pathogenicity of Metarrhizium anisopliae (Metsch.) Sorokin and Beauveria bassiana (Bals.) Vuillemin isolates to Scaptocoris carvalhoi Becker (Hemiptera, Cydnidae)

International Nuclear Information System (INIS)

Xavier, Luciane Modenez Saldivar; Avila, Crebio Jose

2006-01-01

Pathogenicity of the fungi Metarrhizium anisopliae (Metsch.) Sorokin and Beauveria bassiana (Bals.) Vuillemin to stink bug Scaptocoris carvalhoi Becker, 1967 was evaluated under laboratory and greenhouse conditions. Experiments were carried out at EMBRAPA Agropecuaria Oeste, Dourados, Mato Grosso do Sul State, Brazil, in 2003. Ten M. anisopliae and eleven B. bassiana isolates were evaluated in laboratory using a completely randomized experimental design with five replicates (10 adults and 5 nymphs/plot). The pathogenicity of M. anisopliae isolate (Ma69) was also separately evaluated against nymphs and adults in laboratory and greenhouse. The stink bug mortality levels were higher for M. anisopliae isolates (between 73.3% and 94.7% than for B. bassiana isolates (between 10.7% and 78.7%). In greenhouse, stink bug mortality due to the M. anisopliae isolate (Ma69) was 57.3%, and there was no difference of mortality for nymphs and adults of stink bug in laboratory. However, in greenhouse, mortality levels were significantly higher (p<0,05) for nymphs (38,4%) than for adults (16,2%). From these data, we conclude that M. anisopliae isolate Ma69 was efficient to control S. carvalhoi in laboratory and in greenhouse, thus being a promising choice for use as a microbial insecticide under field conditions. (author)

Host and environmental factors influencing "Candidatus Liberibacter asiaticus" acquisition in Diaphorina citri.

Science.gov (United States)

Wu, Fengnian; Huang, Jiaquan; Xu, Meirong; Fox, Eduardo G P; Beattie, G Andrew C; Holford, Paul; Cen, Yijing; Deng, Xiaoling

2018-05-03

Diaphorina citri is a vector of "Candidatus Liberibacter asiaticus" (CLas) associated with citrus Huanglongbing. In this study, the infection and titers of CLas in the psyllid, were monitored for life cycle stage, sex, host-plant CLas titer, host-plant genotype, and ambient temperature. Acquisition efficiency of CLas by D. citri was highest in nymphs reared at 25 °C on a host plant with high CLas titers but was independent of the host genotypes assessed and of vector sex. We further observed that D. citri nymphs acquired CLas more rapidly than adults based on acquisition access periods (AAPs). CLas did not multiply in the alimentary canal, hemolymph, and salivary glands of adults for 18 d after a 3-day AAP as adult. However, CLas multiplication was detected in hemolymph and salivary gland of adults after the bacterium was acquired by nymphs. Eighty percent of salivary glands of adults contained CLas 18 d after a 3-day AAP as nymph compared to 10% 18 d after a 3-day AAP as adults. Different factors tested herein influenced CLas acquisition efficiency of D. citri, CLas multiplication and spread inside the psyllid. These observations serve to better understand mechanisms of CLas infection in D. citri. This article is protected by copyright. All rights reserved.

Pathogenicity of Metarrhizium anisopliae (Metsch.) Sorokin and Beauveria bassiana (Bals.) Vuillemin isolates to Scaptocoris carvalhoi Becker (Hemiptera, Cydnidae); Patogenicidade de isolados de Metarhizium anisopliae (Metsch.) Sorokin e de Beauveria bassiana (Bals.) Vuillemin a Scaptocoris carvalhoi Becker (Hemiptera, Cydnidae)

Energy Technology Data Exchange (ETDEWEB)

Xavier, Luciane Modenez Saldivar [Universidade Federal da Grande Dourados (UFGD), Dourados, MS (Brazil)], e-mail: luciane_modenez@ibest.com.br; Avila, Crebio Jose [EMBRAPA Agropecuaria Oeste, Dourados, MS (Brazil)], e-mail: crebio@cpao.embrapa.br

2006-12-15

Pathogenicity of the fungi Metarrhizium anisopliae (Metsch.) Sorokin and Beauveria bassiana (Bals.) Vuillemin to stink bug Scaptocoris carvalhoi Becker, 1967 was evaluated under laboratory and greenhouse conditions. Experiments were carried out at EMBRAPA Agropecuaria Oeste, Dourados, Mato Grosso do Sul State, Brazil, in 2003. Ten M. anisopliae and eleven B. bassiana isolates were evaluated in laboratory using a completely randomized experimental design with five replicates (10 adults and 5 nymphs/plot). The pathogenicity of M. anisopliae isolate (Ma69) was also separately evaluated against nymphs and adults in laboratory and greenhouse. The stink bug mortality levels were higher for M. anisopliae isolates (between 73.3% and 94.7% than for B. bassiana isolates (between 10.7% and 78.7%). In greenhouse, stink bug mortality due to the M. anisopliae isolate (Ma69) was 57.3%, and there was no difference of mortality for nymphs and adults of stink bug in laboratory. However, in greenhouse, mortality levels were significantly higher (p<0,05) for nymphs (38,4%) than for adults (16,2%). From these data, we conclude that M. anisopliae isolate Ma69 was efficient to control S. carvalhoi in laboratory and in greenhouse, thus being a promising choice for use as a microbial insecticide under field conditions. (author)

A new species of Cryptonympha Lugo-Ortiz McCafferty (Ephemeroptera, Baetidae) from Cerro Duida (Venezuela).

Science.gov (United States)

Derka, TomÁŠ; Nieto, Carolina

2018-02-05

The genus Cryptonympha includes three species: C. copiosa Lugo-Ortiz McCafferty, 1998; C. dasilvai Salles Francischetti, 2004 and C. genevievae Thomas, Manchon Glémet, 2013, known only from the nymphal stage. A description of the nymph of a fourth representative, Cryptonympha tracheata sp. n. is provided here, based on material collected in a blackwater stream on the slopes of the Cerro Duida mountain in south-western Venezuela. The nymph of the new species can be easily distinguished from the other species of the genus by very long tracheal gills II-VII, 2.5 times the length of each tergum, gill I small, nearly half length of gill IV and by posterior margin of terga with rounded spines. A complete description of the new species and a key for nymphs of all known Cryptonympha species are provided.

Linguatula serrata prevalence and morphometrical features: an abattoir survey on water buffaloes in Iran

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Hossein Tajik

2010-09-01

Full Text Available The prevalence and morphometrical characteristics of Linguatula serrata (L. serrata nymphs in mesenteric lymph nodes (MLNs, livers and lungs of 366 Iranian water buffaloes were investigated. The infestation rate increased with age (P0.1. In this study, 7.65% of animals had L. serrata nymphs with infection rates of 5.73% for MLNs, 1.63% for livers and 0.27% for lungs. Greyish-white coloured nymphs measured 3.5 to 4.5 mm in length, 82 to 84 mm in body segments, 44 to 46 mm in transversely striated spines and 4 mm in oral hooks. The results indicated a high rate of infestation of lymph nodes in buffaloes in Iran. Due to consumption of raw or under-cooked liver and visceral organs of buffaloes by local people, the importance of a thorough inspection at slaughter-time seems imperative.

INFLUENCE OF TEMPERATURE ON NYMPHAL DEVELOPMENT OF Podisus distinctus (DALLAS (HETEROPTERA: PENTATOMIDAE

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Germi Porto Santos

2004-07-01

Full Text Available The objective of this research was to study the effect of five temperatures (17ºC; 21ºC; 25ºC; 29ºC and 33oC on survival and nymph development of Podisus distinctus (Dallas (Heteroptera: Pentatomidae in laboratory. Period of egg incubation decreased with temperature elevation being lower at 29oC and lethal at 33oC. This indicates that superior thermal limit for this species can be found between these temperatures. Optimal temperature for egg viability was 23.7oC. Nymphs of Podisus distinctus completed its development between 17 and 29oC with optimal temperature at 26.3oC with higher nymph viability at intermediate temperatures (19ºC and 25oC. Optimal temperature for rearing this predator lay between 25ºC and 27oC.

Novos relatos de carrapatos em Rondônia, Amazônia ocidental brasileira

OpenAIRE

LABRUNA, Marcelo Bahia; BARBIERI, Fábio Silva; MARTINS, Thiago Fernandes; BRITO, Luciana Gatto; RIBEIRO, Francisco Dimas Sales

2010-01-01

In the present study, we provide new tick records from Vilhena Municipality, in the Southeast of the State of Rondônia, Northern Brazil. Ticks collected from a capybara, Hydrochoerus hydrochaeris (Linnaeus), were identified as Amblyomma romitii Tonelli-Rondelli (1 female), and Amblyomma sp. (1 larva). Ticks collected from a harpy eagle, Harpia harpyja (Linnaeus), were identified as Amblyomma cajennense (Fabricius) (16 nymphs) and Haemaphysalis juxtakochi Cooley (1 nymph). Ticks collected from...

New tick records in Rondônia, Western Brazilian Amazon

OpenAIRE

Labruna,Marcelo Bahia; Barbieri,Fábio Silva; Martins,Thiago Fernandes; Brito,Luciana Gatto; Ribeiro,Francisco Dimas Sales

2010-01-01

In the present study, we provide new tick records from Vilhena Municipality, in the Southeast of the State of Rondônia, Northern Brazil. Ticks collected from a capybara, Hydrochoerus hydrochaeris (Linnaeus), were identified as Amblyomma romitii Tonelli-Rondelli (1 female), and Amblyomma sp. (1 larva). Ticks collected from a harpy eagle, Harpia harpyja (Linnaeus), were identified as Amblyomma cajennense (Fabricius) (16 nymphs) and Haemaphysalis juxtakochi Cooley (1 nymph). Ticks collected from...

Nymphal RNAi: systemic RNAi mediated gene knockdown in juvenile grasshopper

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Dong Ying

2005-10-01

Full Text Available Abstract Background Grasshopper serves as important model system in neuroscience, development and evolution. Representatives of this primitive insect group are also highly relevant targets of pest control efforts. Unfortunately, the lack of genetics or gene specific molecular manipulation imposes major limitations to the study of grasshopper biology. Results We investigated whether juvenile instars of the grasshopper species Schistocerca americana are conducive to gene silencing via the systemic RNAi pathway. Injection of dsRNA corresponding to the eye colour gene vermilion into first instar nymphs triggered suppression of ommochrome formation in the eye lasting through two instars equivalent to 10–14 days in absolute time. QRT-PCR analysis revealed a two fold decrease of target transcript levels in affected animals. Control injections of EGFP dsRNA did not result in detectable phenotypic changes. RT-PCR and in situ hybridization detected ubiquitous expression of the grasshopper homolog of the dsRNA channel protein gene sid-1 in embryos, nymphs and adults. Conclusion Our results demonstrate that systemic dsRNA application elicits specific and long-term gene silencing in juvenile grasshopper instars. The conservation of systemic RNAi in the grasshopper suggests that this pathway can be exploited for gene specific manipulation of juvenile and adult instars in a wide range of primitive insects.

Characterization of tick-borne encephalitis (TBE) foci in Germany and Latvia (1997-2000).

Science.gov (United States)

Süss, Jochen; Schrader, Christina; Abel, Ulrich; Bormane, Antra; Duks, Arnis; Kalnina, Vaira

2002-06-01

Knowledge concerning the prevalence of the tick-borne encephalitis virus (TBEV) in wild living tick populations is very important for understanding the epidemiology of the disease and for immuno prophylactic strategy. In Germany high and low risk areas of TBE exist. In the years 1997-2000, 533 autochthonous clinical TBE cases were recorded, in the high-risk areas of Bavaria and Baden-Wuerttemberg 140 and 363, and in the low risk areas in Hesse (Odenwald) and Rhineland-Palatinate 22 and 8, respectively. Corresponding to these case reports we have measured the virus prevalence in free living ticks in these four risk areas and compared these findings with the situation in high-risk areas in Latvia. In the years 1997-2000, 2,797 clinical TBE cases were recorded in Latvia. For the studies in Germany, a total of 17,398 Ixodesricinus ticks (14,860 nymphs and 2,538 adults) were collected by flagging and examined for TBEV, in Latvia the corresponding numbers were 525 I. ricinus ticks (350 adults and 175 nymphs) and 281 I. persulcatus ticks (adults only). Information concerning annual and seasonal differences of the TBEV prevalence in natural TBE foci is not available in Germany. This paper is a continuation of the study (Süss et al., 1999), starting in 1997. We investigated every year, in May and September, the virus prevalence in ticks in high risk areas of Bavaria (8 foci) and Baden-Wuerttemberg (5 foci). A total of 15,400 ticks (13,100 nymphs and 2,300 adults) were examined for TBEV. The ticks were tested for the presence of TBEV-RNA using a sensitive, nested-RT-PCR. The virus prevalence in the Bavarian foci of the whole tick population ranged from 0.3 to 2.0% during these four years, in adults between 1.2 and 5.3% and in nymphs between 0.1 and 1.4%. In the high-risk areas of Baden-Wuerttemberg, in the Black Forest, the estimated virus prevalence rates of investigated ticks varied from 0.2 to 3.4%, in adults from 0 to 4.8%, and in nymphs from 0.2 to 3.4%. Using the same

The phenology of ticks and the effects of long-term prescribed burning on tick population dynamics in southwestern Georgia and northwestern Florida.

Science.gov (United States)

Gleim, Elizabeth R; Conner, L Mike; Berghaus, Roy D; Levin, Michael L; Zemtsova, Galina E; Yabsley, Michael J

2014-01-01

Some tick populations have increased dramatically in the past several decades leading to an increase in the incidence and emergence of tick-borne diseases. Management strategies that can effectively reduce tick populations while better understanding regional tick phenology is needed. One promising management strategy is prescribed burning. However, the efficacy of prescribed burning as a mechanism for tick control is unclear because past studies have provided conflicting data, likely due to a failure of some studies to simulate operational management scenarios and/or account for other predictors of tick abundance. Therefore, our study was conducted to increase knowledge of tick population dynamics relative to long-term prescribed fire management. Furthermore, we targeted a region, southwestern Georgia and northwestern Florida (USA), in which little is known regarding tick dynamics so that basic phenology could be determined. Twenty-one plots with varying burn regimes (burned surrounded by burned [BB], burned surrounded by unburned [BUB], unburned surrounded by burned [UBB], and unburned surrounded by unburned [UBUB]) were sampled monthly for two years while simultaneously collecting data on variables that can affect tick abundance (e.g., host abundance, vegetation structure, and micro- and macro-climatic conditions). In total, 47,185 ticks were collected, of which, 99% were Amblyomma americanum, 0.7% were Ixodes scapularis, and fewer numbers of Amblyomma maculatum, Ixodes brunneus, and Dermacentor variabilis. Monthly seasonality trends were similar between 2010 and 2011. Long-term prescribed burning consistently and significantly reduced tick counts (overall and specifically for A. americanum and I. scapularis) regardless of the burn regimes and variables evaluated. Tick species composition varied according to burn regime with A. americanum dominating at UBUB, A. maculatum at BB, I. scapularis at UBB, and a more even composition at BUB. These data indicate that

Increased Relative Risk of Tick-Borne Encephalitis in Warmer Weather

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Milan Daniel

2018-03-01

Full Text Available Tick-borne encephalitis (TBE is a serious acute neuroinfection of humans caused by a tick-borne flavivirus. The disease is typically seasonal, linked to the host-seeking activity of Ixodes ricinus (predominantly nymphs, the principal European tick vector species. To address the need for accurate risk predictions of contracting TBE, data on 4,044 TBE cases reported in the Czech Republic during 2001–2006 were compared with questing activity of I. ricinus nymphs monitored weekly at a defined location for the same 6-year period. A time shift of 21 days between infected tick bite and recorded disease onset provided the optimal model for comparing the number of cases of TBE with numbers of questing nymphs. Mean annual distribution of TBE cases and tick counts showed a similar bimodal distribution. Significantly, the ratio of TBE cases to questing nymphs was highest in the summer-autumn period even though the number of questing nymphs peaked in the spring-summer period. However, this pattern changed during a period of extreme meteorological events of flooding and abnormally high temperatures, indicating that changes in climate affect the incidence of TBE. Previous studies failed to link human behavior with changes in incidence of TBE but showed extrinsic temperature impacts arbovirus replication. Hence, we hypothesize the apparent discrepancy between peak nymphal tick activity and greatest risk of contracting TBE is due to the effect of temperature on virus replication in the tick vector. Relative proportions of questing nymphs and the numbers of weeks in which they were found were greater in summer-autumn compared with spring-summer at near-ground temperatures >5°C and at standard day and weekly average temperatures of >15°C. Thus, during the summer-autumn period, the virus dose in infected tick bites is likely greater owing to increased virus replication at higher microclimatic temperatures, consequently increasing the relative risk of

Evaluation of Piper aduncum Linn. Essential Oil (Fam:Piperaceae against Periplaneta americana(L.

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I Ling A

2009-12-01

Full Text Available Background: The efficacy of Piper aduncum essential oil was evaluated against Periplaneta americana adults and nymphs in the laboratory."nMethods: The plant essential oil at varying concentrations ranging between 10,000 to 80,000 ppm were placed inside glass beakers, rolled horizontally to ensure the essential oil covers all sides of the beakers and exposed to adults and nymphs of P. americana. Resigen (R 1ppm was used as positive control and distilled water as negative control. The LT50 and LT90 was obtained using Log Probit programme."nResults: Exposure of essential oil to females P. americana at concentrations between 10,000 to 80,000 ppm indicated the LT50 and LT90 values between 5.31 h-189.19 h and 14.90 h-2105.31 h, respectively. Treatment with the same con­centrations against males P. americana ,the LT50 and LT90 were 2.08 h-181.73 h and 5.4 h-8460.51 h, respectively. Treatment against the nymphal stage with the same range of concentrations indicated the LT50 and LT 90 of 4.68 h-381.02 h and 28.71 h-5313.36 h, respectively.The nymphs and males were more susceptible than the females cock­roaches. Treatment with Resigen (R at 1ppm indicated much lower LT 50 and LT 90 values of 2.54 h-9.47 h for the fe­males, 1.47 h-4.22 h for the males and 4.69 h-8.92 h for the nymphs.The negative control indicated no mortality for all stages of the cockroach."nConclusion: Piper aduncum essential oil can be used as an alternative natural product for controlling the cockroach Peri­patetic americana. "nKeywords: Piper aduncum essential oil, Periplaneta americana, Adults, Nymphs

Effects of 5-Gy irradiation on fertility and mating behaviour of Nezara viridula (Heteroptera: Pentatomidae)

International Nuclear Information System (INIS)

Zunic, A.; Cokl, A.; Sersa, G.

2002-01-01

Background. The polyphagous and cosmopolitan species Nezara viridula is one of the most important insect pests. The sterile insect technique (SIT) is a pest control strategy that involves sterilising males by exposing them to ionising radiation. Sterile males, released into wild population, mate with females, but eggs are not fertilised and the population gradually declines. Exposing insects to radiation during their growth stage might require lower sterilising dose. The aim of our study was to test whether 5-Gy irradiation of 5 th instar nymphs significantly affects: (1) moulting and further development of the irradiated nymphs, (2) the male's and female's reproductive system and (3) the mating competitiveness of treated males, with special focus on vibrational communication. Methods: The 5 th instar nymphs were irradiated with 5 Gy using X-ray generator and monitored daily. Results: The observed effects of irradiation were: prolonged moulting, increased mortality during development and during the first day of adult life, decreased males to females ratio, decreased fecundity, egg production, proportion of fertile eggs and progeny survival. The reaction of a male to stimulation with the model female calling song was tested. The irradiated and non-irradiated males responded to stimulation with emission of the courtship song (MCrS). Temporal parameters of MCrS emitted by non-irradiated males differed when compared with those of irradiated ones. Conclusions: The 5-Gy irradiation of 5 th instar nymphs did not affect mating behaviour. However since the irradiation during growth stage decreased the fertility and fecundity of emerged adults, this technique, in combination with certain other suppression techniques, could be a successful control strategy for management of Nezara viridula. On the other hand observed effects on moulting and further development of the irradiated nymphs could decrease the efficiency and application of this strategy. (author)

Occurrence of Hepatozoon canis and Cercopithifilaria bainae in an off-host population of Rhipicephalus sanguineus sensu lato ticks.

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Ramos, Rafael Antonio Nascimento; Giannelli, Alessio; Carbone, Domenico; Baneth, Gad; Dantas-Torres, Filipe; Otranto, Domenico

2014-04-01

Hepatozoon canis (Eucoccidiorida, Hepatozoidae) and the filarioid Cercopithifilaria bainae (Spirurida, Onchocercidae) are tick-transmitted infectious agents of dogs, highly prevalent in the Mediterranean basin in association with Rhipicephalus sanguineus sensu lato. Ticks were collected from the environment every 25±2 days in a confined location in southern Italy where a community of dogs lives, from August 2012 to July 2013. In order to study the occurrence of H. canis and C. bainae, 1091 tick specimens (770 adults; 271 nymphs, and 50 larvae) were dissected, and oocysts of H. canis and larvae of C. bainae were morphologically identified. Out of 1091 dissected ticks, 13.47% (n=147) were positive for H. canis, with the highest prevalence recorded in unfed adults (16.4%; 126/770), followed by nymphs collected as larvae and allowed to moult (14%; 7/50), unfed nymphs dissected immediately after collection (3%; 8/271), and adults collected as nymphs and allowed to moult (2%; 6/271). The highest number of H. canis-positive ticks (35.5%; 43/121; Pcanis and C. bainae infections in the study area seem to be dependent on the seasonality of vector tick populations. Hence, dogs living in these areas are more exposed to both pathogens during the warmer months. These findings provide new insights into the ecology of both H. canis and C. bainae. Copyright © 2014 Elsevier GmbH. All rights reserved.

Insecticidal Properties of Essential Oils and Some of Their Constituents on the Turkestan Cockroach (Blattodea: Blattidae).

Science.gov (United States)

Gaire, Sudip; O'Connell, Mary; Holguin, Francisco O; Amatya, Anup; Bundy, Scott; Romero, Alvaro

2017-04-01

The Turkestan cockroach, Blatta lateralis (Walker), has become the most important peridomestic species in urban areas of the Southwestern United States. The aim of this study was to evaluate the use of botanical compounds to control this urban pest. We tested the acute toxicity and repellency of six botanical constituents and three essential oils on Turkestan cockroach nymphs. Chemical composition of the essential oils was also determined. Topical and fumigant assays with nymphs showed that thymol was the most toxic essential oil constituent, with a LD50 of 0.34 mg/nymph and a LC50 of 27.6 mg/liter air, respectively. Contact toxicity was also observed in assays with trans-Cinnamaldehyde, eugenol, geraniol, methyl eugenol, and p-Cymene. Methyl eugenol and geraniol had limited fumigant toxicity. The essential oils from red thyme, clove bud, and Java citronella exhibited toxicity against nymphs. Cockroaches avoided fresh dry residues of thymol and essential oils. Chemical analysis of the essential oils confirmed high contents of effective essential oil constituents. Our results demonstrated that essential oils and some of their constituents have potential as eco-friendly insecticides for the management of Turkestan cockroaches. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Occurrence of Quesada gigas on Schizolobium amazonicum trees in Maranhão and Pará States, Brazil.

OpenAIRE

ZANUNCIO, J.C.; PEREIRA, F.F.; ZANUNCIO, T.V.; MARTINELLI, N.M.; PINON, T.B.M.; GUIMARÃES, E.M.

2004-01-01

An infestation of Quesada gigas Olivier (Hemiptera: Cicadidae) on "paricá" Schizolobium amazonicum (Huber) Ducken (Fabales: Fabaceae) was reported in the Municipalities of Itinga, Maranhão State and Paragominas, Pará State. Nymphs of this insect on roots and adults and exuvias on trunks of the plant were observed. Exit holes of nymphs in the soil were also observed. The occurrence of Q. gigas on S. amazonicum shows the damage potential of this species and the necessity of developing integrate...

Ocorrência de Quesada gigas em Schizolobium amazonicum em municípios do Maranhão e do Pará

OpenAIRE

Zanuncio, José Cola; Pereira, Fabrício Fagundes; Zanuncio, Teresinha Vinha; Martinelli, Nilza Maria; Pinon, Tobias Baruc Moreira; Guimarães, Edylene Marota

2004-01-01

An infestation of Quesada gigas Olivier (Hemiptera: Cicadidae) on "paricá" Schizolobium amazonicum (Huber) Ducken (Fabales: Fabaceae) was reported in the Municipalities of Itinga, Maranhão State and Paragominas, Pará State. Nymphs of this insect on roots and adults and exuvias on trunks of the plant were observed. Exit holes of nymphs in the soil were also observed. The occurrence of Q. gigas on S. amazonicum shows the damage potential of this species and the necessity of developing integrate...

Does host complement kill Borrelia burgdorferi within ticks?

Science.gov (United States)

Rathinavelu, Sivaprakash; Broadwater, Anne; de Silva, Aravinda M

2003-02-01

The Lyme disease spirochete, Borrelia burgdorferi, inhabits the gut lumen of the tick vector. At this location the spirochete is exposed to host blood when a tick feeds. We report here on studies that were done with normal and complement-deficient (C3-knockout) mice to determine if the host complement system killed spirochetes within the vector. We found that spirochete numbers within feeding nymphs were not influenced by complement, most likely because host complement was inactivated within the vector. The Lyme disease outer surface protein A (OspA) vaccine is a transmission-blocking vaccine that targets spirochetes in the vector. In experiments with mice hyperimmunized with OspA, complement was not required to kill spirochetes within nymphs and to block transmission from nymphs to the vaccinated host. However, host complement did enhance the ability of OspA antibody to block larvae from acquiring spirochetes. Thus, the effects of OspA antibody on nymphal transmission and larval acquisition appear to be based on different mechanisms.

An upcoming project: Latitudinal life history pattern in Ischnura pumilio (Charpentier, 1825)

DEFF Research Database (Denmark)

Olsen, Kent

due to the warmer climate, but the nymph responses in populations across latitudes is still mostly unresolved. Stress levels and physical fitness are affected by a change in phenology and accelerated growth rate. By a specific shift in temperature nymphs at low latitudes (e.g. southern France) may...... and then placed separately in a disposable cup with a piece of wet filter paper in the bottom for egg laying substrate. After collecting the eggs the filter paper is sent express from France and Belgium to Denmark, where the eggs are hatched and the nymphs transferred to climate units. We use four water tanks...... that each simulate modelled climate scenarios, i.e. one tank follow standard temperature whereas the other three follows a 2, 4 and 6 ° C temperature elevation. The water temperature is dictated by a computer and based on empirical data measured in situ in a shallow Danish lake, thus through thermostats...

Copper, cadmium, and zinc concentrations in aquatic food chains from the Upper Sacramento River (California) and selected tributaries

Science.gov (United States)

Saiki, M.K.; Castleberry, D. T.; May, T. W.; Martin, B.A.; Bullard, F. N.

1995-01-01

Metals enter the Upper Sacramento River above Redding, California, primarily through Spring Creek, a tributary that receives acid-mine drainage from a US EPA Superfund site known locally as Iron Mountain Mine. Waterweed (Elodea canadensis) and aquatic insects (midge larvae, Chironomidae; and mayfly nymphs, Ephemeroptera) from the Sacramento River downstream from Spring Creek contained much higher concentrations of copper (Cu), cadmium (Cd), and zinc (Zn) than did similar taxa from nearby reference tributaries not exposed to acid-mine drainage. Aquatic insects from the Sacramento River contained especially high maximum concentrations of Cu (200 mg/kg dry weight in midge larvae), Cd (23 mg/kg dry weight in mayfly nymphs), and Zn (1,700 mg/kg dry weight in mayfly nymphs). Although not always statistically significant, whole-body concentrations of Cu, Cd, and Zn in fishes (threespine stickleback, Gasterosteus aculeatus; Sacramento sucker, Catostomus occidentalis; Sacramento squawfish, Ptychocheilus grandis; and chinook salmon, Oncorhynchus tshawytasch) from the Sacramento River were generally higher than in fishes from the reference tributaries.

Tick fauna of wild animals received and attended at the Santarém Zoological Park, western Pará State, Brazil

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Kelly Karoline Gomes do Nascimento

2017-08-01

Full Text Available ABSTRACT: Ticks are known worldwide for parasitizing a number of wild hosts. However, few studies have been conducted on ticks in zoos in Brazil. The objective of the present study was to collect, identify, and report the parasitic tick fauna found on wild Amazon animals received and attended at the Santarém Zoological Park from September 2004 to September 2013. In all, 56 animals, including 26 mammals and 30 reptiles, were sampled, from which 1172 ticks were collected and identified, comprising 862 adults, 284 nymphs, and 26 larvae. Nymphs of Amblyomma geayi on three-toed sloth (Bradypus tridactylus, adults of Amblyomma longirostre on black dwarf porcupine (Coendou nycthemera, and nymphs of Amblyomma naponense on southern tamandua (Tamandua tetradactyla were identified for the first time in the country in the present study. Although, the North region is the largest among the five Brazilian regions, this is the first study conducted with ticks and animals attended in a zoo in the Brazilian Amazon.

Life cycle, feeding and defecation patterns of Rhodnius ecuadoriensis (Lent & León 1958) (Hemiptera: Reduviidae: Triatominae) under laboratory conditions.

Science.gov (United States)

Villacís, Anita G; Arcos-Terán, Laura; Grijalva, Mario J

2008-11-01

Rhodnius ecuadoriensis is the second most important vector of Chagas Disease (CD) in Ecuador. The objective of this study was to describe (and compare) the life cycle, the feeding and defecation patterns under laboratory conditions of two populations of this specie [from the provinces of Manabí (Coastal region) and Loja (Andean region)]. Egg-to-adult (n = 57) development took an average of 189.9 +/- 20 (Manabí) and 181.3 +/- 6.4 days (Loja). Mortality rates were high among Lojan nymphs. Pre-feeding time (from contact with host to feeding initiation) ranged from 4 min 42 s [nymph I (NI)] to 8 min 30 s (male); feeding time ranged from 14 min 45 s (NI)-28 min 25 s (male) (Manabí) and from 15 min 25 s (NI)-28 min 57 s (nymph V) (Loja). The amount of blood ingested increased significantly with instar and was larger for Manabí specimens (p Ecuador and Northern Peru.

Feeding Preferences of the Endangered Diving Beetle Cybister tripunctatus orientalis Gschwendtner (Coleoptera: Dytiscidae

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Shin-ya Ohba

2012-01-01

Full Text Available The numbers of Cybister tripunctatus orientalis Gschwendtner diving beetles are declining in most regions of Japan, and it is included in the Red Data List of species in 34 of 47 prefectures of Japan. However, basic ecological information about C. tripunctatus orientalis, such as its feeding habits, remains unknown. In order to elucidate the feeding habits of C. tripunctatus orientalis larvae, feeding preference experiments were carried out in 2nd and 3rd instar larvae. The number of Odonata nymphs consumed was significantly higher than the number of tadpoles consumed, indicating that C. tripunctatus orientalis larvae prefer Odonata nymphs to tadpoles. In addition, all the first instar larvae of C. tripunctatus orientalis developed into second instars when they were supplied with motionless Odonata nymphs, but their survival rate was lower when they were supplied with motionless tadpoles. These results suggest that C. tripunctatus orientalis larvae prefer insects to vertebrates.

Some Morphological Data of Various Stages of Linguatula Serrata

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Farid REZAEI

2016-01-01

Full Text Available Linguatula serrata is a zoonotic parasite causing visceral and nasopharyngeal linguatulosis in humans. Dog and other canines are the main definitive hosts while most of herbivores, including ruminants serve as intermediate hosts for linguatulosis. The current abattoir survey aimed to assess some morphological characterizations of different stages (egg, nymphs, male and female adults of L. serrata. Upper respiratory tract of stray dogs and mesenteric lymph nodes (MLNs of domestic ruminants (goats, buffaloes, cattle and sheep were examined for the presence of L .serrata. Eggs, adults and nymphal stages of L. serrata were analyzed for morphometric traits. No significant differences were observed in the size of various parts of nymphs collected from different hosts. Larger body size and absent of spines in adult forms were the major different in compared to the nymphs. Eggs were ovoid shape with semi-thickness shell. Probably, semi-thickness shell in eggs protected them from environmental condition and help to transmission of infections to intermediate hosts.

Molecular Detection and Identification of Rickettsia Species in Ixodes pacificus in California

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Phan, Jimmy Ninh; Lu, Casey Roy; Bender, William Garrett; Smoak, Robert Marion

2011-01-01

Abstract We amplified 16S rRNA, gltA, and ompA genes from Ixodes pacificus by polymerase chain reaction. Sequencing, BLAST analysis, and phylogenetic constructions indicated that two Rickettsia phylotypes are present in I. pacificus. While phylotype G021 has high homology to Ixodes scapularis endosymbiotic Rickettsia, phylotype G022 is a deeply branched novel spotted fever group Rickettsia. PMID:21413886

Evaluation of insecticides in different dosages to control cicadas in parica plantations

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Odineila Martins Monteiro

2014-07-01

Full Text Available This study aimed to determine the more efficient and economically viable dosage of chemical insecticide to control Quesada gigas (Hemiptera: Cicadidae nymphs in parica plantations. Three dosages of three products (carbofuran, imidacloprid and thiamethoxam were tested based on the maximum recommended dosage for the control of cicadas in coffee plants and applied in total area. The dosage of one kilogram of a commercial product based in thiamethoxam per hectare was more efficient economically and environmentally to control nymphs of Q. gigas in parica plantations.

Ixodes ticks belonging to the Ixodes ricinus complex encode a family of anticomplement proteins.

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Daix, V; Schroeder, H; Praet, N; Georgin, J-P; Chiappino, I; Gillet, L; de Fays, K; Decrem, Y; Leboulle, G; Godfroid, E; Bollen, A; Pastoret, P-P; Gern, L; Sharp, P M; Vanderplasschen, A

2007-04-01

The alternative pathway of complement is an important innate defence against pathogens including ticks. This component of the immune system has selected for pathogens that have evolved countermeasures. Recently, a salivary protein able to inhibit the alternative pathway was cloned from the American tick Ixodes scapularis (Valenzuela et al., 2000; J. Biol. Chem. 275, 18717-18723). Here, we isolated two different sequences, similar to Isac, from the transcriptome of I. ricinus salivary glands. Expression of these sequences revealed that they both encode secreted proteins able to inhibit the complement alternative pathway. These proteins, called I. ricinus anticomplement (IRAC) protein I and II, are coexpressed constitutively in I. ricinus salivary glands and are upregulated during blood feeding. Also, we demonstrated that they are the products of different genes and not of alleles of the same locus. Finally, phylogenetic analyses demonstrate that ticks belonging to the Ixodes ricinus complex encode a family of relatively small anticomplement molecules undergoing diversification by positive Darwinian selection.

Pre- and post-hatch trophic egg production in the subsocial burrower bug, Canthophorus niveimarginatus (Heteroptera: Cydnidae)

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Filippi, Lisa; Baba, Narumi; Inadomi, Koichi; Yanagi, Takao; Hironaka, Mantaro; Nomakuchi, Shintaro

2009-02-01

In recent years, three terrestrial bugs, Adomerus triguttulus and Sehirus cinctus (Cydnidae) and the closely related Parastrachia japonensis (Parastrachiidae), have been the focus of several fascinating studies because of the remarkable, extensive parental care they were found to display. This care includes egg and nymph guarding, production of trophic eggs, unfertilized, low cost eggs that are used as food by newly hatched nymphs, and progressive provisioning of the host seed. In this study, we have investigated yet a third related Asian cydnid, Canthophorus niveimarginatus, with regard to the possible occurrence of some or all of these complex traits in order to assess how widespread these maternal investment patterns are in this group of insects and to better understand the implications of their manifestations from an evolutionary context. Manipulative experiments were carried out in the lab to determine whether females provision nests. Observational and egg removal studies were carried out to determine whether trophic eggs are produced, and, if they are, their possible impact on nymphal success. The findings revealed that C. niveimarginatus does, in fact, progressively provision young, and this species also displays all of the other behaviors associated with extended parental care in subsocial insects. Moreover, unlike the other two related species, which place trophic eggs on the surface of the original egg mass, C. niveimarginatus produces both pre- and post-hatch trophic eggs. Nymphs deprived of access to post-hatch trophic eggs had significantly lower body weight and survival rate than those that fed on them. To our knowledge, this is the first time the production of both pre- and post-hatch trophic eggs has been demonstrated in insects outside the Hymenoptera. In this paper, we qualitatively and quantitatively demonstrate the provisioning behavior and patterns of trophic egg production in C. niveimarginatus. When and how trophic eggs are produced and

The attraction of Zonocerus variegatus (Orthoptera: Pyrgomorphidae to different types of lure

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A. Babatunde Idowu

2001-06-01

Full Text Available Zonocerus variegatus is a common grasshopper in parts of west and equtorial Africa.The distribution in Nigeria extends from the lowland rainforest zone to the savannah in the north. The influence of lure on the behaviour of grasshopper inside cages (120 insect per cage was investigated. Nymphs and adults of Zonocerus variegatus responded positively to intact leaves,crushed leaves and inflorescence of the common compositae weed Chromolaena odorata inside muslin bags, and intact plants. There were significant differences in the attraction recorded for starved nymphs, fed nymphs and starved adults. Attraction was more to intact leaves and is by olfaction. The increase in the attraction of starved nymphs is time dependent. Attraction to plant parts ceased after the plants were dried for 24 and 48 hours at room temperature and when plants were placed in transparent polythene bags. Gut motility and gut activity were higher during the day than at night. Nymphs, adults and egg pods placed separately inside muslin bags were not attractive to adults or nymphs.Zococerus variegatus es un saltamontes común en partes de Africa ecuatorial y oeste. La distribución en Nigeria se extiende desde la zona baja del bosque lluvioso hasta la sabana en el norte. La influencia del cebo sobre el comportamiento del saltamontes dentro de las jaulas (120 insectos por jaula fue investigada. Las ninfas y los adultos de Z. variegatus respondieron positivamente a hojas intactas, hojas aplastadas e inflorescencias de la hierba común compuesta Chromolaena odorata dentro de bolsas de muselina y a plantas intactas. Hubo diferencias significativas en la atracción registrada en ninfas mantenidas con hambre, ninfas alimentadas y adultos mantenidos con hambre. La atracción fue más hacia hojas intactas y fue por olfato. El aumento en la atracción de ninfas mantenidas con hambre fue tiempo-dependiente. La atracción a partes de plantas paró luego de que las plantas fueron secadas

Developmental biology, polymorphism and ecological aspects of Stiretrus decemguttatus (Hemiptera, Pentatomidae, an important predator of cassidine beetles

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Lucia Maria Paleari

2013-03-01

Full Text Available Developmental biology, polymorphism and ecological aspects of Stiretrus decemguttatus (Hemiptera, Pentatomidae, an important predator of cassidine beetles. Stiretrus decemguttatus is an important predator of two species of cassidine beetles, Botanochara sedecimpustulata (Fabricius, 1781 and Zatrephina lineata (Fabricius, 1787 (Coleoptera, Cassidinae, on the Marajó Island, Brazil. It attacks individuals in all development stages, but preys preferentially on late-instar larvae. Its life cycle in the laboratory was 43.70 ± 1.09 days, with an egg incubation period of six days and duration from nymph and adult stages of 16.31 ± 0.11 and 22.10 ± 1.67 days, respectively. The duration of one generation (T was 12.65 days and the intrinsic population growth rate (r 0.25. These data reveal the adjustment of the life cycle of S. decemgutattus with those of the two preys, but suggest greater impact on Z. lineata. However, no preference over cassidine species was shown in the laboratory. Up to 17 different color patterns can be found in adults of S. decemguttatus, based on combinations of three basic sets of color markings. Some of them resemble the markings of chrysomelids associated with Ipomoea asarifolia (Convolvulaceae and are possibly a mimetic ring. Three color patterns were identified in nymphs, none of which was associated with any specific adult color pattern.

Environmental Transmission of the Gut Symbiont Burkholderia to Phloem-Feeding Blissus insularis.

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Xu, Yao; Buss, Eileen A; Boucias, Drion G

2016-01-01

The plant-phloem-feeding Blissus insularis possesses specialized midgut crypts, which harbor a dense population of the exocellular bacterial symbiont Burkholderia. Most individual B. insularis harbor a single Burkholderia ribotype in their midgut crypts; however, a diverse Burkholderia community exists within a host population. To understand the mechanism underlying the consistent occurrence of various Burkholderia in B. insularis and their specific association, we investigated potential gut symbiont transmission routes. PCR amplification detected a low titer of Burkholderia in adult reproductive tracts; however, fluorescence in situ hybridization assays failed to produce detectable signals in these tracts. Furthermore, no Burkholderia-specific PCR signals were detected in eggs and neonates, suggesting that it is unlikely that B. insularis prenatally transmits gut symbionts via ovarioles. In rearing experiments, most nymphs reared on St. Augustinegrass treated with cultured Burkholderia harbored the cultured Burkholderia strains. Burkholderia was detected in the untreated host grass of B. insularis, and most nymphs reared on untreated grass harbored a Burkholderia ribotype that was closely related to a plant-associated Burkholderia strain. These findings revealed that B. insularis neonates acquired Burkholderia primarily from the environment (i.e., plants and soils), even though the possibility of acquisition via egg surface cannot be excluded. In addition, our study explains how the diverse Burkholderia symbiont community in B. insularis populations can be maintained.

Interactive Effects of Southern Rice Black-Streaked Dwarf Virus Infection of Host Plant and Vector on Performance of the Vector, Sogatella furcifera (Homoptera: Delphacidae).

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Lei, Wenbin; Liu, Danfeng; Li, Pei; Hou, Maolin

2014-10-01

Performance of insect vectors can be influenced by the viruses they transmit, either directly by infection of the vectors or indirectly via infection of the host plants. Southern rice black-streaked dwarf virus (SRBSDV) is a propagative virus transmitted by the white-backed planthopper, Sogatella furcifera (Hovath). To elucidate the influence of SRBSDV on the performance of white-backed planthopper, life parameters of viruliferous and nonviruliferous white-backed planthopper fed rice seedlings infected or noninfected with SRBSDV were measured using a factorial design. Regardless of the infection status of the rice plant host, viruliferous white-backed planthopper nymphs took longer to develop from nymph to adult than did nonviruliferous nymphs. Viruliferous white-backed planthopper females deposited fewer eggs than nonviruliferous females and both viruliferous and nonviruliferous white-backed planthopper females laid fewer eggs on infected than on noninfected plants. Longevity of white-backed planthopper females was also affected by the infection status of the rice plant and white-backed planthopper. Nonviruliferous white-backed planthopper females that fed on infected rice plants lived longer than the other three treatment groups. These results indicate that the performance of white-backed planthopper is affected by SRBSDV either directly (by infection of white-backed planthopper) or indirectly (by infection of rice plant). The extended development of viruliferous nymphs and the prolonged life span of nonviruliferous adults on infected plants may increase their likelihood of transmitting virus, which would increase virus spread. © 2014 Entomological Society of America.

Residual effect of a micro-encapsulated formulation of organophosphates and piriproxifen on the mortality of deltamethrin resistant Triatoma infestans populations in rural houses of the Bolivian Chaco region

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Abraham Gemio Alarico

2010-09-01

Full Text Available The Bolivian Chaco is part of the endemic region of Chagas disease and an area where pyrethroid resistant Triatoma infestans (Hemiptera: Reduviidae populations has been reported. The World Health Organization identified these resistant populations as an important focus for research. The objective of this study was to evaluate the residual effect of a micro-encapsulated formulation containing organophosphate active ingredients and a juvenile hormone analogue (Inesfly 5A IGR on the mortality of T. infestans. Studies took place in rural houses of the Bolivian Chaco that were treated up to 34 months before and evaluated the susceptibility to pyrethroids of the offspring of field collected insects. Thirty houses were randomly selected within three communities to carry out wall bio-assays with T. infestans nymphs. Mortality was recorded 24, 48 and 72 h after wall contact. Eggs laid by females collected in the area were used to obtain first-instar nymphs and carry out pyrethroid susceptibility tests. The wall bio-assays showed that the micro-encapsulated insecticide eliminates T. infestans populations and produces detectable mortality of insects exposed to walls treated 34 months prior to the tests. The discriminant dose of deltamethrin (0.01 mg/mL showed 65% nymph survival, whereas at the highest tested dose (1.0 mg/mL 14% of the nymphs survived. These results show that Inesfly 5A IGR is an appropriate tool for the elimination of intradomestic and peridomestic populations of T. infestans resistant to pyrethroids.

Effects of impoundment and regulation upon the stomach contents of fish at Cow Green, Upper Teesdale

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Crisp, D.T.; Mann, R.H.K.; McCormack, J.C.

1978-04-01

The stomach contents of 1003 brown trout, 1551 bullheads and 800 minnows taken from the reservoir basin and below the dam, before and after impoundment of the river Tees, were examined. Their composition reflected observations by other workers on river and reservoir benthos, except for the increase in numbers of Hydra and Nais below the dam, and Mollusca, Hirudinea and oligochaetes in the reservoir. Trout below the dam ate more Ephemeroptera nymphs and Chironomidae larvae but fewer terrestrial casualties after river regulation, whereas bullheads ate more Mollusca but fewer Plecoptera nymphs. In both species Baetidae nymphs increased in numerical importance relative to Ecdyonuridae. Trout, but not bullheads, took zooplankton discharged from the reservoir. Before impoundment, trout within the reservoir basin ate chiefly benthic organisms and terrestrial casualties. Inundated terrestrial material, mainly earthworms, formed the bulk of their food for at least three years after impoundment, whilst from the second year onwards Chironomidae and, in some years, Gammarus became increasingly important. Zooplankton was taken by all sizes of reservoir trout. Bullheads within the reservoir basin ate chiefly river benthos before impoundment, with Ephemeroptera and Plecoptera nymphs predominant in older fish, and aquatic Diptera and Coleoptera also important in the fry. After impoundment, Chironomidae and Gammarus were the main items taken by older bullheads, and Chironomidae and micro-crustacea by the fry. Among all sizes of minnow, Chironomidae, micro-crustacea and detritus increased in numerical importance after impoundment.

One-Humped Camel (Camelus dromedarius Infestation withLinguatula serrata in Tabriz, Iran

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HR Haddadzadeh

2010-06-01

Full Text Available "n "nBackground: Linguatula serrata is one of well known members of Pentastomida which infects both human and animals. The aim of this study was to evaluate the prevalence of L. serrata in mesenteric lymph nodes, livers and lungs of camels slaughtered in Tabriz area, Iran. "n "nMethods: Mesenteric lymph nodes (MLNs, livers and lungs of 140 one-humped camels slaughtered in Tabriz, north-west of Iran were investigated for nymphs of L. serrata from July 2007 to June 2008. The organs were examined macroscopically and then a tissue digestion method was also done for investigation of liver and lung of the camels that had infected MLN. The liver and lung samples were mostly taken from condemned and rejected part of organs. "n "nResults: The infection rate of L. serrata nymphs in MLNs, livers and lungs was 13.5%, 1.4% and 1.4% respectively. The number of isolated nymph in infected lymph nodes varied from 2 to 18 with a mean of 4.78. Only one nymph was isolated from each infected livers and lungs. The infection rate increased with age (p<0.05. No significant difference in different sex groups and seasons was observed (p>0.05. "n "nConclusion: Considering this fact that consumption of undercooked camel liver was not common in the studied area, the zoonotic importance of this infection should be concluded.

Desempenho de pontas de pulverização em Brachiaria brizantha cv. MG-4 para controle de ninfas de cigarrinhas das pastagens Spray nozzles performance in Brachiaria brizantha cv. MG-4 for pastures spittlebugs nymphs control

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Cleber D. de G. Maciel

2007-01-01

Full Text Available O trabalho teve como objetivo estudar o desempenho de pontas de pulverização na deposição da calda inseticida para o controle de ninfas de cigarrinhas das pastagens em Brachiaria brizantha cv. MG-4. Doze tratamentos foram estudados em esquema fatorial 6x2, constituídos pelo contraste de seis pontas de pulverização e pressões de 196 e 392 kPa: TF-VP2 (336 L ha-1 e 467 L ha-1; AI11002-VS (184 L ha-1 e 200 L ha-1; XR11002-VS (200 L ha-1 e 280 L ha-1; TT11002-VP (200 L ha-1 e 280 L ha-1; TJ60-11002VS (208 L ha-1 e 280 L ha-1 e TX-VK4 (72 L ha-1 e 97 L ha-1. Para monitorar a deposição das caldas de pulverização, utilizaram-se os traçadores Azul Brilhante FD&C-1 (0,3% p/v e Amarelo de Tartrasina FD&C-5 (0,6% p/v. Alvos artificiais, constituídos de lâminas de vidro, foram posicionados na base das plantas, próximos à superfície do solo, e os depósitos por unidade de área das soluções pulverizadas foram quantificados por espectrofotometria. As pontas TF-VP2, XR11002-VS e AI11002-VS, nas pressões de 196 e 392 kPa, proporcionam as maiores deposições da calda de pulverização na região das espumas das cigarrinhas das pastagens, apesar de apresentarem menor uniformidade na distribuição dos depósitos em relação a TX-VK4, XR110.02-VS e TJ110.02-VS. O aumento da pressão de 196 para 392 kPa promoveu aumento na deposição da calda de pulverização sobre a Brachiaria brizantha e na região onde se encontram as espumas das cigarrinhas para todos os tipos de pontas estudadas.The work aimed to study spray nozzles performance in pesticide sprayer deposition for controlling pastures spittlebugs nymphs in Brachiaria brizantha cv. MG-4 pasture. Twelve treatments were studied in factorial scheme 6x2, constituted by the contrast of six spray nozzles and 196 and 392 kPa work pressures: TF-VP2 (336 L ha-1 and 467 L ha-1; AI11002-VS (184 L ha-1 and 200 L ha-1; XR11002-VS (200 L ha-1 and 280 L ha-1; TT11002-VP (200 L ha-1 and 280 L ha¹; TJ60

Ecology of mosquitoes (Diptera: Culicidae in areas of Serra do Mar State Park, State of São Paulo, Brazil. II - Habitat distribution

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Anthony Érico Guimarães

2000-01-01

Full Text Available The mosquito (Diptera: Culicidae ecology was studied in areas of Serra do Mar State Park, State of São Paulo, Brazil. Systematized biweekly human bait collections were made three times a day, for periods of 2 or 3 h each, in sylvatic and rural areas for 24 consecutive months (January 1991 to December 1992. A total of 24,943 adult mosquitoes belonging to 57 species were collected during 622 collective periods. Aedes scapularis, Coquillettidia chrysonotum, Cq. venezuelensis, Wyeomyia dyari, Wy. longirostris, Wy. theobaldi and Wy. palmata were more frequently collected at swampy and at flooded areas. Anopheles mediopunctatus, Culex nigripalpus, Ae. serratus, Ae. fulvus, Psorophora ferox, Ps. albipes and the Sabethini in general, were captured almost exclusively in forested areas. An. cruzii, An. oswaldoi and An. fluminensis were captured more frequently in a residence area. However, Cx. quinquefasciatus was the only one truly eusynanthropic. An. cruzii and Ae. scapularis were captured feeding on blood inside and around the residence, indicating that both species, malaria and arbovirus vectors respectively, may be involved in the transmission of these such diseases in rural areas.

Morphological anomalies in Ixodes ricinus and Ixodes inopinatus collected from tick-borne encephalitis natural foci in Central Europe

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Chitimia-Dobler, Lidia; Bestehorn, Malena; Bröker, Michael

2017-01-01

in Germany, Slovakia and Denmark. A total of 278 (1.9%) out of 14,602 nymph and adult ticks showed morphological anomalies. The anomalies were divided into general anomalies (body asymmetry) and local anomalies (anomalies of appendages, malformation of capitulum, exoskeleton anomalies and anal groove......, palps and exoskeleton. Anal groove deformation was observed in three females and three nymphs. In 2016, the frequency of anomalies in I. inopinatus was found five times higher (9.3%) than in I. ricinus (1.9%). This is the first report of anomaly (ectromely, leg atrophy, idiosoma deformation) in flagged...

Amblyomma americanum as a Bridging Vector for Human Infection with Francisella tularensis.

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Rinosh J Mani

Full Text Available The γ-proteobacterium Francisella tularensis causes seasonal tick-transmitted tularemia outbreaks in natural rabbit hosts and incidental infections in humans in the south-central United States. Although Dermacentor variabilis is considered a primary vector for F. tularensis, Amblyomma americanum is the most abundant tick species in this endemic region. A systematic study of F. tularensis colonization of A. americanum was undertaken to better understand its potential to serve as an overwintering reservoir for F. tularensis and as a bridging vector for human infections. Colony-reared A. americanum were artificially fed F. tularensis subspecies holarctica strain LVS via glass capillaries and colonization levels determined. Capillary-fed larva and nymph were initially infected with 10(4 CFU/tick which declined prior to molting for both stages, but rebounded post-molting in nymphs and persisted in 53% at 10(3 to 10(8 CFU/nymph at 168 days post-capillary feeding (longest sampling time in the study. In contrast, only 18% of adults molted from colonized nymphs maintained LVS colonization at 10(1 to 10(5 CFU/adult at 168 days post-capillary feeding (longest sampling time. For adults, LVS initially colonized the gut and disseminated to salivary glands by 24 h and had an ID50 of <5CFU in mice. Francisella tularensis infected the ovaries of gravid females, but transmission to eggs was infrequent and transovarial transmission to hatched larvae was not observed. The prolonged persistence of F. tularensis in A. americanum nymphs supports A. americanum as an overwintering reservoir for F. tularensis from which seasonal epizootics may originate; however, although the rapid dissemination of F. tularensis from gut to salivary glands in adults A. americanum is compatible with intermittent feeding adult males acting as bridging vectors for incidental F. tularensis infections of humans, acquisition of F. tularensis by adults may be unlikely based on adult feeding

Two-Spotted Ladybeetle Adalia bipunctata L. (Coleoptera: Coccinellidae): A Commercially Available Predator to Control Asian Citrus Psyllid Diaphorina citri (Hemiptera: Liviidae).

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Khan, Azhar A; Qureshi, Jawwad A; Afzal, Muhammad; Stansly, Philip A

2016-01-01

The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is an economically important pest of citrus because it serves as a vector of the causal pathogens of huanglongbing (HLB) also known as citrus greening disease. The increased use of insecticides for control of D. citri negatively impacts several natural enemies including some effective ladybeetle species which are not available commercially. The two-spotted ladybeetle, Adalia bipunctata (Coleoptera: Coccinellidae) is found in some crop and forest ecosystems of Asia, Europe and North America and available commercially. It is known to attack aphids and mealybugs but there are no published records of feeding on psyllids. We evaluated suitability and preference of A. bipunctata for nymphs of D. citri compared to corn leaf aphid Rhopalosiphum maidis (Hemiptera: Aphididae) a global pest of cereal crops and prey for many predaceous insects. We also compared development and reproduction of A. bipunctata on these two species with frozen eggs of the Mediterranean flour moth Ephestia kuehniella (Lepidoptera: Pyralidae) at 25°C. Initially, more D. citri than R. maidis nymphs were consumed in the no-choice tests although final consumption by larva and adult of A. bipunctata did not differ in the choice and no-choice tests. Larval development was prolonged by one day on D. citri compared to R. maidis nymphs but did not differ between either of these diets and E. kuehniella. Larval survival to adult averaged 93-100% and was not impacted by diet. Adult life span did not differ between diets although those on D. citri and R. maidis nymphs weighed less and produced fewer but more fertile eggs than on E. kuehniella eggs. Significant reduction of D. citri nymphs averaging 54% was observed in colonies caged with adult A. bipunctata on field planted citrus. R° (net reproductive rate) was least for beetles fed R. maidis, but otherwise there were no significant differences in demographic parameters. Successful

Biologia de Imaturos e Adultos de Podisus nigrispinus (Dallas (Hemiptera: Pentatomidae Alimentados com Lagartas de Dione juno juno (Cramer (Lepidoptera: Nymphalidae, criadas em Diferentes Genótipos de Maracujazeiro

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Marina Angelini

2015-12-01

Abstract. The development of Podisus nigrispinus (Dallas (Hemiptera: Pentatomidae nymphs fed with Dione juno juno (Cramer (Lepidoptera: Nymphalidae larvae reared on leaves of the passion fruit genotypes Passiflora edulis Sims., Passiflora edulis f. flavicarpa Deg. (Seleção de Jaboticabal, P. edulis f. flavicarpa (cv. Sul Brasil and P. edulis f. flavicarpa (cv. Maguary FB-100, P. alata, P. serrato-digitata and P. foetida. The experiment was conducted under controlled conditions (temperature: 26 ± 1°C, RH = 60 ± 10% and photophase of 14 hours. Second instar nymphs of the predator were kept in plastic cups (4.5 cm high and 7.5 cm wide groups of five. Ten-day-old (approx. 2 cm D. juno juno larvae reared on leaves of different passion fruit genotypes were provided daily to P. nigrispinus. The experiment was carried out with 10 replications, totalizing 50 nymphs per treatment. Daily evaluations were performed to measure the duration and viability of each instar, the body mass of nymphs (24 hours after each ecdysis and adults, and the duration and viability of the nymph phase and adult longevity under starvation. Results show the influence of passion fruit genotypes at the third trophic level, since larvae reared with P. edulis f. flavicarpa (Seleção de Jaboticabal have shown to be more adequate for predator development. The results of this experiment show the influence of passion fruit genotypes on the third trophic level. The genotype P. edulis f. flavicarpa cv. Sul Brasil has a less appropriate to the predator, suggesting a negative way the association between host plant resistance and use of biological control. Already P. edulis and genotypes P. edulis f. flavicarpa Jaboticabal Selection can be used along with the predator because these cultivars did not affect the third trophic level. P. edulis f. flavicarpa cv. Maguary FB-100, considered ill-suited to the development of larvae of D. juno juno, affected the predator, resulting in a negative

The Tick Salivary Protein Sialostatin L Inhibits the Th9-Derived Production of the Asthma-Promoting Cytokine IL-9 and Is Effective in the Prevention of Experimental Asthma

Czech Academy of Sciences Publication Activity Database

Horká, Helena; Staudt, V.; Klein, M.; Taube, Ch.; Reuter, S.; Dehzad, N.; Andersen, J. F.; Kopecký, Jan; Schild, H.; Kotsyfakis, Michalis; Hoffmann, M.; Gerlitzki, B.; Stassen, M.; Bopp, T.; Schmitt, E.

2012-01-01

Roč. 188, č. 6 (2012), s. 2669-2676 ISSN 0022-1767 R&D Projects: GA ČR GCP302/11/J029; GA MŠk(CZ) LC06009 Institutional support: RVO:60077344 Keywords : experimental asthma * airway hyperresponsiveness * eosinophilia * interleukin-9 * Th9 cells * Sialostatin L * therapeutic * Ixodes scapularis * cysteine protease inhibitor * tick saliva Subject RIV: EC - Immunology Impact factor: 5.520, year: 2012

The phenology of ticks and the effects of long-term prescribed burning on tick population dynamics in southwestern Georgia and northwestern Florida.

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Elizabeth R Gleim

Full Text Available Some tick populations have increased dramatically in the past several decades leading to an increase in the incidence and emergence of tick-borne diseases. Management strategies that can effectively reduce tick populations while better understanding regional tick phenology is needed. One promising management strategy is prescribed burning. However, the efficacy of prescribed burning as a mechanism for tick control is unclear because past studies have provided conflicting data, likely due to a failure of some studies to simulate operational management scenarios and/or account for other predictors of tick abundance. Therefore, our study was conducted to increase knowledge of tick population dynamics relative to long-term prescribed fire management. Furthermore, we targeted a region, southwestern Georgia and northwestern Florida (USA, in which little is known regarding tick dynamics so that basic phenology could be determined. Twenty-one plots with varying burn regimes (burned surrounded by burned [BB], burned surrounded by unburned [BUB], unburned surrounded by burned [UBB], and unburned surrounded by unburned [UBUB] were sampled monthly for two years while simultaneously collecting data on variables that can affect tick abundance (e.g., host abundance, vegetation structure, and micro- and macro-climatic conditions. In total, 47,185 ticks were collected, of which, 99% were Amblyomma americanum, 0.7% were Ixodes scapularis, and fewer numbers of Amblyomma maculatum, Ixodes brunneus, and Dermacentor variabilis. Monthly seasonality trends were similar between 2010 and 2011. Long-term prescribed burning consistently and significantly reduced tick counts (overall and specifically for A. americanum and I. scapularis regardless of the burn regimes and variables evaluated. Tick species composition varied according to burn regime with A. americanum dominating at UBUB, A. maculatum at BB, I. scapularis at UBB, and a more even composition at BUB. These data

Resistance to Starvation of Triatoma rubrofasciata (De Geer, 1773 under Laboratory Conditions (Hemiptera: Reduviidae: Triatominae

Directory of Open Access Journals (Sweden)

Rojas Cortéz Mirko G

1998-01-01

Full Text Available The present work aims at learning the period of resistance to starvation (molting/death of Triatoma rubrofasciata in different stages of development and the respective loss of weight until death. Eggs of specimens from the greater area of the city of São Luis in the State of Maranhão, Brazil, yielded approximately 300 nymphs. These nymphs were placed in labelled Borrel glasses, in which they were weekly fed on rats (Rattus norvegicus, until reaching the stage to be observed. The experiments were conducted in a climatic chamber regulated at 29 ± 1° C, 70% relative humidity and 12 hr photoperiod. The resistance to starvation increased according to the stage of development, except for adult bugs, whose results were similar to the 3rd stage nymphs. In all these development stages there was an abrupt loss of weight in the first week, followed by a gradual loss until death. Comparing this work with those of other authors, it was observed that T. rubrofasciata is among the less resistant triatomine species.

Experimental evidence against transmission of Hepatozoon canis by Ixodes ricinus.

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Giannelli, Alessio; Ramos, Rafael Antonio Nascimento; Dantas-Torres, Filipe; Mencke, Norbert; Baneth, Gad; Otranto, Domenico

2013-09-01

Hepatozoon canis is among the most widespread tick-borne protozoa infecting domestic and wild carnivores. Its distribution is related to the occurrence of its major vector, the brown dog tick Rhipicephalus sanguineus. However, the role of Ixodes ricinus as a vector of H. canis has been hypothesized. In the present study, the development of H. canis was investigated in I. ricinus and R. sanguineus nymphs collected from a naturally infested dog. All I. ricinus ticks examined (n=133) were negative by cytological examination at days 20, 30, and 90 post collection, although H. canis DNA was detected in one nymph at day 20 and in 2 nymphs at day 30 post collection. On the other hand, H. canis sporogony was documented by cytology, and H. canis DNA was detected by PCR in R. sanguineus at day 30 post collection. These results indicate that H. canis sporogony does not occur in I. ricinus, but in R. sanguineus, suggesting that I. ricinus does not act as a vector of H. canis. Copyright © 2013 Elsevier GmbH. All rights reserved.

Effect of Zohar LQ-215, a biorational surfactant, on the sweetpotato whitefly Bemisia tabaci (biotype b).

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Ishaaya, I; Khasdan, V; Horowitz, A Rami

2006-01-01

Zohar LQ-215, a surfactant based on plant oils, able to control nymphs of the whitefly, Bemisia tabaci (Gennadius), under laboratory and field conditions. To evaluate the effects of the surfactant on the nymph stages of whitefly under laboratory conditions, potted cotton seedlings infested with 1st- or 3rd-instars were treated with the compound aqueous solutions. LC90 values of Zohar LQ-215 on 1st and 3rd-nymphs, based on mortality curves, were 0.78% and 1.14%, respectively. Adult mortality of 12% and 19% was obtained at concentrations of 0.5% and 1%, respectively. Under both laboratory and, in some cases, under field conditions, greater mortality was achieved when combining Zohar LQ-215 with the insect growth regulator buprofezin than when either insecticide was applied separately. Our results indicate that Zohar LQ-215 could serve as a potential compound for controlling whiteflies under light to moderate infestation and could be used in combination with other rational insecticides such as buprofezin for controlling whiteflies in integrated pest management programs.

Dose-response relationships of clothianidin, imidacloprid, and thiamethoxam to Blissus occiduus (Hemiptera: Blissidae).

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Stamm, M D; Baxendale, F P; Heng-Moss, T M; Siegfried, B D; Blankenship, E E; Gaussoin, R E

2011-02-01

The western chinch bug, Blissus occiduus Barber (Hemiptera: Blissidae), has emerged as a serious pest of buffalograss, Buchlod dactyloides (Nuttall) Engelmann. In general, neonicotinoid insecticides effectively control a variety of turfgrass insects, particularly phloem-feeding pests. However, because of well documented inconsistencies in control, these compounds are generally not recommended for chinch bugs. This study was designed to document the contact and systemic toxicity of three neonicotinoid insecticides (clothianidin, imidacloprid, and thiamethoxam) to B. occiduus. In contact bioassays, thiamethoxam was approximately 20-fold less toxic than clothianidin or imidacloprid to B. occiduus nymphs and three-fold more toxic to adults. In adult systemic bioassays, thiamethoxam was up to five-fold more toxic than clothianidin or imidacloprid. Interestingly, thiamethoxam was significantly more toxic to adults than to nymphs in both contact and systemic bioassays. This was not observed with clothianidin or imidacloprid. Bifenthrin, used for comparative purposes, exhibited 1844-fold and 122-fold increase in toxicity to nymphs and adults, respectively. These results provide the first documentation of the relative toxicity of these neonicotinoid insecticides to B. occiduus.

Killing Effects of an Isolated Serratia marcescens KH-001 on Diaphorina citri via Lowering the Endosymbiont Numbers.

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Hu, Wei; Kuang, Fan; Lu, Zhanjun; Zhang, Ning; Chen, Tingtao

2018-01-01

Huanglongbing (HLB) is the most devastating citrus disease worldwide, and suppression of the Asian citrus psyllid ( Diaphorina citri ) is regarded as an effective method to inhibit the spread of HLB. In this study, we isolated a strain named as Serratia marcescens KH-001 from D. citri nymphs suffering from disease, and evaluated its killing effect on D. citri via toxicity test and effect on microbial community in D. citri using high-throughput sequencing. Our results indicated that S. marcescens KH-001 could effectively kill 83% of D. citri nymphs, while the fermentation products of S. marcescens KH-001 only killed 40% of the D. citri nymphs. High-throughput sequencing results indicated that the S. marcescens KH-001 increased the OTU numbers from 62.5 (PBS buffer) to 81.5, while significantly lowered the Shannon index compared with Escherichia coli DH5α (group E) ( p citri endow S. marcescens KH-001 a sound killing effect on D. citri . Further work need to do before this strain is used as a sound biological control agents.

Influence of Mahanarva fimbriolata (Stael) (Hemiptera: Cercopidae) injury on the quality of cane juice

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Madaleno, Leonardo L.; Ravaneli, Gisele C.; Presotti, Leandro E.; Mutton, Marcia J.R. [UNESP, Jaboticabal, SP (Brazil). Faculdade de Ciencias Agrarias e Veterinarias. Dept. de Tecnologia; Mutton, Miguel A. [UNESP, Jaboticabal, SP (Brazil). Faculdade de Ciencias Agrarias e Veterinarias. Dept. de Producao Vegetal; Fernandes, Odair A. [UNESP, Jaboticabal, SP (Brazil). Faculdade de Ciencias Agrarias e Veterinarias. Dept. de Fitossanidade

2008-01-15

Mahanarva fimbriolata (Stael) is an important pest in Latin America and causes significant reduction in sugarcane productivity. There is no information regarding the effect of this pest on the quality of cane juice used for sugar and alcohol production. This work aimed at evaluating the quality of sugarcane juice from plants attacked by spittlebugs. The experiment was arranged in a completely randomized design with 15 replications, and comprised two treatments: control and chemical treatment with thiamethoxam. An average of 9.2 {+-} 4.44 spittlebug nymphs m-1 were found in the plots prior to insecticide application. Nymphs were counted 18, 35, 55, and 82 days after the initial sampling (december/2003). During the mid growing season (July 2004), the juice was extracted from stalks and analyzed for Brix, Pol, RS, pH, fiber, purity, TRS, dextran, starch, and total phenolic compounds. Stalk yield was also measured. Chemical treatment was efficient in reducing spittlebug population, and elevated both stalk yield and juice pH. The accumulated infestation expressed as insect-days was significantly and negatively correlated to yield, Pol, pH, and purity. The concentration of phenolic compounds increased with pest infestation, while dextran and starch levels were not affected. The infestation of 2.4 and 7.3 nymphs m-1 day-1 caused reductions of 8.3% and 29.8% in yield; 1.9% and 5.8% in Pol; 0.4% and 1.1% in pH and 0.4% and 1.2% in purity, respectively, in comparison to areas where the pest population was extremely low (< 0.1 nymphs m-1). (author)

A dynamic population model to investigate effects of climate and climate-independent factors on the lifecycle of the tick Amblyomma americanum (Acari: Ixodidae)

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Ludwig, Antoinette; Ginsberg, Howard; Hickling, Graham J.; Ogden, Nicholas H.

2016-01-01

The lone star tick, Amblyomma americanum, is a disease vector of significance for human and animal health throughout much of the eastern United States. To model the potential effects of climate change on this tick, a better understanding is needed of the relative roles of temperature-dependent and temperature-independent (day-length-dependent behavioral or morphogenetic diapause) processes acting on the tick lifecycle. In this study, we explored the roles of these processes by simulating seasonal activity patterns using models with site-specific temperature and day-length-dependent processes. We first modeled the transitions from engorged larvae to feeding nymphs, engorged nymphs to feeding adults, and engorged adult females to feeding larvae. The simulated seasonal patterns were compared against field observations at three locations in United States. Simulations suggested that 1) during the larva-to-nymph transition, some larvae undergo no diapause while others undergo morphogenetic diapause of engorged larvae; 2) molted adults undergo behavioral diapause during the transition from nymph-to-adult; and 3) there is no diapause during the adult-to-larva transition. A model constructed to simulate the full lifecycle of A. americanum successfully predicted observed tick activity at the three U.S. study locations. Some differences between observed and simulated seasonality patterns were observed, however, identifying the need for research to refine some model parameters. In simulations run using temperature data for Montreal, deterministic die-out of A. americanum populations did not occur, suggesting the possibility that current climate in parts of southern Canada is suitable for survival and reproduction of this tick.

Phenology of Asian citrus psyllid (Hemiptera: Liviidae) and associated parasitoids on two species of Citrus, kinnow mandarin and sweet orange, in Punjab Pakistan.

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Khan, Shouket Zaman; Arif, Muhammad Jalal; Hoddle, Christina D; Hoddle, Mark S

2014-10-01

The population phenology of Asian citrus psyllid, Diaphorina citri Kuwayama, was monitored weekly for 110 wk on two species of Citrus, kinnow mandarin and sweet orange, at two different research sites in Faisalabad, Punjab Pakistan. Citrus flush growth patterns were monitored and natural enemy surveys were conducted weekly. Flush patterns were similar for kinnow and sweet orange. However, flush on sweet orange was consistently more heavily infested with Asian citrus psyllid than kinnow flush; densities of Asian citrus psyllid eggs, nymphs, and adults were higher on sweet orange when compared with kinnow. When measured in terms of mean cumulative insect or Asian citrus psyllid days, eggs, nymphs, and adults were significantly higher on sweet orange than kinnow. Two parasitoids were recorded attacking Asian citrus psyllid nymphs, Tamarixia radiata (Waterston) and Diaphorencyrtus aligarhensis (Shafee, Alam and Agarwal). The dominant parasitoid species attacking Asian citrus psyllid nymphs on kinnow and sweet orange was T. radiata, with parasitism averaging 26%. D. aligarhensis parasitism averaged 17%. Generalist predators such as coccinellids and chrysopids were collected infrequently and were likely not important natural enemies at these study sites. Immature spiders, in particular, salticids and yellow sac spiders, were common and may be important predators of all Asian citrus psyllid life stages. Low year round Asian citrus psyllid densities on kinnow and possibly high summer temperatures, may, in part, contribute to the success of this cultivar in Punjab where Candidatus Liberibacter asiaticus, the putative causative agent of huanglongbing, a debilitating citrus disease, is widespread and vectored by Asian citrus psyllid.

Stage-Related Defense Response Induction in Tomato Plants by Nesidiocoris tenuis

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Naselli, Mario; Urbaneja, Alberto; Siscaro, Gaetano; Jaques, Josep A.; Zappalà, Lucia; Flors, Víctor; Pérez-Hedo, Meritxell

2016-01-01

The beneficial effects of direct predation by zoophytophagous biological control agents (BCAs), such as the mirid bug Nesidiocoris tenuis, are well-known. However, the benefits of zoophytophagous BCAs’ relation with host plants, via induction of plant defensive responses, have not been investigated until recently. To date, only the females of certain zoophytophagous BCAs have been demonstrated to induce defensive plant responses in tomato plants. The aim of this work was to determine whether nymphs, adult females, and adult males of N. tenuis are able to induce defense responses in tomato plants. Compared to undamaged tomato plants (i.e., not exposed to the mirid), plants on which young or mature nymphs, or adult males or females of N. tenuis fed and developed were less attractive to the whitefly Bemisia tabaci, but were more attractive to the parasitoid Encarsia formosa. Female-exposed plants were more repellent to B. tabaci and more attractive to E. formosa than were male-exposed plants. When comparing young- and mature-nymph-exposed plants, the same level of repellence was obtained for B. tabaci, but mature-nymph-exposed plants were more attractive to E. formosa. The repellent effect is attributed to the signaling pathway of abscisic acid, which is upregulated in N. tenuis-exposed plants, whereas the parasitoid attraction was attributed to the activation of the jasmonic acid signaling pathway. Our results demonstrate that all motile stages of N. tenuis can trigger defensive responses in tomato plants, although these responses may be slightly different depending on the stage considered. PMID:27472328

Effect of alternative prey on development and consumption of Orius insidiosus (Say) (Hemiptera, Anthocoridae) and oviposition behavior on chrysantemum cultivars

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Soglia, Maria da Conceicao M.; Bueno, Vanda Helena Paes; Carvalho, Livia Mendes

2007-01-01

This work aimed to evaluate the development time and the consumption of Orius insidiosus (Say, 1832) feeding on Aphis gossypii Glover, 1877 as well as its oviposition behavior on two chrysanthemum cut cultivars. The trials were conducted in climatic chamber at 25 ± 1 deg C, RH 70 ± 10% and 12h photo phase. Nymphs of the predator, less than 24h old, were kept individually in petri dishes (5cm) with 20 nymphs of A. gossypii (first, second and third instar) on leaf disc (4 cm) of each cultivar ('White Reagan' and 'Yellow Snowdon') in a layer of agar-water (1%). Petiole of each chrysanthemum cultivar as oviposition substrate was evaluated and the females were feeding on eggs of Anagasta kuehniella (Zeller, 1879). The predator complete its development feeding on A. gossypii kept in both cultivars. The duration of nymphal phase of O. insidiosus were 21.1 and 18.3 days on 'White Reagan' and 'Yellow Snowdon', respectively. The consumption of the females of O. insidiosus was higher (P<0.01) on A. gossypii in 'White Reagan' (2.63 nymphs) compared to the consumption in 'Yellow Snowdon' (0.7 nymphs). Females of O. insidiosus oviposited in petiole of both cultivars with 22.5 and 23.3 eggs/female on 'White Reagan' and 'Yellow Snowdon', respectively. Release of O. insidiosus on chrysanthemum crops could be important to decrease the A. gossypii population, as the predator completes its development having this aphid as prey, and the chrysanthemum cultivars offer conditions to colonization and establishment of O. insidiosus. (author)

Cuticle Fatty Acid Composition and Differential Susceptibility of Three Species of Cockroaches to the Entomopathogenic Fungi Metarhizium anisopliae (Ascomycota, Hypocreales).

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Gutierrez, Alejandra C; Gołębiowski, Marek; Pennisi, Mariana; Peterson, Graciela; García, Juan J; Manfrino, Romina G; López Lastra, Claudia C

2015-04-01

Differences in free fatty acids (FFAs) chemical composition of insects may be responsible for susceptibility or resistance to fungal infection. Determination of FFAs found in cuticular lipids can effectively contribute to the knowledge concerning insect defense mechanisms. In this study, we have evaluated the susceptibility of three species of cockroaches to the entomopathogenic fungi Metarhizium anisopliae (Metschnikoff) Sorokin by topical application. Mortality due to M. anisopliae was highly significant on adults and nymphs of Blattella germanica L. (Blattodea: Blattellidae). However, mortality was faster in adults than in nymphs. Adults of Blatta orientalis L. (Blattodea: Blattidae) were not susceptible to the fungus, and nymphs of Blaptica dubia Serville (Blattodea: Blaberidae) were more susceptible to the fungus than adults. The composition of cuticular FFAs in the three species of cockroaches was also studied. The analysis indicated that all of the fatty acids were mostly straight-chain, long-chain, saturated or unsaturated. Cuticular lipids of three species of cockroaches contained 19 FFAs, ranging from C14:0 to C24:0. The predominant fatty acids found in the three studied species of cockroaches were oleic, linoleic, palmitic, and stearic acid. Only in adults of Bl. orientalis, myristoleic acid, γ-linolenic acid, arachidic acid, dihomolinoleic acid, and behenic acid were identified. Lignoceric acid was detected only in nymphs of Bl. orientalis. Heneicosylic acid and docosahexaenoic acid were identified in adults of Ba. dubia. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Metabolic alterations in the nymphal instars of Diaphorina citri induced by Candidatus Liberibacter asiaticus, the putative pathogen of huanglongbing.

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Nabil Killiny

Full Text Available Currently, huanglongbing is the most damaging disease of citrus causing huge economic losses. The disease is caused by the Gram-negative bacterium Candidatus Liberibacter asiaticus (CLas. The pathogen is transmitted in a persistent propagative circulative manner within its vector, the Asian citrus psyllid, Diaphorina citri. Exploring the metabolic alteration in the vector may lead to a better understanding of the nutritional needs of CLas and to designing an artificial medium for culturing the pathogen. It has been shown that the nymphal stages have a greater role in transmission mainly because they feed on plants more actively than adults. In this study, we carried out an untargeted comparative metabolomic analysis for healthy and CLas-infected 4th / 5th instar nymphs. The metabolic analysis was performed using trimethylsilylation and methyl chloroformate derivatization followed by Gas Chromatography-Mass Spectrometry (GC-MS. Overall, the changes in the nymph metabolism due to the infection with CLas were more pronounced than in adults, as we previously published. Nymphs reared on CLas-infected Valencia sweet orange were higher in many metabolites, mainly those of the TCA cycle, C16 and C18 fatty acids, glucose, sucrose, L-proline, L-serine, pyroglutamic acid, saccharic acid, threonic acid and myo-inositol than those reared on healthy plants. In contrast, CLas-infected nymphs were lower in putrescine, glycine, L -phenylalanine, L -tyrosine, L -valine, and chiro-inositol. The information provided from this study may contribute in acceleration of the availability of CLas in culture and consequent screening of antibacterial compounds to discover a definitive solution for huanglongbing.

Metabolic alterations in the nymphal instars of Diaphorina citri induced by Candidatus Liberibacter asiaticus, the putative pathogen of huanglongbing.

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Killiny, Nabil; Jones, Shelley E

2018-01-01

Currently, huanglongbing is the most damaging disease of citrus causing huge economic losses. The disease is caused by the Gram-negative bacterium Candidatus Liberibacter asiaticus (CLas). The pathogen is transmitted in a persistent propagative circulative manner within its vector, the Asian citrus psyllid, Diaphorina citri. Exploring the metabolic alteration in the vector may lead to a better understanding of the nutritional needs of CLas and to designing an artificial medium for culturing the pathogen. It has been shown that the nymphal stages have a greater role in transmission mainly because they feed on plants more actively than adults. In this study, we carried out an untargeted comparative metabolomic analysis for healthy and CLas-infected 4th / 5th instar nymphs. The metabolic analysis was performed using trimethylsilylation and methyl chloroformate derivatization followed by Gas Chromatography-Mass Spectrometry (GC-MS). Overall, the changes in the nymph metabolism due to the infection with CLas were more pronounced than in adults, as we previously published. Nymphs reared on CLas-infected Valencia sweet orange were higher in many metabolites, mainly those of the TCA cycle, C16 and C18 fatty acids, glucose, sucrose, L-proline, L-serine, pyroglutamic acid, saccharic acid, threonic acid and myo-inositol than those reared on healthy plants. In contrast, CLas-infected nymphs were lower in putrescine, glycine, L -phenylalanine, L -tyrosine, L -valine, and chiro-inositol. The information provided from this study may contribute in acceleration of the availability of CLas in culture and consequent screening of antibacterial compounds to discover a definitive solution for huanglongbing.

Distinct expression profiles and different functions of odorant binding proteins in Nilaparvata lugens Stål.

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Peng He

Full Text Available BACKGROUND: Odorant binding proteins (OBPs play important roles in insect olfaction. The brown planthopper (BPH, Nilaparvata lugens Stål (Delphacidae, Auchenorrhyncha, Hemiptera is one of the most important rice pests. Its monophagy (only feeding on rice, wing form (long and short wing variation, and annual long distance migration (seeking for rice plants of high nutrition imply that the olfaction would play a central role in BPH behavior. However, the olfaction related proteins have not been characterized in this insect. METHODOLOGY/PRINCIPAL FINDINGS: Full length cDNA of three OBPs were obtained and distinct expression profiles were revealed regarding to tissue, developmental stage, wing form and gender for the first time for the species. The results provide important clues in functional differentiation of these genes. Binding assays with 41 compounds demonstrated that NlugOBP3 had markedly higher binding ability and wider binding spectrum than the other two OBPs. Terpenes and Ketones displayed higher binding while Alkanes showed no binding to the three OBPs. Focused on NlugOBP3, RNA interference experiments showed that NlugOBP3 not only involved in nymph olfaction on rice seedlings, but also had non-olfactory functions, as it was closely related to nymph survival. CONCLUSIONS: NlugOBP3 plays important roles in both olfaction and survival of BPH. It may serve as a potential target for developing behavioral disruptant and/or lethal agent in N. lugens.

Toxicological profile of deltamethrin in Triatoma brasiliensis (Hemiptera: Reduviidae) in State of Ceará, Northeastern Brazil.

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Pessoa, Grasielle Caldas D'Ávila; Trevizani, Nathália Abreu Borges; Dias, Letícia Sena; Bezerra, Claudia Mendonça de; Melo, Bernardino Vaz de; Diotaiut, Liléia

2015-01-01

Triatoma brasiliensis is the species of greatest epidemiological relevance in the semi-arid region of Brazil. This species is predominantly found in domestic environments, and it has the ability to build large colonies with high levels of natural infection via Trypanosoma cruzi. Thus, T. brasiliensis is one of the most efficient transmitters of Chagas disease (CD) to humans. Despite household spraying with residual insecticides, many areas report persistent reinfestations for reasons that remain poorly understood. Therefore, this study sought to characterize the toxicological profile of deltamethrin in T. brasiliensis from areas with persistent reinfestation in State of Ceará, Brazil. The susceptibility reference lineage (SRL) was derived from Umari. Serial dilutions of deltamethrin were prepared and applied to the dorsal abdomen of first instar nymphs. The control group received only pure acetone. Mortality was evaluated after 72h. Qualitative tests assessed mortality in response to a diagnostic dose of 1xLD99 (0.851 nanograms of active ingredient per treated nymph) of the SRL. The susceptibility profile characterization of the T. brasiliensis populations revealed 50% resistance ratios (RR50) that ranged from 0.32 to 1.21. The percentage of mortality in response to the diagnostic dose was 100%. We demonstrated that T. brasiliensis was highly susceptible to deltamethrin. The control difficulties found might be related to the recolonization of the triatomines originating from neighboring environments and the possible operational failures related to the process of spraying that enabled specimens less susceptible to deltamethrin to survive.

The residual efficacy of a cypermethrin pour-on formulation applied on goats on the mortality and blood intake of Triatoma infestans

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Ivana Amelotti

2012-12-01

Full Text Available Triatoma infestans is the main vector of Trypanosoma cruzi, the aetiological agent of Chagas disease in the Gran Chaco region of South America. As a frequent blood meal source for triatomine bugs, domestic goats play a key role in the eco-epidemiology of Chagas disease. The aim of this study was to evaluate the mortality and blood intake of T. infestans fed on goats that had been treated with different doses of pour-on insecticide. Third-instar nymphs were fed on goats that had been treated with 0 cc, 5 cc, 10 cc or 15 cc of a pour-on formulation of cypermethrin. The exposure of T. infestans to animals treated at different post-application intervals revealed a residual activity of the insecticide. The mortality rate in the treated groups was higher than in the control groups until 30 days post-insecticide application (p = 0.03, except in the group treated with 5 cc, in which no mortality was detected after seven days of insecticide application. Rainfall affected the triatomicide effect, reducing the time of residual activity. The cypermethrin pour-on treatment decreased the blood intake of T. infestans. Thirty days after the cypermethrin application, nymph mortality was 16% (± 13 with both doses (10 cc and 15 cc. The 15 cc dose did not result in higher insect mortality or increased persistence compared to the 10 cc dose.

Association of vectors and environmental conditions during the emergence of Peruvian horse sickness orbivirus and Yunnan orbivirus in northern Peru.

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Méndez-López, María R; Attoui, Houssam; Florin, David; Calisher, Charles H; Florian-Carrillo, J Christian; Montero, Stephanie

2015-12-01

Since 1983, cases of diseased donkeys and horses with symptoms similar to those produced by alphaviruses were identified in two departments in northern Peru; however serological testing ruled out the presence of those viruses and attempts to isolate an agent were also unproductive. In 1997, also in northern Peru, two new orbiviruses were discovered, each recognized as a causative agent of neurological diseases in livestock and domestic animals and, at the same time, mosquitoes were found to be infected with these viruses. Peruvian horse sickness virus (PHSV) was isolated from pools of culicid mosquitoes, Aedes serratus and Psorophora ferox, and Yunnan virus (YUOV) was isolated from Aedes scapularis in the subtropical jungle (upper jungle) located on the slope between the east side of the Andes and the Amazonian basin in the Department of San Martín. Both viruses later were recovered from mosquitoes collected above the slope between the west side of the Andes and the coast (Department of Piura) in humid subtropical areas associated with the Piura River basin. In this region, PHSV was isolated from Anopheles albimanus and YUOV was isolated from Ae. scapularis. We discuss the ecology of vector mosquitoes during the outbreaks in the areas where these mosquitoes were found. © 2015 The Society for Vector Ecology.

Molecular diagnostics reveal spiders that exploit prey vibrational signals used in sexual communication.

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Virant-Doberlet, Meta; King, R Andrew; Polajnar, Jernej; Symondson, William O C

2011-05-01

Vibrational signalling is a widespread form of animal communication and, in the form of sexual communication, has been generally regarded as inherently short-range and a private communication channel, free from eavesdropping by generalist predators. A combination of fieldwork and laboratory experiments was used to test the hypothesis that predators can intercept and exploit such signals. First, we developed and characterized PCR primers specific for leafhoppers of the genus Aphrodes and specifically for the species Aphrodes makarovi. Spiders were collected from sites where leafhoppers were present and screened with these primers to establish which spider species were significant predators of this species during the mating period of these leafhoppers. Analysis using PCR of the gut contents of tangle-web spiders, Enoplognatha ovata (Theridiidae), showed that they consume leafhoppers in the field at a greater rate when signalling adults were present than when nymphs were dominant, suggesting that the spiders were using these vibrations signals to find their prey. Playback and microcosm experiments then showed that E. ovata can use the vibrational signals of male leafhoppers as a cue during foraging and, as a result, killed significantly more male than female A. makarovi. Our results show, for the first time, that arthropod predators can exploit prey vibrational communication to obtain information about prey availability and use this information to locate and capture prey. This may be a widespread mechanism for prey location, one that is likely to be a major unrecognized driver of evolution in both predators and prey. © 2011 Blackwell Publishing Ltd.

No direct effects of resistant soybean cultiva IAC-24 on Podisus nigrispinus (Heteroptera: Pentatomidae Efectos no directos de resistencia del cultivar de soya IAC-24 sobre Podisus nigrispinus (Heteroptera: Pentatomidae

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José Cola Zanuncio

2012-12-01

Full Text Available The parameters of survival, development and reproduction of Podisus nigrispinus Dallas, 1851 (Heteroptera: Pentatomidae may be affected by feeding on soybean (Glycine max L. Merr.; Fabaceae cultivars. The direct effect was evaluated of the insect-resistant soybean 'IAC-24' (insect-susceptible soybean 'UFVS-2006' + pupae of Tenebrio molitor L., 1758 Coleoptera: Tenebrionidae versus 'IAC-24' plants + pupae of T. molitor in the nymph and adult stages of the predator P. nigrispinus. The duration of the nymph stage was similar between treatments, but 'IAC-24' reduced the duration of the IV instar of this predator. The survival of P. nigrispinus was similar between treatments in the instars I, II, IV and V and in the nymph stage, but the survival of the III instar was longer with 'IAC-24' plants. The body mass of nymphs in the first day of the III, IV, and V instars after ecdysis and newly emerged adults; reproductive characteristics (periods of pre-oviposition, oviposition, post-oviposition and egg incubation; egg laying interval, number of egg masses per female, nymphs per female, nymphs per egg mass and percentage of nymphs hatching and life span of males and females of P. nigrispinus were similar between treatments. The resistant soybean 'IAC-24' showed no direct deleterious effects on P. nigrispinus, which implies its innocuity and compatibility with this predator.Los par ámetros de supervivencia, desarrollo y reproducción de Podìsus nìgrìspìnus Dallas, 1851 (Heteroptera: Pentatomidae pueden verse afectados por la alimentación en cultivos de soya (Glycìne max L. Merr.; Fabaceae. Se evaluó el efecto directo de la soya 'IAC-24' resistente a insectos (soya 'UFVS-2006' susceptible a insectos + pupas de Tenebrìo molìtor L., 1758 Coleoptera: Tenebrionidae vs. plantas 'IAC-24' + pupas de T. molìtor sobre los estados de ninfa y adulto del depredador P. nìgrìspìnus. La duración del estado ninfal fue similar entre tratamientos, no obstante

Efficiency of neem oil nanoformulations to Bemisia tabaci (GENN. Biotype B (Hemiptera: AleyrodidaeEficiência de nanoformulações a base de óleo de nim sobre Bemisia tabaci (GENN. Biótipo B (Hemiptera: Aleyrodidae

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Sheila Salles Carvalho

2012-04-01

Full Text Available The nanotechnology, through encapsulation of active ingredients, has showed an important way to avoid problems with quickly degradation of the pesticide molecules. Thus, neem (Azadirachta indica oil nanoformulations containing ?-ciclodextrin and poli-?-caprolactone (PCL were tested as to their control efficiency against eggs and nymphs of Bemisia tabaci (Genn. biotype B reared in soybean. The Lethal Concentration (LC50 was estimated using a commercial neem oil (Organic Neem® on first-instar nymphs to establish the adequate volume of the nanoformulations per treatment. After that, they were sprayed on eggs and first-instar nymphs in laboratory and greenhouse and on third-instar nymphs in greenhouse. The commercial neem oil and distilled water were used as controls. Egg viability was not affected by any treatment. Among six nanoformulations, only one was efficient against the first-instar nymphs in laboratory conditions. However, its effective period was not increased as expected. In greenhouse, first-instar nymphs were more affected by two nanoformulations which were significantly different of the commercial neem oil - the most effective one. No mortality differences among the formulations in the third-instar test were observed. The nanoformulations were less efficient to control the B. tabaci biotype B nymphs than the commercial neem oil. A nanotecnologia, através do encapsulamento de ingredientes ativos, tem-se revelado uma importante estratégia para evitar problemas com a rápida degradação de moléculas inseticidas. Assim, nanoformulações à base de óleo de nim (Azadirachta indica utilizando os polímeros ?-ciclodextrina e poli-?-caprolactona (PCL foram testadas quanto a sua eficiência de controle de ovos e ninfas de Bemisia tabaci (Genn. biótipo B mantidas em soja. Foi estimada a CL50 utilizando uma formulação comecial de óleo de nim (Organic Neem® sobre ninfas em 1º ínstar da qual se estipulou o volume das nanoformula

Volatile compound diversity and conserved alarm behaviour in Triatoma dimidiata.

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May-Concha, Irving; Rojas, Julio C; Cruz-López, Leopoldo; Ibarra-Cerdeña, Carlos N; Ramsey, Janine M

2015-02-06

Triatoma dimidiata (Latreille) is a key vector complex of Trypanosoma cruzi, etiologic agent of Chagas disease, as it spans North, Central, and South America. Although morphological and genetic studies clearly indicate existence of at least five clades within the species, there has been no robust or systematic revision, or appropriate nomenclature change for species within the complex. Three of the clades (haplogroups) are distributed in Mexico, and recent evidence attests to dispersal of clades across previously "presumed" monotypic geographic regions. Evidence of niche conservatism among sister species of this complex suggests that geographic dispersal is possible for non-sympatric populations, although no information is available on the behavioural aspects of potential interclade interactions, for instance whether differentiation of chemical signaling or response to these signals could impede communication among the haplogroups. Volatiles emitted by disturbed bugs, Brindley's (BGs), and metasternal (MGs) glands were identified using solid-phase micro-extraction (SPME) and gas chromatography coupled mass spectrometry (GC-MS). Volatile compounds emitted by BGs and MGs, and those secreted by disturbed nymphs and adults, of the three Mexican T. dimidiata haplogroups were tested for avoidance behaviour by conspecific nymphs and adults using an olfactometer. Triatoma dimidiata haplogroups all have three age-related alarm responses: absence of response by early stage nymphs, stage-specific response by 4-5th stage nymphs, and a shared 4-5th nymph and adult response to adult compounds. Disturbed bugs released 15 to 24 compounds depending on the haplogroup, among which were three pyrazines, the first report of these organoleptics in Triatominae. Isobutyric acid from BGs was the most abundant molecule in the response in all haplogroups, in addition to 15 (h1) to 21 (h2 and h3) MG compounds. Avoidance behaviour of disturbed bugs and volatiles emitted by BGs were haplogroup

[Double-ambient CO2 concentration affects the growth, development and sucking behavior of non-target brown plant hopper Nilaparvata lugens fed on transgenic Bt rice.

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Lu, Yong Qing; Dai, Yang; Yu, Xiu Ying; Yu, Fu-Lan; Jiang, Shou Lin; Zhou, Zong Yuan; Chen, Fa Jun

2018-02-01

In recent years, the two issues of climate change including elevated CO 2 etc., and resistance of transgenic Bt crops against non-target insect pests have received widespread attention. Elevated CO 2 can affect the herbivorous insects. To date, there is no consensus about the effect of elevated CO 2 on the suck-feeding insect pests (non-target insect pests of transgenic Bt crops). Its effects on the suck-feeding behavior have rarely been reported. In this study, CO 2 levels were set up in artificial climate chamber to examined the effects of ambient (400 μL·L -1 ) and double-ambient (800 μL·L -1 ) CO 2 levels on the suck-feeding behavior, growth, development, and reproduction of the non-target insect pest of transgenic Bt rice, brown planthopper, Nilaparvata lugens. The results showed that CO 2 level significantly affected the egg and nymph duration, longevity and body mass of adults, and feeding behavior of the 4th and 5th instar nymphs, while had no effect on the fecundity of N. lugens. The duration of eggs and nymphs, and the longevity of female adults were significantly shortened by 4.0%, 4.2% and 6.6% respectively, the proportion of the macropterous adults was significantly increased by 11.6%, and the body mass of newly hatched female adults was significantly decreased by 2.2% by elevated CO 2 . In addition, elevated CO 2 significantly enhanced the stylet puncturing efficiency of the 4th and 5th instar nymphs of N. lugens. The duration ofphloem ingestion of the N4b waveform was significantly prolonged by 60.0% and 50.1%, and the frequency significantly was increased by 230.0% and 155.9% for the 4th and 5th instar nymphs of N. lugens by elevated CO 2 , respectively. It was concluded that double-ambient CO 2 could promote the growth and development of N. lugens through enhancing its suck-feeding, shorten the generation life-span and increase the macropertous adults' proportion of N. lugens. Thus, it could result in the occurrence of non-target rice

Efeito de extratos aquosos de meliáceas sobre Bemisia tabaci biótipo B em tomateiro Effect of aqueous extracts of meliaceous plants on Bemisia tabaci B biotype on tomato plants

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ANTONIO PANCRÁCIO DE SOUZA

2000-01-01

Full Text Available Comparou-se a bioatividade de extratos aquosos a 3% (p/v de três meliáceas, Melia azedarach L. (frutos verdes, Trichilia pallida Swartz (ramos e Azadirachta indica A. Juss (sementes, em relação à mosca branca Bemisia tabaci (Gennadius biótipo B, criada em tomateiro. No primeiro experimento os extratos foram aplicados sobre ovos e sobre ninfas com três dias de idade, avaliando-se a mortalidade e a duração das fases de ovo e de ninfa. No segundo experimento os extratos foram aplicados apenas sobre as ninfas, avaliando-se a mortalidade nessa fase e a longevidade e fecundidade dos adultos. Em relação à fase de ovo, o extrato de T. pallida foi o que provocou maior mortalidade, seguindo-se os de A. indica e M. azedarach. A maior mortalidade ninfal foi constatada com o extrato de A. indica, seguindo-se os de T. pallida e M. azedarach. Nenhum dos extratos afetou a duração das fases de ovo e de ninfa, assim como a longevidade e fecundidade.The objective of this research was to compare the effect of aqueous extracts of fresh fruits of Melia azedarach L., twigs of Trichilia pallida Swartz and seeds of zadirachta indica A. Juss, on eggs and nymphs of silverleaf whitefly Bemisia tabaci (Gennadius B biotype reared on tomato plants. The extracts were tested at a concentration of 3%. In the first experiment, the extracts were applied on eggs and 3-day-old nymphs. Records were taken on mortality, duration of egg and nymphal stages. In the second experiment the extracts were applied on 3-day-old nymphs and records were taken on nymphal mortality, adult longevity and fecundity. The extracts of T. pallida were the most effective on eggs, followed by A. indica and M. azedarach. The extracts of A. indica were the most effective on nymphs followed by T. pallida and M. azedarach. In both experiments, the duration of egg and nymph stages, longevity and fecundity were not affected by the extracts.

Influence of Mahanarva fimbriolata (Stael) (Hemiptera: Cercopidae) injury on the quality of cane juice

International Nuclear Information System (INIS)

Madaleno, Leonardo L.; Ravaneli, Gisele C.; Presotti, Leandro E.; Mutton, Marcia J.R.; Mutton, Miguel A.; Fernandes, Odair A.

2008-01-01

Mahanarva fimbriolata (Stael) is an important pest in Latin America and causes significant reduction in sugarcane productivity. There is no information regarding the effect of this pest on the quality of cane juice used for sugar and alcohol production. This work aimed at evaluating the quality of sugarcane juice from plants attacked by spittlebugs. The experiment was arranged in a completely randomized design with 15 replications, and comprised two treatments: control and chemical treatment with thiamethoxam. An average of 9.2 ± 4.44 spittlebug nymphs m-1 were found in the plots prior to insecticide application. Nymphs were counted 18, 35, 55, and 82 days after the initial sampling (december/2003). During the mid growing season (July 2004), the juice was extracted from stalks and analyzed for Brix, Pol, RS, pH, fiber, purity, TRS, dextran, starch, and total phenolic compounds. Stalk yield was also measured. Chemical treatment was efficient in reducing spittlebug population, and elevated both stalk yield and juice pH. The accumulated infestation expressed as insect-days was significantly and negatively correlated to yield, Pol, pH, and purity. The concentration of phenolic compounds increased with pest infestation, while dextran and starch levels were not affected. The infestation of 2.4 and 7.3 nymphs m-1 day-1 caused reductions of 8.3% and 29.8% in yield; 1.9% and 5.8% in Pol; 0.4% and 1.1% in pH and 0.4% and 1.2% in purity, respectively, in comparison to areas where the pest population was extremely low (< 0.1 nymphs m-1). (author)

Deltamethrin-resistant German Cockroaches Are Less Sensitive to the Insect Repellents DEET and IR3535 than Non-resistant Individuals.

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Mengoni, Sofía L; Alzogaray, Raúl A

2018-04-02

The German cockroach, Blattella germanica (L.) (Blattodea: Blattellidae), is a serious worldwide pest with a considerable economical and sanitary impact. It is mainly controlled by the application of synthetic insecticides, but repeated use of these substances has promoted the appearance of resistance in cockroach populations throughout the world. The aim of this study was to compare the behavior of deltamethrin-susceptible (CIPEIN colony) and deltamethrin-resistant (JUBA and VGBA colonies) first instar nymphs exposed to the repellents N,N-diethyl-3-methylbenzamide (DEET) and ethyl 3-[acetyl(butyl)amino]propanoate (IR3535). Firstly, the behavior of the nymphs was assessed in an experimental arena in the absence of repellents. The parameters Distance Traveled, Velocity, Mobility Time, and Time Spent (in each half of the arena) were quantified using an image analyser, and showed that the behavior elicited by the three colonies was similar. After this, the behavior of the nymphs was quantified in an arena, half of which had been treated with repellent. The repellency of DEET increased as a linear function of log concentration for the three colonies. DEET elicited repellency as from a concentration of 97.49 µg/cm2 for the CIPEIN and JUBA colonies and 194.98 µg/cm2 for the VGBA colony. The repellency of IR3535 was weaker and started at a concentration of 389.96 µg/cm2 for the CIPEIN colony, 779.92 μg/cm2 for JUBA, and 1559.84 μg/cm2 for VGBA . Finally, nymphs were exposed to 3:1, 1:1, and 1:3 DEET:IR3535 mixtures, and a synergistic effect was observed only in the CIPEIN colony.

Evaluation of Piper aduncum Linn. Essential Oil (Fam:Piperaceae) against Periplaneta americana (L.).

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Ling A, I; Sulaiman, S; Othman, H

2009-01-01

The efficacy of Piper aduncum essential oil was evaluated against Periplaneta americana adults and nymphs in the laboratory. The plant essential oil at varying concentrations ranging between 10,000 to 80,000 ppm were placed inside glass beakers, rolled horizontally to ensure the essential oil covers all sides of the beakers and exposed to adults and nymphs of P. americana. Resigen (R) 1ppm was used as positive control and distilled water as negative control. The LT50 and LT90 was obtained using Log Probit programme. Exposure of essential oil to females P. americana at concentrations between 10,000 to 80,000 ppm indicated the LT50 and LT90 values between 5.31 h-189.19 h and 14.90 h-2105.31 h, respectively. Treatment with the same concentrations against males P. americana ,the LT50 and LT90 were 2.08 h-181.73 h and 5.4 h-8460.51 h, respectively. Treatment against the nymphal stage with the same range of concentrations indicated the LT50 and LT 90 of 4.68 h-381.02 h and 28.71 h-5313.36 h, respectively.The nymphs and males were more susceptible than the females cockroaches. Treatment with Resigen (R) at 1ppm indicated much lower LT 50 and LT 90 values of 2.54 h-9.47 h for the females, 1.47 h-4.22 h for the males and 4.69 h-8.92 h for the nymphs.The negative control indicated no mortality for all stages of the cockroach. Piper aduncum essential oil can be used as an alternative natural product for controlling the cockroach Peripatetic americana.

Effects of dietary esfenvalerate exposures on three aquatic insect species representing different functional feeding groups.

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Palmquist, Katherine R; Jenkins, Jeffrey J; Jepson, Paul C

2008-08-01

Given the chemical properties of synthetic pyrethroids, it is probable that compounds, including esfenvalerate, that enter surface waters may become incorporated into aquatic insect food sources. We examined the effect of dietary esfenvalerate uptake in aquatic insects representing different functional feeding groups. We used three field-collected aquatic insect species: A grazing scraper, Cinygmula reticulata McDunnough (Ephemeroptera: Heptageniidae); an omnivorous filter feeder, Brachycentrus americanus Banks (Trichoptera: Brachycentridae); and a predator, Hesperoperla pacifica Banks (Plecoptera: Perlidae). Laboratory-cultured algae were preexposed for 24 h to esfenvalerate concentrations of 0, 0.025, 0.05, and 0.1 microg/L and provided to two C. reticulata age classes (small and final-instar nymphs). Reduction in small nymph growth was observed following three weeks of feeding on algae exposed to 0.05 and 0.1 microg/L of esfenvalerate, and the highest dietary exposure reduced egg production in final-instar nymphs. The diet for B. americanus and H. pacifica consisted of dead third-instar Chironomus tentans larvae preexposed for 24 h to esfenvalerate concentrations ranging between 0.1 and 1.0 microg/L. Consumption of larvae exposed to 0.5 to 1.0 microg/L of esfenvalerate caused case abandonment and mortality in B. americanus caddisfly larvae. Although H. pacifica nymphs readily consumed esfenvalerate-exposed larvae, no adverse effects were observed during the present study. Furthermore, no evidence of esfenvalerate-induced feeding deterrence was found in any of the species tested, suggesting that aquatic insects may not be able to distinguish between pyrethroid-contaminated and uncontaminated food sources. These findings indicate that feeding deterrence is not a factor in regulating aquatic insect dietary exposures to synthetic pyrethroids.

Borrelia burgdorferi Sensu Lato in Siberian chipmunks (Tamias sibiricus) introduced in suburban forests in France.

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Vourc'h, Gwenaël; Marmet, Julie; Chassagne, Michelle; Bord, Séverine; Chapuis, Jean-Louis

2007-01-01

Numerous vertebrate reservoirs have been described for Borrelia burgdorferi sensu lato (sl), which includes the etiological agents of Lyme Borreliosis (LB). The Siberian chipmunk (Tamias sibiricus) is a rodent originating from Asia, where it is suspected to be a B. burgdorferi reservoir. It has been intentionally released into the wild in Europe since the 1970s, but has not yet been subject to any study regarding its association with the LB agent. In this paper we studied Siberian chipmunk infestation with the LB vector (Ixodes ricinus) and infection prevalence by LB spirochetes in a suburban introduced population. We compared these findings with known competent reservoir hosts, the bank vole (Myodes [clethrionomys] glareolus) and wood mouse (Apodemus sylvaticus). All Siberian chipmunks were infested with larvae and larval abundance was higher in this species (mean number of larvae [95% Confidence Interval]: 73.5 [46.0, 117.2]) than in the two other rodent species (bank voles: 4.4 [3.0, 6.3] and wood mice: 10.2 [4.9, 21.2]). Significant factors affecting abundance of larvae were host species and sampling season. Nymphs were most prevalent on chipmunks (86.2%, mean: 5.1 [3.3, 8.0]), one vole carried only two nymphs, and none of the mice had any nymphs. Nymph abundance in chipmunks was affected by sampling season and sex. Furthermore, the infection prevalence of B. burgdorferi sl in the Siberian chipmunk was the highest (33.3%) and predominantly of B. afzelii. The infection prevalence was 14.1% in bank voles, but no wood mouse was found to be infected. Our results suggest that the Siberian chipmunk may be an important reservoir host for LB.

Effect of alternative prey on development and consumption of Orius insidiosus (Say) (Hemiptera, Anthocoridae) and oviposition behavior on chrysantemum cultivars; Efeito da presa alternativa no desenvolvimento e consumo de Orius insidiosus (Say) (Hemiptera, Anthocoridae) e comportamento de oviposicao em cultivares de crisantemo

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Soglia, Maria da Conceicao M. [Universidade Federal da Bahia (UFBA), Cruz das Almas, BA (Brazil). Centro de Ciencias Agrarias e Ambientais], e-mail: mcsoglia@yahoo.com.br; Bueno, Vanda Helena Paes; Carvalho, Livia Mendes [Universidade Federal de Lavras (UFLA), MG (Brazil). Dept. de Entomologia], e-mail: vhpbueno@ufla.br

2007-10-15

This work aimed to evaluate the development time and the consumption of Orius insidiosus (Say, 1832) feeding on Aphis gossypii Glover, 1877 as well as its oviposition behavior on two chrysanthemum cut cultivars. The trials were conducted in climatic chamber at 25 {+-} 1 deg C, RH 70 {+-} 10% and 12h photo phase. Nymphs of the predator, less than 24h old, were kept individually in petri dishes (5cm) with 20 nymphs of A. gossypii (first, second and third instar) on leaf disc (4 cm) of each cultivar ('White Reagan' and 'Yellow Snowdon') in a layer of agar-water (1%). Petiole of each chrysanthemum cultivar as oviposition substrate was evaluated and the females were feeding on eggs of Anagasta kuehniella (Zeller, 1879). The predator complete its development feeding on A. gossypii kept in both cultivars. The duration of nymphal phase of O. insidiosus were 21.1 and 18.3 days on 'White Reagan' and 'Yellow Snowdon', respectively. The consumption of the females of O. insidiosus was higher (P<0.01) on A. gossypii in 'White Reagan' (2.63 nymphs) compared to the consumption in 'Yellow Snowdon' (0.7 nymphs). Females of O. insidiosus oviposited in petiole of both cultivars with 22.5 and 23.3 eggs/female on 'White Reagan' and 'Yellow Snowdon', respectively. Release of O. insidiosus on chrysanthemum crops could be important to decrease the A. gossypii population, as the predator completes its development having this aphid as prey, and the chrysanthemum cultivars offer conditions to colonization and establishment of O. insidiosus. (author)

New data on the presence of hemocyanin in Plecoptera: recomposing a puzzle.

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Amore, Valentina; Gaetani, Brunella; Puig, Maria Angeles; Fochetti, Romolo

2011-01-01

The specific role of hemocyanin in Plecoptera (stoneflies) is still not completely understood, since none of the hypotheses advanced have proven fully convincing. Previous data show that mRNA hemocyanin sequences are not present in all Plecoptera, and that hemocyanin does not seem to be uniformly distributed within the order. All species possess hexamerins, which are multifunction proteins that probably originated from hemocyanin. In order to obtain an increasingly detailed picture on the presence and distribution of hemocyanin across the order, this study presents new data regarding nymphs and adults of selected Plecoptera species. Results confirm that the hemocyanin expression differs among nymphs in the studied stonefly species. Even though previous studies have found hemocyanin in adults of two stonefly species it was not detected in the present study, even in species where nymphs show hemocyanin, suggesting that the physiological need of this protein can change during life cycle. The phylogenetic pattern obtained using hemocyanin sequences matches the accepted scheme of traditional phylogeny based on morphology, anatomy, and biology. It is remarkable to note that the hemocyanin conserved region acts like a phylogenetic molecular marker within Plecoptera.

Natural insecticide based-leaves extract of Piper aduncum (Piperaceae in the control of stink bug brown soybean

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Ludmila Porto Piton

2014-11-01

Full Text Available This research aimed to evaluate the insecticide potential of the leaves extract of Piper aduncum (L. (Piperaceae on development of brown stink bug, Euschistus heros (F., major pest in soybean crop in Mato Grosso State. For this a bioassay was conducted with eggs, nymphs and adults of this stink bug, using the concentrations 0.5; 1.0; 2.0; 4.0 and 8.0%, of the extract acetonic of P. aduncum and acetone for control. It was evaluated the numbers of unviable eggs, nymphs death and longevity, fecundity and fertility of the adults. In the immersing eggs bioassay, all concentrations greater than 1% unviable more than 70% of the eggs, while in the contact bioassay only 19% of the eggs were unviable in 8% concentration, differing of control. In nymphs bioassay the concentrations of 8% and 4% caused death of 72% and 52%, respectively. In adults bioassay all concentrations tested reduced significantly the survival and reproduction of the insects. Thus is evidence that P. aduncum is a potential plant for stink bug control, because it had deleterious action in all development phases on E. heros.

Differential infectivity of two Pseudomonas species and the immune response in the milkweed bug, Oncopeltus fasciatus (Insecta: Hemiptera).

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Schneider, M; Dorn, A

2001-10-01

Pseudomonas aeruginosa and Pseudomonas putida show a profound differential infectivity after inoculation in Oncopeltus fasciatus. Whereas P. putida has no significant impact on nymphs, P. aeruginosa kills all experimental animals within 48 h. Both Pseudomonas species, however, induce the same four hemolymph peptides in O. fasciatus. Also injection of saline solution and injury induced these peptides. In general peptide induction was stronger in nymphs than in adult males. A significantly higher number of nymphs survived a challenge with P. aeruginosa when an immunization with P. putida preceded. The antibacterial properties of the hemolymph were demonstrated in inhibition experiments with P. putida. Two of the four inducible peptides (peptides 1 and 4) could be partially sequenced after Edman degradation and were compared with known antibacterial peptides. Peptide 1, of 15 kDa, showed 47.1% identity with the glycine-rich hemiptericin of Pyrrhocoris apterus. Peptide 4, of 2 kDa, had a 77.8% identity with the proline-rich pyrrhocoricin of P. apterus and a 76.9% identity with metalnikowin 1 of Palomena prasina. Peptides 2 and 3 are also small, with molecular weights of 8 and 5 kDa.

Prevalence of Linguatula serrata Infection in Domestic Bovids Slaughtered in Tabriz Abattoir, Iran

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G Anaraki-Mohammadi

2009-07-01

Full Text Available "nBackground:  Linguatulosis is a rare zoonotic parasitic infection, in which human plays the role of both defini­tive and intermediate host and can be occasionally infected. This study determines the status of infection in live­stock and its po­tential risk to men in the northwestern province of Azarbaijan-e-Sharghi, Iran. "nMethods: In a cross-sectional study from June 2007 to June 2008, 800 slaughtered animals including 400 cattle and 400 buffaloes from Tabriz abattoir in Azarbaijan-e-Sharghi Province were randomly selected and examined for L. serrata nymphs. After primary macroscopical inspection, all liver and lung samples were cut to small pieces, treated with a tissue digestion method and checked macroscopically and micro­scopically for free or encapsulated nymphs. "nResults: Out of 800 animals, 3 (0.38% were found to be infected with L. serrata nymphs and the preva­lence of infection in cattle and buffaloes was determined to be 0.25% and 0.5%, respectively. "nConclusion: Linguatula infection occurs as an endemic zoonosis in the study area and has an active transmission life cycle.

New tick records in Rondônia, Western Brazilian Amazon.

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Labruna, Marcelo Bahia; Barbieri, Fábio Silva; Martins, Thiago Fernandes; Brito, Luciana Gatto; Ribeiro, Francisco Dimas Sales

2010-01-01

In the present study, we provide new tick records from Vilhena Municipality, in the Southeast of the State of Rondônia, Northern Brazil. Ticks collected from a capybara, Hydrochoerus hydrochaeris (Linnaeus), were identified as Amblyomma romitii Tonelli-Rondelli (1 female), and Amblyomma sp. (1 larva). Ticks collected from a harpy eagle, Harpia harpyja (Linnaeus), were identified as Amblyomma cajennense (Fabricius) (16 nymphs) and Haemaphysalis juxtakochi Cooley (1 nymph). Ticks collected from a yellow-footed tortoise, Chelonoidis denticulada (Linnaeus), were identified as Amblyomma rotundatum Koch (10 females, 2 nymphs), and Amblyomma sp. (2 larvae). The present record of A. romitii is the first in the State of Rondônia, and represents the southernmost record for this tick species, indicating that its distribution area is much larger than currently recognized. Although both A. cajennense and H. juxtakochi have been reported parasitizing various bird species, we provide the first tick records on a harpy eagle. A. rotundatum is widespread in the State of Rondônia, and has been previously reported on the yellow-footed tortoise. The present records increase the tick fauna of Rondônia to 26 species.

New records for Amblyomma sculptum (Ixodidae) on non-passerine birds in Brazil.

Science.gov (United States)

Luz, Hermes Ribeiro; Faccini, João Luiz Horacio; Landulfo, Gabriel Alves; Costa Neto, Sócrates Fraga; Famadas, Kátia Maria

2016-01-01

The aim of this paper was to provide new records of Amblyomma sculptum on two species of terricolous birds in two areas of the Cerrado (savannah- like) bioma: two specimens of Cariama cristata were captured in the state of Goiás and one specimen ofCrax fasciolata was captured in the state of Minas Gerais. One of the C. cristata was parasitized by 15 larvae, six nymphs, one male and two females whereas the C. fasciolata was parasitized by seven larvae and eight nymphs. This paper presents a new locality for occurrence of parasitism A. sculptum in C. cristata and a new host for C fasciolata.

New records for Amblyomma sculptum (Ixodidae on non-passerine birds in Brazil

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Hermes Ribeiro Luz

2016-03-01

Full Text Available Abstract The aim of this paper was to provide new records of Amblyomma sculptum on two species of terricolous birds in two areas of the Cerrado (savannah- like bioma: two specimens of Cariama cristata were captured in the state of Goiás and one specimen ofCrax fasciolata was captured in the state of Minas Gerais. One of the C. cristata was parasitized by 15 larvae, six nymphs, one male and two females whereas the C. fasciolata was parasitized by seven larvae and eight nymphs. This paper presents a new locality for occurrence of parasitism A. sculptum in C. cristata and a new host for C fasciolata.

Modelling tick abundance using machine learning techniques and satellite imagery

DEFF Research Database (Denmark)

Kjær, Lene Jung; Korslund, L.; Kjelland, V.

satellite images to run Boosted Regression Tree machine learning algorithms to predict overall distribution (presence/absence of ticks) and relative tick abundance of nymphs and larvae in southern Scandinavia. For nymphs, the predicted abundance had a positive correlation with observed abundance...... the predicted distribution of larvae was mostly even throughout Denmark, it was primarily around the coastlines in Norway and Sweden. Abundance was fairly low overall except in some fragmented patches corresponding to forested habitats in the region. Machine learning techniques allow us to predict for larger...... the collected ticks for pathogens and using the same machine learning techniques to develop prevalence maps of the ScandTick region....

Taxonomical studies of ticks infesting wild rodents from Asir Province in Saudi Arabia.

Science.gov (United States)

Al-Mohammed, Hamdan I

2008-04-01

Ticks infesting rodents in Asir Province, which is about 3000 meter above sea level, were surveyed in Wadi Dalaghan and Wadi Bin Hachbal. They were examined from September to December 2006, where ten local life baited traps were distributed for 3 days each month. The rodents were Acomys c. dimitatus (20), Meriones rex (19) & one Gerbillus cheesmani. Fifty three nymphs were dropped off from the rodents in the laboratory 3 to 12 days post-trapping. Forty eight nymphs were reared to adults for identification and 5 ones died. The reared ticks were Rhipicephalus turanicus and R. sanguineus. The medical and veterinary importance was discussed.

Soluble cysteine-rich tick saliva proteins Salp15 and Iric-1 from E. coli

OpenAIRE

Kolb, Philipp; Vorreiter, Jolanta; Habicht, J?ri; Bentrop, Detlef; Wallich, Reinhard; Nassal, Michael

2014-01-01

Ticks transmit numerous pathogens, including borreliae, which cause Lyme disease. Tick saliva contains a complex mix of anti-host defense factors, including the immunosuppressive cysteine-rich secretory glycoprotein Salp15 from Ixodes scapularis ticks and orthologs like Iric-1 from Ixodes ricinus. All tick-borne microbes benefit from the immunosuppression at the tick bite site; in addition, borreliae exploit the binding of Salp15 to their outer surface protein C (OspC) for enhanced transmissi...

Traveler's encounter with nymphs in a hotel bed.

Science.gov (United States)

Sandlund, Johanna; Banaei, Niaz

2014-01-01

This case illustrates skin lesions in a traveler staying in a hotel bed infested with tics. Although infestation of hotels with bedbugs belonging to the Cimex genus is a growing problem worldwide, tick infestation has never been reported before.

DNA of Piroplasms of Ruminants and Dogs in Ixodid Bat Ticks.

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Sándor Hornok

Full Text Available In this study 308 ticks (Ixodes ariadnae: 26 larvae, 14 nymphs, five females; I. vespertilionis: 89 larvae, 27 nymphs, eight females; I. simplex: 80 larvae, 50 nymphs, nine females have been collected from 200 individuals of 17 bat species in two countries, Hungary and Romania. After DNA extraction these ticks were molecularly analysed for the presence of piroplasm DNA. In Hungary I. ariadnae was most frequently identified from bat species in the family Vespertilionidae, whereas I. vespertilionis was associated with Rhinolophidae. Ixodes ariadnae was not found in Romania. Four, four and one new bat host species of I. ariadnae, I. vespertilionis and I. simplex were identified, respectively. DNA sequences of piroplasms were detected in 20 bat ticks (15 larvae, four nymphs and one female. I. simplex carried piroplasm DNA sequences significantly more frequently than I. vespertilionis. In I. ariadnae only Babesia vesperuginis DNA was detected, whereas in I. vespertilionis sequences of both B. vesperuginis and B. crassa. From I. simplex the DNA of B. canis, Theileria capreoli, T. orientalis and Theileria sp. OT3 were amplified, as well as a shorter sequence of the zoonotic B. venatorum. Bat ticks are not known to infest dogs or ruminants, i.e. typical hosts and reservoirs of piroplasms molecularly identified in I. vespertilionis and I. simplex. Therefore, DNA sequences of piroplasms detected in these bat ticks most likely originated from the blood of their respective bat hosts. This may indicate either that bats are susceptible to a broader range of piroplasms than previously thought, or at least the DNA of piroplasms may pass through the gut barrier of bats during digestion of relevant arthropod vectors. In light of these findings, the role of bats in the epidemiology of piroplasmoses deserves further investigation.

Evaluation of Piper aduncum Linn. Essential Oil (Fam:Piperaceae against Periplaneta americana(L.

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I Ling A

2009-12-01

Full Text Available Background: The efficacy of Piper aduncum essential oil was evaluated against Periplaneta americana adults and nymphs in the laboratory.Methods: The plant essential oil at varying concentrations ranging between 10,000 to 80,000 ppm were placed inside glass beakers, rolled horizontally to ensure the essential oil covers all sides of the beakers and exposed to adults and nymphs of P. americana. Resigen (R 1ppm was used as positive control and distilled water as negative control. The LT50 and LT90 was obtained using Log Probit programme.Results: Exposure of essential oil to females P. americana at concentrations between 10,000 to 80,000 ppm indicated the LT50 and LT90 values between 5.31 h-189.19 h and 14.90 h-2105.31 h, respectively. Treatment with the same con­centrations against males P. americana ,the LT50 and LT90 were 2.08 h-181.73 h and 5.4 h-8460.51 h, respectively. Treatment against the nymphal stage with the same range of concentrations indicated the LT50 and LT 90 of 4.68 h-381.02 h and 28.71 h-5313.36 h, respectively.The nymphs and males were more susceptible than the females cock­roaches. Treatment with Resigen (R at 1ppm indicated much lower LT 50 and LT 90 values of 2.54 h-9.47 h for the fe­males, 1.47 h-4.22 h for the males and 4.69 h-8.92 h for the nymphs.The negative control indicated no mortality for all stages of the cockroach.Conclusion: Piper aduncum essential oil can be used as an alternative natural product for controlling the cockroach Peri­patetic americana.

Thermotolerance and Heat-Shock Protein Gene Expression Patterns in Bemisia tabaci (Hemiptera: Aleyrodidae) Mediterranean in Relation to Developmental Stage.

Science.gov (United States)

Jiang, Rui; Qi, Lan-Da; Du, Yu-Zhou; Li, Yuan-Xi

2017-10-01

Temperature plays an important role in the growth, development, and geographic distribution of insects. There is convincing evidence that heat-shock proteins (HSPs) play important roles in helping organisms adapt to thermal stress. To better understand the physiological and ecological influence of thermal stress on the different development stages of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Mediterranean species (MED), nymphs and adults were shocked with temperatures of 35, 38, and 41℃ for 1 and 2 h, respectively, and the survival rate, fecundity, and developmental duration were investigated in the laboratory. The expression levels of the hsp40, hsp70, and hsp90 genes were assessed using real-time PCR. The results indicate that the survival rates of the nymphs and adults decreased with increased temperature. A 2-h heat shock at 41℃ induced a significant reduction in fecundity in adults and an increase in developmental duration in young nymphs. Hsp90 showed higher temperature responses to thermal stress than hsp40 or hsp70. The expression levels of the hsps in the adults were significantly down-regulated by a 2-h heat shock at 41℃ compared with that by a 1-h treatment. A significant decrease in the expression levels of the hsps also occurred in the adults when the temperature increased from 38 to 41℃ for the 2-h treatment, whereas no significant decrease occurred in the nymphs. Compared with previous studies, we provide some evidence indicating that MED has the potential to adapt to a wider temperature range than the Middle East-Asia Minor 1 species. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Ran Involved in the Development and Reproduction Is a Potential Target for RNA-Interference-Based Pest Management in Nilaparvata lugens.

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Kai-Long Li

Full Text Available Ran (RanGTPase in insects participates in the 20-hydroxyecdysone signal transduction pathway in which downstream genes, FTZ-F1, Krüppel-homolog 1 (Kr-h1 and vitellogenin, are involved. A putative Ran gene (NlRan was cloned from Nilaparvata lugens, a destructive phloem-feeding pest of rice. NlRan has the typical Ran primary structure features that are conserved in insects. NlRan showed higher mRNA abundance immediately after molting and peaked in newly emerged female adults. Among the examined tissues ovary had the highest transcript level, followed by fat body, midgut and integument, and legs. Three days after dsNlRan injection the NlRan mRNA abundance in the third-, fourth-, and fifth-instar nymphs was decreased by 94.3%, 98.4% and 97.0%, respectively. NlFTZ-F1 expression levels in treated third- and fourth-instar nymphs were reduced by 89.3% and 23.8%, respectively. In contrast, NlKr-h1 mRNA levels were up-regulated by 67.5 and 1.5 folds, respectively. NlRan knockdown significantly decreased the body weights, delayed development, and killed >85% of the nymphs at day seven. Two apparent phenotypic defects were observed: (1 Extended body form, and failed to molt; (2 The cuticle at the notum was split open but cannot completely shed off. The newly emerged female adults from dsNlRan injected fifth-instar nymphs showed lower levels of NlRan and vitellogenin, lower weight gain and honeydew excretion comparing with the blank control, and no offspring. Those results suggest that NlRan encodes a functional protein that was involved in development and reproduction. The study established proof of concept that NlRan could serve as a target for dsRNA-based pesticides for N. lugens control.

A SURVEY OF SIZES AND WEIGHTS OF BEMISIA TABACI（HOMOPTERA： ALEYRODIDAE）B BIOTYPE LIFE STAGES FROM FIELD GROWN COTTON AND CANTALOUPES

Institute of Scientific and Technical Information of China (English)

Chang-chiChu; JamesS.Buckner; KamilKarut; ThomasP.Freeman; DennisR.Nelson; ThomasJ.Henneberryl

2003-01-01

Size and weight measurements were made for all the life stages of Bemisia tabaci (Gennadius) B biotype from field grown cotton ( Gossypium hirsutum L. ) and cantaloupe ( Cucumis melo L., var. cantalupensis )in Phoenix, AZ and Fargo, ND, USA in 2000 and 2001. Nymphal volumes were derived from the measurements.The average nymphal volume increase for settled 1 st to the late 4th instar was exponential. The greatest increase in body volume occurred during development from the 3rd to early 4th instar. Nymphs on cotton leaves were wider,but not longer compared with those on cantaloupe. Ventral and dorsal depth ratios of nymphal bodies from 1st tolate 4th instars from cantaloupe leaves were significantly greater compared with those from cotton leaves. During nymphal development from 1st to 4th instar, the average (from the two host species) ventral body half volume in-creased by nearly 51 times compared with an increase of 28 times for the dorsal body half volume. Adult female and male average lengths, from heads to wing tips, were 1 126 μm and 953 μm, respectively. Average adult fe-male and male weights were 39 and 17 μg, respectively. Average widths, lengths, and weights of eggs from cottonand cantaloupe were, 99 μm, 197 μm, and 0.8 μg, respectively. Average widths, lengths, and weights for exu-viae of non-parasitized nymphs from both cotton and cantaloupe were 492 μm, 673 μm, and 1.20 μg, respective-ly; and widths, lengths, and weights of parasitized nymph exuviae were 452 μm, 665 μm, and 3.62 μg, respec-tively. Both exuviae from non-parasitized and parasitized nymphs from cotton leaves were wider, longer, and heavier than those from cantaloupe leaves.

Modelling the Phenological Relationships of Questing Immature Ixodes Ricinus (Ixodidae) Using Temperature and NDVI Data.

Science.gov (United States)

Alonso-Carné, J; García-Martín, A; Estrada-Peña, A

2016-02-01

All active stages of the tick Ixodes ricinus were collected monthly at two sites in northern Spain between the years 2000 and 2007. We used percentile accumulation of the active stage in the environment to evaluate simple and coherent correlations between accumulation of the active stages of larvae and nymphs and medium-resolution MODIS satellite-derived information on the climate, including monthly and accumulated temperature and the Normalized Difference Vegetation Index (NDVI). This framework is not intended to predict the actual abundance of ticks in the field as a measure of the hazard to humans, but to provide a basic structure for addressing the phenology of the tick in its geographic range. We demonstrated that the accumulation of larval ticks in the active stage is a sigmoid function of the accumulated temperature from the beginning of the calendar year. We also demonstrated that the accumulated temperature necessary to recruit nymphs from the questing larval stage is a function of the changes in accumulated larvae and nymphs and the accumulated temperature and NDVI recorded by the Aqua sensor. The low p-values obtained in the regressions confirmed that such recruitment can be calculated using time intervals to estimate, for example, the beginning of the questing period or the time of the year when a population peak can be expected. The comparison among predicted and actual accumulated temperatures between larvae and nymph recruitment had an averaged error of ±20 days in one complete year. The use of accumulated temperature and NDVI proposed in this study opens up the re-evaluation of reports on the phenology of the tick in Europe. This framework is intended to evaluate the same correlations along the tick's range and predict its phenological patterns in areas of pathogen transmission risk for humans. © 2015 Blackwell Verlag GmbH.

DNA of Piroplasms of Ruminants and Dogs in Ixodid Bat Ticks.

Science.gov (United States)

Hornok, Sándor; Szőke, Krisztina; Kováts, Dávid; Estók, Péter; Görföl, Tamás; Boldogh, Sándor A; Takács, Nóra; Kontschán, Jenő; Földvári, Gábor; Barti, Levente; Corduneanu, Alexandra; Sándor, Attila D

2016-01-01

In this study 308 ticks (Ixodes ariadnae: 26 larvae, 14 nymphs, five females; I. vespertilionis: 89 larvae, 27 nymphs, eight females; I. simplex: 80 larvae, 50 nymphs, nine females) have been collected from 200 individuals of 17 bat species in two countries, Hungary and Romania. After DNA extraction these ticks were molecularly analysed for the presence of piroplasm DNA. In Hungary I. ariadnae was most frequently identified from bat species in the family Vespertilionidae, whereas I. vespertilionis was associated with Rhinolophidae. Ixodes ariadnae was not found in Romania. Four, four and one new bat host species of I. ariadnae, I. vespertilionis and I. simplex were identified, respectively. DNA sequences of piroplasms were detected in 20 bat ticks (15 larvae, four nymphs and one female). I. simplex carried piroplasm DNA sequences significantly more frequently than I. vespertilionis. In I. ariadnae only Babesia vesperuginis DNA was detected, whereas in I. vespertilionis sequences of both B. vesperuginis and B. crassa. From I. simplex the DNA of B. canis, Theileria capreoli, T. orientalis and Theileria sp. OT3 were amplified, as well as a shorter sequence of the zoonotic B. venatorum. Bat ticks are not known to infest dogs or ruminants, i.e. typical hosts and reservoirs of piroplasms molecularly identified in I. vespertilionis and I. simplex. Therefore, DNA sequences of piroplasms detected in these bat ticks most likely originated from the blood of their respective bat hosts. This may indicate either that bats are susceptible to a broader range of piroplasms than previously thought, or at least the DNA of piroplasms may pass through the gut barrier of bats during digestion of relevant arthropod vectors. In light of these findings, the role of bats in the epidemiology of piroplasmoses deserves further investigation.

BIOLOGY AND CONTROL OF THE APPLE MEALYBUG PHENACOCCUS ACERIS (SIGNORET) IN BELGIUM.

Science.gov (United States)

Bangels, E; Peusens, G; Bylemans, D; Belien, T

2014-01-01

Although in general very rare, some outbreaks of the apple mealybug Phenococcus aceris (Signoret) (Hemiptera: Pseudococcidae) were reported in the Belgian fruit growing area recently. This insect is known to be geographically widespread, to have a broad host range and to infest apple trees. Damage at harvest is considerable when sooty molds, a consequence of the pest's honeydew production, cover the fruits. Indirect damage of an infection is caused in cherry cultivation through transmission of the Little cherry virus (LChV2). Efficacy trials were executed in infested apple orchards in the Belgian fruit growing area and the life cycle of the pest on apple was studied more into detail. Apple mealybugs are univoltine, overwinter as 2nd instar nymphs inside a white cocoon on the tree (under the bark, in crevices) and leave their overwintering site in early spring (mid March). On sunny days the nymphs become active, move around and attach to start feeding (mid April). After a final moult into the adult form, females lay eggs in a cocoon-like white structure (from flowering on). Following hatching (end May), massive numbers of young nymphs spread out on the underside of the leaves (mid June) where they feed through suction. In order to manage this pest the efficacy of several plant protection products was tested in two infested apple orchards. Results indicated that mortality was high after an application of compounds belonging to the neonicotinoid insecticides. Different application timings and control strategies are possible, with active nymphs being the most vulnerable life stage. The observed degree of parasitation in our trial orchards also indicates a biological control contribution of parasitic wasps that should be taken into account. A decent IPM-strategy based on our results solved the problem in both apple orchards.

Revisiting Trypanosoma rangeli Transmission Involving Susceptible and Non-Susceptible Hosts.

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Luciana de Lima Ferreira

Full Text Available Trypanosoma rangeli infects several triatomine and mammal species in South America. Its transmission is known to occur when a healthy insect feeds on an infected mammal or when an infected insect bites a healthy mammal. In the present study we evaluated the classic way of T. rangeli transmission started by the bite of a single infected triatomine, as well as alternative ways of circulation of this parasite among invertebrate hosts. The number of metacyclic trypomastigotes eliminated from salivary glands during a blood meal was quantified for unfed and recently fed nymphs. The quantification showed that ~50,000 parasites can be liberated during a single blood meal. The transmission of T. rangeli from mice to R. prolixus was evaluated using infections started through the bite of a single infected nymph. The mice that served as the blood source for single infected nymphs showed a high percentage of infection and efficiently transmitted the infection to new insects. Parasites were recovered by xenodiagnosis in insects fed on mice with infections that lasted approximately four months. Hemolymphagy and co-feeding were tested to evaluate insect-insect T. rangeli transmission. T. rangeli was not transmitted during hemolymphagy. However, insects that had co-fed on mice with infected conspecifics exhibited infection rates of approximately 80%. Surprisingly, 16% of the recipient nymphs became infected when pigeons were used as hosts. Our results show that T. rangeli is efficiently transmitted between the evaluated hosts. Not only are the insect-mouse-insect transmission rates high, but parasites can also be transmitted between insects while co-feeding on a living host. We show for the first time that birds can be part of the T. rangeli transmission cycle as we proved that insect-insect transmission is feasible during a co-feeding on these hosts.

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment: 6 - Breeding in empty conditions of rice fields in South-Eastern Brazil

OpenAIRE

Forattini,Oswaldo Paulo; Kakitani,Iná; Massad,Eduardo; Marucci,Daniel

1994-01-01

Studies on culicid breeding in empty rice fields were carried out during the cultivation cycle from May to November 1993. This period corresponded to stages 1 and 2, when empty conditions prevailed. Breeding occurred in stage 1 and the first part of stage 2, corresponding respectively to fallow uncultivated and ploughing situations. No breeding was found to take place during the second part of stage 2 when transient floods and harrowing occurred. The predominant species were Aedes scapularis,...

The Tick Salivary Protein Salp15 Inhibits the Killing of Serum-Sensitive Borrelia burgdorferi Sensu Lato Isolates▿

OpenAIRE

Schuijt, Tim J.; Hovius, Joppe W. R.; van Burgel, Nathalie D.; Ramamoorthi, Nandhini; Fikrig, Erol; van Dam, Alje P.

2008-01-01

Borrelia burgdorferi, the agent of Lyme disease, is transmitted by ticks. During transmission from the tick to the host, spirochetes are delivered with tick saliva, which contains the salivary protein Salp15. Salp15 has been shown to protect spirochetes against B. burgdorferi-specific antibodies. We now show that Salp15 from both Ixodes ricinus and Ixodes scapularis protects serum-sensitive isolates of Borrelia burgdorferi sensu lato against complement-mediated killing. I. ricinus Salp15 show...

Sterility and mating competitiveness of irradiated males of the large milkweed bug, Oncopeltus fasciatus

International Nuclear Information System (INIS)

Moursy, L.E.; Eesa, N.M.; Cutkomp, L.K.

1991-01-01

Low level gamma radiation adversely affected the reproductive capacity of the large milkweed bug, oncopeltus fasciatus dallas, as expressed by fecundity and fertility. Treatment was applied to late 5th instar male nymphs. Both fecundity and fertility decreased linearly with the treatment dose and complete sterility occurred when males were exposed to 6 kilorads and mated with normal females. The mating competitiveness of O. fasciatus males irradiated at late 5th instar nymphs decreased linearly with the treatment dose. A strong negative relationship existed between dose and mating competitiveness ( r = -0.93). A 3:2 ratio of irradiated males at 4 kilorads ( as late 5th instar as many progeny as normal in F 1 .2 tab.,1 fig

Description of the last nymphal instar of Talipes appendiculatus (Hemiptera: Membracidae: Membracinae, and notes on the biology of the immatures and adults

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Frederico Lencioni-Neto

Full Text Available ABSTRACT The last instar nymph of Talipes appendiculatus (Fonseca is described and illustrated, and biological data are given on the immatures and adults. The 5th instar nymph has the body covered with tuberculate chalazae; head and thorax without scoli; abdomen with terga III-VIII with single dorsal scoli, all different in size, III and VIII small, V the largest about 2x longer than wide. Descriptions of the adults (male and female are also provided, with the addition of some new characters. The species (adults, immatures of various stages has been collected on branches of Cassia fistula L. (Leguminosae: Caesalpinioidea, and is frequently attended by bees and wasps.

FIRST RECORD OF GRYLLOPHILA SKRJABINI SERGIEV, 1923 AND CEPHALOBELLUS MAGALHAESI SCHWENK, 1926 (NEMATODA: THELASTOMATIDAE PARASITES OF NEOCURTILLA CLARAZIANA SAUSSURE, 1874 (ORTHOPTERA: GRYLLOTALPIDAE IN ARGENTINA

Directory of Open Access Journals (Sweden)

JOSÉ MATIAS RUSCONI

Full Text Available ABSTRACT Thelastomatidae is one of the largest families parasitizing insects, within the order Oxyurida. In this work we reported parasitism in nymphs and adults of Neocurtilla claraziana by two different thelastomatid species as a part of a field survey on agricultural pests. Nymphs and adults of this insect were isolated from grasslands of Buenos Aires State, Argentina using a tensio-active solution. The nematode species Gryllophila skrjabini Sergiev, 1923 and Cephalobellus magalhaesi Schwenk, 1926 are briefly described and measurements are given. Both nematodes are reported for the first time in Argentina with C. magalhaesi being the second isolation of this species in the world. Neocurtilla clarziana is a new host record for G. skrjabini.

Pop / DJ Drummie

Index Scriptorium Estoniae

DJ Drummie

2008-01-01

Heliplaatidest: Mr. Scruff "Ninja Tuna", "The Nymph", "Eesti Filharmoonia Kammerkoor/Tallinna Kammerorkester/Tõnu Kaljuste/Cyrillus Kreek "Requiem"/Tõnu Kõrvits "Kreegi vihik", Snow Patrol "A Hundred Million Suns"

Minimal role of eastern fence lizards in Borrelia burgdorferi transmission in central New Jersey oak/pine woodlands

Science.gov (United States)

Rulison, Eric L.; Kerr, Kaetlyn T; Dyer, Megan C; Han, Seungeun; Burke, Russell L.; Tsao, Jean I.; Ginsberg, Howard S.

2014-01-01

The Eastern fence lizard, Sceloporus undulatus, is widely distributed in eastern and central North America, ranging through areas with high levels of Lyme disease, as well as areas where Lyme disease is rare or absent. We studied the potential role of S. undulatus in transmission dynamics of Lyme spirochetes by sampling ticks from a variety of natural hosts at field sites in central New Jersey, and by testing the reservoir competence of S. undulatus for Borrelia burgdorferi in the laboratory. The infestation rate of ticks on fence lizards was extremely low (proportion infested = 0.087, n = 23) compared to that on white footed mice and other small mammals (proportion infested = 0.53, n = 140). Of 159 nymphs that had fed as larvae on lizards that had previously been exposed to infected nymphs, none was infected with B. burgdorferi, compared with 79.9% of 209 nymphs that had fed as larvae on infected control mice. Simulations suggest that changes in the numbers of fence lizards in a natural habitat would have little effect on the infection rate of nymphal ticks with Lyme spirochetes. We conclude that in central New Jersey S. undulatus plays a minimal role in the enzootic transmission cycle of Lyme spirochetes.

A review of the genus Capulinia Signoret (Hemiptera: Coccoidea: Eriococcidae) with description of two new species.

Science.gov (United States)

Kondo, T; Gullan, P J; Cook, L G

2016-05-17

The eriococcid genus Capulinia Signoret currently comprises four Neotropical species (the type species C. sallei Signoret, C. crateraformis Hempel, C. jaboticabae Ihering and an undescribed species recognised in the literature) and one species from New Zealand (C. orbiculata Hoy). All species feed on plants in the family Myrtaceae and the undescribed species is a pest of guava, Psidium guajava, in Venezuela and Colombia. Here we describe the pest species based on the adult female and first-instar nymph and name it Capulinia linarosae Kondo & Gullan sp. n. We provide a summary of published information on the biology and pest status of C. linarosae by translating the Spanish literature. We also describe the adult female and first-instar nymph of a new Argentine species that we name as C. luma Kondo & Gullan sp. n. after its host Luma apiculata. In addition, we redescribe the adult female of C. jaboticabae and include notes on C. crateraformis, C. orbiculata and C. sallei. We provide a revised generic diagnosis and keys to all Capulinia species based on adult females and, where available, first-instar nymphs, as well as a revised key to South American eriococcid genera. Phylogenetic analyses of 18S rDNA place Capulinia within the "Gondwanan" clade of eriococcids, mostly likely within the Myrtaceae-feeding group.

Effect of Climate and Land Use on the Spatio-Temporal Variability of Tick-Borne Bacteria in Europe

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Roberto Rosà

2018-04-01

Full Text Available The incidence of tick-borne diseases caused by Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and Rickettsia spp. has been rising in Europe in recent decades. Early pre-assessment of acarological hazard still represents a complex challenge. The aim of this study was to model Ixodes ricinus questing nymph density and its infection rate with B. burgdorferi s.l., A. phagocytophilum and Rickettsia spp. in five European countries (Italy, Germany, Czech Republic, Slovakia, Hungary in various land cover types differing in use and anthropisation (agricultural, urban and natural with climatic and environmental factors (Normalized Difference Vegetation Index (NDVI, Normalized Difference Water Index (NDWI, Land Surface Temperature (LST and precipitation. We show that the relative abundance of questing nymphs was significantly associated with climatic conditions, such as higher values of NDVI recorded in the sampling period, while no differences were observed among land use categories. However, the density of infected nymphs (DIN also depended on the pathogen considered and land use. These results contribute to a better understanding of the variation in acarological hazard for Ixodes ricinus transmitted pathogens in Central Europe and provide the basis for more focused ecological studies aimed at assessing the effect of land use in different sites on tick–host pathogens interaction.

Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton

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Martin D. Oliveira

2014-03-01

Full Text Available Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae on cotton. The striped mealybug, Ferrisia virgata (Cockerell (Hemiptera, Pseudococcidae, is a widely distributed and polyphagous pest species, which naturally occurs on cotton plants in Brazil. This study evaluated the establishment and population growth as well as the within-plant distribution of F. virgata on four cotton cultivars: CNPA 7H (white fibers, BRS Verde, BRS Safira, and BRS Rubi (colored fibers. The experiment was conducted in a complete randomized design with four treatments (cultivars and 18 replications of each. Thus, cotton plants of each cultivar were infested with 100 newly hatched nymphs of F. virgata. The number of adult female mealybugs and the total number of mealybugs per plant were quantified, respectively, at 25 and 50 days after infestation. The developmental and pre-reproductive periods were also determined. Furthermore, we verified the distribution of F. virgata on the plant parts at 25 and 50 days after infestation. Ferrisia virgata showed similar growth of 412-fold in the four cotton cultivars studied. Also, the nymphs were spread on infested leaves; the secondgeneration nymphs were spread and established in all plant parts. Our results characterize F. virgata as having much potential as an important cotton pest in Brazil.

Toxicological profile of deltamethrin in Triatoma brasiliensis (Hemiptera: Reduviidae in State of Ceará, Northeastern Brazil

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Grasielle Caldas D'Ávila Pessoa

2015-02-01

Full Text Available INTRODUCTION: Triatoma brasiliensis is the species of greatest epidemiological relevance in the semi-arid region of Brazil. This species is predominantly found in domestic environments, and it has the ability to build large colonies with high levels of natural infection via Trypanosoma cruzi. Thus, T. brasiliensis is one of the most efficient transmitters of Chagas disease (CD to humans. Despite household spraying with residual insecticides, many areas report persistent reinfestations for reasons that remain poorly understood. Therefore, this study sought to characterize the toxicological profile of deltamethrin in T. brasiliensis from areas with persistent reinfestation in State of Ceará, Brazil. METHODS: The susceptibility reference lineage (SRL was derived from Umari. Serial dilutions of deltamethrin were prepared and applied to the dorsal abdomen of first instar nymphs. The control group received only pure acetone. Mortality was evaluated after 72h. Qualitative tests assessed mortality in response to a diagnostic dose of 1xLD99 (0.851 nanograms of active ingredient per treated nymph of the SRL. RESULTS: The susceptibility profile characterization of the T. brasiliensis populations revealed 50% resistance ratios (RR50 that ranged from 0.32 to 1.21. The percentage of mortality in response to the diagnostic dose was 100%. CONCLUSIONS: We demonstrated that T. brasiliensis was highly susceptible to deltamethrin. The control difficulties found might be related to the recolonization of the triatomines originating from neighboring environments and the possible operational failures related to the process of spraying that enabled specimens less susceptible to deltamethrin to survive.

Índice de defecación y éxito reproductivo de Triatoma maculata (Hemiptera:Reduviidaeen condiciones de laboratorio

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E Aldana

2004-12-01

Full Text Available Se estudió el comportamiento reproductivo y de defecación de Triatoma maculata (Erichson 1848alimentando artificialmente con sangre humana.Los estadios II y III mostraron mayor frecuencia de defecaciones (ID=0.6 n=40,el estadio V no alcanzó la diferenciación sexual, la fertilidad fue 55%(n=865,fecundidad 8 huevos/hembra/semana (n=26,22 días de desarrollo embrionario (n=477,longevidad de hembras 51 días (n=26,el tiempo intermuda aumenta progresivamente desde 35 días en el estadio I hasta 46 días en el estadio IV,el porcentaje de muda varió desde 0%en el estadio V hasta 63%en el estadio III,la mortalidad varió desde 8%en el estadio III hasta 100%en el estadio V (n=40.Los resultados del presente trabajo aportan evidencias que explican la menor capacidad vectorial y la baja densidad de T.maculata en el domicilio humano.Defecation index and reproductive success of Triatoma maculata (Hemiptera: Reduviidae under laboratory conditions.The reproductive and defecating behavior of Triatoma maculata (Erichson 1848was studied on animals from an university culture in Venezuela.This species does not reach the importance of Rhodnius prolixus Stal 1859 as Chagas disease vector in Venezuela.This study addressed the role of defecating frequency,an index of how dangerous the animals are for the human population,and its relationship with why T.maculata is a less important vector than R.prolixus .Human blood was fed to the insects through an artificial feeding device.The 2nd and 3rd instar nymphs defecated more frequently (Id=0.6,n=40,and our Vth instar nymphs did not complete sexual differentiation.Fertility was 55%(n=865and fecundity 8 eggs/female/week (n=26. Egg incubation lasted 22 days (n=477.Female longevity was 51 days (n=26.Intermould time grew progressively from 35 days for 1st to 40 days for 4th instar nymphs (n=40.Mould percentage varied from 0% for Vth to 63%for 3rd instar nymphs.Mortality varied from 8% for 3rd to 100% for Vth instar nymphs

A Novel Scoring System Approach to Assess Patients with Lyme Disease (Nutech Functional Score)

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Geeta Shroff; Petra Hopf-Seidel

2018-01-01

Introduction: A bacterial infection by Borrelia burgdorferi referred to as Lyme disease (LD) or borreliosis is transmitted mostly by a bite of the tick Ixodes scapularis in the USA and Ixodes ricinus in Europe. Various tests are used for the diagnosis of LD, but their results are often unreliable. We compiled a list of clinically visible and patient-reported symptoms that are associated with LD. Based on this list, we developed a novel scoring system. Methodology: Nutech functional Score (NF...

Feeding and defaecation patterns in Triatoma sordida

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LB Crocco

1996-08-01

Full Text Available Triatoma sordida is a peridomestic Triatominae that could play an important role in the transmission of Trypanosoma cruzi, although its vectorial competence is not well known. The aim of this work was to evaluate two aspects of the vectorial competence: the feeding behaviour and defaecation patterns, and to compare them with T. infestans. The feeding and defaecation patterns were studied in adults and fifth instar nymphs of T. sordida fed ad libitum on a restrained pigeon. The results showed how the blood meal size controls excretion behaviour. Blood intake and time to first defaecation showed a significant negative correlation. Adults and nymphs frequently defaecated during the blood meal, reaching the maximum frequency within the first 10 minutes.

Aquatic to terrestrial transfer of sediment associated persistent organic pollutants is enhanced by bioamplification processes.

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Daley, Jennifer M; Corkum, Lynda D; Drouillard, Ken G

2011-09-01

Ephemeral emergent insects, such as mayflies (Hexagenia spp.), are commonly used as biomonitors of persistent organic pollutants (POPs) and provide a vector for aquatic-terrestrial contaminant transfer. Mayflies bioaccumulate sediment-associated contaminants by bioconcentration and biomagnification during the aquatic stage and concentrate POP residues postemergence due to bioamplification, which occurs as a result of weight and lipid loss without contaminant loss. The present study quantified polychlorinated biphenyl (PCB) bioamplification in male and female emergent mayflies at three sites. Male mayflies used 36 to 68% of their lipids during emergence, with the exception of caged males that were prevented from flight. Females did not lose lipid content between pre-emergent nymph and emerged life stages. Mass balance indicated no PCB elimination between life stages. The mean PCB bioamplification factor, expressed as the ratio of lipid-equivalent PCB concentrations across life stages, was 2.05 ± 0.38 for male imagos/nymphs and 1.91 ± 0.18 for male imago/subimago life stages. For females, bioamplification factors were close to unity. Wildlife consumers of imago stages of emergent mayflies can potentially increase their total daily intake of PCBs by 36% depending on the sex-ratio composition of their diet relative to animals that feed predominantly on nymph or subimago stages during mass emergence events. Copyright © 2011 SETAC.

Population models of burrowing mayfly recolonization in Western Lake Erie

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Madenjian, C.P.; Schloesser, D.W.; Krieger, K.A.

1998-01-01

Burrowing mayflies, Hexagenia spp. (H. limbata and H. rigida), began recolonizing western Lake Erie during the 1990s. Survey data for mayfly nymph densities indicated that the population experienced exponential growth between 1991 and 1997. To predict the time to full recovery of the mayfly population, we fitted logistic models, ranging in carrying capacity from 600 to 2000 nymphs/m2, to these survey data. Based on the fitted logistic curves, we forecast that the mayfly population in western Lake Erie would achieve full recovery between years 1998 and 2000, depending on the carrying capacity of the western basin. Additionally, we estimated the mortality rate of nymphs in western Lake Erie during 1994 and then applied an age-based matrix model to the mayfly population. The results of the matrix population modeling corroborated the exponential growth model application in that both methods yielded an estimate of the population growth rate, r, in excess of 0.8 yr-1. This was the first evidence that mayfly populations are capable of recolonizing large aquatic ecosystems at rates comparable with those observed in much smaller lentic ecosystems. Our model predictions should prove valuable to managers of power plant facilities along the western basin in planning for mayfly emergences and to managers of the yellow perch (Perca flavescens) fishery in western Lake Erie.

Diatomaceous earth and oil enhance effectiveness of Metarhizium anisopliae against Triatoma infestans.

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Luz, Christian; Rodrigues, Juscelino; Rocha, Luiz F N

2012-04-01

Entomopathogenic fungi, especially Metarhizium anisopliae, have potential for integrated control of peridomestic triatomine bugs. However, the high susceptibility of these vectors to fungal infection at elevated ambient humidities decreases in the comparatively dry conditions that often prevail in their microhabitats. A formulation adapted to this target pest that induces high and quick mortality can help to overcome these drawbacks. In the present study diatomaceous earth, which is used against pests of stored grains or as an additive to mycoinsecticides, delayed but did not reduce in vitro germination of M. anisopliae s.l. IP 46 conidia after >24h agitation without affecting viability, and did not hamper the survival of Triatoma infestans nymphs exposed to treated surfaces. The settling behavior of nymphs on a treated surface in choice tests depended on the concentration of diatomaceous earth and ambient light level. Conidia formulated with diatomaceous earth and a vegetable oil synergized the insecticidal effect of the fungus in nymphs, and quickly killed all treated insects, even at 75% relative humidity (LT(90) 8.3 days) where unformulated conidia caused only 25% mortality after a 25 days exposure. The improved performance of a combined oil and desiccant dust formulation of this Metarhizium isolate raises the likelihood for its successful mycoinsecticidal use for triatomine control and, apparently, against other domestic insect pests. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparative ecotoxicity of imidacloprid and dinotefuran to aquatic insects in rice mesocosms.

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Kobashi, Koji; Harada, Takaaki; Adachi, Yoshihiro; Mori, Miho; Ihara, Makoto; Hayasaka, Daisuke

2017-04-01

There are growing concerns about the impacts of neonicotinoid insecticides on ecosystems worldwide, and yet ecotoxicity of many of these chemicals at community or ecosystem levels have not been evaluated under realistic conditions. In this study, effects of two neonicotinoid insecticides, imidacloprid and dinotefuran, on aquatic insect assemblages were evaluated in experimental rice mesocosms. During the 5-month period of the rice-growing season, residual concentrations of imidacloprid were 5-10 times higher than those of dinotefuran in both soil and water. Imidacloprid treatment (10kg/ha) reduced significantly the populations of, Crocothemis servilia mariannae and Lyriothemis pachygastra nymphs, whereas those of Orthetrum albistylum speciosum increased slightly throughout the experimental period. However, Notonecta triguttata, which numbers were high from the start, later declined, indicating possible delayed chronic toxicity, while Guignotus japonicus disappeared. In contrast, dinotefuran (10kg/ha) did not decrease the populations of any species, but rather increased the abundance of some insects, particularly Chironominae spp. larvae and C. servilia mariannae nymphs, with the latter being 1.7x higher than those of controls. This was an indirect effect resulting from increased prey (e.g., chironomid larvae) and lack of competition with other dragonfly species. The susceptibilities of dragonfly nymphs to neonicotinoids, particularly imidacloprid, were consistent with those reported elsewhere. In general, imidacloprid had higher impacts on aquatic insects compared to dinotefuran. Copyright © 2016 Elsevier Inc. All rights reserved.

Note on a nest of Saunders’ Embiid Oligotoma saundersii (Westwood (Insecta: Embioptera: Oligotomidae from Kolkata, India.

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P. Dawn

2014-09-01

Full Text Available The biology and life stages of the Embioptera were less known though they are very interesting due to their web spinning ability and social living. This study shows the presence of three different life stages of hemimetabolous metamorphosis of Oligotoma saundersii (Westwood at a time in the nest. Larvae show both increase in size and changes in mandible structure during development. The male and female nymphs look similar but distinguishable by the presence of a dumbbell-shaped wing bud in the male. The wing bud is white, covered in a sac marked with light brown lines and minute hairs and hair follicles as well. The adult male shows increased pigmentation and chitinization, lengthening of antennae, development of wings and a drastic modification of the 10th tergum into distinct abdominal appendages upon the final stage nymph. Female nymphs are morphologically similar to adult females except for body sclerotization and are also able to produce silk-web. Reproductive structures of the species are simple; in the male there is a vesicular testis, a thick vas deferens and a swollen seminal vesicle and in the female there are 3-4 rows of ovarian follicles meeting together to form a thick oviduct on both sides. The presence of more than one generation in a nest and the community structure indicates their interesting social life.

Silverleaf whitefly induces salicylic acid defenses and suppresses effectual jasmonic acid defenses.

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Zarate, Sonia I; Kempema, Louisa A; Walling, Linda L

2007-02-01

The basal defenses important in curtailing the development of the phloem-feeding silverleaf whitefly (Bemisia tabaci type B; SLWF) on Arabidopsis (Arabidopsis thaliana) were investigated. Sentinel defense gene RNAs were monitored in SLWF-infested and control plants. Salicylic acid (SA)-responsive gene transcripts accumulated locally (PR1, BGL2, PR5, SID2, EDS5, PAD4) and systemically (PR1, BGL2, PR5) during SLWF nymph feeding. In contrast, jasmonic acid (JA)- and ethylene-dependent RNAs (PDF1.2, VSP1, HEL, THI2.1, FAD3, ERS1, ERF1) were repressed or not modulated in SLWF-infested leaves. To test for a role of SA and JA pathways in basal defense, SLWF development on mutant and transgenic lines that constitutively activate or impair defense pathways was determined. By monitoring the percentage of SLWF nymphs in each instar, we show that mutants that activate SA defenses (cim10) or impair JA defenses (coi1) accelerated SLWF nymphal development. Reciprocally, mutants that activate JA defenses (cev1) or impair SA defenses (npr1, NahG) slowed SLWF nymphal development. Furthermore, when npr1 plants, which do not activate downstream SA defenses, were treated with methyl jasmonate, a dramatic delay in nymph development was observed. Collectively, these results showed that SLWF-repressed, JA-regulated defenses were associated with basal defense to the SLWF.

Silverleaf Whitefly Induces Salicylic Acid Defenses and Suppresses Effectual Jasmonic Acid Defenses1[W][OA

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Zarate, Sonia I.; Kempema, Louisa A.; Walling, Linda L.

2007-01-01

The basal defenses important in curtailing the development of the phloem-feeding silverleaf whitefly (Bemisia tabaci type B; SLWF) on Arabidopsis (Arabidopsis thaliana) were investigated. Sentinel defense gene RNAs were monitored in SLWF-infested and control plants. Salicylic acid (SA)-responsive gene transcripts accumulated locally (PR1, BGL2, PR5, SID2, EDS5, PAD4) and systemically (PR1, BGL2, PR5) during SLWF nymph feeding. In contrast, jasmonic acid (JA)- and ethylene-dependent RNAs (PDF1.2, VSP1, HEL, THI2.1, FAD3, ERS1, ERF1) were repressed or not modulated in SLWF-infested leaves. To test for a role of SA and JA pathways in basal defense, SLWF development on mutant and transgenic lines that constitutively activate or impair defense pathways was determined. By monitoring the percentage of SLWF nymphs in each instar, we show that mutants that activate SA defenses (cim10) or impair JA defenses (coi1) accelerated SLWF nymphal development. Reciprocally, mutants that activate JA defenses (cev1) or impair SA defenses (npr1, NahG) slowed SLWF nymphal development. Furthermore, when npr1 plants, which do not activate downstream SA defenses, were treated with methyl jasmonate, a dramatic delay in nymph development was observed. Collectively, these results showed that SLWF-repressed, JA-regulated defenses were associated with basal defense to the SLWF. PMID:17189328

Development and reproduction of Podisus distinctus (Heteroptera: Pentatomidae) fed on larva of Bombyx mori (Lepidoptera: Bombycidae).

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Lacerda, M C; Ferreira, A M R M; Zanuncio, T V; Zanuncio, J C; Bernardino, A S; Espindula, M C

2004-05-01

Biological control has been reducing the use of chemical products against insect pests, especially predatory Pentatomidae. Species of this group can present high variations in their life cycle as a result of their diet. Thus, the objective of this research was to study nymph development and reproduction of Podisus distinctus (Stäl, 1860) (Heteroptera: Pentatomidae) fed on Bombyx mori L., 1758 (Lepidoptera: Bombycidae) larvae (T1), compared to those fed on Tenebrio molitor L., 1758 (Coleoptera: Tenebrionidae) (T2) and Musca domestica L., 1758 (Diptera: Muscidae) larvae (T3) at a temperature of 25 +/- 0.5 degrees C, relative humidity of 70 +/- 2%, and photophase of 12 h. Predators fed on B. mori showed duration of the nymph phase (18.68 +/- 1.02) similar to those fed on T. molitor (18.32 +/- 1.49). Pre-oviposition and oviposition periods and number of egg masses, besides eggs and nymphs per female, were higher with B. mori (5.83 +/- 2.02; 15.00 +/- 7.40; 8.42 +/- 1.84; 296.69 +/- 154.75; and 228.55 +/- 141.04, respectively) while longevity of males and females of P. distinctus was 25.76 +/- 16.15 and 35.00 +/- 16.15 days with T. molitor, and 20.57 +/- 13.60 and 23.46 +/- 12.35 days with B. mori, respectively.

Description of the immature stages and redescription of the female of Ixodes schulzei Aragão & Fonseca, 1951 (Acari: Ixodidae), an endemic tick species of Brazil.

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Barros-Battesti, Darci M; Onofrio, Valeria C; Faccini, João L H; Labruna, Marcelo B; Arruda-Santos, Ana D; Giacomin, Flávia G

2007-11-01

Ixodes schulzei Aragão & Fonseca, 1951 is a tick endemic to Brazil, where nine species of Ixodes Latreille, 1796 are currently known to occur. Larvae, nymphs and females of I. schulzei were obtained from a laboratory colony originating from an engorged female collected on a free-living water rat Nectomys squamipes from the Santa Branca municipality, São Paulo State. Only female ticks were obtained from engorged nymphs. Unfed immature and female adult specimens were measured and the descriptions were based on optical and scanning electron microscopy, as were drawings of some features of the larva. Both immature stages present the very long palpi and basis capituli, and the female has large, contiguous porose areas. However, the basis capituli is triangular, with a slight central elevation in the larva and nymph, whereas in the female this area is depressed. The I. schulzei types deposited at the FIOCRUZ (Instituto Oswaldo Cruz) were also examined, as was other material from collections, such as the IBSP (Coleção Acarológica do Instituto Butantan), CNC-FMVZ/USP (Coleção Nacional de Carrapatos da Faculdade de Medicina Veterinária e Zootecnia da USP) and USNTC (United States National Tick Collection). In addition, the relationship between I. schulzei and other immature neotropical species of Ixodes is discussed.

Effect of two dosages of Metarhizium anisopliae var. acridum against Rhammatocerus schistocercoides Rehn

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Faria Marcos Rodrigues de

2002-01-01

Full Text Available The fungus Metarhizium anisopliae var. acridum, strain CG 423, was tested under field conditions against the gregarious grasshopper Rhammatocerus schistocercoides (Rehn (Orthoptera: Acrididae. Conidia formulated in a racemic mixture of soybean oil and kerosene were sprayed under field conditions using an ultralow-volume hand-held atomizer Ulva Plus adjusted to deliver 2.9 L/ha. Bands composed of 2nd instar nymphs were treated with either 5.0x10(12 or 1.0x10(13 viable conidia/ha. The number of insects in each band was estimated at day one following spraying and by the end of the field trial (15 to 16 days post-treatment. Reductions in population size reached, in average, 65.8% and 80.4% for bands treated with the higher and lower dosage, respectively. For both dosages, total mortality rates of insects collected at two days post-application, and kept in cages for 14 days under lab conditions, showed no significant differences as compared to that obtained with insects collected immediately after spraying. Healthy insects were fed to native grasses sprayed on the field with 1.0x10(13 viable conidia/ha. Mortality levels of the nymphs fed on grasses collected two and four days post-application were not affected when compared to nymphs fed on grasses collected immediately following application.

Induced resistance against the Asian citrus psyllid, Diaphorina citri, by β-aminobutyric acid in citrus.

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Tiwari, Siddharth; Meyer, Wendy L; Stelinski, Lukasz L

2013-10-01

β-Aminobutyric acid (BABA) is known to induce resistance to microbial pathogens, nematodes and insects in several host plant/pest systems. The present study was undertaken to determine whether a similar effect of BABA occurred against the Asian citrus psyllid, Diaphorina citri Kuwayama, in citrus. A 25 mM drench application of BABA significantly reduced the number of eggs/plant as compared with a water control, whereas 200 and 100 mM applications of BABA reduced the numbers of nymphs/plant and adults/plants, respectively. A 5 mM foliar application of BABA significantly reduced the number of adults but not eggs or nymphs when compared with a water control treatment. In addition, leaf-dip bioassays using various concentrations (25–500 mM) of BABA indicated no direct toxic effect on 2nd and 5th instar nymphs or adult D. citri. BABA-treated plants were characterized by significantly lower levels of iron, magnesium, phosphorus, sodium, sulfur and zinc as compared with control plants. The expression level of the PR-2 gene (β-1,3-glucanase) in BABA-treated plants that were also damaged by D. citri adult feeding was significantly higher than in plants exposed to BABA, D. citri feeding alone or control plants. Our results indicate the potential for using BABA as a systemic acquired resistance management tool for D. citri.

An assessment of interspecific competition between two introduced parasitoids of Diaphorina citri (Hemiptera: Liviidae) on caged citrus plants.

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Vankosky, Meghan A; Hoddle, Mark S

2017-06-07

Two parasitoids attacking nymphs of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae) and Diaphorencyrtus aligarhensis (Shafee, Alam & Agarwal) (Hymenoptera: Encyrtidae) are being released in California, USA in a classical biological control program. To evaluate the effect of multiple parasitoid species on D. citri mortality, we conducted mesocosm experiments under controlled conditions using a complete block design with 6 treatments (D. citri nymphs exposed to: no parasitoids; D. aligarhensis or T. radiata alone; D. aligarhensis or T. radiata released first (by 48 h); and both species released simultaneously). Parasitism of D. citri nymphs by T. radiata exceeded 60% and was unchanged when D. aligarhensis were present. Parasitism by D. aligarhensis was greatest when T. radiata was absent (∼28%) and was reduced in all treatments with T. radiata present (citri mortality and parasitoid-related mortality of D. citri was consistent across parasitoid treatments. Laboratory results suggest that competition between D. aligarhensis and T. radiata is asymmetric and favors T. radiata. It may be difficult for D. aligarhensis to contribute significantly to D. citri biological control where T. radiata is present. However, results reported here suggest that competition between T. radiata and D. aligarhensis is not likely to reduce parasitism by T. radiata or reduce parasitoid-induced mortality of D. citri. © 2017 Institute of Zoology, Chinese Academy of Sciences.

REVEAL: Software Documentation and Platform Migration

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Wilson, Michael A.; Veibell, Victoir T.; Freudinger, Lawrence C.

2008-01-01

The Research Environment for Vehicle Embedded Analysis on Linux (REVEAL) is reconfigurable data acquisition software designed for network-distributed test and measurement applications. In development since 2001, it has been successfully demonstrated in support of a number of actual missions within NASA s Suborbital Science Program. Improvements to software configuration control were needed to properly support both an ongoing transition to operational status and continued evolution of REVEAL capabilities. For this reason the project described in this report targets REVEAL software source documentation and deployment of the software on a small set of hardware platforms different from what is currently used in the baseline system implementation. This report specifically describes the actions taken over a ten week period by two undergraduate student interns and serves as a final report for that internship. The topics discussed include: the documentation of REVEAL source code; the migration of REVEAL to other platforms; and an end-to-end field test that successfully validates the efforts.

Expression of spoT in Borrelia burgdorferi during Serum Starvation

OpenAIRE

Concepcion, Marc B.; Nelson, David R.

2003-01-01

Borrelia burgdorferi, the causative agent of Lyme disease, is transmitted by the tick Ixodes scapularis. A 2.9-kb fragment containing a putative spoT gene was isolated from B. burgdorferi genomic DNA by PCR amplification and cloned into a pBAD24 vector. The cloned gene complemented Escherichia coli mutant strain CF1693, which contains deletions of both the relA and spoT genes. The spoT gene in E. coli encodes a bifunctional enzyme capable of synthesizing and degrading (p)ppGpp, which mediates...

Comparative evaluation of Amblyomma ovale ticks infected and noninfected by Rickettsia sp. strain Atlantic rainforest, the agent of an emerging rickettsiosis in Brazil.

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Krawczak, Felipe S; Agostinho, Washington C; Polo, Gina; Moraes-Filho, Jonas; Labruna, Marcelo B

2016-04-01

In 2010, a novel spotted fever group rickettsiosis was reported in the Atlantic rainforest coast of Brazil. The etiological agent was identified as Rickettsia sp. strain Atlantic rainforest, and the tick Amblyomma ovale was incriminated as the presumed vector. The present study evaluated under laboratory conditions four colonies of A. ovale: two started from engorged females that were naturally infected by Rickettsia sp. strain Atlantic rainforest (designated as infected groups); the two others started from noninfected females (designated as control groups). All colonies were reared in parallel from F0 engorged female to F2 unfed nymphs. Tick-naïve vesper mice (Calomys callosus) or domestic rabbits were used for feeding of each tick stage. Rickettsia sp. strain Atlantic rainforest was preserved by transstadial maintenance and transovarial transmission in A. ovale ticks for at least 2 generations (from F0 females to F2 nymphs), because nearly 100% of the tested larvae, nymphs, and adults from the infected groups were shown by PCR to contain rickettsial DNA. All vesper mice and rabbits infested by larvae and nymphs, and 50% of the rabbits infested by adults from the infected groups seroconverted, indicating that these tick stages were vector competent for Rickettsia sp. strain Atlantic rainforest. Expressive differences in mortality rates and reproductive performance were observed between engorged females from the infected and control groups, as indicated by 75.0% and 97.1% oviposition success, respectively, and significantly lower egg mass weight, conversion efficiency index, and percentage of egg hatching for the infected groups. Our results indicate that A. ovale can act as a natural reservoir for Rickettsia sp. strain Atlantic rainforest. However, due to deleterious effect caused by this rickettsial agent on engorged females, amplifier vertebrate hosts might be necessary for persistent perpetuation of Rickettsia sp. strain Atlantic rainforest in A. ovale under

Soul, butterfly, mythological nymph: psyche in philosophy and neuroscience.

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Antonakou, Elena I; Triarhou, Lazaros C

2017-03-01

The term "psyche" and its derivatives - including "Psychology" and "Psychiatry" - are rooted in classical philosophy and in mythology. Over the centuries, psyche has been the subject of discourse and contemplation, and of fable; it has also come to signify, in entomology, the order of Lepidoptera. In the current surge of research on brain and mind, there is a gradual transition from the psyche (or the "soul") to the specified descriptors defined by the fields of Behavioral, Cognitive and Integrative Neuroscience.

A Rare Tropical Stonefly Brahmana flavomarginata (Plecoptera: Perlidae: Acroneuriinae from Vietnam

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Thi Kim Thu Cao

2013-04-01

Full Text Available The perlid stonefly Brahmana flavomarginata Wu, originally described from China from the male adult, is described using reared male and female adults and nymphs from Vietnam. The male adult of B. flavomarginata is distinguished from its congeners by the blackish-brown body color and distinct head marking, hemitergal triangular chitin plates, and a median semicircular smooth subgenital plate (hammer on the abdominal sternum IX. The female adult has a large and round subgenital plate which extends to the posterior margin of the abdominal sternum X. The nymph can be distinguished by the relatively small compound eyes and the body covered by many long stout setae and short golden brown hair-like setae. This species is known in southwestern China (Yunnan Province and northern Vietnam (Lao Cai Province, Cao Bang Province.

The Distribution and Movement of American Cockroaches in Urban Niches of New Orleans.

Science.gov (United States)

Carlson, John C; Rabito, Felicia A; Werthmann, Derek; Fox, Mark

2017-10-01

American cockroaches are an important source of household allergens in tropical and semitropical climates. To determine which outdoor niches produce American cockroaches, traps were placed at 40 homes in New Orleans to collect nymphs. Nymphs were collected from the sewers, yards, and within the homes themselves. To compare sewers and yards as sources of cockroaches entering homes, adult cockroaches were collected, marked, and released into yards and sewers. No sewer-released cockroaches were collected in homes. Cockroaches released into yards were collected in the homes, suggesting that yards, rather than sewers, are a more important source niche. A field trial applying boric acid granules to the yard was performed in an effort to reduce entry of cockroaches. There was a significant reduction in the cockroach antigen collected in intervention homes compared with controls.

Nymphal Linguatulosis in Indian Crested Porcupines (Histrix Indica in Southwest of Iran

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Mohammad Rajabloo

2015-10-01

Full Text Available Linguatula serrata is one of the important zoonotic parasites. Carnivores serve as definitive host. The larvae existed in mesenteric lymph nodes (MLNs, liver, lungs, etc of intermediate herbivores. The definitive host becomes infected by ingesting viscera containing the infective nymphal stage. Humans may be infected with Linguatula either by ingestion of nymphs resulting in a condition called nasopharyngeal linguatulosis or Halzoun syndrome or by ingestionof infective eggs which develop in internal organs resulting in visceral linguatulosis. Indian crested porcupine (Hystrix indica is a common rodent in Middle East. Based on some tradition, consumption of Histrix meat andviscera is common in some parts of Iran. The present study reports the occurrence of Linguatula serrata nymph in H. indica as a new intermediate host from southwest of Iran.

Population Growth Parameters of Rose Aphid, Macrosiphum rosae (Hemiptera: Aphididae) on Different Rose Cultivars.

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Golizadeh, A; Jafari-Behi, V; Razmjou, J; Naseri, B; Hassanpour, M

2017-02-01

The rose aphid, Macrosiphum rosae (L.), is one of the most important pests on rose plants (Rosa spp.) with a worldwide distribution. As resistance indices, the development, survivorship, and reproduction of this aphid were evaluated on 10 rose cultivars, including Bella Vita, Cool Water, Dolce Vita, Maroussia, Orange Juice, Pinkpromise, Roulette, Tea, Valentine, and Persian Yellow in laboratory at 25 ± 1°C, 65 ± 5% relative humidity, and photoperiod of 16:8 (L/D) h. Rose aphid successfully survived on all 10 rose cultivars, although mortality rate was higher on Tea and Bella Vita. The number of offspring per female differed significantly among the tested rose cultivars, and ranged from 9.2 on Tea to 38.7 nymphs on Orange Juice. Population growth parameters were significantly affected by rose cultivars. The longest mean generation time (T) was observed on Bella Vita (14.8 days) and Tea (14.7 days) and the shortest on Orange Juice (10.0 days). The net reproductive rate (R 0 ) ranged from 6.9 on Tea to 33.2 nymphs on Orange Juice cultivar. Correspondingly, the highest value of intrinsic rate of increase (r m ) was observed on Orange Juice (0.348 day -1 ) and lower values on Tea (0.131 day -1 ) followed by Bella Vita (0.154 day -1 ). Cluster analysis of all the measured parameters of rose aphid on different rose cultivars revealed that Tea and Bella Vita were relatively resistant to M. rosae. These findings could be useful in developing an integrated pest management (IPM) program for this aphid in urbanized areas and commercial rose potting.

Revealing conceptual understanding of international business

NARCIS (Netherlands)

Sue Ashley; Dr. Harmen Schaap; Prof.Dr. Elly de Bruijn

2017-01-01

This study aims to identify an adequate approach for revealing conceptual understanding in higher professional education. Revealing students’ conceptual understanding is an important step towards developing effective curricula, assessment and aligned teaching strategies to enhance conceptual

Mathematics revealed

CERN Document Server

Berman, Elizabeth

1979-01-01

Mathematics Revealed focuses on the principles, processes, operations, and exercises in mathematics.The book first offers information on whole numbers, fractions, and decimals and percents. Discussions focus on measuring length, percent, decimals, numbers as products, addition and subtraction of fractions, mixed numbers and ratios, division of fractions, addition, subtraction, multiplication, and division. The text then examines positive and negative numbers and powers and computation. Topics include division and averages, multiplication, ratios, and measurements, scientific notation and estim

Enhancement of resistance to aphids by introducing the snowdrop ...

Indian Academy of Sciences (India)

Unknown

The nymph production was significantly reduced by 46⋅9% on GNA-expressing plants. Field evaluation of ... toxicity towards higher animals, care is necessary when we use it. ..... transgenic plants were regenerated after antibiotic selec- tion.

Homogeneity of Powassan virus populations in naturally infected Ixodes scapularis

International Nuclear Information System (INIS)

Brackney, Doug E.; Brown, Ivy K.; Nofchissey, Robert A.; Fitzpatrick, Kelly A.; Ebel, Gregory D.

2010-01-01

Powassan virus (POWV, Flaviviridae: Flavivirus) is the sole North American member of the tick-borne encephalitis complex and consists of two distinct lineages that are maintained in ecologically discrete enzootic transmission cycles. The underlying genetic mechanisms that lead to niche partitioning in arboviruses are poorly understood. Therefore, intra- and interhost genetic diversity was analyzed to determine if POWV exists as a quasispecies in nature and quantify selective pressures within and between hosts. In contrast to previous reports for West Nile virus (WNV), significant intrahost genetic diversity was not observed. However, pN (0.238) and d N /d S ratios (0.092) for interhost diversity were similar to those of WNV. Combined, these data suggest that purifying selection and/or population bottlenecks constrain quasispecies diversity within ticks. These same selective and stochastic mechanisms appear to drive minor sequence changes between ticks. Moreover, Powassan virus populations seem not to be structured as quasispecies in naturally infected adult deer ticks.

Revealing Conceptual Understanding of International Business

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Ashley, Sue; Schaap, Harmen; de Bruijn, Elly

2017-01-01

This study aims to identify an adequate approach for revealing conceptual understanding in higher professional education. Revealing students' conceptual understanding is an important step towards developing effective curricula, assessment and aligned teaching strategies to enhance conceptual understanding in higher education. Essays and concept…

Sarcoptic mange in raccoons in Michigan.

Science.gov (United States)

Fitzgerald, Scott D; Cooley, Thomas M; Murphy, Alice; Cosgrove, Melinda K; King, Betty A

2004-04-01

Sarcoptic mange is a cause of pruritic skin disease in domestic dogs and a wide range of wildlife species. We describe sarcoptic mange in free-ranging raccoons (Procyon lotor). Three adult raccoons from upper Wayne County, Michigan (USA), were captured, killed, and submitted for diagnostic evaluation. The animals were intensely pruritic, and two had advanced alopecic and crusting lesions over their dorsum and hind limbs. Skin scrapings and skin biopsies revealed crusting and hyperkeratotic dermatitis with high numbers of Sarcoptes scabiei adults, larvae, nymphs, and eggs. These raccoons were not otherwise debilitated, with minimal internal parasites, good body condition, and no evidence of infectious bacterial or viral diseases. Because sarcoptic mange is highly contagious and affects many species, including humans, transiently, it is important that wildlife biologists and rehabilitators include sarcoptic mange in their differential list for raccoons exhibiting pruritus and alopecia.

[Mastitis revealing Churg-Strauss syndrome].

Science.gov (United States)

Dannepond, C; Le Fourn, E; de Muret, A; Ouldamer, L; Carmier, D; Machet, L

2014-01-01

Churg-Strauss syndrome often involves the skin, and this may sometimes reveal the disease. A 25-year-old woman was referred to a gynaecologist for inflammation of the right breast with breast discharge. Cytological analysis of the liquid showed numerous inflammatory cells, particularly polymorphonuclear eosinophils and neutrophils. Ultrasound examination of the breast was consistent with galactophoritis. CRP was normal, and hypereosinophilia was seen. The patient was subsequently referred to a dermatology unit. Skin examination revealed inflammation of the entire breast, which was painful, warm and erythematous; the border was oedematous with blisters. Necrotic lesions were also present on the thumbs and knees. Skin biopsy of the breast showed a dermal infiltrate with abundant infiltrate of polymorphonuclear eosinophils, including patchy necrosis and intraepidermal vesicles. Histological examination of a biopsy sample from a thumb revealed eosinophilic granuloma and leukocytoclastic vasculitis. The patient was also presenting asthma, pulmonary infiltrates and mononeuropathy at L3, consistent with Churg-Strauss syndrome. Breast involvement in Churg-Strauss syndrome is very rare (only one other case has been reported). This is the first case in which the breast condition revealed the disease. Cutaneous involvement of the breast is, however, also compatible with Wells' cellulitis. The lesions quickly disappeared with 1mg/kg/d oral prednisolone. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Toxicity, repellency and flushing out in Triatoma infestans (Hemiptera: Reduviidae exposed to the repellents DEET and IR3535

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Mercedes M.N. Reynoso

2017-05-01

Full Text Available DEET and IR3535 are insect repellents present worldwide in commercial products; their efficacy has been mainly evaluated in mosquitoes. This study compares the toxicological effects and the behavioral responses induced by both repellents on the blood-sucking bug Triatoma infestans Klug (Hemiptera: Reduviidae, one of the main vectors of Chagas disease. When applied topically, the Median Lethal Dose (72 h for DEET was 220.8 µg/insect. Using IR3535, topical application of 500 µg/insect killed no nymphs. The minimum concentration that produced repellency was the same for both compounds: 1,15 µg/cm2. The effect of a mixture DEET:IR3535 1:1 was similar to that of their pure components. Flushing out was assessed in a chamber with a shelter containing groups of ten nymphs. The repellents were aerosolized on the shelter and the number of insects leaving it was recorded for 60 min. During that time, 0.006 g/m3 of the positive control tetramethrin flushed out 76.7% of the nymphs, while 1.76 g/m3 of DEET or IR3535 flushed out 30 and 0%, respectively. The concentrations required for both compounds to produce toxicity or flushing out are too high to have any practical applications. However, they showed a promising repellency. Additional research should be done to evaluate their possible use for personal protection against T. infestans bites.

A comparative study on the effects of electron beam irradiation on imidacloprid-resistant and -susceptible Aphis gossypii (Hemiptera: Aphididae)

Science.gov (United States)

Yun, Seung-Hwan; Koo, Hyun-Na; Lee, Seon-Woo; Kim, Hyun Kyung; Kim, Yuri; Han, Bumsoo; Kim, Gil-Hah

2015-07-01

The melon and cotton aphid, Aphis gossypii, is a polyphagous insect pest. This study compared the development, reproduction, DNA damage, recovery, and gene expression in imidacloprid-resistant (IMI-R) and -susceptible (S) strains of A. gossypii by electron beam irradiation. When 1st instar nymphs were irradiated with 100 Gy, the fecundity (nymphs of F1 generation) of the resultant adults were completely inhibited. When adults were irradiated with 200 Gy, the number of total 1st instar nymphs produced per adult was 3.0±1.7 and 1.9±1.4 in the S and IMI-R strains, respectively, but adult development was completely suppressed. However, electron beam irradiation did not affect adult longevity in either the S or IMI-R strain. There was no statistically significant difference between the effect of irradiation on the S and IMI-R strains. Therefore, electron beam irradiation at 200 Gy could be used as a phytosanitary irradiation treatment for both S and IMI-R strains of A. gossypii. The DNA damage caused by electron beam irradiation was evaluated by an alkaline comet assay. Exposure to an electron beam (50 Gy) induced DNA damage that was repaired to a similar level as the untreated control group (0 Gy) over time. However, at more than 100 Gy, the DNA damage was not completely repaired. The expression of P450, HSP70, cuticle protein, and elongation factor genes were higher in the IMI-R strain than in the S strain.

Population Dynamics of Empoasca fabae (Hemiptera: Cicadellidae) in Central Iowa Alfalfa Fields

Science.gov (United States)

Weiser Erlandson, L. A.; Obrycki, J. J.

2015-01-01

Adults and nymphs of Empoasca fabae Harris (Hemiptera: Cicadellidae) and adults of predatory species in the families Coccinellidae, Anthocoridae, Nabidae, Chrysopidae, and Hemerobiidae were sampled in Iowa alfalfa fields from June to September in 1999 and 2000. The relationship between each predatory taxa and E. fabae was examined using regression analysis. In 2000, all predators were found to be positively correlated with the presence of E. fabae during all periods sampled and most likely contributed to mortality. Orius insidiosus (Say) (Hemiptera: Anthoridae) was the most numerous insect predatory species; population numbers ranged from 0 to 1 and 0.1 to 3.7 adults per 0.25 m2 in 1999 and 2000, respectively. Partial life tables were constructed for E. fabae nymphs for two alfalfa-growing periods. Nymphs were grouped into three age intervals: first and second, third and fourth, and fifth instars. For the first alfalfa growing period examined, E. fabae nymphal mortality was 70% in 1999 and 49% in 2000. During the last growing period of each season (August–September), total nymphal mortality was relatively low (<25%). Adult E. fabae density ranged from 5.4 to 25.6 and 1.4–9.2 per 0.25 m2 in 1999 and 2000, respectively. E. fabae population peaks were similar for each age interval in all growing periods. This study provides further information on the population dynamics of E. fabae and its relationship with select predatory species in Iowa alfalfa fields. PMID:26320260

Impact of aquatic insect life stage and emergence strategy on sensitivity to esfenvalerate exposure.

Science.gov (United States)

Palmquist, Katherine R; Jepson, Paul C; Jenkins, Jeffrey J

2008-08-01

We investigated the impact of aquatic insect life stage and emergence strategy on sensitivity to esfenvalerate, a synthetic pyrethroid insecticide, using field-collected Brachycentrus americanus Banks (Trichoptera: Brachycentridae) and Cinygmula reticulata McDunnough (Ephemeroptera: Heptageniidae) insects. Final-instar C. reticulata emergence was observed for one week following three environmentally relevant, 48-h esfenvalerate exposures (0.005, 0.01, and 0.015 microg/L). Emergence was significantly depressed following exposure to esfenvalerate and resulted from an increase in nymph mortality during the emergence process. This experiment was duplicated for late-instar C. reticulata nymphs, which were similar in size to the final-instar nymphs but were not near emergence. Late-instar C. reticulata mayflies were approximately fivefold less sensitive to esfenvalerate exposures as gauged by one-week mortality rates. Brachycentrus americanus pupal mortality was significantly increased over that in controls following 48-h esfenvalerate exposures of 0.1 and 0.2 microg/L. These response concentrations correlated closely with those for case-abandonment rates of fourth-instar B. americanus larvae (a sublethal effect of esfenvalerate exposure). Pupal mortality rates were approximately 16-fold higher than those observed in larvae. Adult female egg weight as a percentage of total body weight was significantly decreased following pupal esfenvalerate exposures of 0.05, 0.1, and 0.2 microg/L. These findings suggest that exposure to esfenvalerate may impair hemimetabolous insect emergence behaviors and may decrease fecundity in holometabolous aquatic insects.

Selection of housekeeping genes and demonstration of RNAi in cotton leafhopper, Amrasca biguttula biguttula (Ishida)

Science.gov (United States)

Gupta, Mridula; Pandher, Suneet; Kaur, Gurmeet; Rathore, Pankaj; Palli, Subba Reddy

2018-01-01

Amrasca biguttula biguttula (Ishida) commonly known as cotton leafhopper is a severe pest of cotton and okra. Not much is known on this insect at molecular level due to lack of genomic and transcriptomic data. To prepare for functional genomic studies in this insect, we evaluated 15 common housekeeping genes (Tub, B-Tub, EF alpha, GADPH, UbiCF, RP13, Ubiq, G3PD, VATPase, Actin, 18s, 28s, TATA, ETF, SOD and Cytolytic actin) during different developmental stages and under starvation stress. We selected early (1st and 2nd), late (3rd and 4th) stage nymphs and adults for identification of stable housekeeping genes using geNorm, NormFinder, BestKeeper and RefFinder software. Based on the different algorithms, RP13 and VATPase are identified as the most suitable reference genes for quantification of gene expression by reverse transcriptase quantitative PCR (RT-qPCR). Based on RefFinder which comprehended the results of three algorithms, RP13 in adults, Tubulin (Tub) in late nymphs, 28S in early nymph and UbiCF under starvation stress were identified as the most stable genes. We also developed methods for feeding double-stranded RNA (dsRNA) incorporated in the diet. Feeding dsRNA targeting Snf7, IAP, AQP1, and VATPase caused 56.17–77.12% knockdown of targeted genes compared to control and 16 to 48% mortality of treated insects when compared to control. PMID:29329327

Selection of housekeeping genes and demonstration of RNAi in cotton leafhopper, Amrasca biguttula biguttula (Ishida.

Directory of Open Access Journals (Sweden)

Satnam Singh

Full Text Available Amrasca biguttula biguttula (Ishida commonly known as cotton leafhopper is a severe pest of cotton and okra. Not much is known on this insect at molecular level due to lack of genomic and transcriptomic data. To prepare for functional genomic studies in this insect, we evaluated 15 common housekeeping genes (Tub, B-Tub, EF alpha, GADPH, UbiCF, RP13, Ubiq, G3PD, VATPase, Actin, 18s, 28s, TATA, ETF, SOD and Cytolytic actin during different developmental stages and under starvation stress. We selected early (1st and 2nd, late (3rd and 4th stage nymphs and adults for identification of stable housekeeping genes using geNorm, NormFinder, BestKeeper and RefFinder software. Based on the different algorithms, RP13 and VATPase are identified as the most suitable reference genes for quantification of gene expression by reverse transcriptase quantitative PCR (RT-qPCR. Based on RefFinder which comprehended the results of three algorithms, RP13 in adults, Tubulin (Tub in late nymphs, 28S in early nymph and UbiCF under starvation stress were identified as the most stable genes. We also developed methods for feeding double-stranded RNA (dsRNA incorporated in the diet. Feeding dsRNA targeting Snf7, IAP, AQP1, and VATPase caused 56.17-77.12% knockdown of targeted genes compared to control and 16 to 48% mortality of treated insects when compared to control.

Phenology of Cornops aquaticum (Bruner) (Orthoptera: Acrididae) in Eichhornia azurea (Pontederiaceae) in the northern region of pantanal of Mato Grosso, Brazil

International Nuclear Information System (INIS)

Silva, Fatima R.J da; Marques, Marinez I.; Battirola, Leandro D.; Lhano, Marcos G.

2010-01-01

Cornops aquaticum (Bruner) has Eichhornia crassipes, E. azurea, Pontederia cordata and P. lanceolata (Pontederiaceae) as the known host plants. This grasshopper species is cited as a possible agent of biological control for native aquatic macrophytes E. azurea and E. crassipes. This study, carried out from March, 2006 to February, 2007, aimed to evaluate the phenology and age structure of the population of C. aquaticum associated with E. azurea in Piuval bay, Pantanal of Pocone, MT, and to identify possible relationships of its life cycle to abiotic factors such as insolation, temperature and precipitation. Monthly collections of 50 individuals were carried out according to the protocol defined by the - Host - Insect Coevolution on Waterhyacinth - project. Adults and nymphs were separated and the females dissected in order to evaluate ovary maturation. The population presented adults and nymphs during the whole year, suggesting the occurrence of more than one reproductive period. The nymphs from the fi rst stage predominated in August 2006 and the adults in September and October 2006, synchronized with the dry period and beginning of the flooding period, respectively. The highest relative abundance of the females with mature ovaries occurred in July 2006 (50%), indicating that this may be a more propitious period for reproduction. The data suggest that C. aquaticum is a species in continual reproduction in Piuval bay and its cycle is associated with the environmental conditions guided by the flood pulse in the Pantanal of Mato Grosso. (author)

High prevalence of Hepatozoon-infection among shepherd dogs in a region considered to be free of Rhipicephalus sanguineus.

Science.gov (United States)

Hornok, Sándor; Tánczos, Balázs; Fernández de Mera, Isabel G; de la Fuente, José; Hofmann-Lehmann, Regina; Farkas, Róbert

2013-09-01

Blood samples and ticks were collected from 100 shepherd dogs, 12 hunting dogs and 14 stray dogs in southern Hungary, in order to screen them for the presence of Hepatozoon spp. by PCR. Out of 126 blood samples, 33 were positive (26%). Significantly more shepherd dogs (31%) were infected, than hunting (8%) and stray dogs (7%). Three genotypes of Hepatozoon canis were identified by sequencing, differing from each other in up to six nucleotides in the amplified portion of their 18S rRNA gene. In Dermacentor marginatus larvae/nymphs and Dermacentor reticulatus nymphs, H. canis was present only if they had been collected from PCR-positive dogs, and the genotypes were identical in the ticks and their hosts. However, two Haemaphysalis concinna nymphs removed from a PCR-negative dog were found positive for H. canis, and the genotype detected in specimens of this tick species differed from that in the blood of their respective hosts. These results indicate that canine hepatozoonosis may be highly prevalent in regions where Rhipicephalus sanguineus is considered to be non-endemic. In addition, H. canis was identified for the first time in Hungary, as well as in D. marginatus, D. reticulatus and Ha. concinna ticks. Canine hepatozoonosis was significantly more prevalent west of the Danube river (where higher densities of red fox and golden jackal populations occur), suggesting a role of wild carnivores in its epidemiology. Copyright © 2013 Elsevier B.V. All rights reserved.

Phenology of Cornops aquaticum (Bruner) (Orthoptera: Acrididae) in Eichhornia azurea (Pontederiaceae) in the northern region of pantanal of Mato Grosso, Brazil; Fenologia de Cornops aquaticum (Bruner) (Orthoptera: Acrididae) em Eichhornia azurea (Pontederiaceae) no norte do pantanal de Mato Grosso

Energy Technology Data Exchange (ETDEWEB)

Silva, Fatima R.J da; Marques, Marinez I., E-mail: fateca@gmail.com.b, E-mail: marinez@ufmt.b [Universidade Federal de Mato Grosso (UFMT), Cuiaba, MT (Brazil). Programa de Pos-graduacao em Ecologia e Conservacao da Biodiversidade; Battirola, Leandro D., E-mail: ldbattirola@uol.com.b [Universidade Federal de Mato Grosso (UFMT), Sinop, MT (Brazil). Inst. de Ciencias Naturais, Humanas e Sociais; Lhano, Marcos G., E-mail: marcos@ufrb.edu.b [Universidade Federal do Reconcavo da Bahia, Cruz das Almas, BA (Brazil). Centro de Ciencias Agrarias, Ambientais e Biologicas

2010-07-15

Cornops aquaticum (Bruner) has Eichhornia crassipes, E. azurea, Pontederia cordata and P. lanceolata (Pontederiaceae) as the known host plants. This grasshopper species is cited as a possible agent of biological control for native aquatic macrophytes E. azurea and E. crassipes. This study, carried out from March, 2006 to February, 2007, aimed to evaluate the phenology and age structure of the population of C. aquaticum associated with E. azurea in Piuval bay, Pantanal of Pocone, MT, and to identify possible relationships of its life cycle to abiotic factors such as insolation, temperature and precipitation. Monthly collections of 50 individuals were carried out according to the protocol defined by the - Host - Insect Coevolution on Waterhyacinth - project. Adults and nymphs were separated and the females dissected in order to evaluate ovary maturation. The population presented adults and nymphs during the whole year, suggesting the occurrence of more than one reproductive period. The nymphs from the fi rst stage predominated in August 2006 and the adults in September and October 2006, synchronized with the dry period and beginning of the flooding period, respectively. The highest relative abundance of the females with mature ovaries occurred in July 2006 (50%), indicating that this may be a more propitious period for reproduction. The data suggest that C. aquaticum is a species in continual reproduction in Piuval bay and its cycle is associated with the environmental conditions guided by the flood pulse in the Pantanal of Mato Grosso. (author)

Comparative Toxicities of Newer and Conventional Insecticides: Against Four Generalist Predator Species.

Science.gov (United States)

Prabhaker, Nilima; Naranjo, Steven; Perring, Thomas; Castle, Steven

2017-12-05

Generalist insect predators play an essential role in regulating the populations of Bemisia tabaci and other pests in agricultural systems, but may be affected negatively by insecticides applied for pest management. Evaluation of insecticide compatibility with specific predator species can provide a basis for making treatment decisions with the aim of conserving natural enemies. Eleven insecticides representing six modes of action groups were evaluated for toxicity against four predator species and at different developmental stages. Full-concentration series bioassays were conducted on laboratory-reared or insectary-supplied predators using Petri dish and systemic uptake bioassay techniques. Highest toxicities were observed with imidacloprid and clothianidin against first and second instar nymphs of Geocoris punctipes (Say) (Hemiptera: Geocoridae). Later instar nymphs were less susceptible to neonicotinoid treatments based on higher LC50s observed with imidacloprid, thiamethoxam, and dinotefuran against third or fourth instar nymphs. The pyrethroid insecticide bifenthrin was highly toxic against adults of G. punctipes and Orius insidiosus (Say) (Hemiptera: Anthocoridae). Standard concentration/mortality evaluation of nonacute toxicity insecticides, including buprofezin, pyriproxyfen, spirotetramat, and spiromesifen, was inconclusive in terms of generating probit statistics. However, low mortality levels of insects exposed for up to 120 h suggested minimal lethality with the exception of pyriproxyfen that was mildly toxic to Chrysoperla rufilabris (Burmeister) (Neuroptera: Chrysopidae). Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Laboratory evaluation of a native strain of Beauveria bassiana for controlling Dermanyssus gallinae (De Geer, 1778) (Acari: Dermanyssidae).

Science.gov (United States)

Immediato, Davide; Camarda, Antonio; Iatta, Roberta; Puttilli, Maria Rita; Ramos, Rafael Antonio Nascimento; Di Paola, Giancarlo; Giangaspero, Annunziata; Otranto, Domenico; Cafarchia, Claudia

2015-09-15

The poultry red mite, Dermanyssus gallinae (De Geer, 1778) (Acari: Dermanyssidae) is one of the most economically important ectoparasites of laying hens worldwide. Chemical control of this mite may result in environmental and food contamination, as well as the development of drug resistance. High virulence of Beauveria bassiana sensu lato strains isolated from naturally infected hosts or from their environment has been demonstrated toward many arthropod species, including ticks. However, a limited number of studies have assessed the use of B. bassiana for the control of D. gallinae s.l. and none of them have employed native strains. This study reports the pathogenicity of a native strain of B. bassiana (CD1123) against nymphs and adults of D. gallinae. Batches of nymph and adult mites (i.e., n=720 for each stage) for treated groups (TGs) were placed on paper soaked with a 0.1% tween 80 suspension of B. bassiana (CIS, 10(5), 10(7) and 10(9) conidia/ml), whilst 240 untreated control mites for each stage (CG) were exposed only to 0.1% tween 80. The mites in TG showed a higher mortality at all stages (pbassiana suspension containing 10(9) conidia/ml was highly virulent towards nymph and adult stages of D. gallinae, therefore representing a possible promising natural product to be used in alternative or in combination to other acaricidal compounds currently used for controlling the red mite. Copyright © 2015 Elsevier B.V. All rights reserved.

Development and reproduction of Podisus distinctus (Heteroptera: Pentatomidae fed on larva of Bombyx mori (Lepidoptera: Bombycidae

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M. C. Lacerda

Full Text Available Biological control has been reducing the use of chemical products against insect pests, specially predatory Pentatomidae. Species of this group can present high variations in their life cycle as a result of their diet. Thus, the objective of this research was to study nymph development and reproduction of Podisus distinctus (Stäl, 1860 (Heteroptera: Pentatomidae fed on Bombyx mori L., 1758 (Lepidoptera: Bombycidae larvae (T1, compared to those fed on Tenebrio molitor L., 1758 (Coleoptera: Tenebrionidae (T2 and Musca domestica L., 1758 (Diptera: Muscidae larvae (T3 at a temperature of 25 ± 0.5ºC, relative humidity of 70 ± 2%, and photophase of 12 h. Predators fed on B. mori showed duration of the nymph phase (18.68 ± 1.02 similar to those fed on T. molitor (18.32 ± 1.49. Pre-oviposition and oviposition periods and number of egg masses, besides eggs and nymphs per female, were higher with B. mori (5.83 ± 2.02; 15.00 ± 7.40; 8.42 ± 1.84; 296.69 ± 154.75; and 228.55 ± 141.04, respectively while longevity of males and females of P. distinctus was 25.76 ± 16.15 and 35.00 ± 16.15 days with T. molitor, and 20.57 ± 13.60 and 23.46 ± 12.35 days with B. mori, respectively.

Age dependent radiation sensitivity of eggs of Dysdercus koenigii Fabricius

International Nuclear Information System (INIS)

Harwalkar, M.R.

1992-01-01

Eggs of Dysdercus koenigii Fabricius aged 0 to 2, 24, 48 and 72 hr were irradiated with X-ray doses ranging between 3 to 15 Gy to determine radiation sensitivity. It was observed that age of the eggs greatly influenced their response to radiation treatment. A dose of 6 Gy was required to prevent hatching of 0 to 2 hr old eggs but older eggs (24 and 48 hr) required 9 and 15 Gy, respectively, to bring about the same effect. At all the doses hatchability of 72 hr old irradiated eggs was much higher than those irradiated at younger age. Survival of nymphs emerging from 72 hr irradiated eggs at different dose levels was found to be dose dependent. Percentage of nymphs metamorphosing into adults decreased with increasing radiation dose received at the embryonic stage. (author). 21 refs., 2 figs

Detection of Anaplasma phagocytophilum DNA in Ixodes Ticks (Acari: Ixodidae) from Madeira Island and Setúbal District, Mainland Portugal

Science.gov (United States)

Santos-Silva, Maria Margarida; Almeida, Victor Carlos; Bacellar, Fátima; Dumler, John Stephen

2004-01-01

A total of 278 Ixodes ticks, collected from Madeira Island and Setúbal District, mainland Portugal, were examined by polymerase chain reaction (PCR) for the presence of Anaplasma phagocytophilum. Six (4%) of 142 Ixodes ricinus nymphs collected in Madeira Island and 1 nymph and 1 male (2%) of 93 I. ventalloi collected in Setúbal District tested positive for A. phagocytophilum msp2 genes or rrs. Infection was not detected among 43 I. ricinus on mainland Portugal. All PCR products were confirmed by nucleotide sequencing to be identical or to be most closely related to A. phagocytophilum. To our knowledge, this is the first evidence of A. phagocytophilum in ticks from Setúbal District, mainland Portugal, and the first documentation of Anaplasma infection in I. ventalloi. Moreover, these findings confirm the persistence of A. phagocytophilum in Madeira Island's I. ricinus. PMID:15498168

Detection of Anaplasma phagocytophilum DNA in Ixodes ticks (Acari: Ixodidae) from Madeira Island and Setubal District, mainland Portugal.

Science.gov (United States)

Santos, Ana Sofia; Santos-Silva, Maria Margarida; Almeida, Victor Carlos; Bacellar, Fátima; Dumler, John Stephen

2004-09-01

A total of 278 Ixodes ticks, collected from Madeira Island and Setubal District, mainland Portugal, were examined by polymerase chain reaction (PCR) for the presence of Anaplasma phagocytophilum. Six (4%) of 142 Ixodes ricinus nymphs collected in Madeira Island and 1 nymph and 1 male (2%) of 93 I. ventalloi collected in Setubal District tested positive for A. phagocytophilum msp2 genes or rrs. Infection was not detected among 43 I. ricinus on mainland Portugal. All PCR products were confirmed by nucleotide sequencing to be identical or to be most closely related to A. phagocytophilum. To our knowledge, this is the first evidence of A. phagocytophilum in ticks from Setubal District, mainland Portugal, and the first documentation of Anaplasma infection in I. ventalloi. Moreover, these findings confirm the persistence of A. phagocytophilum in Madeira Island's I. ricinus.

Triatoma rubrovaria (Blanchard 1843: tábua de vida das ninfas, duração das formas e oviposição das fêmeas Triatoma rubrovaria (Blanchard 1843: life table of nymphs, duration of the forms and posture of the females

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Vera Lúcia Cortiço Corrêa Rodrigues

2005-05-01

Full Text Available Os autores acompanharam a evolução de 150 ovos de Triatoma rubrovaria o que permitiu a construção de uma tábua de sobrevida das ninfas. A forma alada foi atingida por 94,64% dos exemplares, sendo 79 deles machos e 65 fêmeas. O tempo médio dos alados machos foi de 115 dias e das fêmeas, 99 dias. Parte desses exemplares formaram 30 casais, mantidos isolados, o que possibilitou o levantamento da postura de cada fêmea. Outro lote, também formado por 30 machos e 30 fêmeas, foi mantido em um único cristalizador de vidro, o que permitiu constatar sua maior postura (7.832 ovos em relação aquela das fêmeas acasaladas por único macho (5.167. O bom desenvolvimento dos exemplares no processo de evolução e de reprodução da espécie, nas condições do experimento, mostrou a boa capacidade de manutenção das colônias do Triatoma rubrovaria, em condições de laboratório.The authors followed the development of 150 eggs of Triatoma rubrovaria to enable the construction of a life table for the nymphs. The winged form was reached by 94.64% of the individuals, of which 79 were males and 65 females. The mean lifetime of the males was 115 days and 99 days for the females. Part of this group was divided into 30 couples and kept separated to facilitate the count of egg laying by each female. Another lot was also formed of 30 males and 30 females but these were housed together in a glass crystallizer that allowed the observation of a larger number of eggs laid (7,832 eggs in relationship to that of the females with only one male (total 5,167 eggs. The good development of the individuals and reproduction of the species in the experimental conditions demonstrated the capacity to maintain colonies of Triatoma rubrovaria in laboratory conditions.

Rändlinnud tulevad kevadel, plaadid nokas / Mart Niineste

Index Scriptorium Estoniae

Niineste, Mart, 1983-

2008-01-01

Uute heliplaatide tutvustus: Pia Fraus "After Summer", Taak "Läbi halli kivi", Vaiko Eplik ja Eliit "3. Kosmoseodüsseia", HU? "Film", Kolumbus Kris "Eesti roki annaalid", Me, Myself and I "Aastaajad", "The Nymph", Allan Vainola & Kelder "Vikerkaar ja latimeeria"

Asymmetric consequences of host plant occupation on the competition between the whiteflies Bemisia tabaci cryptic species MEAM1 and Trialeurodes vaporariorum (Hemiptera: Aleyrodidae)

DEFF Research Database (Denmark)

Zhang, Gui-Fen; Lövei, Gabor L; Hu, Man

2014-01-01

. RESULTS: Resource preoccupied by T. vaporariorum had mostly negative effects on the life history parameters of later-arriving conspecifics. Red-eyed nymph and immature survival of T. vaporariorum decreased when resource was preoccupied by conspecifics, irrespective of the previous occupation scenario...

2003-IJBCS-Article-Amadou Bocar Bal

African Journals Online (AJOL)

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Plots were field enclosures of 20 m2 (5 x 4 m) containing millet plants to feed nymphs. .... in order to minimize predation by birds. ..... these droplets are acceptable for insects of large size .... Changing Oviposition preferences of the desert.

Puerto Rico Revealed Preference Survey Data 2004

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Revealed preference models provide insights into recreational angler behavior and the economic value of recreational fishing trips. Revealed preference data is...

The 'revealed preferences' theory: Assumptions and conjectures

International Nuclear Information System (INIS)

Green, C.H.

1983-01-01

Being kind of intuitive psychology the 'Revealed-Preferences'- theory based approaches towards determining the acceptable risks are a useful method for the generation of hypotheses. In view of the fact that reliability engineering develops faster than methods for the determination of reliability aims the Revealed-Preferences approach is a necessary preliminary help. Some of the assumptions on which the 'Revealed-Preferences' theory is based will be identified and analysed and afterwards compared with experimentally obtained results. (orig./DG) [de

Rearing the southern green stink bug using an artificial dry diet and an artificial plant Criação do percevejo-verde usando dieta artificial seca e planta artificial

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ANTÔNIO RICARDO PANIZZI

2000-09-01

Full Text Available Laboratory and greenhouse studies were conducted with an artificial dry diet to rear nymphs, and with an artificial plant as substrate for egg laying by the southern green stink bug, Nezara viridula (L.. The artificial diet was composed of: soybean protein (15 g; potato starch (7.5 g; dextrose (7.5 g; sucrose (2.5 g; cellulose (12.5 g; vitamin mixture (niacinamide 1 g, calcium pantothenate 1 g, thiamine 0.25 g, riboflavin 0.5 g, pyridoxine 0.25 g, folic acid 0.25 g, biotin 0.02 mL, vitamin B12 1 g - added to 1,000 mL of distilled water (5.0 mL; soybean oil (20 mL; wheat germ (17.9 g; and water (30 mL. Nymphs showed normal feeding behavior when fed on the artificial diet. Nymphal development time was longer than or similar to that of nymphs fed on soybean pods. Total nymphal mortality was low (ca. 30%, both for nymphs reared on the artificial diet, and for nymphs fed on soybean pods. At adult emergence, fresh body weights were significantly (PForam conduzidos estudos em laboratório e em casa de vegetação, com uma dieta artificial seca para a criação de ninfas e com um modelo de planta artificial como substrato para a colocação de ovos por adultos do percevejo-verde, Nezara viridula (L.. Os componentes da dieta artificial foram: proteína de soja (15 g; fécula de batata (7,5 g; dextrose (7,5 g; sacarose (2,5 g; celulose (12,5 g; mistura vitamínica (niacinamida 1 g, pantotenato de cálcio 1 g, tiamina 0,25 g, riboflavina 0,5 g, piridoxina 0,25 g, ácido fólico 0,25 g, biotina 0,02 mL, vitamina B12 1 g, adicionada em 1.000 mL de água destilada (5,0 mL; óleo de soja (20 mL; germe de trigo (17,9 g; e água (30 mL. As ninfas alimentaram-se normalmente da dieta, embora o tempo de desenvolvimento tenha sido em um caso, maior, e em outro, semelhante, ao das ninfas que se alimentaram de vagens da soja. A mortalidade total das ninfas foi baixa (ca. 30%, tanto na dieta como na vagem de soja. Na emergência, os adultos apresentaram peso fresco

Diversidade e distribuição de ninfas de Plecoptera (Insecta por substratos em rios do Parque Estadual da Pedra Branca, Rio de Janeiro, Brasil

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Fernanda Avelino Capistrano

2017-08-01

Full Text Available Resumo. No presente estudo procuramos entender o principal substrato de ocorrência de ninfas de Plecoptera (Insecta em rios do Parque Estadual da Pedra Branca (Rio de Janeiro, RJ, Brasil. As coletadas das ninfas foram realizadas entre agosto/2008 a março/2009, em cinco riachos localizados a 200 m de altitude. Foram investigados cinco tipos diferentes de substrato: areia, folhiço retido, folhiço de fundo, rocha com musgo e rocha solta lisa. Além da coleta de imaturos, a temperatura da água e do ar, o pH, a largura e a profundidade dos riachos, e a velocidade da água (método de flutuação foram medidas. A Análise de Espécies Indicadoras e o Teste de Monte Carlo foram utilizados para determinar a preferência de habitats pelas morfoespécies. O índice de Shannon foi utilizado para verificar a maior diversidade entre os substratos e os rios. Uma análise de agrupamento foi realizada a fim de verificar a similaridade física e biológica dos rios. Um total de 559 ninfas foi coletado e distribuídos em seis morfoespécies. O substrato ‘folhiço retido’ mostrou-se como o de maior abundância e riqueza em todos os riachos estudados. A heterogeneidade de substratos foi apontada como principal fator de diversidade entre os pontos de coleta. Diversity and substrate distribution of Plecoptera nymphs (Insecta in strems of Parque Estadual da Pedra Branca, Rio de Janeiro, Brazil Abstract. The present study contributes to the understanding the main substrate where Plecoptera nymphs have occur in streams of Parque Estadual da Pedra Branca (Rio de Janeiro municipality, Rio de Janeiro State, Brazil. The collects of the nymphs were realized between August 2008 to March 2009, in five streams located at 200 m. asl. Five different substrates were investigated: sand, litter deposited in pool areas, litter in riffle areas, stones with moss and free stones. In addition to the collection of nymphs, water and air temperatures, pH, width and depth of the

Effect of recombinant glutathione S-transferase as vaccine antigen against Rhipicephalus appendiculatus and Rhipicephalus sanguineus infestation.

Science.gov (United States)

Sabadin, Gabriela Alves; Parizi, Luís Fernando; Kiio, Irene; Xavier, Marina Amaral; da Silva Matos, Renata; Camargo-Mathias, Maria Izabel; Githaka, Naftaly Wang'ombe; Nene, Vish; da Silva Vaz, Itabajara

2017-12-04

The ticks Rhipicephalus appendiculatus and Rhipicephalus sanguineus are the main vectors of Theileria parva and Babesia spp. in cattle and dogs, respectively. Due to their impact in veterinary care and industry, improved methods against R. appendiculatus and R. sanguineus parasitism are under development, including vaccines. We have previously demonstrated the induction of a cross-protective humoral response against Rhipicephalus microplus following vaccination with recombinant glutathione S-transferase from Haemaphysalis longicornis tick (rGST-Hl), suggesting that this protein could control tick infestations. In the present work, we investigated the effect of rGST-Hl vaccine against R. appendiculatus and R. sanguineus infestation in rabbits. In silico analysis revealed that GST from H. longicornis, R. appendiculatus and R. sanguineus have >80% protein sequence similarity, and multiple conserved antigenic sites. After the second vaccine dose, rGST-Hl-immunized rabbits showed elevated antibody levels which persisted until the end of experiment (75 and 60 days for R. appendiculatus and R. sanguineus, respectively). Western blot assays demonstrated cross-reactivity between anti-rGST-Hl antibodies and native R. appendiculatus and R. sanguineus GST extracts from ticks at different life stages. Vaccination with rGST-Hl decreased the number, weight, and fertility of engorged R. appendiculatus adults, leading to an overall vaccine efficacy of 67%. Interestingly, histological analysis of organ morphology showed damage to salivary glands and ovaries of R. appendiculatus adult females fed on vaccinated animals. In contrast, rGST-Hl vaccination did not affect R. appendiculatus nymphs, and it was ineffective against R. sanguineus across the stages of nymph and adult. Taken together, our results show the potential application of rGST-Hl as an antigen in anti-tick vaccine development, however indicating a broad difference in efficacy among tick species. Copyright © 2017 Elsevier

Temperature studies with the Asian citrus psyllid, Diaphorina citri: cold hardiness and temperature thresholds for oviposition.

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Hall, David G; Wenninger, Erik J; Hentz, Matthew G

2011-01-01

This study was conducted to obtain information on the cold hardiness of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), in Florida and to assess upper and lower temperature thresholds for oviposition. The psyllid is an important pest in citrus because it transmits the bacterial pathogens responsible for citrus greening disease, Huanglongbing, considered the most serious citrus disease worldwide. D. citri was first found in Florida during 1998, and the disease was discovered during 2005. Little was known regarding cold hardiness of D. citri, but Florida citrus is occasionally subjected to notable freeze events. Temperature and duration were each significant sources of variation in percent mortality of D. citri subjected to freeze events. Relatively large percentages of adults and nymphs survived after being exposed for several hours to temperatures as low as -5 to -6 °C. Relatively large percentages of eggs hatched after being exposed for several hours to temperatures as low as -8 °C. Research results indicated that adult D. citri become cold acclimated during the winter through exposure to cooler winter temperatures. There was no evidence that eggs became cold acclimated during winter. Cold acclimation in nymphs was not investigated. Research with adult D. citri from laboratory and greenhouse colonies revealed that mild to moderate freeze events were usually nonlethal to the D. citri irrespective of whether they were cold acclimated or not. Upper and lower temperature thresholds for oviposition were investigated because such information may be valuable in explaining the geographic distribution and potential spread of the pest from Florida as well as how cooler winter temperatures might limit population growth. The estimated lower and upper thresholds for oviposition were 16.0 and 41.6 °C, respectively; the estimated temperature of peak oviposition over a 48 h period was 29.6 °C.

Efficacy of pyriproxyfen for control of stored-product psocids (Psocoptera) on concrete surfaces

Science.gov (United States)

The insect growth regulator pyriproxyfen was evaluated as a surface treatment for control of three stored-product psocid pests, Liposcelis bostrychophila Badonnel, L. decolor (Pearman), and L. paeta Pearman (Psocoptera: Liposcelididae). Nymphs were exposed for 35 d on a concrete surface treated with...

Effect of buprofezin on survival of immature stages of Harmonia axyridis, Stethorus punctum picipes (Coleoptera: Coccinellidae), Orius tristicolor (Hemiptera: Anthocoridae), and Geocoris spp. (Hemiptera: Geocoridae).

Science.gov (United States)

James, David G

2004-06-01

The effect of buprofezin, a chitin synthesis inhibitor, on development and survival of immature stages of Harmonia axyridis (Pallas), Stethortus punctum picipes Casey, Orius tristicolor (White), Geocoris pallens Stål, and Geocoris punctipes (Say), was examined in a series of laboratory bioassays. Very few H. axyridis larvae (3.1%) treated with buprofezin reached adulthood, although 65% of treated pupae emerged successfully. Buprofezin caused no mortality to eggs of S. punctum picipes but 71.1% of treated early instar larvae failed to complete development. Eighty percent of treated late instars and 92.3% of pupae produced viable adults. Early instar nymphs of O. tristicolor were unaffected by buprofezin, whereas 47.7 and 85% of G. punctipes and G. pallens nymphs, respectively, failed to complete development. Treated eggs of G. pallens hatched successfully. The use of buprofezin in integrated pest management in Washington state wine grapes is discussed.

Triazophos up-regulated gene expression in the female brown planthopper, Nilaparvata lugens.

Science.gov (United States)

Bao, Yan-Yuan; Li, Bao-Ling; Liu, Zhao-Bu; Xue, Jian; Zhu, Zeng-Rong; Cheng, Jia-An; Zhang, Chuan-Xi

2010-09-01

The widespread use of insecticides has caused the resurgence of the brown planthopper, Nilaparvata lugens, in Asia. In this study, we investigated an organo-phosphorous insecticide, triazophos, and its ability to induce gene expression variation in female N. lugens nymphs just before emergence. By using the suppression subtractive hybridization method, a triazophos-induced cDNA library was constructed. In total, 402 differentially expressed cDNA clones were obtained. Real-time qPCR analysis confirmed that triazophos up-regulated the expression of six candidate genes at the transcript level in nymphs on day 3 of the 5th instar. These genes encode N. lugens vitellogenin, bystin, multidrug resistance protein (MRP), purine nucleoside phosphorylase (PNP), pyrroline-5-carboxylate reductase (P5CR) and carboxylesterase. Our results imply that the up-regulation of these genes may be involved in the induction of N. lugens female reproduction or resistance to insecticides.

Tick as a model for the study of a primitive complement system.

Science.gov (United States)

Kopacek, Petr; Hajdusek, Ondrej; Buresova, Veronika

2012-01-01

Ticks are blood feeding parasites transmitting a wide variety of pathogens to their vertebrate hosts. The transmitted pathogens apparently evolved efficient mechanisms enabling them to evade or withstand the cellular or humoral immune responses within the tick vector. Despite its importance, our knowledge of tick innate immunity still lags far beyond other well established invertebrate models, such as drosophila, horseshoe crab or mosquitoes. However, the recent release of the American deer tick, Ixodes scapularis, genome and feasibility of functional analysis based on RNA interference (RNAi) facilitate the development of this organism as a full-value model for deeper studies of vector-pathogen interactions.

Attachment site selection of life stages of Ixodes ricinus ticks on a main large host in Europe, the red deer (Cervus elaphus).

Science.gov (United States)

Mysterud, Atle; Hatlegjerde, Idar Lauge; Sørensen, Ole Jakob

2014-11-13

Ticks and tick-borne diseases are increasing in many areas of Europe and North America due to climate change, while land use and the increased abundances of large hosts play a more controversial role. The pattern of host selection involves a crucial component for tick abundance. While the larvae and nymphs feed on a wide range of different sized hosts, the adult female ticks require blood meal from a large host (>1 kg), typically a deer, to fulfil the life cycle. Understanding the role of different hosts for abundances of ticks is therefore important, and also the extent to which different life stages attach to large hosts. We studied attachment site selection of life stages of I. ricinus ticks on a main large host in Europe, the red deer (Cervus elaphus). We collected from 33 felled red deer pieces of skin from five body parts: leg, groin, neck, back and ear. We counted the number of larval, nymphal, adult male and adult female ticks. Nymphs (42.2%) and adult (48.7%) ticks dominated over larvae (9.1%). There were more larvae on the legs (40.9%), more nymphs on the ears (83.7%), while adults dominated in the groins (89.2%) and neck (94.9%). Large mammalian hosts are thus a diverse habitat suitable for different life stages of ticks. The attachment site selection reflected the life stages differing ability to move. The spatial separation of life stages may partly limit the role of deer in co-feeding transmission cycles.

Nuevos aspectos del método de xenodiagnóstico con Rhodnius prolixus

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Ernesto Osorno Mesa

1963-04-01

Full Text Available The efficiency of Xenodiagnostico is noted, as a biological method of making an etiological diagnosis of Chagas disease, It is pointed out that the fourth and fifth nymph stages are the most appropriate, not only because of the great amount of blood which they ingurgitate to repletion, but also because of the facility of the routine operations without the necessity of extraeting and placing the specimens in receptacles of superficial cleanliness in order to separate the full specimens from the empty ones. The advantages of a partial diet of blood is indicated in order to prevent the nymphs from becoming adults. The technique used in the study of spontaneous dejection in Rhodnius prolixus experimentally infected is described and the advantages noted. The article describes an original method "Dejectograma" of recording the total digestion of blood during one month in normal and infected fifth stage nymphs. The recording apparatus is an adapted thermograph which we call a "Dejectografo". Some observations are made concerning the discovery of evolved forms of S. cruzi, in several spontaneous dejections and the survival of metacyclic forms in hyaline for 30 hours between the slide and cover slide at a temperature of 150 C. Attention is called to the intermission of ejection of evolved forms of S. cruzi, with the conclusion that in order to avoid false negative results, dissection of the digestive tracts is necessary in these cases. The possibility of complete studies is set forth, aided by the techniques explained, and along the lines of the few observations made from pilot experiments.

Influence of gamma radiation for controlling Brevipalpus phoenicis (Acari: Tenuipalpidae) (Geijskes, 1939) in oxygen atmosphere

International Nuclear Information System (INIS)

Machi, Andre R.; Arthur, Valter

2013-01-01

Brevipalpus phoenicis mite are controlled across of solutions acaricides, which are chemicals and leave residues in addition there is the difficulty of an effective pulverization due to the small size of the mite, the objective of this study was to evaluate of the influence of oxygen combined with gamma radiation on B.phoenicis as alternative control. Were used 70 mites per arena in 9 reps on 3 treatments at doses of 0 (control), 200 and 300 Gy. For irradiation, the leaves containing the mites, were cut and placed on bottles with bladder tied with ribbons and strings, before was put pure oxygen and the bottle was then sealed, these were taken to a gamma irradiator of Cobalt 60-type Gammacell 220, under a dose rate of 0.381 kGy/hour located in the CENA/USP. Was evaluated daily (eggs, nymphs and adults) of the mites observed viability, fertility and mortality across of the analysis of variance design with completely randomized design using the Statistical Analysis System (SAS) version 9.2® and by the Tukey test, the verification of means. After 22 days of irradiation the hatchability in 200 Gy dose was 41% after 3 days and 57% in control dose, this differed statistically of the other doses, where the nymphs arrived to the adult stage, which did not occurred in the 200 Gy dose and higher due to mutations, generated by the gamma radiation. In 300 Gy not was observed the presence of nymphs and eggs, being the sterilizing dose for all stages of the B.phoenicis. (author)

Survey on morphometric characteristic of different developmental stages of Dermacentor marginatus under laboratory conditions

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Mohammad Mehdi Darvishi

2014-09-01

Full Text Available Objective: To study the morphometric characteristics and biology of different developmental stages of Dermacentor marginatus (D. marginatus under laboratory conditions. Methods: D. marginatus ticks were collected from sheep in Shahmirzad and suburb. The identification of D. marginatus was carried out by means of stereoscope and light microscope according to available systematic keys. Nourished female ticks weight and their length of body, capitulum and mouth parts were measured. After laying eggs and breeding, the weight of all developmental larva stages and the length of mouth parts were measured and recorded carefully. Results: The mean of egg dimension was 566 µm伊436 µm. The length of unfed larva body, hypostome and capitulum were (690依10 µm, (75依5 µm and (172依7 µm, respectively. The weight of egg was calculated 0.05 mg and the weight of unfed larva, nymph and female were 0.02 mg, 0.14 mg and 4.66 mg, respectively; whereas the weight of replete larva, nymph and female were recorded 0.5 mg, 11 mg and 380 mg, respectively. Moreover, the length of unfed nymph, hypostome and capitulum were recorded (1300依50 µm, (135依5 µm and (280依10 µm, respectively. The longest length and width in replete female were observed to be 12.6 mm伊8.4 mm. Conclusions: The current investigation presents new information on biology of D. marginatus under standard laboratory conditions. Besides, investigation on ticks under laboratory conditions increases our knowledge regarding their biology and potential risks.

The emergence densities of annual cicadas (Hemiptera: Cicadidae) increase with sapling density and are greater near edges in a bottomland hardwood forest.

Science.gov (United States)

Chiavacci, Scott J; Bednarz, James C; McKay, Tanja

2014-08-01

The emergence densities of cicadas tend to be patchy at multiple spatial scales. While studies have identified habitat conditions related to these patchy distributions, their interpretation has been based primarily on periodical cicada species; habitat factors associated with densities of nonperiodical (i.e., annual) cicadas have remained under studied. This is despite their widespread distribution, diversity, and role as an important trophic resource for many other organisms, particularly within riparian areas. We studied habitat factors associated with the emergence densities of Tibicen spp. in a bottomland hardwood forest in east-central Arkansas. We found emergence densities were greatest in areas of high sapling densities and increased toward forest edges, although sapling density was a much stronger predictor of emergence density. Emergence densities also differed among sample areas within our study system. The habitat features predicting nymph densities were likely driven by a combination of factors affecting female selection of oviposition sites and the effects of habitat conditions on nymph survival. The differences in nymph densities between areas of our system were likely a result of the differential effects of flooding in these areas. Interestingly, our findings were similar to observations of periodical species, suggesting that both types of cicadas select similar habitat characteristics for ovipositing or are under comparable selective pressures during development. Our findings also imply that changes in habitat characteristics because of anthropogenically altered disturbance regimes (e.g., flooding) have the potential to negatively impact both periodical and annual species, which could have dramatic consequences for organisms at numerous trophic levels.

(Neuroptera: Chrysopidae fed with Aleurocanthus woglumi (Hemiptera: Aleyrodidae

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Robério de Oliveira

2016-02-01

Full Text Available This study evaluated the development and reproduction of Ceraeochrysa cubana when fed the citrus blackfly Aleurocanthus woglumi. The study was carried out at the Laboratory of Entomology, Department of Plant and Environmental Sciences, Federal University of Paraíba – Areia/PB. It used a completely randomized design. The study was conducted in climate chambers, regulated to 26 ± 2°C and a relative humidity of 70 ± 10% with a 12 h photoperiod. The treatments were as follows: eggs, nymphs of only the 1st, 2nd, 3rd, or 4th instars, and nymphs of multiple instars (1st, 2nd, 3rd, and 4th instars of A. woglumi, with eggs of Sitotroga cerealella as a control. The 1st instar of C. cubana lasted 5.8 to 10.7 days, the 2nd instar lasted 6.0 to 13.3 days, and the 3rd instar lasted 8.2 to 18.5 days. The larvae of C. cubana did not survive when the food provided was only the eggs of A. woglumi, since the predator could not eat them. C. cubana, when provided nymphs of multiple instars (1st, 2nd, 3rd, and 4th instars of the citrus blackfly, had a shorter pre-pupal period and lower longevity than when consuming the eggs of S. cerealella, but the sex ratio and oviposition period were not affected. However, changes occurred in the pre-oviposition period, the total number of eggs, and the number of viable eggs.

Influence of gamma radiation for controlling Brevipalpus phoenicis (Acari: Tenuipalpidae) (Geijskes, 1939) in oxygen atmosphere

Energy Technology Data Exchange (ETDEWEB)

Machi, Andre R., E-mail: rica_machi@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN- SP), Sao Paulo, SP (Brazil); Arthur, Valter, E-mail: arthur@cena.usp.br [Centro de Energia na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

2013-07-01

Brevipalpus phoenicis mite are controlled across of solutions acaricides, which are chemicals and leave residues in addition there is the difficulty of an effective pulverization due to the small size of the mite, the objective of this study was to evaluate of the influence of oxygen combined with gamma radiation on B.phoenicis as alternative control. Were used 70 mites per arena in 9 reps on 3 treatments at doses of 0 (control), 200 and 300 Gy. For irradiation, the leaves containing the mites, were cut and placed on bottles with bladder tied with ribbons and strings, before was put pure oxygen and the bottle was then sealed, these were taken to a gamma irradiator of Cobalt 60-type Gammacell 220, under a dose rate of 0.381 kGy/hour located in the CENA/USP. Was evaluated daily (eggs, nymphs and adults) of the mites observed viability, fertility and mortality across of the analysis of variance design with completely randomized design using the Statistical Analysis System (SAS) version 9.2® and by the Tukey test, the verification of means. After 22 days of irradiation the hatchability in 200 Gy dose was 41% after 3 days and 57% in control dose, this differed statistically of the other doses, where the nymphs arrived to the adult stage, which did not occurred in the 200 Gy dose and higher due to mutations, generated by the gamma radiation. In 300 Gy not was observed the presence of nymphs and eggs, being the sterilizing dose for all stages of the B.phoenicis. (author)

Alimentación y defecación en triatominos del género Rhodnius (Hemiptera: Reduviidae alimentados con sangre humana

Directory of Open Access Journals (Sweden)

E. Aldana

2001-06-01

Full Text Available Se estudió el comportamiento alimenticio y de defecación de Rhodnius prolixus Stal, 1859, R. robustus Larrousse, 1927, R. neivai Lent, 1953 y R. pictipes Stal, 1872 alimentados artificialmente con sangre humana en condiciones de laboratorio. La ninfa I de todas las especies no defecaron en la primera media hora después de haber iniciado la ingesta. R. pictipes no se acercó a picar en el alimentador artificial aunque si lo hizo cuando el alimento se ofreció directamente sobre el cuerpo humano. Las ninfas y adultos de R. prolixus mostraron índices de defecación (ID superiores a los correspondientes de las otras especies, y la ninfa III presentó el mayor ID=1.62. La mayoría de individuos de todos los estadíos de desarrollo aceptaron el alimento en un tiempo entre 0 y 3 min y se alimentaron en menos de 15 minutos.Feeding and defecaction behavior of Rhodnius prolixus Stal, 1859, R. robustus Larrousse, 1927, R. neivai Lent, 1953 and R. pictipes Stal, 1872, artificially fed on human blood, were studied under laboratory conditions. In all species, first instar nymphs did not defecate in the first 30 minutes after feeding. R. pictipes did not accept artificial feeding but fed directly on humans. Nymph and adult R. prolixus had a higher defecation index (DI than other species; third instar nymphs had the highest DI=1.62. In all instars, most individuals accepted the food in £ 3 minutes and finished feeding in less than 15 minutes.

Induction of insect plant resistance to the spittlebug Mahanarva fimbriolata Stal (Hemiptera: Cercopidae) in sugarcane by silicon application

International Nuclear Information System (INIS)

Korndorfer, A.P.; Grisoto, E.; Vendramim, J.D.

2011-01-01

Changes in the agroecosystem with the increase of green cane harvesting in Brazil affected the insect populations associated to this crop, and secondary pests like the spittlebug Mahanarva fimbriolata Stal, became much more important. Many studies have demonstrated the active role played by silicon in plant defense against herbivory. The objective of this study was to evaluate the effects of silicon applications on the biology of the spittlebug reared on two resistant (SP79-1011 and SP80-1816) and one susceptible (SP81-3250) sugarcane cultivars. Sugarcane plants were grown under greenhouse conditions and submitted to different treatments: with and without silicon fertilizer in two different soil type (sandy and clay soil). The newly hatched nymphs were transferred to sugarcane roots and placed into boxes with lids, to keep a moistened and dark environment favoring their growth and maintenance of the root system, providing food access to the developing nymphs. After emergence, adult males and females were placed in cages for mating and oviposition. The silicon absorbed and accumulated in the plant caused an increase in nymphal mortality, and depending on the sugarcane cultivar tested this element also provided an increase in the duration of the nymphal stage and a decrease in the longevity of males and females. 'SP79-1011' presented the highest silicon content in leaves, and M. fimbriolata had the highest nymph mortality and the shortest female longevity. The pre-oviposition period, fecundity and egg viability were not affected by the silicon content in plants or the cultivar used. (author)

Influence of Tree Size and Application Rate on Expression of Thiamethoxam in Citrus and Its Efficacy Against Diaphorina citri (Hemiptera: Liviidae).

Science.gov (United States)

Langdon, K W; Schumann, R; Stelinski, L L; Rogers, M E

2018-04-02

Neonicotinoids are a key group of insecticides used to manage Diaphorina citri Kuwayama (Hemiptera: Liviidae), in Florida citrus. Diaphorina citri is the vector of Candidatus Liberibacter asiaticus, the presumed causal agent of huanglongbing, a worldwide disease of citrus. A two-season field study was conducted to evaluate the effect of tree size and application rate on the expression of thiamethoxam in young citrus following application to the soil. D. citri adult and nymph abundance was also correlated with thiamethoxam titer in leaves. Tree size and application rate each significantly affected thiamethoxam titer in leaf tissue. The highest mean thiamethoxam titer observed (33.39 ppm) in small trees (mean canopy volume = 0.08 m3) occurred after application of the high rate (0.74 g Platinum 75SG per tree) tested. There was a negative correlation between both nymph and adult abundance with increasing thiamethoxam titer in leaves. A concentration of 64.63 ppm thiamethoxam was required to reach a 1% probability of encountering a flush shoot with at least one adult D. citri, while 19.05 ppm was required for the same probability of encountering nymphs. The LC90 for the field population was 7.62 ppm thiamethoxam when administered through ingestion. Exposure to dosages as low as 7.62 ppm would likely result in sublethal exposure of some proportion of the population, which could exacerbate resistance development. Based on our results, subsequent work should investigate the use of neonicotinoids by foliar rather than soil application to maintain the chemical class in future insecticide management programs in Florida citrus.

Population ecology and movement of the American cockroach (Dictyoptera: Blattidae) in sewers.

Science.gov (United States)

Tee, Hui-Siang; Saad, Ahmad Ramli; Lee, Chow-Yang

2011-07-01

The population size, age-class structure, and movement of the American cockroach, Periplaneta americana (L.) (Dictyoptera: Blattidae), were studied in three sewers in Penang, Malaysia, from September 2008 to October 2009. Eighteen to 20 glass-jar traps (two per manhole) were deployed for a 24-h period during each sampling occasion at each sewer. Adults and nymphs were active throughout the study period, with an average monthly trap catch of 57-97 adults and 79-99 nymphs. The mean proportions of adults and nymphs at the three sewers ranged from 0.47 to 0.57. Of the 2177 male and 2717 female cockroaches marked and released over the three sewers, recapture rates were 29.4-45.8 and 30.8-47.0%, respectively. The proportion of marked males and females did not differ significantly from the proportion of recaptured marked males and females. However, the mean number of times a marked female was recaptured was significantly greater than that of males. Of the 783 males and 1,030 females that were marked and recaptured, 19.4 and 24.7%, respectively, had moved between manholes, and significantly more females than males moved between manholes. Of the 406 recaptured marked adults that moved between manholes, 90.4% moved a distance of 2-20 m from their initial release site; one male moved 192 m, the longest distance recorded. Trap catch on each sampling occasion was positively correlated with daily mean temperature. The number of cockroach movements between manholes also was correlated with the mean daily minimum temperature.

Dispersion patterns and sampling plans for Diaphorina citri (Hemiptera: Psyllidae) in citrus.

Science.gov (United States)

Sétamou, Mamoudou; Flores, Daniel; French, J Victor; Hall, David G

2008-08-01

The abundance and spatial dispersion of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) were studied in 34 grapefruit (Citrus paradisi Macfad.) and six sweet orange [Citrus sinensis (L.) Osbeck] orchards from March to August 2006 when the pest is more abundant in southern Texas. Although flush shoot infestation levels did not vary with host plant species, densities of D. citri eggs, nymphs, and adults were significantly higher on sweet orange than on grapefruit. D. citri immatures also were found in significantly higher numbers in the southeastern quadrant of trees than other parts of the canopy. The spatial distribution of D. citri nymphs and adults was analyzed using Iowa's patchiness regression and Taylor's power law. Taylor's power law fitted the data better than Iowa's model. Based on both regression models, the field dispersion patterns of D. citri nymphs and adults were aggregated among flush shoots in individual trees as indicated by the regression slopes that were significantly >1. For the average density of each life stage obtained during our surveys, the minimum number of flush shoots per tree needed to estimate D. citri densities varied from eight for eggs to four flush shoots for adults. Projections indicated that a sampling plan consisting of 10 trees and eight flush shoots per tree would provide density estimates of the three developmental stages of D. citri acceptable enough for population studies and management decisions. A presence-absence sampling plan with a fixed precision level was developed and can be used to provide a quick estimation of D. citri populations in citrus orchards.

Induction of insect plant resistance to the spittlebug Mahanarva fimbriolata Stal (Hemiptera: Cercopidae) in sugarcane by silicon application

Energy Technology Data Exchange (ETDEWEB)

Korndorfer, A.P.; Grisoto, E.; Vendramim, J.D., E-mail: korndorfer@hotmail.co [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Entomologia e Acarologia

2011-05-15

Changes in the agroecosystem with the increase of green cane harvesting in Brazil affected the insect populations associated to this crop, and secondary pests like the spittlebug Mahanarva fimbriolata Stal, became much more important. Many studies have demonstrated the active role played by silicon in plant defense against herbivory. The objective of this study was to evaluate the effects of silicon applications on the biology of the spittlebug reared on two resistant (SP79-1011 and SP80-1816) and one susceptible (SP81-3250) sugarcane cultivars. Sugarcane plants were grown under greenhouse conditions and submitted to different treatments: with and without silicon fertilizer in two different soil type (sandy and clay soil). The newly hatched nymphs were transferred to sugarcane roots and placed into boxes with lids, to keep a moistened and dark environment favoring their growth and maintenance of the root system, providing food access to the developing nymphs. After emergence, adult males and females were placed in cages for mating and oviposition. The silicon absorbed and accumulated in the plant caused an increase in nymphal mortality, and depending on the sugarcane cultivar tested this element also provided an increase in the duration of the nymphal stage and a decrease in the longevity of males and females. 'SP79-1011' presented the highest silicon content in leaves, and M. fimbriolata had the highest nymph mortality and the shortest female longevity. The pre-oviposition period, fecundity and egg viability were not affected by the silicon content in plants or the cultivar used. (author)

REVEAL: Software Documentation and Platform Migration

Science.gov (United States)

Wilson, Michael A.; Veibell, Victoir T.

2011-01-01

The Research Environment for Vehicle Embedded Analysis on Linux (REVEAL) is reconfigurable data acquisition software designed for network-distributed test and measurement applications. In development since 2001, it has been successfully demonstrated in support of a number of actual missions within NASA's Suborbital Science Program. Improvements to software configuration control were needed to properly support both an ongoing transition to operational status and continued evolution of REVEAL capabilities. For this reason the project described in this report targets REVEAL software source documentation and deployment of the software on a small set of hardware platforms different from what is currently used in the baseline system implementation. This presentation specifically describes the actions taken over a ten week period by two undergraduate student interns and serves as an overview of the content of the final report for that internship.

Genomic and transcriptomic insights into the cytochrome P450 monooxygenase gene repertoire in the rice pest brown planthopper, Nilaparvata lugens.

Science.gov (United States)

Lao, Shu-Hua; Huang, Xiao-Hui; Huang, Hai-Jian; Liu, Cheng-Wen; Zhang, Chuan-Xi; Bao, Yan-Yuan

2015-11-01

The cytochrome P450 monooxygenase (P450) gene family is one of the most abundant eukaryotic gene families that encode detoxification enzymes. In this study, we identified an abundance of P450 gene repertoire through genome- and transcriptome-wide analysis in the brown planthopper (Nilaparvata lugens), the most destructive rice pest in Asia. Detailed gene information including the exon-intron organization, size, transcription orientation and distribution in the genome revealed that many P450 loci were closely situated on the same scaffold, indicating frequent occurrence of gene duplications. Insecticide-response expression profiling revealed that imidacloprid significantly increased NlCYP6CS1v2, NLCYP4CE1v2, NlCYP4DE1, NlCYP417A1v2 and NlCYP439A1 expression; while triazophos and deltamethrin notably enhanced NlCYP303A1 expression. Expression analysis at the developmental stage showed the egg-, nymph-, male- and female-specific expression patterns of N. lugens P450 genes. These novel findings will be helpful for clarifying the P450 functions in physiological processes including development, reproduction and insecticide resistance in this insect species. Copyright © 2015 Elsevier Inc. All rights reserved.

The neonicotinoid imidachloprid shows high chronic toxicity to mayfly nymphs

NARCIS (Netherlands)

Roessink, I.; Merga, L.B.; Zweers, A.J.; Brink, van den P.J.

2013-01-01

The present study evaluated the acute and chronic toxicity of imidacloprid to a range of freshwater arthropods. Mayfly and caddisfly species were most sensitive to short-term imidacloprid exposures (10 tests), whereas the mayflies showed by far the most sensitive response to long-term exposure of

Utilization of tall goldenrod by the tarnished plant bug (Hemiptera: Miridae) in the production of overwintering adults and as a possible winter food source

Science.gov (United States)

Tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), nymphs and adults were collected from tall goldenrod, Solidago canadensis L. var. scabra Torr. and Gray, in Washington County, MS during October and November 2008 and 2009. Adults were dissected to determine their reproductive status in o...

Time course study of feeding damage to pin head cotton squares by Lygus hesperus (Hemiptera: Miridae)

Science.gov (United States)

Lygus hesperus (Hemiptera: Miridae) is an economically important pest affecting cotton crops in California. Lygus feeding causes abscission of cotton squares, with damage severity dependent on size of the square and life stage of the insect. Fifth instar nymphs are the most damaging stage; however, ...

A new genus and species of felt scale (Hemiptera: Coccomorpha: Eriococcidae) from New Caledonia on an endemic species of Casuarinaceae.

Science.gov (United States)

Hodgson, Chris; Germain, Jean-franÇois; Matile-Ferrero, DaniÈle

2018-02-26

A new genus of Eriococcidae, Dzumacoccus Hodgson gen. n., is erected for a new species, Dzumacoccus baylaci Hodgson, Germain Matile-Ferrero, feeding on Gymnostoma poissonianum, a species of Casuarinaceae endemic to New Caledonia. The adult female and first-instar nymph are described and illustrated.

Description and key to the fifth-instars of some Cicadas (Hemiptera: Cicadidae) associated with coffee plants in Brazil.

Science.gov (United States)

Maccagnan, D H B; Martinelli, N M

2011-01-01

Fifth-instars of the cicada species Dorisiana drewseni (Stål), Dorisiana viridis (Olivier), Fidicina mannifera (Fabricius), Fidicinoides pronoe (Walker) and Carineta fasciculata (Germar) are described and illustrated. Moreover, a key to the nymphs of these species along with Quesada gigas (Olivier) is also provided.

Baseline susceptibility of Lygus lineolaris (Hemiptera:Miridae) to novaluron

Science.gov (United States)

Tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), populations were collected from field locations in the Mississippi River Delta of Arkansas, Louisiana, and Mississippi. Third instar F1 nymphs from each field location, in addition to a laboratory colony, were screened for susceptibility t...

THE RELIGION OF BEAUTY AND THE VEIL OF THE GRACES

African Journals Online (AJOL)

User

beauty” and the filth of the modern history and the world; it's a word that encloses ... a new tradition of spiritual fecundity and of energy poured from. Venus' body divine ... waves of the seas and in the forests water nymphs, naiads, dryads and ...

Genetics of Pseudococcusmicrocirculus on orchids RESEARCH

Indian Academy of Sciences (India)

Navya

Genetic Structure of Pseudococcusmicrocirculus (Hemiptera: .... these orchids are listed as endangered on Florida's Regulated Plant Index (Coile and Garland 2003). .... other samples, which we did not have sufficient statistical power to detect. ... males and minute first instar nymphs can use wind currents for dispersal.

Estimating potential stylet penetration of southern green stink bug (Hemiptera: Pentatomidae) - A mathematical modeling approach

Science.gov (United States)

Southern green stink bugs, Nezara viridula (L.), and related species are significant pests of cotton in the U.S. Cotton Belt. Using their stylets, adults introduce disease pathogens of cotton into cotton bolls, and preliminary data indicates nymphs can also ingest these pathogens. Data is lacking ...

Entomopathogenic fungi associated with Ixodes ricinus ticks

DEFF Research Database (Denmark)

Kalsbeek, Vibeke; Frandsen, F.; Steenberg, Tove

1995-01-01

to the Hyphomycetes. Paecilomyces farinosus and Verticillium lecanii were the predominant species. Other species, found only on engorged females were: Beauveria bassiana, B. brongniartii, P. fumosoroseus and V. araneanrm. Eight out of 1833 ticks collected from the vegetation and three out of 269 engorged nymphs were...

Patterns of parasitism by Amblyomma rotundatum (Ixodidae on Rhinella schneideri (Bufonidae in islands of São Francisco River, Minas Gerais, Brazil

Directory of Open Access Journals (Sweden)

Hermes Ribeiro Luz

2015-06-01

Full Text Available Abstract: We sampled ticks from specimens of the rococo toad Rhinella schneideriby flannel dragging on two Islands located in the São Francisco River near the Três Marias hydroelectric dam, southeastern Brazil. A total of 120 toads was examined, of which 63 (52.5% were parasitized only by Amblyomma rotundatumtotaling 96 larvae, 163 nymphs and 134 females. The burden of parasitism ranged from one to 43 ticks, with a mean intensity of infestation of 6.2±5.5 ticks per host. The tick A. rotundatumexhibited highly aggregated distribution. Peak abundance of larvae and nymphs occurred in the dry season (May to September, whereas peak abundance of females occurred in the wet season (October to April. We collected most ticks near the head and hind limbs of R. schneideri. The finding of two engorged A. rotundatumnymphs in the same resting places of two toads and the absence of this species in the dragged areas suggest a nidicolous behavior at the studied site.

Absence of domestic triatomine colonies in an area of the coastal region of Ecuador where Chagas disease is endemic

Directory of Open Access Journals (Sweden)

Mario J Grijalva

2010-08-01

Full Text Available Rhodnius ecuadoriensis is considered the second most important vector of Chagas disease in Ecuador. It is distributed across six of the 24 provinces and occupies intradomiciliary, peridomiciliary and sylvatic habitats. This study was conducted in six communities within the coastal province of Guayas. Triatomine searches were conducted in domestic and peridomestic habitats and bird nests using manual searches, live-bait traps and sensor boxes. Synantrhopic mammals were captured in the domestic and peridomestic habitats. Household searches (n = 429 and randomly placed sensor boxes (n = 360 produced no live triatomine adults or nymphs. In contrast, eight nymphs were found in two out of six searched Campylorhynchus fasciatus (Troglodytidae nests. Finally, Trypanosoma cruzi DNA was amplified from the blood of 10% of the 115 examined mammals. Environmental changes in land use (intensive rice farming, mosquito control interventions and lack of intradomestic adaptation are suggested among the possible reasons for the lack of domestic triatomine colonies.

Free-living ixodid ticks in an urban Atlantic Forest fragment, state of Rio de Janeiro, Brazil.

Science.gov (United States)

Pinheiro, Michele da Costa; Lourenço, Elizabete Captivo; Patrício, Priscilla Maria Peixoto; Sá-Hungaro, Iwine Joyce Barbosa de; Famadas, Kátia Maria

2014-01-01

As a consequence of the importance of ticks in forests in protected areas, was conducted survey of species of free-living ticks in the Natural Park Municipal Curió, state of Rio de Janeiro, Brazil. Monthly samples were taken by dragging method, dry ice traps and visual search in two transects. Adults and nymphs of Amblyomma cajennense (n= 147), Amblyomma brasiliense (n= 4) and Amblyomma parvum (n= 1) were collected. This is the first occurrence of A. parvum in the state. No correlation was found between the abundance of stages of A. cajennense and rainfall, temperature and relative humidity. The highest abundances of adults were in the months of January and May, and nymphs in September and October. The low diversity of parasites on Curió Park can be attributed to the proximity of households with pets, which would also explain the higher abundance of A. cajennense that is commonly found in areas impacted by anthropogenic pressure.

Effects of precocene and azadirachtin in Rhodnius prolixus: some data on development and reproduction

Directory of Open Access Journals (Sweden)

Eloi S. Garcia

1987-01-01

Full Text Available The results presented in this paper clearly indicate that precocene and azadirachtin are effective inhibitors of moulting and reproduction in the hemipteran Rhodnius prolixus. The time of application is important and only applications of these substances early in the intermoulting period cause their effects in nymphs. The inhibition of moulting is fully reversed by ecdysone therapy. Precocene and azadirachtin also affected drastically the oogenesis and egg deposition in this insect. Precocene-induced sterilization is reversed by application of juvenile hormone III. However, this hormone is unable to reverse the effect of azadirachtin on reproduction. Ecdysteroid titers in nymphs and adult females are decreased by these treatments. In vitro analysis suggest that precocene and azadirachtin may act directly on the prothoracic glands and ovaries producing ecdysteroids. Based on these and other findings the possible mode of action of these compounds on the development and reproduction of Rhodnius prolixus is discussed.

Potential of ultraviolet radiation for control of American cockroach populations

International Nuclear Information System (INIS)

Gingrich, J.B.; Pratt, J.J. Jr.; Mandels, G.R.

1977-01-01

Populations of Periplaneta americana (L.) were exposed for 8-20 week periods in specially designed rooms to 254 nm UV radiation at low intensity (50-115 ergs s -1 cm -2 ), high intensity (160-220 ergs s -1 cm -2 ), or to white light. The rooms contained tables and chairs to simulate occupied space, with food and water placed in positions exposed to UV radiation. 'General' irradiation (where the whole room was exposed to UV) at 115 ergs s -1 cm -2 and above was effective in producing high mortality in all stages except 8-10th instar nymphs and adults. 'Hot-spots' irradiation (where UV lamps were placed behind table and chair harborages) produced high mortality only in 1st-3rd instar nymphs which would result in slower elimination of a population. Crude aggregation pheromone was not successful in holding cockroaches close to radiation sources or substantially increasing mortality under the conditions of the experiments

First evidence of Babesia venatorum and Babesia capreoli in questing Ixodes ricinus ticks in the Czech Republic.

Science.gov (United States)

Venclikova, Kristyna; Mendel, Jan; Betasova, Lenka; Hubalek, Zdenek; Rudolf, Ivo

2015-01-01

Ixodes ricinus is the most common tick species occurring in Central Europe and it serves as a principal vector of emerging human pathogens. The aim of this study was to determine the prevalence of Babesia spp. in host-seeking I. ricinus in urban and natural habitats. PCR was applied on samples to assess prevalence of Babesia spp. in questing ixodid ticks. Sequencing was used for Babesia species determination. 1,473 I. ricinus ticks (1,294 nymphs, 99 males and 80 females) were examined for the presence of Babesia spp. at the two study sites. Minimum infection rate for Babesia spp. was found to be 0.5% (infected I. ricinus nymphs were only detected in the natural ecosystem). Two Babesia species were identified by sequencing: B. venatorum (formerly called Babesia sp. EU1) and B. capreoli. The results obtained represent the first evidence of the occurrence of B. venatorum and B. capreoli in host-seeking I. ricinus ticks in the Czech Republic.

Dynamical System and Nonlinear Regression for Estimate Host-Parasitoid Relationship

Directory of Open Access Journals (Sweden)

Ileana Miranda Cabrera

2010-01-01

Full Text Available The complex relationships of a crop with the pest, its natural enemies, and the climate factors exist in all the ecosystems, but the mathematic models has studied only some components to know the relation cause-effect. The most studied system has been concerned with the relationship pest-natural enemies such as prey-predator or host-parasitoid. The present paper shows a dynamical system for studying the relationship host-parasitoid (Diaphorina citri, Tamarixia radiata and shows that a nonlinear model permits the estimation of the parasite nymphs using nymphs healthy as the known variable. The model showed the functional answer of the parasitoid, in which a point arrives that its density is not augmented although the number host increases, and it becomes necessary to intervene in the ecosystem. A simple algorithm is used to estimate the parasitoids level using the priori relationship between the host and the climate factors and then the nonlinear model.

Evaluation of gamma irradiated essential oils to control stored-grain weevil, Sitophilus zeamais and cockroach, Blattella germanica

International Nuclear Information System (INIS)

Potenza, Marcos Roberto; Gomes, Davinni Habral Passini; Silvestre, Denise de Fatima; Da Silva, Rita de Cassia; Arthur, Valter

2004-01-01

Most of the essential oils have insecticidal activity and are alternatives to plant protection and urban pest control. The gamma radiation has been used to control microorganisms and insects in dehydrate herbs, spices, medicinal plants and other materials. This work aimed to evaluate the effect of irradiated essential oils as contact poison on Stored grain, weevil, Sitophilus zeamais and as stomach poison in cockroach, Blattella germanica. The bioassay with B. germanica demonstrated efficiency between 22.0 and 30.0% and between 30.0 and 42.0% respectively, to irradiated essential oils of E. citriodora and E. globulus and they demonstrated too repellency to the nymphs. The gamma radiation promoted changes in essential oils Eucalyptus citriodora and E. globulus and showed increased effectiveness on B. germanica nymphs besides a significative reduction of repellency. Gamma radiation thus interfered on behavior of some essential oils by increasing or reducing activating or inactivating their efficiency to pest control. (author)

A Study on the Feeding and Growth Patterns of the Variegated ...

African Journals Online (AJOL)

The feeding and growth patterns of the variegated grasshopper, Zonocerus variegatus (L) were studied in the laboratory to ascertain the amount of food intake, food assimilated and faeces excreted by its nymph and adult stages on a mixed diet of Cassava (Manihot esculenta) and Siam weed (Chromolaena odorata) leaves.

For-Profit Colleges and American Salesmanship — A Unique Opportunity

Directory of Open Access Journals (Sweden)

Robert Oliphant

2010-07-01

Full Text Available Robert Oliphant’s best known book is A Piano for Mrs. Cimino, the film version of which won a Golden Nymph Award at Monte Carlo for Bette Davis. He is a WWII air corps veteran, and his eBooks are available from the Nonpartisan Education Review.

Sina English and American Dictionaries — A New Partnership

Directory of Open Access Journals (Sweden)

Robert Oliphant

2010-06-01

Full Text Available Robert Oliphant’s best known book is A Piano for Mrs. Cimino, the film version of which won a Golden Nymph Award at Monte Carlo for Bette Davis. He is a WWII air corps veteran, and his eBooks are available from the Nonpartisan Education Review.

Influence of meteorological parameters during the preceding fall and winter on the questing activity of nymphal Ixodes ricinus ticks

DEFF Research Database (Denmark)

Vollack, Ken; Sodoudi, Sahar; Névir, Peter

2017-01-01

November through February affect the questing activity of ticks during their subsequent season of activity. We related the number of host-seeking nymphs to meteorological parameters measured in close proximity at minutely intervals over the period of 6 years (2010-2015) in an urban park in Berlin. We...

Effect of climate and land use on the spatio-temporal variability of tick-borne bacteria in Europe

Czech Academy of Sciences Publication Activity Database

Rosà, R.; Andreo, V.; Tagliapietra, V.; Baráková, I.; Arnoldi, D.; Hauffe, H. C.; Manica, M.; Rosso, F.; Blaňarová, L.; Bona, M.; Derdáková, M.; Hamšíková, Z.; Kazimírová, M.; Kraljik, J.; Kocianová, E.; Mahríková, L.; Minichová, L.; Mošanský, L.; Slovák, M.; Stanko, M.; Špitalská, E.; Ducheyne, E.; Neteler, M.; Hubálek, Zdeněk; Rudolf, Ivo; Venclíková, Kristýna; Silaghi, C.; Overzier, E.; Farkas, R.; Földvári, G.; Hornok, S.; Takács, N.; Rizzoli, A.

2018-01-01

Roč. 15, č. 4 (2018), č. článku 732. ISSN 1660-4601 EU Projects: European Commission(XE) 261504 - EDENEXT Keywords : Acarological hazard * Anaplasma phagocytophilum * Borrelia burgdorferi sensu lato * Density of infected nymphs * Land use * Normalized difference vegetation index * Rickettsia spp Impact factor: 2.101, year: 2016

A Rickettsia Genome Overrun by Mobile Genetic Elements Provides Insight into the Acquisition of Genes Characteristic of an Obligate Intracellular Lifestyle

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Joardar, Vinita; Williams, Kelly P.; Driscoll, Timothy; Hostetler, Jessica B.; Nordberg, Eric; Shukla, Maulik; Walenz, Brian; Hill, Catherine A.; Nene, Vishvanath M.; Azad, Abdu F.; Sobral, Bruno W.; Caler, Elisabet

2012-01-01

We present the draft genome for the Rickettsia endosymbiont of Ixodes scapularis (REIS), a symbiont of the deer tick vector of Lyme disease in North America. Among Rickettsia species (Alphaproteobacteria: Rickettsiales), REIS has the largest genome sequenced to date (>2 Mb) and contains 2,309 genes across the chromosome and four plasmids (pREIS1 to pREIS4). The most remarkable finding within the REIS genome is the extraordinary proliferation of mobile genetic elements (MGEs), which contributes to a limited synteny with other Rickettsia genomes. In particular, an integrative conjugative element named RAGE (for Rickettsiales amplified genetic element), previously identified in scrub typhus rickettsiae (Orientia tsutsugamushi) genomes, is present on both the REIS chromosome and plasmids. Unlike the pseudogene-laden RAGEs of O. tsutsugamushi, REIS encodes nine conserved RAGEs that include F-like type IV secretion systems similar to that of the tra genes encoded in the Rickettsia bellii and R. massiliae genomes. An unparalleled abundance of encoded transposases (>650) relative to genome size, together with the RAGEs and other MGEs, comprise ∼35% of the total genome, making REIS one of the most plastic and repetitive bacterial genomes sequenced to date. We present evidence that conserved rickettsial genes associated with an intracellular lifestyle were acquired via MGEs, especially the RAGE, through a continuum of genomic invasions. Robust phylogeny estimation suggests REIS is ancestral to the virulent spotted fever group of rickettsiae. As REIS is not known to invade vertebrate cells and has no known pathogenic effects on I. scapularis, its genome sequence provides insight on the origin of mechanisms of rickettsial pathogenicity. PMID:22056929

Principales criaderos para Aedes aegypti y culícidos asociados, Argentina Main breeding-containers for Aedes aegypti and associated culicids, Argentina

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Marina Stein

2002-10-01

Full Text Available Se identificaron criaderos de Aedes (Stegomyia aegypti en dos ciudades de la provincia del Chaco (Noreste de Argentina: Presidencia Roque Saenz Peña y Machagai. Los recipientes encontrados en los patios de las viviendas capaces de colectar agua se clasificaron según tipo y tamaño, se contaron y examinaron. Aedes aegypti y Culex quinquefasciatus fueron las especies mas abundantes, encontrándose además Cx. maxi, Cx. saltanensis y Ochlerotatus scapularis. Los neumáticos y cajas de baterías para autos fueron los recipientes que más aportaron a la producción de formas inmaduras de los culícidos colectados. Las lluvias fueron un factor importante para la proliferacion de Ae. aegypti, así como también el habito comun en la población de guardar recipientes en sus casas que permitan el desarrollo de estos culícidos.Breeding containers for Aedes (Stegomyia aegypti were identified in two cities of Chaco Province (northeast Argentina: Presidencia Roque Saenz Peña and Machagai. All water-retaining recipients found in house backyards capable to retain water were classified according to their type and size, counted and checked. Aedes aegypti and Culex quinquefasciatus were the most frequently collected species, being also found Cx. maxi, Cx. saltanensis and Ochlerotatus scapularis. Tires and car batteries represented the most important type of container where immature forms of culicids could be found. Rain was an important factor for Ae. aegypti proliferation, as well as the widespread habit of the population of keeping useless containers at home, which allows the development of culicids.

Lousy mums: patterns of vertical transmission of an amphibious louse.

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Leonardi, M S; Crespo, E A; Raga, J A; Aznar, F J

2013-09-01

In this study, we document patterns of vertical transmission of the amphibious louse Antarctophthirus microchir (Echinophthiriidae) in pups of South American sea lion, Otaria flavescens, from Patagonia. Vertical transmission is fundamental for the long-term stability of A. microchir populations because only pups stay long enough (1 month) on land for the louse to reproduce. A total of 72 pups ≤7 days old from a single rookery were captured and examined for lice. Infection parameters and population structure of A. microchir did not differ among pups collected at the beginning, middle, and end of the reproductive season, suggesting that patterns of early vertical transmission are not affected by the increase of rookery size during this period. Over 60% of 1-day-old pups were infected with A. microchir, and recruitment increased in pups up to 3 days old and then leveled off. In 1-day-old pups, significantly more adults than nymphs were found, but the pattern was reversed in older pups. The number of first-stage nymphs was significantly smaller than that of second- and third-stage nymphs, as it was the number of males vs. females, particularly in 1-day-old pups. Three non-exclusive hypotheses could account for these patterns, i.e., recruitment merely reflects the population structure of A. microchir is cows; the relative ability of lice to pass from cows onto pups increases in advanced instars; and/or natural selection favors transmission of adults, especially females, because they accrue greater fitness. The importance of latter hypothesis should not be underestimated in a species with a tight reproductive schedule.

Nymphal and adult performance of Euschistus heros (Fabr.) (Hemiptera: Pentatomidae), as a potential alternative host for egg parasitoids multiplication

International Nuclear Information System (INIS)

Peres, Wilsimar A.A.; Correa-Ferreira, Beatriz S.

2001-01-01

This research aimed to evaluate the potential of Euschistus heros (Fabr.) (Hemiptera: Pentatomidae) as host for multiplication of egg parasitoids, by determining the nymphal and adult performance of E. heros from laboratory and the field, comparing with Nezara viridula (L.) (Hemiptera: Pentatomidae), under mass conditions. One hundred eggs of E. heros and N. viridula were placed among the leaves of soybean plants contained in cages (50x50x70 cm) and observation were made until adult emergence. The nymphs fed on soybean pods, dry soybean and peanuts seeds. The number of nymphs that reached adulthood and the development time were calculated. The survivorship and reproduction performance of laboratory and field populations of E. heros and N. viridula were evaluated during 13 weeks in February-May 1999. The number of eggs produced by 100 pairs of stink bugs per cage containing the same diet was recorded. Nymphal development time of E. heros and N. viridula was 33.0 and 34.0 days and 65.0% and 71.3% of nymphs reached adulthood, respectively. Adults of E. heros reared under laboratory conditions produced 2.5 times more eggs (5547.0 eggs/cage) than those collected in the field (2262.7 eggs/cage). The adult field population of E. heros had reduced reproduction and longevity due to parasitism by Hexacladia smithii Ash. (Hymenoptera: Encyrtidae). The N. viridula adults collected in the field produced 1.7 times more eggs (6304.9 eggs/cage) than those reared in the laboratory (3609.2 eggs/cage). E. heros laboratory reared is a promising host for egg parasitoids multiplication when compared with N. viridula collected in the field. (author)

Analysis of Inter-Individual Bacterial Variation in Gut of Cicada Meimuna mongolica (Hemiptera: Cicadidae).

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Zhou, Wenting; Nan, Xiaoning; Zheng, Zhou; Wei, Cong; He, Hong

2015-01-01

Intestinal bacterial community plays a crucial role in the nutrition, development, survival, and reproduction of insects. When compared with other insects with piercing-sucking mouthparts, the habitats of cicada nymphs and adults are totally different. However, little is known about the differences in the gut bacterial communities in the nymphs and adults within any cicada species. The diversity of bacteria in the gut of nymphs and adults of both genders of Meimuna mongolica (Distant) was studied using the denaturing gradient gel electrophoresis (DGGE) method. Few inter-individual variations among gut microbiota were observed, suggesting that M. mongolica typically harbors a limited and consistent suite of bacterial species. Bacteria in the genera Pseudomonas and Enterobacter were the predominant components of the gut microflora of M. mongolica at all life stages. Bacteria of Pantoea, Streptococcus, and Uruburuella were also widespread in the cicada samples but at relatively lower concentrations. The relative stability and similarity of the PCR-DGGE patterns indicate that all individuals of this cicada species harbor a characteristic bacterial community which is independent from developmental stages and genders. Related endosymbionts that could be harbored in bacteromes of cicadas were not detected in any gut samples, which could be related to the cicada species and the distribution of these endosymbionts in the cicada cavity, or due to some of the possible limitations of PCR-DGGE community profiling. It is worthwhile to further address if related cicada endosymbiont clades distribute in the alimentary canals and other internal organs through diagnostic PCR using group-specific primer sets. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Age structure and feeding of the neotropical grasshopper Cornops aquaticum (Bruner) (Orthoptera: Acrididae) on water hyacinth.

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Franceschini, M C; de Wysiecki, M L; Poi, A

2013-08-01

We aimed to evaluate the variation in the age structure of Cornops aquaticum (Bruner) population and its relation to the host plant biomass and the feeding of the different age classes of this grasshopper on the water hyacinth Eichhornia crassipes along 2 years, in a Paraná River floodplain lake (Chaco, Argentina). Individuals of C. aquaticum were captured with a 70-cm diameter sweep and separated in nymphs A (instars I and II), nymphs B (instars III to VI), adult females, and adult males; host plant biomass was sampled using a ring with a 0.30-m(2) diameter. Relative daily feeding of C. aquaticum population was calculated by multiplying the number of individuals captured per minute by the daily consumption by individual obtained in each age classes. We found that the age structure and the relative daily feeding of C. aquaticum varied between seasons and years. The highest values of grasshopper abundance, leaf biomass, and relative daily feeding of C. aquaticum population were observed in summer 2006. Plant biomass was directly correlated with nymph abundance and not correlated with adult abundance. Plant biomass available as refuge (leaves), food (laminas), and oviposition site (petioles) to C. aquaticum represented up to 62% of the total plant biomass. The results obtained in C. aquaticum show the importance of considering total plant biomass and plant biomass available for herbivores separately. Our study highlights the need to find an adequate method to estimate the density of C. aquaticum and other semiaquatic grasshoppers in the Paraná River floodplain involving different seasons, years, and water phases (rising and falling).

Nymphal and adult performance of Euschistus heros (Fabr.) (Hemiptera: Pentatomidae), as a potential alternative host for egg parasitoids multiplication

Energy Technology Data Exchange (ETDEWEB)

Peres, Wilsimar A.A. [Universidade Federal do Parana, Curitiba, PR (Brazil). Dept. de Zoologia; Correa-Ferreira, Beatriz S. [EMBRAPA, Londrina, PR (Brazil). Centro Nacional de Pesquisa de Soja

2001-12-15

This research aimed to evaluate the potential of Euschistus heros (Fabr.) (Hemiptera: Pentatomidae) as host for multiplication of egg parasitoids, by determining the nymphal and adult performance of E. heros from laboratory and the field, comparing with Nezara viridula (L.) (Hemiptera: Pentatomidae), under mass conditions. One hundred eggs of E. heros and N. viridula were placed among the leaves of soybean plants contained in cages (50x50x70 cm) and observation were made until adult emergence. The nymphs fed on soybean pods, dry soybean and peanuts seeds. The number of nymphs that reached adulthood and the development time were calculated. The survivorship and reproduction performance of laboratory and field populations of E. heros and N. viridula were evaluated during 13 weeks in February-May 1999. The number of eggs produced by 100 pairs of stink bugs per cage containing the same diet was recorded. Nymphal development time of E. heros and N. viridula was 33.0 and 34.0 days and 65.0% and 71.3% of nymphs reached adulthood, respectively. Adults of E. heros reared under laboratory conditions produced 2.5 times more eggs (5547.0 eggs/cage) than those collected in the field (2262.7 eggs/cage). The adult field population of E. heros had reduced reproduction and longevity due to parasitism by Hexacladia smithii Ash. (Hymenoptera: Encyrtidae). The N. viridula adults collected in the field produced 1.7 times more eggs (6304.9 eggs/cage) than those reared in the laboratory (3609.2 eggs/cage). E. heros laboratory reared is a promising host for egg parasitoids multiplication when compared with N. viridula collected in the field. (author)

Effects of buprofezin and diflubenzuron on various developmental stages of Asian citrus psyllid, Diaphorina citri.

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Tiwari, Siddharth; Clayson, Paul J; Kuhns, Emily H; Stelinski, Lukasz L

2012-10-01

Diaphorina citri populations in Florida are developing resistance to commonly used neurotoxic insecticides. Alternatives to neurotoxins, such as insect growth regulators, are needed to control this season-long subtropical pest to prevent or delay development of insecticide resistance. In the present investigation, two insect growth regulators (IGRs), buprofezin and diflubenzuron, were evaluated against various developmental stages of D. citri. The 0-1-day-old D. citri eggs were more susceptible to buprofezin and diflubenzuron than the 3-4-day-old eggs. Adult emergence was completely suppressed by treating first- or third-instar nymphs with buprofezin or diflubenzuron at 30-240 or 23-184 µg mL(-1) rates respectively. Treatment of fifth-instar nymphs with diflubenzuron at a rate of 184 µg mL(-1) and with buprofezin at 30-240 µg mL(-1) rates resulted in approximately 20 and 15-80% reductions in adult emergence respectively. The mean number of eggs per plant was reduced at 5 days after topical treatment with diflubenzuron. Mean egg hatch per plant was reduced at 5 and 6-15 days after topical treatments with buprofezin and diflubenzuron respectively. Buprofezin and diflubenzuron effectively suppressed D. citri adult emergence. D. citri were more susceptible as early (first-third-instar) than late (fifth-instar) nymphs. Both IGRs inhibited egg production and egg hatch. Reduction in the number of subsequent offspring suggests reduced vertical transmission of Candidatus Liberibacter asiaticus, the pathogen thought to cause citrus greening disease. The present results indicate that both IGRs tested here should be effective tools for rotation in insecticide-based D. citri management programs. Copyright © 2012 Society of Chemical Industry.

Feeding and development of the glassy-winged sharpshooter, Homalodisca vitripennis, on Australian native plant species and implications for Australian biosecurity.

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Anna A Rathé

Full Text Available In any insect invasion the presence or absence of suitable food and oviposition hosts in the invaded range is a key factor determining establishment success. The glassy-winged sharpshooter, Homalodisca vitripennis, is an important insect vector of the xylem-limited bacterial plant pathogen, Xylella fastidiosa, which causes disease in numerous host plants including food and feedstock crops, ornamentals and weeds. Both the pathogen and the vector are native to the Americas and are considered to be highly invasive. Neither has been detected in Australia. Twelve Australian native plant species present in the USA were observed over two years for suitability as H. vitripennis feeding, oviposition and nymph development hosts. Hosts providing evidence of adult or nymph presence were Leptospermum laevigatum, Acacia cowleana, Eremophila divaricata, Eucalyptus wandoo, Hakea laurina, Melaleuca laterita and Swainsona galegifolia. An oviposition-suitability field study was conducted with citrus, a favoured oviposition host, as a positive control. Citrus and L. laevigatum, A. cowleana, B. ericifolia×B. spinulosa, C. pulchella, E. divaricata, E. wandoo, H. laurina, and S. galegifolia were found to be oviposition hosts. Egg parasitism by the mymarid parasitoid Gonatocerus ashmeadi was observed on all Australian plants. A number of Australian plants that may facilitate H. vitripennis invasion have been identified and categorised as 'high risk' due to their ability to support all three life stages (egg, nymph and adult of the insect in the field (L. laevigatum, A. cowleana, E. divaricata, H. laurina, and S. galegifolia. The implications of these host status and natural enemy research findings are discussed and placed in an Australian invasion context.

Thermal requirements and estimated number of generations of Neopamera bilobata (Say in strawberry-producing regions of Brazil

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Taciana Melissa de Azevedo Kuhn

2017-12-01

Full Text Available ABSTRACT: The thermal threshold and thermal requirements of Neopamera bilobata were determined, and the number of generations that this species may produce in the main strawberry-producing regions of Brazil was estimated. In a climate chamber (70±10% RH and 12h photophase at 16, 19, 22, 25, 28, or 30±1°C, the development of 120 eggs was monitored until the adult stage, at each temperature. Nymphs were maintained in individual cages and fed on strawberry fruits of the cultivar Aromas. The mean duration and viability of the egg and nymph stages were calculated by estimating the lower and upper developmental thresholds and the thermal constant, and this information was used to estimate the number of generations per year in different strawberry-producing regions of Brazil. The egg-to-adult duration decreased as temperatures increased, up to 28°C (93.4, 83.2, 43.9, and 31.4 days at 19, 22, 25, and 28°C, respectively. Viability of nymphs was highest between 22 and 28°C. At 30°C, the egg-to-adult duration increased (36 days, while the viability decreased (11.11%. The lower egg-to-adult developmental threshold was 15.2°C and the thermal constant was 418.4 degree-days. Calculating the number of generations indicated that the largest number (5.1 generations yr-1 was obtained for the municipality of Jaboti, Paraná, and the smallest for Caxias do Sul, Rio Grande do Sul (1.9 generations yr-1. Our findings demonstrated that important strawberry-producing regions in Brazil are suitable for the development of N. bilobata.

Susceptibility of Diaphorina citri (Hemiptera: Liviidae) and Its Parasitoid Tamarixia radiata (Hymenoptera: Eulophidae) to Entomopathogenic Fungi under Laboratory Conditions.

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Ibarra-Cortés, K H; Guzmán-Franco, A W; González-Hernández, H; Ortega-Arenas, L D; Villanueva-Jiménez, J A; Robles-Bermúdez, A

2018-02-01

Diaphorina citri (Kuwayama) is a global pest of citrus that transmits the bacteria associated with the disease, Huanglongbing. Entomopathogenic fungi and the parasitoid Tamarixia radiata (Waterston) are important biological control agents of this pest and likely to interact in D. citri populations. As a basis for interaction studies, we determined the susceptibility of nymphs and adults of D. citri and adults of the parasitoid T. radiata to six fungal isolates from the species Beauveria bassiana s.l. (Bals.-Criv.) Vuill. (isolates B1 and B3), Metarhizium anisopliae s.s. (Metsch.) (Ma129 and Ma65) and Isaria fumosorosea Wize (I2 and Pae). We conducted experiments evaluating infection levels in all three insect groups following inoculation with a series of conidial concentrations (1 × 10 4 -1 × 10 8 conidia mL -1 ). Results showed that D. citri nymphs and T. radiata were more susceptible to fungal isolates than D. citri adults. Overall, B. bassiana and M. anisopliae isolates caused the greatest infection compared with I. fumosorosea isolates in all three groups of insects. Isolates B1 (B. bassiana) and Ma129 (M. anisopliae) infected a greater proportion of adults and nymphs of D. citri, respectively. Both isolates of B. bassiana caused greater infection in T. radiata compared with isolates of the other fungal species. We propose that isolates B1 and Ma129 are the strongest candidates for control of D. citri. Our results represent the first report of entomopathogenic fungi infecting T. radiata, and the basis for future studies to design a biological control programme that uses both agents more efficiently against D. citri populations.

Asian Citrus Psyllid Expression Profiles Suggest Candidatus Liberibacter Asiaticus-Mediated Alteration of Adult Nutrition and Metabolism, and of Nymphal Development and Immunity.

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Meenal Vyas

Full Text Available The Asian citrus psyllid (ACP Diaphorina citri Kuwayama (Hemiptera: Psyllidae is the insect vector of the fastidious bacterium Candidatus Liberibacter asiaticus (CLas, the causal agent of citrus greening disease, or Huanglongbing (HLB. The widespread invasiveness of the psyllid vector and HLB in citrus trees worldwide has underscored the need for non-traditional approaches to manage the disease. One tenable solution is through the deployment of RNA interference technology to silence protein-protein interactions essential for ACP-mediated CLas invasion and transmission. To identify psyllid interactor-bacterial effector combinations associated with psyllid-CLas interactions, cDNA libraries were constructed from CLas-infected and CLas-free ACP adults and nymphs, and analyzed for differential expression. Library assemblies comprised 24,039,255 reads and yielded 45,976 consensus contigs. They were annotated (UniProt, classified using Gene Ontology, and subjected to in silico expression analyses using the Transcriptome Computational Workbench (TCW (http://www.sohomoptera.org/ACPPoP/. Functional-biological pathway interpretations were carried out using the Kyoto Encyclopedia of Genes and Genomes databases. Differentially expressed contigs in adults and/or nymphs represented genes and/or metabolic/pathogenesis pathways involved in adhesion, biofilm formation, development-related, immunity, nutrition, stress, and virulence. Notably, contigs involved in gene silencing and transposon-related responses were documented in a psyllid for the first time. This is the first comparative transcriptomic analysis of ACP adults and nymphs infected and uninfected with CLas. The results provide key initial insights into host-parasite interactions involving CLas effectors that contribute to invasion-virulence, and to host nutritional exploitation and immune-related responses that appear to be essential for successful ACP-mediated circulative, propagative CLas

Feeding by whiteflies suppresses downstream jasmonic acid signaling by eliciting salicylic acid signaling.

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Zhang, Peng-Jun; Li, Wei-Di; Huang, Fang; Zhang, Jin-Ming; Xu, Fang-Cheng; Lu, Yao-Bin

2013-05-01

Phloem-feeding whiteflies in the species complex Bemisia tabaci cause extensive crop damage worldwide. One of the reasons for their "success" is their ability to suppress the effectual jasmonic acid (JA) defenses of the host plant. However, little is understood about the mechanisms underlying whitefly suppression of JA-regulated defenses. Here, we showed that the expression of salicylic acid (SA)-responsive genes (EDS1 and PR1) in Arabidopsis thaliana was significantly enhanced during feeding by whitefly nymphs. Whereas upstream JA-responsive genes (LOX2 and OPR3) also were induced, the downstream JA-responsive gene (VSP1) was repressed, i.e., whiteflies only suppressed downstream JA signaling. Gene-expression analyses with various Arabidopsis mutants, including NahG, npr-1, ein2-1, and dde2-2, revealed that SA signaling plays a key role in the suppression of downstream JA defenses by whitefly feeding. Assays confirmed that SA activation enhanced whitefly performance by suppressing downstream JA defenses.

Detection of Rickettsia and Anaplasma from hard ticks in Thailand.

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Malaisri, Premnika; Hirunkanokpun, Supanee; Baimai, Visut; Trinachartvanit, Wachareeporn; Ahantarig, Arunee

2015-12-01

We collected a total of 169 adult hard ticks and 120 nymphs from under the leaves of plants located along tourist nature trails in ten localities. The results present data examining the vector competence of ticks of different genera and the presence of Rickettsia and Anaplasma species. The ticks belonged to three genera, Amblyomma, Dermacentor, and Haemaphysalis, comprising 11 species. Rickettsia bacteria were detected at three collection sites, while Anaplasma bacteria were detected at only one site. Phylogenetic analysis revealed new rickettsia genotypes from Thailand that were closely related to Rickettsia tamurae, Rickettsia monacensis, and Rickettsia montana. This study was also the first to show that Anaplasma bacteria are found in Haemaphysalis shimoga ticks and are closely related evolutionarily to Anaplasma bovis. These results provide additional information for the geographical distribution of tick species and tick-borne bacteria in Thailand and can therefore be applied for ecotourism management. © 2015 The Society for Vector Ecology.

Visceral pentastomiasis caused by Armillifer armillatus in a captive striped hyena (Hyaena hyaena) in Chiang Mai Night Safari, Thailand.

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Dechkajorn, Sakorn; Nomsiri, Raksiri; Boonsri, Kittikorn; Sripakdee, Duanghatai; Sukontason, Kabkaew L; Wannasan, Anchalee; Chailangkarn, Sasisophin; Tiwananthagorn, Saruda

2016-02-01

Visceral pentastomiasis (porocephalosis) caused by Armillifer armillatus larvae was incidentally diagnosed in a female striped hyena (Hyaena hyaena) of unknown age which died unexpectedly in 2013. The hyena had been imported from Tanzania 8years earlier and have been since then in a zoo in Chiang Mai, northern Thailand. Pathological examination revealed visceral nymph migrans of pentastomes throughout the intestine, liver, diaphragm, omentum and mesentery, spleen, kidneys, and urinary bladder. Polymerase chain reaction and sequencing that targeted the pentastomid-specific 18S rRNA gene determined 100% identity with reference sequence for A. armillatus, suggesting that its ova can infect the hyena to serve as an intermediate host for the parasite. Further studies to identify the source of infection, its risk factors, and host range for A. armillatus are important to determine its zoonotic potential and to better prevent and manage the disease to protect animal and human health. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

An entomoepidemiological investigation of Chagas disease in the state of Ceará, Northeast Region of Brazil

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Carolina Fausto de Souza Coutinho

2014-04-01

Full Text Available The seroprevalence of Chagas disease in humans and the presence of triatomines were investigated in a rural locality in the State of Ceará, Brazil, an historically endemic region. Approximately 80% of the surveyed residents agreed to undergo serological tests. Intradomestic and peridomestic environments were searched for triatomines in both the dry and rainy seasons. The prevalence rate of Chagas disease was 1.2% and the majority of individuals confirmed with the disease over 50 years of age. A total of 761 specimens of triatomines were captured, most of which were from colonies composed of nymphs and adult bugs, and the majority of specimens were obtained in the dry season. Triatoma brasiliensis was the predominant species. Analysis using light microscopy revealed that 28.6% of the insects were Trypanosoma cruzi positive. Results suggest that peridomestic man-made structures, such as animal shelters, improper storage of timber and uninhabited dwellings contribute to the high rate of triatomine infestation in the area.

Revealed preference with limited consideration

NARCIS (Netherlands)

Demuynck, T.; Seel, C.

2014-01-01

We derive revealed preference tests for models where individuals use consideration sets to simplify their consumption problem. Our basic test provides necessary and sufficient conditions for consistency of observed choices with the existence of consideration set restrictions. The same conditions can

Prevention of infectious tick-borne diseases in humans: Comparative studies of the repellency of different dodecanoic acid-formulations against Ixodes ricinus ticks (Acari: Ixodidae

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Dautel Hans

2008-04-01

Full Text Available Abstract Background Ticks of the species Ixodes ricinus are the main vectors of Lyme Borreliosis and Tick-borne Encephalitis – two rapidly emerging diseases in Europe. Repellents provide a practical means of protection against tick bites and can therefore minimize the transmission of tick-borne diseases. We developed and tested seven different dodecanoic acid (DDA-formulations for their efficacy in repelling host-seeking nymphs of I. ricinus by laboratory screening. The ultimately selected formulation was then used for comparative investigations of commercially available tick repellents in humans. Methods Laboratory screening tests were performed using the Moving-object (MO bioassay. All test formulations contained 10% of the naturally occurring active substance DDA and differed only in terms of the quantitative and qualitative composition of inactive ingredients and fragrances. The test procedure used in the human bioassays is a modification of an assay described by the U.S. Environmental Protection Agency and recommended for regulatory affairs. Repellency was computed using the equation: R = 100 - NR/N × 100, where NR is the number of non-repelled ticks, and N is the respective number of control ticks. All investigations were conducted in a controlled laboratory environment offering standardized test conditions. Results All test formulations strongly repelled nymphs of I. ricinus (100-81% protection as shown by the MO-bioassay. The majority of ticks dropped off the treated surface of the heated rotating drum that served as the attractant (1 mg/cm2 repellent applied. The 10% DDA-based formulation, that produced the best results in laboratory screening, was as effective as the coconut oil-based reference product. The mean protection time of both preparations was generally similar and averaged 8 hours. Repellency investigations in humans showed that the most effective 10% DDA-based formulation (~1.67 mg/cm2 applied strongly avoided the

Type of prey influences biology and consumption rate of Orius insidiosus (Say (Hemiptera, Anthocoridae

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Simone M. Mendes

2002-01-01

Full Text Available Generalist predators are capable of consuming different types of prey, and as each prey may have distinct nutritional values, each may have a distinct impact on the biology of the predator. Therefore, the aim of this study was to determine how the consumption of different prey influences certain biological characteristics and the predatory capacity of Orius insidiosus (Say. The investigation was performed in climatic chamber at 25 ±1 ºC, RH 70 ± 10% and fotophase 12. Eggs of Anagasta kuehniella (Zeller, adults of Caliothrips phaseoli (Hood and nymphs of Aphis gossypii Glover were used as prey and were provided daily ad libitum for all the mobile stages of the predator. The results showed that biological parameters of O. insidiosus are affected differently depending on the type of prey ingested. The development time of the nymphal stage was 13.1, 11.23 and 10.25 days for O. insidiosus feeding on eggs of A. kuehniella, nymphs of A. gossypii and adults of C. phaseoli, respectively. Longevity was five times larger for adults fed on eggs of A. kuehniella (56.25 days compared to that of adults that preyed on nymphs of A. gossypii (11.44 days, and four times larger when the prey were adults of C. phaseoli (13.58 days. The consumption of eggs of A. kuehniella by predator females resulted in a shorter pre-oviposition period (3.2 days and a longer oviposition period (44.4 days when compared to the consumption of other types of prey. In addition, fecundity was increased with the consumption of eggs of A. kuehniella (195.25 eggs laid / female when compared to feeding on the other prey, C. phaseoli (70.00 eggs laid / female or A. gossypii (22.50 eggs laid / female. However, the consumption of aphids was larger (148.28 nymphs/ nymphal stage than that of thrips (74.10 thrips / nymphal stage or eggs of A. kuehniella (37.03 eggs /nymphal stage for all of the nymphal stages of the predator. The results indicate that the eggs of A. kuehniella are the type of

RNA interference of acetylcholinesterase in the Asian citrus psyllid, Diaphorina citri, increases its susceptibility to carbamate and organophosphate insecticides.

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Kishk, Abdelaziz; Hijaz, Faraj; Anber, Helmy A I; AbdEl-Raof, Tsamoh K; El-Sherbeni, AbdEl-Hakeem D; Hamed, Sobhy; Killiny, Nabil

2017-11-01

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Lividae) transmits the Candidatus Liberibacter asiaticus, which causes citrus greening disease or Huanglongbing, (HLB). To date, there is no efficient cure for HLB disease and the control of D. citri using insecticides became the most important tools for the management of HLB. However, the extensive use of insecticides could increase D. citri resistance to these insecticides. The objective of this study was to investigate the effect of RNA interference of acetylcholinesterase (AChE) on the mortality and susceptibility of D. citri to the four major insecticides used in Florida. In this study, we used a consensus sequence derived from the two AChE genes and cholinesterase 2-like (ChE-2-like) gene to target all of the three genes. Treatment with dsRNA-AChE increased the mortality percentages of both nymphs and adults of D. citri. The mortality percentage increased with the increase in the concentration of applied dsRNA-AChE, and the highest mortality (> 60%) was observed at the highest applied concentration (125ng/μl). Treatments of nymphs or adults with dsRNA-AChE down-regulated the expression of the three targeted genes of D. citri. Silencing of AChE and ChE in D. citri nymphs increased the susceptibility of emerged adults to chlorpyrifos and carbaryl, which act as AChE inhibitors. However, treatment with dsRNA-AChE did not increase the susceptibility of emerged adults to imidacloprid, which acts as an agonist of nicotinic acetylcholine receptors. In the same manner, treatment of adults with dsRNA-AChE increased their susceptibility to chlorpyrifos and carbaryl, but did not affect their susceptibility to imidacloprid. The ANOVA did not show any significant increase in susceptibility of D. citri adults to fenpropathrin after treatment with dsRNA-AChE, either as nymphs or as adults. However, simple linear regression showed that treatment with dsRNA-AChE increased D. citri susceptibility to fenpropathrin

Entomologic index for human risk of Lyme disease.

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Mather, T N; Nicholson, M C; Donnelly, E F; Matyas, B T

1996-12-01

An entomologic index based on density estimates of Lyme disease spirochete-infected nymphal deer ticks (lxodes scapularis) was developed to assess human risk of Lyme disease. The authors used a standardized protocol to determine tick density and infection in numerous forested sites in six Rhode Island towns. An entomologic risk index calculated for each town was compared with the number of human Lyme disease cases reported to the Rhode Island State Health Department for the same year. A strong positive relation between entomologic risk index and the Lyme disease case rate for each town suggested that the entomologic index was predictive of Lyme disease risk.

The impact of industrial anthropization on mosquito (Diptera, Culicidae) communities in mangrove areas of Guanabara Bay (Rio de Janeiro, Brazil).

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de Souza, A S; Couri, M S; Florindo, L

2012-02-01

The effects of industrial anthropization on species composition and community diversity of Culicidae (Diptera) were studied in a mangrove area impacted by industrial activities as compared to a preserved area, both around Guanabara Bay in the state of Rio de Janeiro, Brazil. Diversity, equitability, and species richness in Culicidae community differed between the studied areas. Indicator species analysis and correspondence analysis were carried out and indicated that the Sabethini, especially Wyeomyia (Phoniomyia) theobaldi Lane, Wyeomyia (Phoniomyia) fuscipes (Edwards), and a non-identified species of Wyeomyia sp. were associated to the preserved area, whereas Aedes taeniorhynchus Wiedemann and Aedes scapularis (Rondani) to the impacted area.

Antivirulence Properties of an Antifreeze Protein

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Martin Heisig

2014-10-01

Full Text Available As microbial drug-resistance increases, there is a critical need for new classes of compounds to combat infectious diseases. The Ixodes scapularis tick antifreeze glycoprotein, IAFGP, functions as an antivirulence agent against diverse bacteria, including methicillin-resistant Staphylococcus aureus. Recombinant IAFGP and a peptide, P1, derived from this protein bind to microbes and alter biofilm formation. Transgenic iafgp-expressing flies and mice challenged with bacteria, as well as wild-type animals administered P1, were resistant to infection, septic shock, or biofilm development on implanted catheter tubing. These data show that an antifreeze protein facilitates host control of bacterial infections and suggest therapeutic strategies for countering pathogens.

TypeScript revealed

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Maharry, Dan

2013-01-01

TypeScript Revealed is a quick 100-page guide to Anders Hejlsberg's new take on JavaScript. With this brief, fast-paced introduction to TypeScript, .NET, Web and Windows 8 application developers who are already familiar with JavaScript will easily get up to speed with TypeScript and decide whether or not to start incorporating it into their own development. TypeScript is 'JavaScript for Application-scale development'; a superset of JavaScript that brings to it an additional object-oriented-like syntax familiar to .NET programmers that compiles down into simple, clean JavaScript that any browse

Seasonal response of feeding, differentiation, and growth in the eastern subterranean termite Reticulitermes flavipes (Kollar) in Wisconsin

Science.gov (United States)

Rachel Ann Arango; Frederick Green; Glenn R. Esenther

2007-01-01

In termites, differentiation plasticity in undifferentiated Reticulitermes progresses with growth stages from larvae to workers, which may then differentiate into soldiers, winged nymphs, or neotenics. Although studies have been done on seasonality of the termite life cycle, data appears to vary from location to location. Reticulitermes populations in Wisconsin appear...