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Communication through vibrational signals is widespread among social insects and regulates crucial social activities. Females of the social wasp Polistes dominula produce substrate-borne vibrations on the combs by performing a conspicuous abdominal oscillatory behavior, known as abdominal wagging. Several studies have reported correlative evidence in support of its signaling role, but direct evidence is still lacking. Because abdominal wagging is strictly associated with the presence of larvae in the nest and with cell inspection, it has been suggested that it could be involved in adult--larvae communication. According to this hypothesis, abdominal wagging vibrations would have short-term effects related to food and trophallactic exchanges between adults and larvae by modulating salivary secretion (decreasing its amount, to prepare larvae to receive food, or stimulating the release of larval saliva to adults). Here, by using an electro-magnetic shaker, we assessed, for the first time, the short-term effects of abdominal wagging on larval behavior by recording larval responses and by measuring the amount of saliva released immediately after abdominal wagging playback. Our results show that larvae are able to perceive the substrate-borne vibrations produced by abdominal wagging and react by increasing the movement of their body, possibly in order to attract the attention of adult females during feeding nest inspection. Yet, we found that vibrations neither increase nor decrease the release of larval saliva. Our results support the hypothesis of the alleged role of vibrations in adult--larvae communications; however, they do not support the long- lasting hypothesis of salivary release modulation. [ABSTRACT FROM AUTHOR]

Third instar larvae of the genus Acroceratitis Hendel from North Thailand are described for the first time. They belong to A. ceratitina (Bezzi), A. distincta (Zia), A. histrionica (de Meijere), A. incompleta Hardy, and A. septemmaculata Hardy. Short descriptions of eggs, empty egg shells, and puparia are also presented. Acroceratitis larvae infest shoots of bamboo (Poaceae). Larval host plants of the studied species are Bambusa polymorpha Munro, Cephalostachyum pergracile Munro, Dendrocalamus hamiltoni Nees and Arnott ex Munro, D. strictus (Roxbourgh), Dendrocalamus sp. (unidentifi ed) and Pseudoxytenanthera albociliata (Munro). The morphological characters of Acroceratitis larvae are compared with those of other Gastrozonini described so far. A key to Acroceratitis larvae is provided. Acroceratitis ceratitina, A. incompleta and A. septemmaculata are morphologically similar and clearly differentiated from A. distincta and A. histrionica by the lack of additional papillar sensilla on the labial lobe, the arrangement of the spinules on the creeping welts and other characters. The morphological differences between the two groups coincide with the type of substrate utilized by their larvae: A. ceratitina, A. incompleta and A. septemmaculata larvae feed in young and soft internode walls, while A. distincta and A. histrionica utilize harder bamboo tissue of already elongated bamboo shoot internodes. Acroceratitis histrionica larvae are special within the Gastrozonini, because they develop exclusively in cavities formed by the internode surface and the protecting culm sheath. Factors infl uencing spatial utilization of larval resources, preference for upright shoots as breeding substrate, larval behavior, types of bamboo damage caused by different species and attraction to sweat and urine in the adults are discussed. [ABSTRACT FROM AUTHOR]

Abstract Anthropogenically-induced ocean acidification (OA) scenarios of decreased pH and altered carbonate chemistry are threatening the fitness of coastal species and hence near-shore ecosystems' biodiversity. Differential tolerances to OA between species at different trophic levels, for example, may alter species interactions and impact community stability. Here we evaluate the effect of OA on the larval stages of the rock oyster, Saccostrea cucullata , a dominant Indo-Pacific ecosystem engineer, and its key predator, the whelk, Reishia clavigera. pH as low as 7.4 had no significant effect on mortality, abnormality or growth of oyster larvae, whereas whelk larvae exposed to pH 7.4 experienced increased mortality (up to ∼30%), abnormalities (up to 60%) and ∼3 times higher metabolic rates compared to controls. Although these impacts' long-term consequences are yet to be investigated, greater vulnerability of whelk larvae to OA could impact predation rates on intertidal rocky shores, and have implications for subsequent community dynamics. [ABSTRACT FROM AUTHOR]

In this study, the concept of metabolic programming has been tested for the first time in whiteleg shrimp ( L. vannamei ). Shrimp were raised under a 70% feed restriction during the post-larval stage over three days and compared to a control group. After 46 days, shrimp were challenged with 3 diets showing different nitrogen free-extract: crude protein ratios (1.5, 1.0 and 0.7) for 70 days. In order to test the existence of metabolic programming, we analyzed shrimp growth performance as well as mRNA levels of different metabolic and digestive actors after the stimulus, and also before and after the challenge. No direct effects of the stimulus were observed for several digestive and metabolic actors, except for the trypsin mRNA (lower in the feed-restricted group, probably linked to a decrease in dietary protein intake). As expected, significant effects associated with the diet challenge were detected for shrimp performance, i.e. , growth was lower in shrimp fed with reduced levels of dietary proteins. More interestingly, some effects linked to the nutritional history were also detected showing an improved growth performance for shrimp previously restricted at the post-larvae stage. After the dietary challenge, significantly lower mRNA levels for hepatopancreatic genes involved in digestion ( lipase , preamylase and trypsin ), amino acid metabolism ( gs ), energy metabolism ( cox VI b ) and glucose metabolism ( lvglut 1, lvglut 2 and pk ) were found in restricted shrimp. The link between an enhanced growth performance and these molecular markers in early feed restricted shrimp requires further studies. Overall, our study has demonstrated for the first time that shrimp can be programmed by an early nutritional stimulus. This will allow the development of new feeding strategies in shrimp for sustainable aquaculture. [ABSTRACT FROM AUTHOR]

1. Predatory larvae often have to face food shortages during their development, and thus the ability to disperse and find new feeding sites is crucial for survival. However, the dispersal capacity of predatory larvae, the host finding cues employed, and their use of alternative food sources are largely unknown. These aspects of the foraging behaviour of the aphidophagous hoverfly (Episyrphus balteatus De Geer) larvae were investigated in the present study. 2. It was shown that these hoverfly larvae do not leave a plant as long as there are aphids available, but that dispersing larvae are able to find other aphid colonies in the field. Dispersing hoverfly larvae accumulated on large aphid colonies, but did not distinguish between different pea aphid race–plant species combinations. Large aphid colonies might be easier to detect because of intensified searching by hoverfly larvae following the encounter of aphid cues like honeydew that accumulate around large colonies. 3. It was further shown that non‐prey food, such as diluted honey or pollen, was insufficient for hoverfly larvae to gain weight, but prolonged the survival of the larvae compared with unfed individuals. As soon as larvae were switched back to an aphid diet, they rapidly gained weight and some pupated after a few days. Although pupation and adult hatching rates were strongly reduced compared with hoverflies continuously fed with aphids, the consumption of non‐prey food most probably increases the probability that hoverfly larvae find an aphid colony and complete their development. [ABSTRACT FROM AUTHOR]

Abstract: The effect of three mono‐specific and four combinations of the diatoms Chaetoceros muelleri, Chaetoceros calcitrans, and the chlorophyte Tetraselmis suecica on survival, development, and dry weight of the western school prawn, Metapenaeus dalli, was assessed from protozoea I until mysis I. The development and dry weight of larvae were significantly greater when fed diets comprising C. muelleri and/or T. suecica. A fourth diet, consisting of all three microalgal species also performed just as well. Survival alone was a poor measure of the performance of the various diets. Larvae fed with C. calcitrans, either alone or in a mixed diet with either C. muelleri or T. suecica, had significantly slower development and lower dry weight. Overall performance, assessed using the normalized biomass development index, determined that both mono‐specific and mixed diets containing C. muelleri and T. suecica were among the best for M. dalli larvae. These results for M. dalli are consistent with those found for commercially grown penaeid prawns. This study enhances the limited knowledge on the feeding requirements of metapenaeid prawn larvae. Moreover, the results will help improve hatchery methods for the aquaculture‐based enhancement of M. dalli in the Swan‐Canning Estuary and potentially increase the abundance of this iconic recreational species. [ABSTRACT FROM AUTHOR]

Abstract: The abundance and distribution of leptocephalus larvae of the European eel (Anguilla anguilla, Anguillidae) were examined using ten historic and recent Sargasso Sea expeditions that were selected on the basis of having the largest number of sampling stations and highest catches. The surveys cover the period 1920–2014. Station data were recalculated to the same unit of larval density per unit area, and the irregular station positions were transformed to a regular spatial grid to allow calculation of comparable measures of abundance of the youngest (0+) leptocephalus cohort. The result is that the mean and maximum densities of 0+ leptocephali after 2007 on average have decreased by 70%–80% from the densities during the period before the drastic decrease in glass eel recruitment, which started in the 1980s. This is of the same magnitude as the change in spawning stock, if the total continental commercial landings are used as a proxy. In the same period, the glass eel recruitment in Europe has decreased by more than 95%. The conclusion is that a major cause for the recruitment decrease may be an increased leptocephalus mortality during the oceanic phase or a large geographic shift in glass eel arrival. Combining the survey data, the spatial distribution of 0+ leptocephali was concentrated south of the northernmost front in the Subtropical Convergence Zone, but high densities were also found far south of the front in the western part of the distribution area and leptocephali were present also north of the average frontal position. [ABSTRACT FROM AUTHOR]

The development of the metacestode stages of Arostrilepis microtis (Eucestoda: Hymenolepididae) studied on the basis of an experimental infection of springtails (Collembola: Entomobryidae) is described for the first time. A complete description of the ontogeny from oncosphere to fully a developed metacestode is given. The postembryonic development within the intermediate host includes one invagination. Cysts are without an anterior invagination pore, and the cercomer does not separate after the full maturation of larva. The comparison of morphology and maturation rate of larval cestodes of A. microtis with A. beringiensis and A. tenuicirrosa is presented. Cysticercoids of A. microtis are significantly larger and require a longer period of development than those of A. beringiensis and A. tenuicirrosa. [ABSTRACT FROM AUTHOR]

Abstract: Larval sinking causes larval mass mortality during seed production in the horsehair crab, Erimacrus isenbeckii. Under normal light conditions, horsehair crab larvae generally show negative phototactic behaviour and sink in their rearing seawater. It has been proposed that culturing larvae in the dark may prevent larval sinking. Herein, we examined the effect of photoperiods on horsehair crab larval survival and development to facilitate the development of larval rearing techniques that prevent sinking. Newly hatched larvae were reared with Artemia to the first crab stage in 2‐L beakers under five photoperiods: 0L:24D, 6L:18D, 12L:12D, 18L:6D and 24L:0D. Larvae survived and molted to the first crab stage under all tested photoperiod conditions. The survival rate improved with increasing light period, whereas the developmental period for each larval stage decreased with increasing light period. Longer light periods increased the carapace length at the first crab stage. Our results suggest that larvae could be cultured to the first crab stage in large‐scale tanks under constant darkness. However, significantly improved larval performance under longer photoperiodic conditions indicates a need for developing alternative culture techniques to control larval behaviour in the seed production tank. [ABSTRACT FROM AUTHOR]

Abstract: The present research describes the complete life cycle in captivity, including spawning, larval culture and fattening of juveniles until commercial size. Additionally, size, weight and age at each moulting stage were recorded, as well as zoeas biochemical composition. The most significant results obtained were as follows. Embryonic development lasted for 33 days. Each female had between three and five spawns, separated by 4–5 days each. Larval culture lasted for 20 days at 14–17°C. The zoeas turn to megalopa at ~11 days after hatch/DAH), and from megalopa to juvenile at ~20 DAH. Average survival was ~13%. Juvenile growth rate was higher during the first 8 months (0.22%–0.46% bw/day), and then gradually decreased when changing from live to frozen diets. Survival during the fattening phase was 63%. The final moult occurs at 450 DAH, when males and females have a carapace total length of 12.38 + 1.23 and 13.57 + 1.23 cm, respectively, and 541.56 + 104.26 and 670.68 + 162.6 g in total weight respectively. Biochemical composition of cultured zoeas showed a high amount of phospholipids and long‐chain fatty acids, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (ARA). Low survival rates in larval culture and especially after passing to the benthic life style are the main problems regarding spider crab culture, and need to be improved. [ABSTRACT FROM AUTHOR]

Berried females of Macrobrachium nipponense were incubated under four different temperatures (20,23,26 and 28 ºC) and two types of tanks with different background coloration (dark and transparent tanks) to determine the best larval release and the post larvae survival were observed. The results show best larval release were 124 ind./L achieved at 26 ºC at dark color tanks, while 68 ind. / L larvae were released at the transparent color tank at the same temperature, while only 16 ind./L were released from berried females incubated at 20 ºC at dark color tanks and 6 ind./L at the transparent tanks. The best survival of larvae was 80 % at 23 ºC at dark color tanks and 75 % at transparent color tanks. Four stages for eggs development were discriminated based on color, size and eyes. [ABSTRACT FROM AUTHOR]

Necrophagous flies breeding on carcasses face high selection pressures and therefore provide interesting opportunities to study social adaptations. We postulated that gregariousness in necrophagous blow fly larvae is an adaptive response to the environmental constraints of fresh carcasses. Cooperation is indeed believed to be key to the global success of social species. To test this idea, the development of Lucilia sericata (Diptera: Calliphoridae) larvae growing on low- or high-digestibility food substrate (control or trypsin-added ground beef muscle, respectively) at different larval densities was monitored. Results showed that larvae developed faster and had decreased mortality at high than low larval density. Furthermore, aggregation had no deleterious effect on the morphological characteristics (e.g. size) of postfeeding larvae and adult flies. We concluded that increased density positively affected population fitness, which is a conclusion consistent with the predictions of the Allee effect. Compared with those fed on regular food, larvae fed on high-digestibility food had reduced mortality and faster development on average. From these results, we postulated that collective exodigestion might be an adaptive response allowing blow flies to colonize fresh carcasses before the arrival of other insects and the multiplication of microbes. This hypothesis is consistent with the idea that cooperation may enable species to expand their niches. [ABSTRACT FROM AUTHOR]

In species with biparental care, begging offspring may preferentially associate with or beg more towards one of their parents. Such preferences may reflect that the benefits of begging vary with the parent's sex given that females and males often differ in the amount of care they provide and/or in their responsiveness to begging levels. Alternatively, they may reflect the outcome of sexual conflict over care as females may deposit compounds into eggs tha talter offspring begging behaviour such that it increases male contributions towards care. For example, females might use male presence during egg laying as a cue for whether they might receive male assistance in care. Here, we studied offspring begging behaviour towards male and female parents in the burying beetle Nicrophorus vespilloides by manipulating male presence or absence during egg laying and providing larvae with a simultaneous choice between an unfamiliar female and male adult beetle. We then recorded begging behaviour of (1) naïve newly hatched larvae that had no prior experience of a parent and (2) larvae after 24 h of care by foster parents. Larvae showed a clear preference for associating with and begging towards females both when naïve and after 24 h of care. We found no evidence for prenatal maternal effects on larval begging behaviour. Our study reveals that offspring are predisposed to preferentially beg towards females independently of prior experiences with parents and highlights the importance of considering responses of begging offspring to parental attributes, such as the parent's sex, for our understanding of family conflicts. [ABSTRACT FROM AUTHOR]

Abstract: Intraspecific variation can promote or inhibit species coexistence, both by increasing species’ competitive abilities, and by altering the relative strengths of intraspecific and interspecific competition. Effects of intraspecific variation on coexistence can occur via complementarity of different variants, and via a selection effect: initially‐variable populations are more likely to contain highly competitive variants that might determine the ability of the population as a whole to both invade and resist invasion. We tested the effects of intraspecific variation and composition on coexistence by assaying the mutual invasibility of populations of two competing bean weevil species (Callosobruchus maculatus and C. chinensis) when each was initiated with one, three, or five genetically‐ and phenotypically‐distinct lineages. Our results reveal that intraspecific variation is a double‐edged sword for species coexistence. Increasing intraspecific variation increased species’ abilities to invade, and to resist invasion, via selection effects and intraspecific niche complementarity among conspecific lineages, thereby creating the potential for exclusion among mismatched competitors. But intraspecific variation also increased the scope for resource partitioning, creating the potential for stable coexistence. Stable coexistence occurred only when intraspecific variation caused species to exhibit both relatively evenly‐matched competitive abilities and sufficiently‐strong resource partitioning. Our work explains the conflicting results of previous studies. [ABSTRACT FROM AUTHOR]

Settlement preferences play a critical role in the successful transition from pelagic larvae to benthic juveniles for many coral reef organisms. Reef fish larvae are capable of recognizing and behaviorally responding to a variety of sensory cues when assessing settlement site locations. The presence of resident conspecifics for site attached coral reef fishes could indicate a quality location, but may result in negative interactions through aggression from already-established individuals. For anemonefishes, where space on a sea anemone is limited and breeding is restricted to one adult pair, settlement preferences may depend on the number and sex of the occupants. Here we undertook both aquarium-based olfactory trials and a field experiment to determine the role resident anemonefish individuals have on sea anemone site selection in the spine cheek anemonefish, Premnas biaculeatus. We show larvae are able to identify the occupant saturation state and sex of the resident occupants based on chemical cues alone, with larvae preferring the chemical cues produced by a single male to a single female, the single fish to an empty sea anemone, and an empty sea anemone to a sea anemone containing an adult pair. These behavioral preferences were reflected in the settlement preferences of larvae when assessed in the natural environment. We hypothesize that the ability of resident fish to evict incoming larvae combined with the selective pressure on larvae to locate an ideal habitat has resulted in the larval ability to accurately identify habitat where settlement and future breeding opportunities are most likely achieved. [ABSTRACT FROM AUTHOR]

Mesophotic coral ecosystems (MCEs) are deep (> 30 m), light-dependent communities that are abundant in many parts of the global ocean. MCEs are potentially connected to shallow reefs via larval exchange and may act as refuges for reef organisms. However, MCE community level recovery after disturbance, and thus, community resilience, are poorly understood components of their capacity as refuges. To assess the potential for disturbance and growth to drive community structure on MCEs with differential biophysical conditions and coral communities, we collected colonies of Orbicella franksi and Porites astreoides and used computerized tomography to quantify calcification. The divergence of coral growth rates in MCEs with different environmental conditions may be species specific; habitat-forming O. franksi have slow and consistent growth rates of ~ 0.2 cm yr−1 below 30 m, regardless of mesophotic habitat, compared to ~ 1.0 cm yr−1 in shallow-water habitats. Slow skeletal growth rates in MCEs suggest that rates of recovery from disturbance will likely also be slow. Localized buffering of MCEs from the stressors affecting shallow reefs is therefore crucial to the long-term capacity of these sites to serve as refugia, given that skeletal extension and recovery from disturbance in MCEs will be significantly slower than on shallow reefs. [ABSTRACT FROM AUTHOR]

We document chigger mite (Acari: Trombiculidae) ectoparasitic infestation (prevalence and intensity) on a population of Catharus ustulatus (Turdidae) wintering at a site (PAD A) in southeastern Peru undergoing development for natural gas exploration. We compare prevalence (i.e., the proportion of individuals infested by chigger mites) and intensity (i.e., the average number of larvae and larvae clusters in infested individuals) at forest edge (<100 m) and interior (>100 m) from PAD A because variations in biotic (e.g., vegetation cover) and abiotic (e.g., relative humidity and temperature) factors are expected to influence chigger mite abundance. Chigger mite prevalence was 100%; all C. ustulatus captured were infested regardless of distance. The range of variation in larvae (2-72 larvae/individual) and cluster intensity (1-4 clusters/individual) did not differ between edge and interior ( P > 0.05), despite differences in herbaceous vegetation cover (UM-W = 180, n = 30, 31; P < 0.01). Ectoparasitic prevalence and intensity in long-distance migratory birds might add risks to an already hazardous journey; because ectoparasitic variation and other selective pressures experienced by individuals at each locality not only may be a cause of within-site mortality, but, by affecting the physical condition of birds, may be carried over to subsequent sites and affect reproductive success and survival. Documenting ectoparasitism at any phase of the life cycle of migrants could improve understanding of population declines of migratory birds. [ABSTRACT FROM AUTHOR]

Members of Cyathostominae are pervasive parasites of equids that can cause larval cyathostominosis, a potentially life-threatening disease that occurs when a multitude of encysted larvae synchronously excyst from the wall of the large intestine. Moxidectin and fenbendazole are the two current labeled drugs that target the encysted larval stages; however, there is limited knowledge of the local inflammatory response to the larvae and to the two treatments in clinically healthy horses. This study is the first to evaluate the local inflammatory response to cyathostomin larvae and to larvicidal treatment at 2 and 5 weeks post treatment. Thirty-six ponies with naturally acquired cyathostomin infections were randomly allocated into 3 groups: Group 1, fenbendazole at 10 mg/kg for 5 days, Group 2, a single dose of moxidectin at 0.4 mg/kg, and Group 3, untreated controls. Tissue samples from the cecum and dorsal and ventral colons were used for histopathological and immunohistochemical evaluation. Tissues were stained with routine hematoxylin and eosin (H&E) for light microscopy and immunohistochemically for MAC387, CD20, and CD3 for differentiation of activated macrophages, B cells, and T cells, respectively. Semiquantitative scores were assigned for all inflammatory cell types and fibrous connective tissue. Larvae observed by light microscopy were enumerated and classified by stage. Mucosal ulcerations and submucosal granulomas were also enumerated. Mean macrophage scores were higher in the moxidectin group than the fenbendazole group (p = 0.0185) and the control group had a higher activated macrophage score than both treatment groups (p = 0.0104, p = 0.0004). T lymphocyte scores were higher in the moxidectin group when compared to the control group (p = 0.0069). Goblet cell hyperplasia scores were elevated at 5 weeks post treatment compared to 2 weeks post treatment (p = 0.0047) and were elevated in the ventral colon compared to the dorsal colon (p = 0.0301). Eosinophil scores were elevated surrounding degenerative larvae when compared to intact larvae (p = 0.0001). Mucosal ulcerations were found only in the control group at 2 weeks post treatment. This study found subtle inflammatory differences between treatment groups but provided new information about goblet cells and eosinophils in relation to encysted cyathostomin larvae. [ABSTRACT FROM AUTHOR]

Understanding the dynamic processes that contribute to reproductive output is vital to determine appropriate harvest controls and sustain marine fisheries. For sequential hermaphrodites, the process of reproduction is complicated by sex transition within the life history. We examined the reproductive dynamics of black sea bass (Centropristis striata), a protogynous serranid, within a major fishing region of the Northwest Atlantic during two consecutive spawning seasons to quantify the strength of size-dependence and the magnitude of temporal variation in several key traits. Specifically, we estimated the size-dependence of sex ratio, maturity, spawning capability, batch fecundity, and spawning frequency at both fine (weeks/months) and broad (years) temporal scales. We observed fecundity to be highest in females of intermediate body size, which was entirely a function of reduced spawning frequency among the largest females. Female fecundity peaked at sizes well below the estimated size at sex transition, and contrary to the pattern typically observed for gonochoristic fishes in which the largest females yield the greatest number of eggs. Among protogynous fishes, females may decrease egg production prior to sex change and instead allocate energy to somatic growth, benefitting from larger body size during the subsequent male phase. The production of fewer batches of eggs by larger females directly impacted estimates of annual fecundity. In addition, we detected large interannual differences in the proportion of spawning capable females, and also spawning frequency, which resulted in considerable variation between annual fecundity estimates. The inclusion of temporal and size-dependent variation in female egg production should produce more robust estimates of stock reproductive potential and its response to changing harvest scenarios. [ABSTRACT FROM AUTHOR]

The oriental fruit fly ( Bactrocera dorsalis ) larvae may commonly experience a hypoxia microenvironment and have evolved the ability to survive in the low oxygen condition with some physiological and biochemical mechanisms. However, little is known about the response of B. dorsalis to hypoxia or anoxia. In this study, the effect of anoxia on the survival of B. dorsalis was investigated . The results showed that the B. dorsalis larvae were quite tolerant to anoxia conditions and can tolerate up to 24 h of anoxia exposure without a significant reduction in survival, 100% mortality was reached after 84 h of anoxia exposure. The cDNA of hypoxia inducible factor (HIF) 1α and HIF-1β is 2912 and 3618 bp in length, encoding 766 and 648 amino acid residues, respectively. Both HIF-1α and HIF-1β contain conserved basic helix-loop-helix (bHLH) domain and Per-Arnt-Sim (PAS) domain. HIF-1α can be induced by hypoxia, whereas HIF-1β expression was not significantly changed with the oxygen concentration. Three major heat shock proteins (Hsps) expression increased significantly during anoxia and recovery and Hsp70 was the most responsive to anoxia. Four superoxide dismutase (SOD) genes expression were also up-regulated during anoxia exposure. These data suggest that B. dorsalis has a strategy to induce HIF-1α and HIF-1-responsive genes to survive in the low oxygen condition. [ABSTRACT FROM AUTHOR]

The European Seabass (Dicentrarchus labrax) is a slow-growing late maturing fish. The northern stock has been declining since 2010 and is thought to be caused by a combination of fishing and weak year classes. Large inter-annual variation in settlement has been observed, so a better understanding of the mechanisms driving settlement success will aid interpretation of the variation between years, and help to improve the stock assessment models and management strategies. In this study, an individual-based model (IBM) was developed to investigate the factors affecting sea bass settlement on nursery grounds of the northern sea bass stock. The IBM was coupled with hydrodynamics to track particles, whereas egg and larval development, and vertical migration behaviour are fully incorporated. The IBM successfully predicted inter-annual differences in settlement regardless of larval behaviour. The highest settlement success was predicted with neutrally buoyant eggs, hatchlings, and larval stages, in combination with tidal migration at the final larval stage. Dispersal was driven mainly by the influence of wind on residual currents and water temperature, with warmer temperatures reducing the duration of the pelagic phase and stronger current increasing the potential to drift further. Eggs spawned in the central western English Channel settled in both England and France, with movement from the central to the eastern English Channel occurring only in warm years. Larval duration was driven by water temperature and showed an increase in duration from the southwest to northeast areas of the northern stock. The results are discussed in the context of sea bass management and conservation strategies. [ABSTRACT FROM AUTHOR]

Resource limitation is an important determinant of life history and behavior while mediating competition and reproduction among organisms. Discreet and closed systems such as grain kernels and seeds impose drastic restrictions to grain beetles that spend their immature stages within a single kernel selected by their mother. This is the case of internally feeding stored grain beetles, such as the grain weevils. Female egg-laying decisions and larval competition largely determine resource limitation for such insects where clustered egg distribution and contest competition with larval interference and cannibalism take place. As the clustered eggs within a grain lead to larval competition and conspecific weevil larvae face each other off during development allowing the emergence of one or two larvae per kernel, we hypothesized that such competition and consequent cannibalism will have fitness consequences for the competing individuals and their offspring. Thus, larvae of the granary weevil (Sitophilus granarius L.) and the maize weevil (Sitophilus zeamais Motsch.) were subjected to larval competition with cannibalism, and lack of it, to assess the potential fitness consequence of cannibalism on these noncarnivorous pest species of stored grains. Larval cannibalism reduced developmental time of maize weevil, but not of granary weevil. However, such condition led to heavier adult weevils of both species exhibiting higher reproductive output generating more and better quality progeny than noncannibal weevils. These findings indicate direct nutritional benefits of cannibalism to grain weevils favoring their status of key pest species of stored cereal grains. [ABSTRACT FROM AUTHOR]

Blow flies are worldwide the most important insects from a forensic point of view. In Thailand, aside from the two most common species, Chrysomya megacephala (F.) and Chrysomya rufifacies (Macquart), Chrysomya chani Kurahashi was also found to be of forensic importance. We present a case of a human female cadaver in its bloated stage of decomposition, discovered at Pachangnoi Subdistrict, northern Thailand. Entomological sampling during the autopsy displayed an assemblage of numerous dipteran larvae. Macroscopic observations showed the coexistence of third instar larvae of the three blow flies C. megacephala, Chrysomya villeneuvi Patton, an unknown blow fly species and one muscid, Hydrotaea sp. The minimum post-mortem interval was estimated to be six days, based on the developmental rate of C. megacephala. The ID of the unknown larva, which is the focus of this report, was revealed later as C. chani by DNA sequencing, using a 1205 bp of cytochrome c oxidase subunit I (COI). The occurrence of C. chani on a human body revealed the need to analyse and describe the morphology of its immature stage, to enable forensic entomologists to identify this fly species in future cases. The morphological examination of the third instar was performed, revealing peculiar characteristics: protuberant tubercles encircling abdominal segments; 9-11 lobes on the anterior spiracle; six prominent pairs of tubercles along the peripheral rim of the eighth abdominal segment; a heavily sclerotized complete peritreme of the posterior spiracles. A key to differentiate the third instar of blow flies of forensic importance in Thailand is provided. [ABSTRACT FROM AUTHOR]

Abstract: Fluctuations in marine populations often relate to the supply of recruits by oceanic currents. Variation in these currents is typically driven by large‐scale changes in climate, in particular ENSO (El Nino Southern Oscillation). The dependence on large‐scale climatic changes may, however, be modified by early life history traits of marine taxa. Based on eight years of annual surveys, along 150 km of coastline, we examined how ENSO influenced abundance of juvenile fish, coral spat, and canopy‐forming macroalgae. We then investigated what traits make populations of some fish families more reliant on the ENSO relationship than others. Abundance of juvenile fish and coral recruits was generally positively correlated with the Southern Oscillation Index (SOI), higher densities recorded during La Niña years, when the ENSO‐influenced Leeuwin Current is stronger and sea surface temperature higher. The relationship is typically positive and stronger among fish families with shorter pelagic larval durations and stronger swimming abilities. The relationship is also stronger at sites on the coral back reef, although the strongest of all relationships were among the lethrinids (r = .9), siganids (r = .9), and mullids (r = .8), which recruit to macroalgal meadows in the lagoon. ENSO effects on habitat seem to moderate SOI–juvenile abundance relationship. Macroalgal canopies are higher during La Niña years, providing more favorable habitat for juvenile fish and strengthening the SOI effect on juvenile abundance. Conversely, loss of coral following a La Niña‐related heat wave may have compromised postsettlement survival of coral dependent species, weakening the influence of SOI on their abundance. This assessment of ENSO effects on tropical fish and habitat‐forming biota and how it is mediated by functional ecology improves our ability to predict and manage changes in the replenishment of marine populations. [ABSTRACT FROM AUTHOR]

Abstract: Although the gut microbial communities in adult bumblebees and their associated functionalities are widely studied, descriptive data on the larval gut microbiota are still limited. The gut microbiota of a fully sampled wild Bombus pascuorum nest has been characterized, using the multiplexed Illumina MiSeq 16S ribosomal RNA amplicon sequencing technique. The nesters and foragers inhabiting the same nest showed the typical core bacterial sequences and only marginal differences in their characterized gut microbiota. The gut microbial communities within the adult and larval specimens differed strongly, as the typical core gut bacteria in the adult bumblebees are absent in the larval bumblebees. The bacterial communities within the larval gut are dominated by bacterial phylotypes of Enterobacteriaceae and Lactobacillaceae, supplemented with genera belonging to Corynebacteriales and Bacillales. The function of this larval gut microbiota, being different from the adult, remains to be determined. [ABSTRACT FROM AUTHOR]

Anisakis L3 were subjected to freezing in domestic freezers and the risk posed by those larvae that might possibly survive freezing was analysed by determining their agar penetration ability, survival in gastric juice, allergenic potential and oxygen consumption rate. Anisakis L3 gradually became non-viable as the temperature fell from −1 °C to −28 °C. The faster the freezing rate, the greater the decrease in survival, but viability was not found to be affected by the proportions of Anisakis species per batch ( A. simplex s.s. 83–100%, A. pegreffii 0–17%, and their heterozygote genotypes at the ITS region of rDNA 0–10%). Surviving larvae after freezing presented a drastically reduced ability to penetrate into a layer of solid agar, as compared to controls, but still 5% of them penetrated into this medium. About 80% of surviving larvae died within 24 h under conditions simulating those of gastric fluid, whereas up to 85% of the controls were able to resist for 24 h. Allergen release during freezing and after freezing was higher than in controls, and this release was compatible with a contribution of both passive (by rupture of the cuticle) and active liberation of excretion/secretion allergens during and after freezing, suggesting that the pathogenic potential of these frozen and thawed larvae cannot be discarded. These results could be of use for more precise risk assessment and providing guidelines for consumers. [ABSTRACT FROM AUTHOR]

The dispersal of fish larvae in rivers might result from water movement but also from larval behaviour. Although potentially crucial for dispersion, knowledge of the role of behaviour is still fragmentary. This study intends to contribute to the question of how riverine fish larvae drift or move. All dispersal-relevant movement patterns of larvae of a characteristic rheophilic species were analyzed based on the parameters ( i) swimming activity, ( ii) direction of movement, and ( iii) the orientation towards the current vector. Experiments were conducted in a novel flume mesocosm at three different flow scenarios covering the current velocity range of natural habitats. Mean current velocities in these scenarios were under, near, and over the 'critical current velocity', above which fish larvae are not able to constantly hold their position in the water column. Three consecutive larval stages were tested to account for possible ontogenetic shifts in movement behaviour, both during the day and at night. Our results strongly suggest that the assumption of mainly passively drifting larvae has to be refused; in total, 92.6% of all observed movement events were characterized by swimming activity and directed orientation, whereas only 7.4% could be assigned to passive drift. During downstream movement, a significant portion of movement events (57.1%) was attributed to larvae that orientated in an upstream direction and performed active swimming movements. [ABSTRACT FROM AUTHOR]

Gut microbes positively affect the physiology of many animals, but the molecular mechanisms underlying these benefits remain poorly understood. We recently reported that bacteria-induced gut hypoxia functions as a signal for growth and molting of the mosquito Aedes aegypti. In this study, we tested the hypothesis that transduction of a gut hypoxia signal requires hypoxia-induced transcription factors (HIFs). Expression studies showed that HIF-α was stabilized in larvae containing bacteria that induce gut hypoxia but was destabilized in larvae that exhibit normoxia. However, we could rescue growth of larvae exhibiting gut normoxia by treating them with a prolyl hydroxylase inhibitor, FG-4592, that stabilized HIF-α, and inhibit growth of larvae exhibiting gut hypoxia by treating them with an inhibitor, PX-478' that destabilized HIF-α. Using these tools, we determined that HIF signaling activated the insulin/insulin growth factor pathway plus select mitogen-activated kinases and inhibited the adenosine monophosphate-activated protein kinase pathway. HIF signaling was also required for growth of the larval midgut and storage of neutral lipids by the fat body. Altogether, our results indicate that gut hypoxia and HIF signaling activate multiple processes in A. aegypti larvae, with conserved functions in growth and metabolism. [ABSTRACT FROM AUTHOR]

Mosquitoes (Diptera: Culicidae) are the primary vectors of several serious diseases that affect both animals and humans. Most of these diseases, especially the ones that are caused by arboviruses such as Zika, dengue and Japanese encephalitis, cannot be effectively prevented or treated, thereby rendering the discovery of alternative measures for the control of mosquito-borne diseases an absolute necessity. The current study evaluates the acute toxicity of Amomum subulatum -derived essential oil against Anopheles subpictus , Aedes albopictus , and Culex tritaeniorhynchus . We used gas chromatography–mass spectroscopy to analyze the chemical composition of A. subulatum EO. Analysis revealed thirty-three components. Primary constituents were 1,8- cineole (39.8%) and α-terpineol (11.5%). The essential oil from A. subulatum demonstrated a significant toxic effect against An. subpictus , Ae. albopictus and Cx. tritaeniorhynchus third instar larvae, with LC 50 values of 41.25, 44.11 and 48.12 μg/ml and LC 90 values of 80.29, 85.6 and 89.30 μg/ml, respectively. Concerning non-target effects in the aquatic environment, we evaluated the acute toxicity of A. subulatum oil on 4 mosquito biocontrol agents, Anisops bouvieri , Diplonychus indicus , Poecilia reticulata and Gambusia affinis . We observed that the toxicity of this oil was extremely low, with LC 50 ranging between 3123 and 9104 μg/ml. In conclusion, the A. subulatum essential oil is an interesting bioresource to develop environmental friendly mosquito larvicides. Indeed, it is effective against different Culicidae species with LC 50 always lower than 50 μg/ml, while LC 50 calculated for non-target organisms are about 100-fold higher. [ABSTRACT FROM AUTHOR]

Dipteran flies are responsible of myiasis, a common parasitic infestation leading to the invasion of living, necrotic or dead tissues. They also transmit mycobacterial infections to livestock. In the present investigation, seven plant species employed in Southern India for medical and ethno-veterinary purposes were extracted using ethanol or water and tested against second instar larvae of Lucilia sericata. 100% larval mortality was observed testing Lobelia leschenaultiana ethanol extract at 60 mg/L (LC 50 = 3.4 mg/L). Based on the highest percentage of larval mortality, we selected L. leschenaultiana for fabrication of ZnO nanoparticles to control L. sericata . Zinc acetate showed 82.2% mortality at 60 mg/L (LC 50 = 38.2 mg/L) whereas L. leschenaultiana- coated ZnO nanoparticles (Ll-ZnO NPs) showed 100% mortality at 6 mg/L, the LC 50 was 0.78 mg/L. Overall, our research represents an attempt to integrate current ethno-veterinary knowledge from native tribes of Southern India, in order to identify effective botanicals for the development of nano-biopesticides against livestock pests and parasites. [ABSTRACT FROM AUTHOR]

Insecticide barrier and insufficient awareness to the execution of topical larvicidal and acaricidal are general reason for treatment defeat. Medicinal plants are safe alternatives due to their less toxicity and uncomplicated biodegradability to the organisms. In the present study different solvent extracts of Andrographis echioides were evaluated for larvicidal and acaricidal activity against fourth instar larvae of Aedes aegypti L , Culex quinquefasciatus (say) (Diptera: Culicidae) and Rhipicephalus ( Boophilus ) microplus canestrini (Acari: Ixodidae). The larvicidal and acaricidal mortality were observed after 24 h exposure of extracts like petroleum ether, ethyl acetate, methanol and aqueous extract. Among that, methanolic extract shows maximum activity against A . aegypti, C . quinquefasciatus , and R . microplus , (LC 50 = 93.00, 83.06 and 105.84 ppm; LC 90 = 171.81, 171.76 and 198.73 ppm; χ 2 = 11.038, 1.075 and 7.867) respectively. GC-MS analysis revealed the presence of Oxirane Tridecyl- (34.89% area) for petroleum ether extract, Z,E-2-Methyl-3,13-Octadecadien-1-OL (29.08% area) for ethyl acetate extract, Silane Dimethyl- (59.89% area) for methanolic extract of A . echioides in major amount. These compounds could be responsible for larvicidal and the acaricidal activity of A. echioides . We reports here for the first time on this ideal, eco-friendly and cost effective approach against larvicidal and acaricidal activity from A. echioides leaf extracts. [ABSTRACT FROM AUTHOR]

Trogoderma granarium Everts (Coleoptera: Dermestidae) is an important insect pest of stored products. In this study, the survival strategies of T. granarium fourth instar larvae were investigated at different sub-zero temperatures following different cooling rates, acclimation to different relative humidity (RH) and different starvation times. Our results show that larvae of T. granarium are freeze-intolerant. There was a strong link between cooling rates and supercooling point, which means the slower the decrease in temperature, the lower the supercooling point. Trehalose content was greater in insects cooled at a rate of 0.5 °C/min. According to results, the RH did not affect supercooling point. However, acclimation to an RH of 25% increased mortality following exposure to − 10 °C/24 h. The time necessary to reach 95% mortality was 1737 h and 428 h at − 5 °C and − 10 °C. The lowest lipid and trehalose content was detected in insects acclimated to 25% RH, although, the different RH treatments did not significantly affect glycogen content of T. granarium larvae. The supercooling point of larvae was gradually increased following starvation. By contrast, fed larvae had the greatest lipid, glycogen, and trehalose content, and insects starved for eight days had the lowest energy contents. There was a sharp decline in the survival of larvae between − 11 and − 18 °C after 1 h exposure. Our results indicate the effects of cooling rate and starvation on energy reserves and survival of T. granarium . We conclude that T. granarium may not survive under similar stress conditions of the stored products. [ABSTRACT FROM AUTHOR]

In animal species in which parents provide food to their dependent young, offspring often display conspicuous begging signals. These solicitation behaviors are important components of parent-offspring communication, but it is currently unclear how they and the parental response covary with offspring dependency on parental food provisioning across species. Burying beetles (Nicrophorus) are well known for providing elaborate biparental care, including provisioning of begging larvae. By using a multispecies approach, we show that larval begging intensity, as well as the time parents spend provisioning, differ greatly between individuals of the 3 species: N. orbicollis, N. pustulatus, and N. vespilloides. Our results demonstrate that the most dependent offspring of N. orbicollis invest the most time in begging, whereas the most independent offspring of N. pustulatus invest the least amount of time in begging. Thus, we suggest that begging intensity differs due to intrinsic differences in nutritional need between the species rather than because of an arbitrary divergence in begging behavior. We further show that in all 3 species, females spend significantly more time provisioning than males, although there is considerable divergence between species in the extent to which females and males contribute to the provisioning of larvae. We discuss the potential selective factors leading to this diversification of offspring begging and parental provisioning in relation to the distinct variation in offspring dependence between the 3 species. [ABSTRACT FROM AUTHOR]

The Australian dermestid genus Myrmeanthrenus Armstrong, 1945 is revised. The following taxa are described, illustrated and compared: Myrmeanthrenus (Myrmeanthrenus) fasciatus sp. nov. and Myrmeanthrenus (Weiranthrenus subgen. nov.) planus sp. nov. [ABSTRACT FROM AUTHOR]

Early life exposure to environmental chemicals can have long-termconsequences that are not always apparent until later in life. We recently demonstrated that developmental exposure of zebrafish to low, nonembryotoxic levels of 3,3',4,4',5- pentachlorobiphenyl (PCB126) did not affect larval behavior, but caused changes in adult behavior. The objective of this study was to investigate the underlying molecular basis for adult behavioral phenotypes resulting from early life exposure to PCB126.We exposed zebrafish embryos to PCB126 during early development and measured transcriptional profiles in whole embryos, larvae and adult male brains using RNA-sequencing. Early life exposure to 0.3nM PCB126 induced cyp1a transcript levels in 2-dpf embryos, but not in 5-dpf larvae, suggesting transient activation of aryl hydrocarbon receptor with this treatment. No significant induction of cyp1a was observed in the brains of adults exposed as embryos to PCB126. However, a total of 2209 and 1628 genes were differentially expressed in 0.3 and 1.2nM PCB126-exposed groups, respectively. KEGG pathway analyses of upregulated genes in the brain suggest enrichment of calcium signaling, MAPK and notch signaling, and lysine degradation pathways. Calcium is an important signaling molecule in the brain and altered calcium homeostasis could affect neurobehavior. The downregulated genes in the brain were enriched with oxidative phosphorylation and various metabolic pathways, suggesting that the metabolic capacity of the brain is impaired. Overall, our results suggest that PCB exposure during sensitive periods of early development alters normal development of the brain by reprogramming gene expression patterns, which may result in alterations in adult behavior. [ABSTRACT FROM AUTHOR]

The present investigation reports on larvicidal efficacy of plant extracts of Nux-vomica, Strychnus nuxvomica against Diamond back moth (DBM). In this investigation shade dried and powdered nux-vomica plant samples (leaves, root bark, stem bark, seed and fruit rind) were extracted with organic solvents ethanol, methanol, acetone, hexane and chloroform and also formulated as Emulsifiable Concentrates (EC) using surfactant and solvents. This formulated plant extracts were tested against third instar larvae of DBM for larvicidal efficacy using leaf disc bioassay method under laboratory condition. Among the five solvent extracts tested, hexane extracts of root bark 11.11 EC @ 2 % showed highest larval mortality of 76.66 % followed by seed 14.25 EC, leaf 16.66 EC, stem bark 12.50 EC and fruit rind 12.50 EC extracts exhibited maximum mortality @ 2 % concentration recording 66.66, 63.33, 56.66 and 40.00 per cent mortality respectively. Positive and negative control such as respective solvent and water showed 10.00 and 3.33 % larval mortality respectively. The results of these experiment clearly indicate that nuxvomica plant possess promising larvicidal action against diamond back moth. [ABSTRACT FROM AUTHOR]

The major objective of this study was to introduce a newly designed recirculating aquaculture system ( RAS) for oyster ( Crassostrea angulata) larval culture. The system includes a culture tank, a suspended circular inlet-pipe, an upwelling aeration pipe, combined 'banjo' sieves and a bioreactor chamber containing microalgae life keeping installation. The system was designed to resolve three problems: (i) stranding of larvae caused by water level changes and aeration, (ii) physical clogging of the screens and also (iii) deterioration of diet microalgae. The culture tank, 'banjo' sieve size, water flow rate and light intensity for maintaining microalgae activity were all designed according to the pattern of larval movement and feeding behaviour. Results of this study showed the best average SGR for larval length was 6.36%/d (9.5 μm/d) and survival rate was 80%, with initial rearing density of 50 larvae/ml, indicating the problems above were fully resolved. Consequently, the system is fit for larval culture in mass production of oysters. [ABSTRACT FROM AUTHOR]

Hypoderma spp. larvae cause subcutaneous myiasis in several animal species. The objective of the present investigation was to identify and characterize morphologically and molecularly the larvae of Hypoderma spp. collected from cattle (Bos taurus taurus) and red deer (Cervus elaphus) in the district of Castelo Branco, Portugal. For this purpose, a total of 8 larvae were collected from cattle (n=2) and red deer (n=6). After morphological identification of Hypoderma spp. larvae, molecular characterization was based on PCR-RFLP and mitochondrial CO1 gene sequence analysis. All larvae were morphologically characterized as the third instar larvae (L3) of H. actaeon. Two restriction enzymes were used for molecular identification of the larvae. TaqI restriction enzyme was not able to cut H. actaeon. However, MboII restriction enzyme differentiated Hypoderma species showing 210 and 450 bp bands in H. actaeon. Furthermore, according to the alignment of the mt-CO1 gene sequences of Hypoderma species and to PCR-RFLP findings, all the identified Hypoderma larvae were confirmed as H. actaeon. This is the first report of identification of Hypoderma spp. (Diptera; Oestridae) from cattle and red deer in Portugal, based on morphological and molecular analyses. [ABSTRACT FROM AUTHOR]

Larvae of many insect species, including stag beetles, have a limited mobility from their initial oviposition site. The fate of immature stages, therefore, depends on the maternal choice of oviposition site. Decaying wood preference by stag beetles was studied in a dry-evergreen forest in Chanthaburi province, Thailand. From a total of 270 examined logs, 52 contained stag beetles (255 total), which were identified to eight species from five genera. Aegus chelifer chelifer MacLeay, 1819 (Coleoptera: Lucanidae) was the dominant species both by occurrence and by number of individuals. The occurrence and numbers of stag beetle larvae found in logs was more frequent in those of a moderate decay class, which had moderate hardness and water content. Principal component analysis (PCA) revealed that logs with stag beetles had relatively high nitrogen content and fungal biomass. Thus, selection of oviposition sites by stag beetles was likely to depend on both the log decay stage (or hardness) to protect immature stages from natural enemies and its nutritional properties to enhance the larval performance. [ABSTRACT FROM AUTHOR]

Hyboptera Chaudoir, 1872 of the Cryptobatida group of subtribe Agrina, Lebiini, living in the Neotropics and southernmost Nearctic realms are diagnosed, described, and illustrated, and new species are assigned to two inclusive species groups. Occurrences of species range from Texas, USA, to the state of Santa Caterina in Brazil. Seven new species of Hyboptera are described: Hyboptera biolat Erwin & Henry, sp. n.; Type locality -- Perú, Madre de Dios, Manu Reserved Zone, Río Manu, BIOLAT Biological Station, Pakitza; Hyboptera vestiverdis Henry & Erwin, sp. n.; Type locality -- Perú, Madre de Dios, Manu Reserved Zone, Río Manu, BIOLAT Biological Station, Pakitza; Hyboptera lucida Henry & Erwin, sp. n.; Type locality -- French Guiana, Cayenne, Commune de Roura, Montagne des Chevaux; Hyboptera scheelea Erwin & Henry, sp. n.; Type locality -- Perú, Loreto, Pacaya- Samiria National Reserve, Río Samiria (South Branch), Camp Terry; Hyboptera shasta Erwin, sp. n.; Type locality -- Brazil, Amazonas, north of Manaus on Amazonas 010 at Km 26, Reserva Ducke; Hyboptera tepui Erwin & Henry, sp. n.; Type locality -- Venezuela, Amazonas, Cerro de la Neblina, Río Baria Basecamp; Hyboptera tiputini Erwin & Henry, sp. n.; Type locality -- Ecuador, Orellana, Yasuni National Park (edge), 95.43 km E (heading 101.46°) Coca, Tiputini Biodiversity Station. A revised identification key is provided to the genera of the Cryptobatida group and another to the species of Hyboptera Chaudoir and distributional data are provided for all known species of the latter. Adults of these species often occur in the canopy of many tropical tree species and records are reported where known. In addition, adults are found under the webbing of Psocoptera and in fleshy anther rings of Bombacaceae (Pseudobombax septenatum (Jacq.) Dugand), on the rain forest floor in the dry season. Larval and pupal stages of one species from Panamá are known from under bark of living fence posts; however, these immature stages are not treated in the current paper. [ABSTRACT FROM AUTHOR]

Arthropods including insects grow through several developmental stages by molting. The abrupt changes in their body size and morphology accompanying the molting are responsible for the developmental changes in behavior. While in holometabolous insects, larval behaviors are transformed into adult-specific behaviors with drastic changes in nervous system during the pupal stage, hemimetabolous insects preserve most innate behaviors whole life long, which allow us to trace the maturation process of preserved behaviors after the changes in body. Wind-elicited escape behavior is one of these behaviors and mediated by cercal system, which is a mechanosensory organ equipped by all stages of nymph in orthopteran insects like crickets. However, the maturation process of the escape behavior after the molt is unclear. In this study, we examined time-series of changes in the wind-elicited escape behavior just after the imaginal molt in the cricket. The locomotor activities are developed over the elapsed time, and matured 24 h after the molt. In contrast, a stimulus-angle dependency of moving direction was unchanged over time, meaning that the cercal sensory system detecting airflow direction was workable immediately after the molt, independent from the behavioral maturation. The post-molting development of the wind-elicited behavior was considered to result not simply from maturation of the exoskeleton or musculature because the escape response to heat-shock stimulus did not change after the molt. No effect of a temporal immobilization after the imaginal molt on the maturation of the wind-elicited behavior also implies that the maturation may be innately programmed without experience of locomotion. [ABSTRACT FROM AUTHOR]

Variation in larval development related to duration and number of stages is common among arthropods. This variation appears to be influenced largely by environmental factors such as prey availability and temperature, but the primary causes are poorly understood. We examined the effects of prey density and the use of polyhydroxybutyrate (PHB), an energy-storage compound, on larval duration and survival during the early development of the blue crab, Callinectes sapidus (Rathbun, 1896), using hatchery-raised animals at constant temperature (21- 23 °C). We also determined the daily food consumption by zoeae and the number of zoeal stages that are required to reach the final megalopa stage. Newly-hatched zoeae of C. sapidus were reared until megalopae in 24-well plates under high and low prey density with and without PHB supplementation (50 and 100 mg/l). Food consumption only was significantly different when a high density of Artemia, used as food, during later development. The zoeae raised under a high prey density had a shorter duration by having fewer zoeal stages and greater survival rate than those with a low prey density. PHB supplementation, with a combination of a high prey density, increased the incidences of stage skipping without changing the duration of zoeal development. Prey density, possibly affecting the nutritional status of larvae, is a critical factor that influences the zoeal development of C. sapidus. [ABSTRACT FROM AUTHOR]

The use of macrocyclic lactone drugs for control of equine cyathostomins is threatened by increasing levels of resistance. Detection of changes in drug sensitivity is important for effective and sustainable management of cyathostomins, however, at present such detection relies on the use of the faecal egg count reduction test, which is known to be an insensitive method. The present study therefore aimed to examine the use of a 96-well plate larval migration inhibition test for detection of resistance to macrocyclic lactone drugs in cyathostomins. We optimised conditions for migration of larvae, and examined the effects of larval storage time on drug dose responses. The modified test was able to define the sensitivity of cyathostomin isolates to ivermectin and eprinomectin in terms of dose response curves, and IC 50 and IC 95 values. The IC 95 showed much greater consistency than the IC 50 with larvae that had been stored for different periods prior to the test. Comparisons between two isolates, which had both been defined previously as susceptible using faecal egg count reduction tests, showed more variation at the IC 50 compared to the IC 95 . Limitations of the test included the degree of variation in control-well migration despite optimisation of migration incubation conditions, and the need to incorporate a method to determine the species composition of the larval populations to account for possible species differences in drug sensitivity among cyathostomins. Validation of the technique on reference susceptible and resistant isolates of known species composition is still required. [ABSTRACT FROM AUTHOR]

Predicting dispersal paths of marine larvae with extended pelagic durations, such as American lobster ( Homarus americanus H. Milne Edwards, 1837), requires understanding the cues to which larvae respond, and how that response reflects changes in larval behaviour. If larvae respond to conspecific presence by varying their movement, then this behaviour can bias laboratory estimates of environmental responses. We tested whether larvae actively decreased their local intraspecific density by measuring how the vertical distribution of larvae changed under high versus low concentrations of conspecifics. We observed weak increases in vertical dispersion at higher concentrations both in newly hatched larvae and in postlarvae, but not in intermediate larval stages. We also tested for differences in horizontal swimming behaviour in high and low concentrations, by fitting a novel random walk model that allowed us to model both larval interactions and persistent turning behaviours. We showed substantial reduction in diffusive behaviour under high concentration conditions resulting from more frequent turns by each larva, but no evidence for consistent avoidance of conspecifics. Our study is the first to demonstrate concentration-dependent behaviours in lobster larvae. [ABSTRACT FROM AUTHOR]

Multivariate allometry patterns and length at metamorphosis ( Lm) were determined in Acipenser stellatus by means of principal component analysis from 12 morphometric characters. The multivariate analysis differentiated three growth stanzas: the prelarval, larval, and early juvenile stages. The prelarval stage comprised the period from hatching (9.7 mm in total length, TL) to the transition to exogenous feeding (17.7 mm TL, Lm1), a period characterized by yolk sac depletion and fast growth of the anterior and posterior body regions. These changes coincided with the development of sensory, feeding, respiratory, and swimming systems to improve foraging behavior and predator avoidance. During the larval period (17.7-52.8 mm, Lm1- Lm2), specimens reached a juvenile phenotype characterized by the development of median fins, elongation and flattening of the snout and formation of bony scutes, and the improvement of their swimming capacities, allowing larvae to regulate their dispersal distance from the spawning grounds. The end of the larval period and acquisition of the juvenile phenotype were found after Lm2 when some variables reached isometry or even displayed a negative allometric growth. [ABSTRACT FROM AUTHOR]

Within a common body plan, echinoid plankto-trophic larvae are morphologically diverse, with variations in overall size, the length, and number of arms and the presence or absence of epidermal structures. In this report, we are interested in variation in larval arm-flexing behavior and correlated differences in larval musculature. Larvae of the cidaroid Eucidaris tribuloides exhibit conspicuous and regular arm-flexing behavior. In contrast, Lytechinus variegatus, a representative of the euechinoid clade, does not exhibit this behavior. We hypothesized that there were differences in musculature that correlated with this behavioral contrast and compared the development and structure of larval muscles between these species. We report substantial differences in some aspects of larval musculature. In addition to previously described oral musculature, both larvae possessed polygon-shaped musculature at the basal end of the larva. However, larval musculature in E. tribuloides was larger and contained additional muscles not observed in larvae of L. variegatus. Therefore, a conspicuous larval behavior consisting of repeated flexing of the postoral and posterodorsal larval arms was correlated with a larger, more complex musculature. This simple contrast indicates that larval musculature not associated with endoderm evolves in a manner that relates to differences in larval behavior and that additional comparisons are warranted. [ABSTRACT FROM AUTHOR]

Between 2012 and 2014, in the sub-regions of Lake Balaton (Hungary) and the adjacent swamp called Kis-Balaton having stocks of biting mosquito species with large number of specimens, we regularly performed imago collections. In the pooled samples which were collected by aspirator and contained 6,906 adult insects, a nematode infected specimen was detected. The only worm in the abdomen of the female Anopheles maculipennis complex was proved to be a larval mermithid by its morphology but in consequence of the weak morphological characters more detailed identification was not possible. To avoid destroying this evidentiary specimen no DNA extraction has been performed from it so far. This finding proves that it is worth to inspect not only the larvae but also the adult mosquitoes for the presence of mermithids. In Europe, parasites belonging to the Mermithidae family have been found in biting mosquitoes only in Northern Europe. These larvae were detected in Finland, Norway, Sweden and in Denmark. This is the first mosquito-parasitic mermithid recorded from Central Europe. [ABSTRACT FROM AUTHOR]