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The larval growth of Pacific bluefin tuna (Thunnus orientalis) was compared between two main spawning areas, the Sea of Japan (SOJ) and the western North Pacific (WNP). Growth trajectories indicate that the larval survival depends on their growth in both areas. Until the flexion stage, larvae of the SOJ showed lower growth than those of the WNP, but after the post-flexion stage, there was no significant differences in larval growth between two areas. The observed growth differences were likely driven by the sea surface temperature (SST): the lower SST in the SOJ negatively affected the larvae until they reached to the flexion stage. Survival over the flexion stage is one of the major ontogenetic milestones during the larval development in the SOJ. Chlorophyll-a concentrations were negatively correlated with SST and tended to be higher in the SOJ than in the WNP. Prey availability was presumed to be higher in the SOJ. As larval swimming and feeding abilities improved with flexion, larvae would have been able to capitalize on the favorable feeding environment in the SOJ, thus eliminating the temperature mediated growth difference in pre-flexion larvae. [ABSTRACT FROM AUTHOR]

Larval morphology offers some of the more important characters for the taxonomy of Meristogenys, and larval information of almost all species has been reported for this genus. However, some larval assignments in previous studies were not based on reliable methods and should be reexamined using modern techniques. In this study, we used molecular methods to re-examine the larval assignments for M. poecilus, whose larvae had been assigned previously based on conventional morphological methods. The analysis revealed that the larvae of this species had been misidentified as M. phaeomerus, a sympatric species. Here we correct the erroneous assignment and briefly comment about the taxonomic status of M. phaeomerus and M. orphnocnemis, based on our results. [ABSTRACT FROM AUTHOR]

Antibiotics can effectively protect livestock from pathogen infection, but residual antibiotics in manure bring risks to ecosystems and public health. Here, we demonstrated that black soldier fly larvae (BSFL) could provide an environmentally friendly manure treatment based on their ability to effectively and rapidly degrade tetracycline (TC). Investigation of the biological mechanisms and degradation pathways of TC by BSFL indicated that nearly 97% of TC was degraded within 12 days in a non-sterile BSFL treatment system, which is up to 1.6-fold faster than that achieved by normal composting. Our results showed that rapid TC-degradation was largely carried out by the intestinal microbiota of the larvae, which doubled the TC-degradation rates compared to those achieved in sterile BSFL systems. This conclusion was further supported by highly-efficient TC-biodegradation both in vivo and in vitro by four larval intestinal isolates. Moreover, detailed microbiome analysis indicated that intestinal bacterial and fungal communities were modified along with significantly increased tet gene copy number in the gut, providing the means to tolerate and degrade TC. Through analysis of TC degradation in vitro , four possible biodegradation products, two hydrolysis products and three conceivable inactivation products were identified, which suggested TC degradation reactions including hydrolysis, oxygenation, deamination, demethylation, ring-cleavage, modification, etc. In conclusion, our studies suggested an estimation of the fate of TC antibiotics in manure treatment by BSFL colonized by gut microbes. These results may provide a strategy for accelerating the degradation of antibiotics by adjusting the intestinal microbiota of BSFL. [ABSTRACT FROM AUTHOR]

The fruit fly Drosophila melanogaster is a model organism to study several aspects of metazoan biology. Most of the work has been conducted in adult fruit flies, including laboratory and field‐derived specimens, but Drosophila melanogaster larvae recently became a valuable model to better understand animal physiology, development, or host–microbe interactions. While adult flies can be easily assigned to a given Drosophila species based on morphological characteristics, such visual identification is more intricate at the larval stage. This could explain the limited number of studies focusing on larvae, especially field‐derived samples. Here, we developed a polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) assay that discriminates D. melanogaster from other ecologically relevant Drosophila species at the larval stage. The method, which targets the cytochrome oxidase I (COI) gene, was validated using laboratory‐derived larvae from seven D. melanogaster populations originating from different geographic areas as well as six Drosophila species. We further validated this PCR‐RFLP assay in a natural context, by identifying wild larvae collected in two locations in France. Notably, among all PCR‐RFLP profiles that matched the D. melanogaster species, 100% were correctly identified, as confirmed by COI sequencing. In summary, our work provides a rapid, simple, and accurate molecular tool to identify D. melanogaster from field‐collected larvae. Invertebrates species, like the fruit fly Drosophila melanogaster, are widely used in biology. However, taxonomic identification remains complicated especially at the larval stage. Our work provides a rapid, cost‐effective, and accurate tool to identify Drosophila melanogaster species validated using field‐collected larvae. [ABSTRACT FROM AUTHOR]

The availability of high-quality juveniles is a bottleneck in the farming of many marine fish species. Detrimental larvae-microbe interactions are a main reason for poor viability and quality in larval rearing. In this review, we explore the microbial community of fish larvae from an ecological and eco-physiological perspective, with the aim to develop the knowledge basis for microbial management. The larvae are exposed to a huge number of microbes from external and internal sources in intensive aquaculture, but their relative importance depend on the rearing technology used (especially flow-through vs. recirculating systems) and the retention time of the water in the fish tanks. Generally, focus has been on microbes entering the system, but microbes from growth within the system is normally a substantial part of the microbes encountered by larvae. Culture independent methods have revealed an unexpected high richness of bacterial species associated with larvae, with 100–250 operational taxonomic units associated with one individual. The microbiota of larvae changes rapidly until metamorphosis, most likely due to changes in the selection pressure in the digestive tract caused by changes in host-microbe and microbe-microbe interactions. Even though the microbiota of larvae is distinctly different from the microbiota of the water and the live food, the microbiota of the water strongly affects the microbiota of the larvae. We are in the early phase of understanding larvae-microbe interactions in vivo , but some studies with other animals than fish emphasize that we so far have underestimated the complexity of these interactions. We present examples demonstrating the diversity of these interactions. A large variety of microbial management methods exist, focusing on non-selective reduction of microbes, selective enhancement of microbes, and on improvement of the resistance of larvae against microbes. However, relatively few methods have been studied extensively. We believe that there is a lot to gain by increasing the diversity of approaches for microbial management. As many microbial management methods are perturbations of the microbial community, we argue that ecological theory is needed to foresee and test for longer term consequences in microbe-microbe and microbe-larvae interactions. We finally make some recommendations for future research and development. [ABSTRACT FROM AUTHOR]

Abstract: Two Drosophila melanogaster E‐twenty‐six domain transcription factor isoforms (E74A and E74B) act differentially at the start of the 20‐hydroxyecdysone (20E) signalling cascade to regulate larval–pupal metamorphosis. In the present paper, we identified the two isoforms (LdE74A and LdE74B) in Leptinotarsa decemlineata. During the larval development stage, the mRNA transcript levels of the two LdE74 isoforms were correlated with circulating 20E titres. In vitro midgut culture and in vivo dietary supplementation with 20E revealed that the presence of 20E induced expression peaks of both LdE74A and LdE74B, with similar patterns observed for the two isoforms. Moreover, the mRNA transcript levels of both LdE74A and LdE74B isoforms were significantly downregulated in the L. decemlineata ecdysone receptor RNA interference (RNAi) specimens, but not in the LdE75 RNAi beetles. Ingestion of 20E reduced the larval fresh weights and shortened the larval development period, irrespective of knockdown of LdE74 or not. RNAi of LdE74 did not affect 20E‐induced expression of the Ecdysone induced protein 75‐hormone receptor 3‐fushi tarazu factor 1 (E75‐HR3‐FTZ‐F1) transcriptional cascade. Thus, it seems that LdE74 mediates 20E signalling independent of the E75‐HR3‐FTZ‐F1 transcriptional cascade. Furthermore, silencing of both LdE74 isoforms caused failure of ecdysis. Most of the LdE74 RNAi beetles remained as prepupae. The LdE74 RNAi prepupae exhibited adult character‐like forms underneath after removal of the apolysed larval cuticle. Their appendages such as antennae, legs and wings were shorter than those of control larvae. Only a few LdE74 RNAi larvae finally became deformed pupae, with shortened antennae and legs. Therefore, LdE74 is required for larval–pupal metamorphosis and appendage growth in L. decemlineata. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: The Asian long‐horned beetle [ALB; Anoplophora glabripennis (Motschulsky)] is an invasive, wood‐boring insect posing significant economic and ecological threats to the deciduous forests of North America. An efficacious and environmentally acceptable chemical control technique is a requirement of a comprehensive, integrated response strategy. RESULTS: Results of this study demonstrate statistically significant, concentration‐dependent effects of azadirachtins, a family of natural compounds derived from the neem tree, on both ALB larval and adult life stages. Growth inhibitory effects on ALB larvae were greatest on early life stages. Significant effects on adults included inhibition of female feeding, oviposition effort and fecundity for adults exposed to azadirachtins via maturation feeding on systemically loaded twigs. CONCLUSION: These quarantine laboratory experiments verify multi‐mechanistic, deleterious effects on both larval and adult life stages of ALB, an exotic, invasive insect pest of critical importance in North America. Field efficacy studies are required to further understand dose acquisition by larval and adult ALB life stages following systemic injections to host trees under semi‐operational use scenarios. Such studies could also be used to test postulates regarding optimal deployment strategies to meet objectives such as slowing the spread of this pest and protection of high‐value deciduous forest resources. © 2017 Her Majesty the Queen in Right of Canada Pest Management Science © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Understanding the patterns of connectivity is required by the Strategic Plan for Biodiversity 2011-2020 and will be used to guide the extension of marine protection measures. Despite the increasing accuracy of ocean circulation modelling, the capacity to model the population connectivity of sessile benthic species with dispersal larval stages can be limited due to the potential effect of filters acting before or after dispersal, which modulates offspring release or settlement, respectively. We applied an interdisciplinary approach that combined demographic surveys, genetic methods (assignment tests and coalescent-based analyses) and larval transport simulations to test the relative importance of demographics and ocean currents in shaping the recent patterns of gene flow among populations of a Mediterranean gorgonian (Eunicella singularis) in a fragmented rocky habitat (Gulf of Lion, NW Mediterranean Sea). We show that larval transport is a dominant driver of recent gene flow among the populations, and significant correlations were found between recent gene flow and larval transport during an average single dispersal event when the pelagic larval durations (PLDs) ranged from 7 to 14 d. Our results suggest that PLDs that efficiently connect populations distributed over a fragmented habitat are filtered by the habitat layout within the species competency period. Moreover, a PLD ranging from 7 to 14 d is sufficient to connect the fragmented rocky substrate of the Gulf of Lion. The rocky areas located in the centre of the Gulf of Lion, which are currently not protected, were identified as essential hubs for the distribution of migrants in the region. We encourage the use of a range of PLDs instead of a single value when estimating larval transport with biophysical models to identify potential connectivity patterns among a network of Marine Protected Areas or even solely a seascape. [ABSTRACT FROM AUTHOR]

In this study, the results showed that the population of midgut bacteria and larval mortality due to Cry1Ac are significantly reduced in antibiotic-treated larvae from Bt-susceptible, -resistant and field-collected strains (96S, BtR, FS respectively) of Helicoverpa armigera . The percentage reduction of larval mortality with increasing concentrations of antibiotics was significantly different among strains with the smallest effect observed in FS. It has been suggested that antibiotics could influence the toxicity of Cry1Ac, possibly by eliminating gut bacteria, hence gut bacteria might be playing essential roles in Bt-induced killing of H. armigera . But elimination of midgut microflora with antibiotics had no effect on resistance level. [ABSTRACT FROM AUTHOR]

Nematodes of the Angiostrongylidae family, such as Angiostrongylus vasorum and Angiostrongylus cantonensis, may cause potentially life-threatening diseases in several mammal species. Alongside these well-known species, Angiostrongylus chabaudi has been recently found affecting the cardiopulmonary system of domestic and wild cats from Italy, Germany, Greece, Romania and Bulgaria. Nonetheless, significant gaps in the understanding of A. chabaudi epidemiology include the lack of information of species acting as intermediate host and of the morphological description of larval stages. Cornu aspersum (n = 30) land snails were infected with 100 first-stage larvae of A. chabaudi collected from a naturally infected wildcat in Romania. Larvae at different developmental stages were found in 29 out of 30 (96·7%) infected snails and a total of 282 (mean 9·8 ± 3·02 larvae per each specimen) were collected from the gastropods. Here we demonstrate that A. chabaudi develops in snails and report C. aspersum as potential intermediate host for this parasitic nematode. Findings of this study are central to understand the ecological features of feline angiostrongylosis and its epidemiology within paratenic and intermediate hosts. [ABSTRACT FROM AUTHOR]

In addition to genetic history, environmental conditions during larval stages are critical to the development, success and phenotypic fate of the Aedes aegypti mosquito. In particular, previous studies have shown a strong genotype-by-environment component to adult mosquito body size in response to optimal vs stressed larval conditions. Here, we expand upon those results by investigating the effects of larval-stage crowding and nutritional limitation on the susceptibility of a recent field isolate of Aedes aegypti to dengue virus serotype-2. Interestingly, female mosquitoes from larvae subjected to a stressed regime exhibited significantly reduced susceptibility to disseminated dengue infection 14 days post infection compared to those subjected to optimal regimes. Short term survivorship post-infected blood feeding was not significantly different. As with body size, dengue virus susceptibility of a mosquito population is determined by a combination of genetic and environmental factors and is likely maintained by balancing selection. Here, we provide evidence that under different environmental conditions, the innate immune response of field-reared mosquitoes exhibits a large range of phenotypic variability with regard to dengue virus susceptibility. Further, as with body size, our results suggest that mosquitoes reared under optimal laboratory conditions, as employed in all mosquito-pathogen studies to date, may not always be realistic proxies for natural populations. [ABSTRACT FROM AUTHOR]

An in vitro experiment was carried out to assess the effect of fungal isolates of the genus Arthrobotrys, Duddingtonia, Monacrosporium and Nematoctonus on infective Strongyloides papillosus larvae. A suspension of 1,000 infective S. papillosus larvae was dripped on to Petri dishes containing fungi grown in agar-water. There was a statistically significant difference (p<0.05) among all the isolates and the fungus-free control. Comparing the results between isolates, difference was observed in some isolates of the genus Arthrobotrys (CG 719, I40, A1, A2, C1, B1), D. flagrans (CG722), Monacrosporium (CGI, SF53, NF34A) and N. robustus (D1) that showed a better capture and destruction results and consequently a greater decrease in the average of the uncaptured larvae recovered. The results showed that there may be variations in the predatory capacity of different species and among fungal isolates of the same species on Strongyloides papillosus and indicated that nematophagous fungi may be used for the biological control of this helminth. [ABSTRACT FROM AUTHOR]

The role of Culex pipiens larval ingestion rate in the effectiveness of three Bacillus sphaericus strains, namely 2362, B1-634BNI and 6491 was assessed. Two concentrations, namely LC50 and LC80, were tested. Studied parameters included bacterial exposure time and mosquito larval density. Exposure time periods were 0.5, 1, 2, 4, and 24 h. Larval density varied by exposing different numbers of larvae yielding larval density of 0.1, 0.2, 0.4, 0.8 and 1.6 larva/ml. Larval density also varied by exposing 20 larvae in different water volumes yielding larval density of 0.8, 0.4, 0.2 and 0.1 larva/ml. Strain B1-634BNI was the most active (LC50 = 0.02 ppm) among the tested strains. Mortality rates of larvae varied at different exposure periods and with the different larval densities. Mortality rates of Cx. pipiens larvae increased with the increase of the exposure period of the larvae to the bacterial suspension of strain B1-634BNI either at its LC50 or LC80. As larval density increased, mortality rates of larvae decreased when treated with each of the three tested bacterial strains whether at its LC50 or LC80. Adjusting bacterial application in control programmes according to those elements is thus indispensable to ensure a satisfactory result. [ABSTRACT FROM AUTHOR]

Water extracts were prepared using water-soluble chitosan from Clanis bilineata larva skin. This study also investigated antioxidant and antiageing activities of water-soluble chitosan. Water-soluble chitosan of Clanis bilineata larva skin (CBLSWSC) showed considerable scavenging activities on superoxide anion and hydroxyl radicals and reducing capacity. Different doses of CBLSWSC were intragastrically administered on a d -galactose-induced-aged mouse model over a period of six weeks. Intragastric CBLSWSC administration significantly increased activities of superoxide dismutase and glutathione peroxidase and inhibited formation of malondialdehyde in brains and sera of mice in a dose-dependent manner. Results suggest that CBLSWSC exhibits high antioxidant activity and can be developed as potential dietary supplement to retard ageing in humans. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to evaluate the potential possibility of crude larval and recombinant (rHcp26/23) antigens of Haemonchus contortus for immunization to control sheep hemonchosis. Materials and Methods: A total of 21 lambs were divided into five groups. Lambs were immunized with larval and recombinant (rHcp26/23) proteins at day 0 and day 14 and after that challenged with 5000 infective larvae of H. contortus on day 42. An unvaccinated positive control group was challenged with L3 in the meantime. An unvaccinated negative control group was not challenged. Results: Fecal egg count reduction taking after challenge for rHcp26/23 and larval antigens was 92.2% and 38.2%, respectively, compared with the positive control group. Vaccine incited protection in rHcp26/23 and larval immunization was reflected in significant (p<0.05) decreases in worm burden; 59.9% and 40.1%, respectively. Conclusion: Recombinant rHcp26/23 vaccine induced a partial immune response and had immune-protective effect against sheep hemonchosis. [ABSTRACT FROM AUTHOR]

The small plurivoltine mothAnthophila fabricianais widespread and often abundant in Britain wherever its main larval foodplant, stinging nettle, occurs. It overwinters as a larva (first generation) then has one or more partly overlapping summer broods (notionally second generation). A total of 5017 larvae were collected and reared from widely distributed populations in Britain, and the resulting 2167 host mortalities due to parasitoids were assessed. Small collections of pupae were also made. Altogether 25 parasitoid species, including secondary parasitoids, were found. Larval parasitism was heaviest in the second generation. In each generation there was a dominant parasitoid that was absent from the other. Summary information on the developmental biology and host range (expressed quantitatively and resulting from very broad rearing programmes) for each parasitoid is given. They are classed as ‘absolute specialists’, ‘taxon oligospecialists’, ‘niche oligospecialists’, ‘niche generalists’, ‘casuals’ and ‘strays’. Both kinds of oligospecialists can be ‘paraspecialists’ if only one potential host occurs locally. Although constructing a quantitative food web is not appropriate, providing both source web and sink web data in quantitative form enables the parasitoid complex to be understood in the wider context of the ecosystem, necessary for both biodiversity and nature conservation interests. In Appendix 1, parasitoids reared from other European Choreutidae are listed quantitatively. [ABSTRACT FROM AUTHOR]

In this study, we investigate the impacts of two water treatment regimes, the closed aquaculture system (CAS) and flow-through system (FTS), on the carpet shell clam ( Ruditapes decussatus) larval microbiota, growth and survival. A bacteriological barrier (B) was created among breeder stage treated by florfenicol (FF, 8 mg Lday per 5 days). After spawning, larvae were maintained in five different rearing techniques: CAS; FTS; B + CAS; B + FTS and B + CAS + FF (8 mg L day per 3 days). Significant decrease was observed in both total bacterial count and presumptive Vibrio count (PVC) in FF-treated breeders. Besides, larvae reared in B + FTS showed significantly lower PVC than larvae maintained in other rearing techniques. It was also determined that growth and survival of larvae reared in B + CAS + FF and B + FTS were significantly better than those reared in other systems. One hundred and twelve Vibrio strains, isolated from breeders, eggs and larvae, were subjected to some bacteriological tests (API 20E strips, vibriostatic agent O/129, growth at different temperatures and salinity). Vibrio alginolyticus was the predominant isolated species (36.61 %), followed by V. fluvialis (25 %), V. vunificus (17.86 %), V. cholera (13.39 %) and V. paraheamolyticus (7.14 %). These results may contribute to the understanding of the effect of rearing techniques on the bacterial load, survival and growth of early life stages of R. decussatus larvae. [ABSTRACT FROM AUTHOR]

Entomological protocols for aging blowfly (Diptera: Calliphoridae) larvae to estimate the time of colonization (TOC) are commonly used to assist in death investigations. While the methodologies for analyzing fly larvae differ, most rely on light microscopy, genetic analysis, or, more rarely, electron microscopy. This pilot study sought to improve resolution of larval stage in the forensically important blowfly Chrysomya rufifacies using high‐content fluorescence microscopy and biochemical measures of developmental marker proteins. We established fixation and mounting protocols, defined a set of measurable morphometric criteria and captured developmental transitions of 2nd instar to 3rd instar using both fluorescence microscopy and anti‐ecdysone receptor Western blot analysis. The data show that these instars can be distinguished on the basis of robust, nonbleaching, autofluorescence of larval posterior spiracles. High‐content imaging techniques using confocal microscopy, combined with morphometric and biochemical techniques, may therefore aid forensic entomologists in estimating TOC. [ABSTRACT FROM AUTHOR]

Fungi in the genus Ascosphaera (Ascomycota: Eurotiomycetes: Ascosphaerales) cause chalkbrood disease in larvae of bees. Here, we report the first-ever detection of the fungus in adult bumble bees that were raised in captivity for studies on colony development. Wild queens of Bombus griseocollis, B. nevadensis and B. vosnesenskii were collected and maintained for establishment of nests. Queens that died during rearing or that did not lay eggs within one month of capture were dissected, and tissues were examined microscopically for the presence of pathogens. Filamentous fungi that were detected were plated on artificial media containing broad spectrum antibiotics for isolation and identification. Based on morphological characters, the fungus was identified as Ascosphaera apis (Maasen ex Claussen) Olive and Spiltoir, a species that has been reported earlier only from larvae of the European honey bee, Apis mellifera, the Asian honey bee, Apis cerana, and the carpenter bee Xylocopa californica arizonensis. The identity of the fungus was confirmed using molecular markers and phylogenetic analysis. Ascosphaera apis was detected in queens of all three bumble bee species examined. Of 150 queens dissected, 12 (8%) contained vegetative and reproductive stages of the fungus. Both fungal stages were also detected in two workers collected from colonies with Ascosphaera-infected B. nevadensis queens. In this study, wild bees could have been infected prior to capture for rearing, or, the A. apis infection could have originated via contaminated European honey bee pollen fed to the bumble bees in captivity. Thus, the discovery of A. apis in adult bumble bees in the current study has important implications for commercial production of bumble bee colonies and highlights potential risks to native bees via pathogen spillover from infected bees and infected pollen. [ABSTRACT FROM AUTHOR]

Background Adult traits of holometabolous insects such as reproduction and survival can be shaped by conditions experienced during larval development. These "carry-over" effects influence not only individual life history and fitness, but can also impact interactions between insect hosts and parasites. Despite this, the implications of larval conditions for the transmission of human, wildlife and plant diseases that are vectored by insects remain poorly understood. Methods We used Anopheles stephensi mosquitoes and the rodent malaria, Plasmodium yoelii yoelii, to investigate whether quality of larval habitat influenced vectorial capacity of adult mosquitoes. Larvae were reared under two dietary conditions; one group received a diet commonly used for colony maintenance (0.3 mg/individual/day of Tetrafin fish food) while the other group received a reduced food diet (0.1 mg/individual/day). Upon emergence, adults were provided an infectious blood feed. We assessed the effects of diet on a range of larval and adult traits including larval development times and survival, number of emerging adults, adult body size and survival, gonotrophic cycle length, and mating success. We also estimated the effects of larval diet on parasite infection rates and growth kinetics within the adult mosquitoes. Results Larval dietary regime affected larval survival and development, as well as size, reproductive success and survival of adult mosquitoes. Larval diet also affected the intensity of initial Plasmodium infection (oocyst stage) and parasite replication, but without differences in overall infection prevalence at either the oocyst or sporozoite stage. Conclusions Together, the combined effects led to a relative reduction in vectorial capacity (a measure of the transmission potential of a mosquito population) in the low food treatment of 70%. This study highlights the need to consider environmental variation at the larval stages to better understand transmission dynamics and control of vector-borne diseases. [ABSTRACT FROM AUTHOR]

Environmental conditions during the larval phase (food concentration and temperature) impact recruitment success of marine bivalves by affecting growth and survival. We analysed the seasonal match between environmental conditions and larval presence of six coastal bivalve species over eight consecutive years (2006–2013) in the western Wadden Sea, taking species-specific physiological responses to these conditions into account. The larval occurrence of four species overlapped with their optimum in environmental conditions as calculated following the Dynamic Energy Budget theory: the occurrence of larvae of Cerastoderma edule, Mya arenaria and Mytilus edulis matched with their optimum food conditions, while larvae of Crassostrea gigas were mainly found during the temperature optimum of this species. Larvae of Ensis directus and Macoma balthica, however, only occurred months after their most favourable food conditions. The first group probably uses the energy immediately after uptake for the production and release of gametes (‘income breeders’), whereas the second group accumulates and stores energy reserves for later reproduction (‘capital breeders’). Larvae of C. gigas and M. balthica were observed much earlier in the year than expected from previous occurrences and from formerly know threshold temperatures for spawning. These apparent changes in timing of spawning suggest that Pacific oysters and Baltic tellins have recently acclimated to new environmental conditions. [ABSTRACT FROM PUBLISHER]

The "Spiralia" represent one of the three major clades of bilaterian metazoans.Though members of this clade exhibit tremendous diversity in terms of their larval and adult body plans, many share a highly conserved early pattern of development involving a stereotypic cleavage program referred to as spiral cleavage. This group therefore represents an excellent one in which to undertake comparative studies to understand the origins of such diversity from a seemingly common ground plan. These organisms also present varied and diverse modes in terms of their ecology, development and life history strategies. A number of well established and emerging model systems have been developed to undertake studies at the molecular, genetic, cell and organismal levels.The Special Issue of the Int. J. Dev. Biol, entitled "Spiralian Model Systems" focuses on these organisms and here, I introduce this clade, pointing out different types of studies being undertaken with representative spiralian model systems. [ABSTRACT FROM AUTHOR]

The immunosuppressive and insecticidal activity of culture of the entomopathogenic fungus Cordyceps militaris on the larvae of the Colorado potato beetle Leptinotarsa decemlineata has been established for the first time. It was found that the peroral effect of the fungal culture resulted in dose-dependent decrease in survival, delayed in development time and molting, decreases in the total hemocyt counts, increased activity of phenoloxidases in the hemolymph, and reduced activity of the enzyme in the cuticle, as well as increased sensitivity of larvae to the fungus Beauveria bassiana at the level of the synergistic effect. [ABSTRACT FROM AUTHOR]

For protecting potato tubers from infestation with the potato tuber moth (PTM) Phthorimaea operculella (Zeller) during storage, different concentrations of ten natural plant oils and three commercial monoterpenes were tested through fumigants or dusts against adults or dusts against neonate larvae as well spray of the gunny sacks in which potato tubers were stored. Tuber damage indices as well as persistence indices for tested materials were assessed. Vapors of Cymbopogon citratus, Myristica fragrans (nutmag), Mentha citrata and a-Ionone (monoterpene) caused highly significant reductions in the life span of exposed moths as well as in new adult offspring. Other tested oils as Cinnamonium zeylanicum, Myristica. fragrans (Mace) and Pelargonium graveolens caused an insignificant effect. There was no significant effect of the tested vapors on egg hatchability, except in case of the oils of C. citratus, M. fragrans (nutmag) and M. tragrans (Mace oil) which caused high reduction in egg hatchability. According to the values of damage indices, the most effective oil vapors were arranged ascendingly as follows: Myristica (nutmag) < Cymbopogon < Mentha < a - Ionone. Dusting potato tubers with 1% concentration (mixed with talcum powder) of Myristica, Mentha, Cymbopogons oils and a-Ionone (monoterpene) caused high reduction in egg deposition, adult emergence as well as percentage of penetrated larvae of PTM. According to their damage indices, Cymbopogon and á-Ionone were the most protective oils, followed by Myristica and Mentha. Spraying gunny sacks with 1% concentration of the aforementioned natural oils separately elicited high reduction in PTM progeny; while their combinations did not elicit any significant synergistic effect. According to their tuber damage indices, it was found that Cymbopogon oil alone or mixed with Myristica oil showed the best protective effect, followed by Myristica oil alone and then Mentha oil mixed with Cymbopogon oil. Assessment of the persistence index of various tested materials during storage indicated that vapors of Cymbopogon and Myristica (nutmag) gave a protection from PTM infestation for 20 days. Dusting potato tubers with plant oil of Cymbopogon (mixed with talcum powder) gave a protection for 15 days. Spraying gunny sacks with natural plant oils of Cymbopogon and Myristica, separately or mixed elicited a protection from infestation by PTM for 20 days. [ABSTRACT FROM AUTHOR]

The nuclear polyhedrosis virus of the Egyptian cotton leaf worm Spodoptera littoralis (Boisd.) (SlNPV) and the entomopathogenic bacterium, Bacillus thuringiensis subsp. mexicanesis (Btm) were economically formulated in a form of a storable powder. S. littoralis larvae of 8-day-old were significantly the most preferable host larvae for economic in vivo propagation of SlNPV, followed by larvae of 9-, 10-, and 7-day-old, where the increase in polyhedra yield over inoculum was nearly 478-, 233-, 200-, and 178-fold, respectively. The formulation of each biopreparation contained the microbial agent, SlNPV-polyhedra or Btm-crystals and spores, and the inert materials. The latter was represented by corn flour and starch (as a spreader and sticker) and preservatives (sorbic acid and sodium benzoate), as well as the multifunctional adjuvant, Lepidium sativium seed powder. The active ingredient in each kg of SlNPV-based biopreparation was ca. 7.93×1011 polyhedra. Estimated production cost per kg of this biopreparation was 21.96 L.E. (US$ 3.1), including the estimated cost of rearing 2000 host larvae on their feeding artificial diet. In regard to Btm-based biopreparation, an average yield of 1.23×109 CFU/g biopreparation was obtained from an inoculum of 1×106 CFU. Increase in Btm-CFU yield over inoculum was 1230-fold. Estimated cost per kg of Btm-based biopreparation was 16.60 L.E.(US$ 2.4), including the estimated cost of preparing one-liter-Btm inoculum. The SlNPV, Btm, or SlNPV+Btm mortality response among one-day-old larvae of S. littoralis ranged between 18 and 80, 22 and 79, or 29 and 83%, in respect, four days post-treatment; whereas at seven days post-treatment, mortality response among treated larvae ranged between 80 and 100, 53 and 95, or 89 and 100%, respectively. Values of the median lethal time (LT50) and concentration (LC50) were estimated in order to obtain more detailed information on the present biopreparations-lethal infection toward S. littoralis one-day-old larvae. The LC50 value of the mixture (SlNPV+Btm) for S. littoralis one-day-old larvae was nearly half (3%) the corresponding values of either the SlNPV (6.4%) or the Btm (6%) alone. [ABSTRACT FROM AUTHOR]

In many marine invertebrates with biphasic life cycles, juvenile/adult traits begin to develop before metamorphosis. For structures that are present at multiple developmental stages, but have distinct larval and adult forms, it is unclear whether larval and adult structures have shared or distinct developmental origins. In this study, we examine the relationship between the larval and adult eyes in the polychaete Capitella teleta. In addition, we describe a novel marker for larval and juvenile photoreceptor cells. Infrared laser deletion of individual micromeres in early embryos suggests that the same micromeres at the eight-cell stage that are specified to generate the larval eyes also form the adult eyes. Direct deletion of the larval eye, including the pigment cell and the corresponding photoreceptor cell, resulted in a lack of shading pigment cells in juveniles and adults, demonstrating that this structure does not regenerate. However, a sensory photoreceptor cell was present in juveniles following direct larval eye deletions, indicating that larval and adult photoreceptors are separate cells. We propose that the formation of the adult eye in juveniles of C. teleta requires the presence of the pigment cell of the larval eye, but the adult photoreceptor is either recruited from adjacent neural tissue or arises de novo after metamorphosis. These results are different from the development and spatial orientation of larval and adult eyes found in other polychaetes, in which two scenarios have been proposed: larval eyes persist and function as adult eyes; or, distinct pigmented adult eyes begin developing separately from larval eyes prior to metamorphosis. [ABSTRACT FROM AUTHOR]

Highlights: [•] The introduction of discarded cigarette butt (CB) in container habitats of Aedes aegypti prevented most young larvae from completing development. [•] In the presence of an increased CB amount (3 per 100mL of water), larval mortality was high even for the late developmental stages. [•] Turning CB waste into a control tool against dengue vectors is suggested. [ABSTRACT FROM AUTHOR]

Highlights: [•] Sarcophagids are of medical sanitary value because acts as mechanic vector of pathogen. [•] Many fly species are very similar, so it is necessary to identify them accurately. [ • ] Larval integument is covered with net-like patches only in Peckia (E.) collusor. [•] The intersegmental spines are useful to distinguish the different flesh fly larval instars. [ABSTRACT FROM AUTHOR]

Highlights: [•] Echinococcus larvae dwell in liver and expose to the host mostly carbohydrates. [•] We observe that these carbohydrates engage selectively the Kupffer cell receptor. [•] The Kupffer cell receptor is expressed only in liver macrophages of rodents. [•] Rodents are the likely ancestral hosts for Echinococcus. [•] Liver macrophages are known to contribute to tolerogenicity typical of this organ. [ABSTRACT FROM AUTHOR]

Insects of the family Chironomidae, also known as chironomids, are distributed worldwide in a variety of water habitats. These insects display a wide range of tolerance toward metals and organic pollutions. Bacterial species known for their ability to degrade toxicants were identified from chironomid egg masses, leading to the hypothesis that bacteria may contribute to the survival of chironomids in polluted environments. To gain a better understanding of the bacterial communities that inhabit chironomids, the endogenous bacteria of egg masses and larvae were studied by 454-pyrosequencing. The microbial community of the egg masses was distinct from that of the larval stage, most likely due to the presence of one dominant bacterial Firmicutes taxon, which consisted of 28% of the total sequence reads from the larvae. This taxon may be an insect symbiont. The bacterial communities of both the egg masses and the larvae were found to include operational taxonomic units, which were closely related to species known as toxicant degraders. Furthermore, various bacterial species with the ability to detoxify metals were isolated from egg masses and larvae. Koch-like postulates were applied to demonstrate that chironomid endogenous bacterial species protect the insect from toxic heavy metals. We conclude that chironomids, which are considered pollution tolerant, are inhabited by stable endogenous bacterial communities that have a role in protecting their hosts from toxicants. This phenomenon, in which bacteria enable the continued existence of their host in hostile environments, may not be restricted only to chironomids. [ABSTRACT FROM AUTHOR]

Abstract: Reactive nitrogen compounds such as nitrite ( ) are highly toxic to aquatic animals and are partly responsible for the global decline of amphibians. On some fish and Caudata amphibian species low levels of sodium chloride significantly reduce the toxicity of nitrite. However, the nitrite–salinity interaction has not been properly studied in anuran amphibians. To verify if chloride (Cl−) attenuates toxicity, eggs and larvae of three anuran species were subjected to a series of solutions combined with three salt concentrations (0, 0.4 and 2 or 0, 0.052 and 0.2gL−1 NaCl). One of the species tested originated from two different populations inhabiting highly contrasted nutrient richness environments: lowland Doñana Natural Park and Sierra de Gredos Mountain. In general, the presence of Cl− increased survival and growth of lowland Pelophylax perezi and activity of mountain P. perezi larvae exposed to , thus attenuating the toxicity of to developing amphibians. Mountain amphibian populations appeared to be much more sensitive to the concentrations of and Cl− used in this experiment than coastal conspecifics, suggesting possible adaptation of populations to local conditions. Nitrogen pollution in coastal wetlands poses a serious threat to aquatic organisms, causing direct toxicity or indirect effects via ecosystem eutrophication. The presence of low to medium levels of salinity that would be common in coastal wetlands may attenuate the direct effects of increasing concentrations of nitrogenous compounds in water bodies. Furthermore, treating cultures of endangered anurans with small amounts of NaCl may provide an additional protective measure. [Copyright &y& Elsevier]

Increasing atmospheric CO equilibrates with surface seawater, elevating the concentration of aqueous hydrogen ions. This process, ocean acidification, is a future and contemporary concern for aquatic organisms, causing failures in Pacific oyster ( Crassostrea gigas) aquaculture. This experiment determines the effect of elevated pCO on the early development of C. gigas larvae from a wild Pacific Northwest population. Adults were collected from Friday Harbor, Washington, USA (48°31.7′N, 12°1.1′W) and spawned in July 2011. Larvae were exposed to Ambient (400 μatm CO), MidCO (700 μatm), or HighCO (1,000 μatm). After 24 h, a greater proportion of larvae in the HighCO treatment were calcified as compared to Ambient. This unexpected observation is attributed to increased metabolic rate coupled with sufficient energy resources. Oyster larvae raised at HighCO showed evidence of a developmental delay by 3 days post-fertilization, which resulted in smaller larvae that were less calcified. [ABSTRACT FROM AUTHOR]

Third instar larvae of the cotton bollworm (Helicoverpa armigera) were reared with artificial diet containing a Bacillus thuringiensis - abamectin (BtA) biopesticide mixture that resulted in 20% mortality (LD20). The adult male survivors from larvae treated with BtA exhibited a higher percentage of “orientation” than control males but lower percentages of “approaching” and “landing” in wind tunnel bioassays. Adult female survivors from larvae treated with BtA produced higher sex pheromone titers and displayed a lower calling percentage than control females. The ratio of Z-11-hexadecenal (Z11–16:Ald) and Z-9-hexadecenal (Z9–16:Ald) in BtA-treated females changed and coefficients of variation (CV) of Z11–16:Ald and Z9–16:Ald were expanded compared to control females. The peak circadian calling time of BtA-treated females occurred later than that of control females. In mating choice experiment, both control males and BtA-treated males preferred to mate with control females and a portion of the Bt-A treated males did not mate whereas all control males did. Our Data support that treatment of larvae with BtA had an effect on the sex pheromone communication system in surviving H.armigera moths that may contribute to assortative mating. [ABSTRACT FROM AUTHOR]

Third instar larvae of the cotton bollworm (Helicoverpa armigera) were reared with artificial diet containing a Bacillus thuringiensis - abamectin (BtA) biopesticide mixture that resulted in 20% mortality (LD20). The adult male survivors from larvae treated with BtA exhibited a higher percentage of “orientation” than control males but lower percentages of “approaching” and “landing” in wind tunnel bioassays. Adult female survivors from larvae treated with BtA produced higher sex pheromone titers and displayed a lower calling percentage than control females. The ratio of Z-11-hexadecenal (Z11–16:Ald) and Z-9-hexadecenal (Z9–16:Ald) in BtA-treated females changed and coefficients of variation (CV) of Z11–16:Ald and Z9–16:Ald were expanded compared to control females. The peak circadian calling time of BtA-treated females occurred later than that of control females. In mating choice experiment, both control males and BtA-treated males preferred to mate with control females and a portion of the Bt-A treated males did not mate whereas all control males did. Our Data support that treatment of larvae with BtA had an effect on the sex pheromone communication system in surviving H.armigera moths that may contribute to assortative mating. [ABSTRACT FROM AUTHOR]

Abstract: The objective of the present study was to study the characteristics of lactate dehydrogenase (LDH) from Hypoderma sinense larva. H. sinense larvae were collected from yak (Bos grunniens) and identified by a PCR-RFLP method. Analysis of LDH activity showed that the total LDH activity in H. sinense larva was negatively correlated with the length of larva. Polyacrylamide gel electrophoresis of the extracts of H. sinense larvae revealed one band of LDH, which was then purified by affinity chromatography and gel filtration. This enzyme showed an approximately 36kDa band on SDS-gel under both reducing and non-reducing conditions, in addition, size exclusion chromatography analysis showed that its molecular weight was smaller than bovine serum albumin (67kDa), indicating that it contains only one subunit. Michaelis constants (K m) values assay revealed that LDH from H. sinense larva showed significantly lower K m for lactate than other animals. LDH of H. sinense larva was stable at 60°C for 15min, and also exhibited high catalytic efficiency in a wide range of pH. HgCl2 at the concentration of 0.1mM significantly decreased the activity of LDH from H. sinense larva but not at the concentration of 0.01mM. The results of the present study demonstrate that LDH from H. sinense larva is a thermal stable and pH insensitive enzyme suitable for catalyzing both forward and reverse reactions. [Copyright &y& Elsevier]

Coptera haywardi (Oglobin) is an endoparasitoid of fruit fly pupae that could find itself in competition with other parasitoids, both con- and heterospecific, already resident inside hosts. In choice bioassays, ovipositing C. haywardi females strongly discriminated against conspecifically parasitised Anastrepha ludens (Loew) pupal hosts. They also avoided pupae previously attacked by Diachasmimorpha longicaudata (Ashmead), a larval–prepupal koinobiont endoparasitoid, and the degree of larval-parasitoid superparasitism had no effect on this avoidance. There was no difference in the number of ovipositor insertions when hosts previously parasitised by a conspecific and D. longicaudata were exposed simultaneously. As females aged the degree of host discrimination declined. An ability to discriminate against pupae previously attacked as larvae suggests low levels of both conspecific and heterospecific competition in the field. [ABSTRACT FROM AUTHOR]

The influence of temperature on the development and survival of Toxocara canis larvae was investigated under laboratory conditions, in water at 15, 20, 25, 30 and 35°C and at room temperature 22°C ± 1°C. T. canis eggs were able to develop to the larvated stage at all the tested temperatures. Development rate increased with temperature. Linear regression of development rate against temperature predicted a lower development threshold of 11.8°C. Eggs survived cooling to 1 and −2°C for 6 weeks, and could develop to the infective, larvated stage when transferred to higher temperatures, but their development rates were then retarded compared with non-chilled eggs. Larvated eggs remained viable after 7 weeks of incubation across the tested temperature range, with the highest percentage viability (47%) obtained at 25°C. Development of eggs to the infective larval stage required, on average, 121 degree days between 20°C and 30°C. Results provide a basis for predicting variation in the infectivity of eggs in the environment over time in different climates. [ABSTRACT FROM AUTHOR]

Abstract: We investigated how persistent competitive pressure alters toxicant sensitivity and recovery from a pesticide pulse at community level. Interacting populations of Daphnia (Daphnia magna) and Culex larvae (Culex pipiens molestus) were pulse-exposed (48h) to the pyrethroid fenvalerate. The abundance and biomass of the populations were monitored by non-invasive image analysis. Shortly after exposure, Daphnia showed a concentration–response relationship with the toxicant with an LC50 of 0.9μg/L. Culex larvae were slightly less sensitive with an LC50 of 1.7μg/L. For both species, toxicant sensitivity increased with the population biomass of the respective species before exposure, which is explained by intraspecific competition. Several weeks after exposure to the highest treatment concentration of 1μg/L, the slight differences in sensitivity between the two species were amplified to contrasting long-term effects due to interspecific competition: high interspecific competition impaired the recovery of Daphnia. Subsequently, Culex larvae profited from the slow recovery of Daphnia and showed an increased success of emergence. We conclude that, in natural systems where competition is present, such competitive processes might prolong the recovery of the community structure. Hence, natural communities might be disturbed for a longer period by toxic exposure than predicted from single-species tests alone. [Copyright &y& Elsevier]

Abstract: The distribution of Toxocara cati larvae in the organs of chickens (n =31), experimentally inoculated with 3000 embryonated eggs, was examined 1, 2, 3, 7, 29, 86 and 175–176days post-infection (dpi), and the infectivity of recovered larvae was evaluated by bioassay in mice. The duodenum, liver, lungs, heart, brain, pectoral muscles (white meat), and hindlimb muscles (red meat) of the chickens were HCl–pepsin digested for larval recovery. Larvae were recovered from all chickens [mean=220.4±114.9 (SD)], and although no decrease of total larval recovery was observed over time, predilection sites changed: liver (92.6% of larval recovery) at 1 dpi; lungs (77.3%) and liver (20.9%) at 2 dpi; lungs (80.8%), muscles (9.4%), and liver (8.5%) at 3 dpi; muscles (52.0%) and lungs (45.6%) at 7 dpi, whereafter most larvae were recovered from muscles: 29 dpi (99.5%), 86 dpi (99.3%) and 175–176 dpi (99.6%). In the bioassay, 52.9% of larvae from 175 to 176days old infections in chickens established in mice, which demonstrates that T. cati larvae retain infective in the muscles of chickens for half a year. These results highlight the zoonotic potential of poultry meat as a causative agent of human toxocarosis. [Copyright &y& Elsevier]

Abstract: Anisakids from 5 different species of cetacean, Kogia breviceps, Peponocephala electra, Stenella clymene, Stenella longirostris and Steno bredanensis, were submitted to genetic analysis. Adults and larvae fixed in ethanol–formalin–acetic acid or in 70% ethanol for periods ranging from 10 months to 10 years were isolated from 9 cetaceans stranded on Ceará coast, Northeast Brazil. The 18S rDNA gene, ITS1, and specific Anisakis typica ITS regions were amplified by PCR. 18S rDNA and ITS1 region confirmed Anisakis sp. morphological identification but also detected the presence of Aspergillus sp. in longer preserved samples. All samples were identified as A. typica by ITS species-specific PCR. The study report three new definitive hosts of A. typica from the Brazilian Atlantic coast by genetic analysis: P. electra, K. breviceps, and S. clymene. [Copyright &y& Elsevier]

Understanding predator-prey interactions has a pivotal role in biological control programs. This study evaluated the functional response of three larval instars of the green lacewing, Chrysoperla carnea (Stephens), preying upon eggs and first instar larvae of the cotton bollworm, Helicoverpa armigera Hübner. The first and second instar larvae of C. carnea exhibited type II functional responses against both prey stages. However, the third instar larvae of C. carnea showed a type II functional response to the first instar larvae of H. armigera, but a type III functional response to the eggs. For the first instar larvae of C. carnea, the attack rate on H. armigera eggs was significantly higher than that on the larvae, whereas the attack rate of the second instar C. carnea on H. armigera larvae was significantly higher than that on the eggs. For the third instar larvae of C. carnea, the attack rate on the larvae was 1.015 ± 0.278/h, and the attack coefficient on the eggs was 0.036 ± 0.005. The handling times of the third instar larvae on larvae and eggs were 0.087 ± 0.009 and 0.071 ± 0.001 h, respectively. The highest predation rate was found for the third instar larvae of C. carnea on H. armigera eggs. Results of this study revealed that the larvae of C. carnea, especially the third instar, had a good predation potential in controlling H. armigera eggs and larvae. However, for a comprehensive estimation of the bio-control abilities of C. carnea toward H. armigera, further field-based studies are needed. [ABSTRACT FROM AUTHOR]

Abstract: The present study aimed to demonstrate by scanning electron microscopy (SEM) the in vitro predatory activity of nematophagous fungi Pochonia chlamydosporia (VC1 and VC4 isolates) Duddingtonia flagrans (AC001 isolate) and Monacrosporium thaumasium (NF34a isolate) on eggs of Trichuris trichiura and infective larvae (L3) of Haemonchus contortus. The work was divided into two experimental tests (A and B). In tests A and B, the predatory activity of nematophagous fungi P. chlamydosporia, D. flagrans and M. thaumasium on eggs of T. trichiura and H. contortus L3 was observed. After 6h, in test A, isolates P. chlamydosporia (VC1 and VC4) had a role in destroying eggs of T. trichiura. For fungi D. flagrans and M. thaumasium the ovicidal activity on T. trichiura eggs was not observed. Test B showed that D. flagrans (AC001) and M. thaumasium (NF34a) were capable of predating H. contortus L3, but no predation by the fungus P. chlamydosporia was seen. These fungi can offer potential for the biological control of nematodes. [ABSTRACT FROM AUTHOR]

Abstract: This study aimed at evaluating the effects of urea on Rhipicephalus (Boophilus) microplus. The experiment was divided into two stages. In Stage I, Brachiaria brizantha was placed into 30 pots, each with an area of 18cm2.These were divided into three groups of ten pots each: G1 non-treated control group, G2 treated with 15g of urea per pot and G3 treated with 15g of urea+10% of ammonium sulphate. Three engorged female ticks were placed in each pot and then 1.8l of water were added. In the second stage, a control group was maintained without the addition of urea and another group was treated with urea, each group comprising ten Mombaça grass (Panicum maximum cv. Mombaça) beds. On day zero, 12 engorged females were placed in each grass bed where were then fertilized with 60g of urea per bed, only in the grass beds of the treated group. On the 27th day, the grass was cut in beds 1–5 in both groups and beds 1–5 in the treated group were fertilized a second time. On the 40th day, pieces of white flannel measuring 1.60m×1.00m were spread over the grass to check for larvae presence. In stage I, observations conducted 24h after contact with urea showed a 100% death rate among the engorged females in G2; in group 3, only one engorged female still remained alive. In stage II, the counting of larvae reported 85.97% (P <0.0001) fewer parasites in the treated group compared to the control group. [ABSTRACT FROM AUTHOR]

Abstract: Developmentally arrested infective larvae of strongylid nematodes are activated to resume growth by host-derived cues encountered during invasion of the mammalian host. Exposure of Nippostrongylus brasiliensis infective larvae to elevated temperature (37°C) is sufficient to activate signalling pathways which result in resumption of feeding and protein secretion. This occurs independently of exposure to serum or glutathione, in contrast to the hookworm Ancylostoma caninum, and is not initiated by chemical exsheathment. No qualitative differences in protein secretion were induced by host serum as visualised by two-dimensional SDS–PAGE, although exposure of larvae to an aqueous extract of rat skin did stimulate secretion of a small pre-synthesised bolus of proteins. Infective larvae began feeding after a lag period of 3–4h at 37°C, reaching a maximum of 90% of the population feeding by 48h. Neither a membrane permeant analogue of cyclic GMP nor muscarinic acetylcholine receptor agonists stimulated feeding at 20°C, and high concentrations of both compounds inhibited temperature-induced activation. LY294002, an inhibitor of phosphatidylinositol 3-kinase, Akt inhibitor IV, an inhibitor of Akt protein kinase, and ketoconazole, an inhibitor of cytochrome P450, all blocked resumption of feeding and protein secretion at 37°C. Serotonin increased the rate of feeding assessed by uptake of radiolabelled BSA, but could not initiate feeding independently of elevated temperature. Collectively, the data suggest that the early signalling events for larval activation in N. brasiliensis differ substantially from A. caninum, but that they may converge at pathways downstream of phosphatidylinositol 3-kinase involving steroid hormone synthesis. [ABSTRACT FROM AUTHOR]

Acute toxicity and mutual synergistic effect of six monoterpenoids on Spodoptera littoralis larvae was recorded. Out of the essential oils compounds tested for topical acute toxicity, the most potent were thymol and carvacrol, with LD90 values < 100 ìg per larva (weight 25 - 30 mg). In comparison for fumigant acute toxicity, the most potent were ã-terpinene, p-cymene and 1,8-cineole, with LD90 values < 100 ìg per cm3. Nine binary mixtures out of 15 tested couples showed the synergistic effect in topical application. The most significant synergism was found in p-cymene in the mixture with ã-terpinene or carvacrol. In the fumigant application, 9 binary mixtures showed a synergistic effect; 5 mixtures showed an additive effect, and one mixture showed an antagonistic effect. The most profound synergistic effect was found in ã - terpinene in the mixture with carvacrol and in p-cymene in the mixture with thymol or carvacrol. [ABSTRACT FROM AUTHOR]

In the present study, the potential of RNA interference (RNAi) as a gene silencing tool and the resultant effects on Ascaris suum larval development was examined by targeting a gene (represented by the EST 06G09) specifically expressed in the infective larvae of A. suum. BALB/c mice were infected with RNAi-treated larvae. The results showed that the target gene was silenced after soaking for 72 h, and the survival rate of the RNAi-treated larvae was reduced by 17.25% ( P < 0.01). A significant difference ( P < 0.05) was detected in the numbers of larvae collected from the livers and lungs of infected mice 4 days after infection with untreated larvae (164.29 ± 21.51) and RNAi-treated larvae (71.43 ± 14.35). Significant differences ( P < 0.01) were also found in the body length and width between untreated larvae (480 ± 105.77 μm for length and 23.93 ± 3.72 μm for width) and RNAi-treated larvae (400.57 ± 71.31 μm for length and 20.20 ± 2.43 μm for width). These results show that the gene represented by EST 06G09 may play a role in the development of A. suum larvae. [ABSTRACT FROM AUTHOR]

Abstract: During the study of metazoan parasites of freshwater fish in the Pantanal wetland (state of Mato Grosso do Sul, Brazil), third-stage larvae of Brevimulticaecum sp. were collected from the abdominal cavity, liver parenchyma, mesentery, skeletal muscles and stomach wall of the following species: Gymnotus inaequilabiatus, Hemisorubim platyrhynchos, Hoplias aff. malabaricus, Myleus levis, Pseudoplatystoma corruscans, Pygocentrus nattereri, Serrasalmus marginatus and Sorubim lima. The larvae exhibited the main characteristics of the genus Brevimulticaecum, such as short ventricular appendices and the position of excretory pore and excretory nucleus. This is the first report and description of larval specimens of Brevimulticaecum parasitic in these hosts, which are fish species distributed throughout South America. [ABSTRACT FROM AUTHOR]

Abstract: Metastrongyloid induced pneumonia has been described sporadically in the red panda (Ailurus fulgens). Early descriptions in pandas recently imported to the USA from China involved parasites morphologically similar to Angiostrongylus spp. and Crenosomatidae. More recently, four cases of severe verminous pneumonia associated with Angiostrongylus vasorum have been reported from European zoos. A coprological survey of the red panda population within European zoos was conducted in 2008. Faecal samples from 115 pandas originating from 54 zoos were collected on 3 consecutive days. Using Baermann technique, 40 animals (35%) from 20 zoos (37%) were found to shed metastrongyloid first stage larvae (L1). Based on their morphology and size, the L1 observed could be divided into three morphologically distinct types: (1) a Crenosoma sp. type (n =5, overall prevalence: 4.3%), (2) an A. vasorum type (n =3, 2.6%), and (3) an unidentified metastrongyloid species, similar to, but morphologically distinct from A. vasorum (n =32, 27.8%). Further confirmation of species identification was provided by PCR amplification and sequencing of the 18S rRNA gene, which confirmed three different species. The novel Crenosoma species was most genetically analogous to Crenosoma mephitidis and the unidentified metastrongyloid species was most similar to Stenurus minor and Torynurus convulutus. Routine and quarantine health care of red pandas in captivity should take account of the risk of Angiostrongylus and Crenosoma infection in endemic areas, but should also be cognisant of the widespread presence of an apparently less pathogenic species of lungworm. The identity of the two potentially novel species is subject to further work. [ABSTRACT FROM AUTHOR]

Abstract: The aims of this study were to test the action of the fungal extract of Pochonia chlamydosporia (VC4) on the hatching of cyathostomin eggs plated in Petri dishes containing 2% water-agar (2% WA) and its enzymatic activity in fecal cultures, in two experimental assays (A and B). The fungus P. chlamydosporia (VC4) was cultured in Erlenmeyer flasks (250ml) containing 50ml of liquid minimal medium supplemented with 0.2% gelatin for production of the crude enzymatic extract. Approximately 1kg of fresh feces was collected directly from the rectum of crossbred horses naturally infected with cyathostomins. The fecal material was used to obtain eggs and prepare fecal cultures. For assay A, one thousand eggs were plated on 4.5cm diameter Petri dishes together with 5ml of VC4 fungal filtrate and incubated at 26°C in the dark for 24h. The control group consisted of 1000 eggs in Petri dishes containing 10ml of distilled water, which were incubated under the same conditions. After 24h, the total number of cyathostomin larvae present in each plate of the treated and control groups was counted. For assay B, about 20g of feces were added with 10ml of fungal extract of P. chlamydosporia (VC4) and incubated at 26°C for 8 days. Third stage larvae (L3) were recovered at the end of this period. Significant difference (p <0.01) was found for the number of larvae between the treated group and the control at end of assay A. A 72.8% reduction in the hatching of cyathostomin eggs was found in the plates of the treated group compared with the control group. At the end of 8 days, the fungal extract of P. chlamydosporia (VC4), in assay B, was effective in reducing the number of L3 cyathostomins in the treated group by 67.0% compared with the control group. Significant difference (p <0.01) was found between the means of L3 recovered from the treated group and the control group. The results of this work showed that crude enzymatic extract of P. chlamydosporia (VC4) was effective in reducing hatching of cyathostomin eggs and therefore could be used as a biological control agent of this nematode. [Copyright &y& Elsevier]