Complete Larval Development Research Articles

Effect of methoprene treated polymer packaging on fecundity, egg hatchability, and egg-to-adult emergence of Tribolium castaneum and Trogoderma variabile

The fecundity, egg hatchability, and egg-to-adult emergence of the red flour beetle, Tribolium castaneum (Herbst) and warehouse beetle, Trogoderma variabile Ballion, were evaluated on untreated and methoprene-treated polyethylene-to-polyethylene (PE-PE) and polyethylene terephthalate-to-polyethylene (PET-PE) packaging at 27 and 32 °C and 60% r.h. Inside and outside surfaces of the packaging were fit into ∼62 cm2 Petri dishes, and 500 mg of flour (T. castaneum) or vanilla shake mix diet (T. variabile) were added to arenas as food for developing larvae. On methoprene-treated PE-PE packaging, hatchability of added T. castaneum eggs was consistently lower than on untreated packaging. On PET-PE packaging, hatchability of T. castaneum eggs on inside surfaces at both temperatures was significantly lower than on untreated packaging. No consistent trends were observed in T. variabilile hatchability between the packaging types, temperatures, and on inside and outside surfaces of untreated and methoprene-treated packaging. The fecundity of T. variabile was not significantly different between the packaging types. None of the T.castaneum eggs on inside and outside surfaces of the PE-PE methoprene-treated packaging emerged as adults. Methoprene-treated PET-PE packaging reduced fecundity of T. castaneum. Generally, hatchability of eggs laid by both species was not significantly different among the treatment combinations. Only the inside surface of PET-PE packaging gave 100% suppression of egg-to-adult adult emergence of T. castaneum. Development of T. variabile larvae was arrested at the pupal stage at both temperatures on the outside surface of methoprene-treated PE-PE packaging, whereas on the inside surface larvae completed development to adulthood. A 87–97% reduction in egg-to-adult emergence of T. variabile was observed on the inside surface of the PET-PE packaging relative to emergence in corrresponding control treatments at both temperatures. The packaging types evaluated in this study can potentially protect food products stored in these packages from infestations of T. castaneum and T. variable.

Formation of the inner ear during embryonic and larval development of the cichlid fish (Oreochromis mossambicus)

ABSTRACTBackground: The vertebrate inner ear comprises mineralized elements, namely the otoliths (fishes) or the otoconia (mammals). These elements serve vestibular and auditory functions. The formation of otoconia and otoliths is described as a stepwise process, and in fish, it is generally divided into an aggregation of the otolith primordia from precursor particles and then a growth process that continues throughout life. Results: This study was undertaken to investigate the complex transition between these two steps. Therefore, we investigated the developmental profiles of several inner ear structural and calcium-binding proteins during the complete embryonic and larval development of the cichlid fish Oreochromis mossambicus in parallel with the morphology of inner ear and especially otoliths. We show that the formation of otoliths is a highly regulated temporal and spatial process which takes place throughout embryonic and larval development. Conclusions: Based on our data we defined eight phases of otolith differentiation from the primordia to the mature otolith.

Suitability of monotypic and mixed diets for Anopheles hermsi larval development.

The developmental time and survival to eclosion of Anopheles hermsi Barr & Guptavanij fed monotypic and mixed diets of ten food types were examined in laboratory studies. Larvae fed monotypic diets containing animal detritus (freeze-dried rotifers, freeze-dried Daphnia pulicaria, and TetraMin® fish food flakes) and the mixotrophic protistan Cryptomonas ovata developed faster and survived better than larvae that were fed other monotypic diets. Survival to adulthood of larvae fed several concentrations of the diatom Planothidium (=Achnanthes) lanceolatum was poor (<13%) and larval development time was approximately twice that of larvae fed TetraMin® fish food flakes, the standard laboratory diet. Larvae fed monotypic diets containing prokaryotes (bacteria [Bacillus cereus] and cyanobacteria [Oscillatoria prolifera]) and brewer's yeast (Saccharomyces cerevisiae) failed to survive beyond the 1(st) and 2(nd) instar, respectively. Larvae fed only chlorophytes, single-celled Chlamydomonas reinhardtii and filamentous Spirogyra communis, failed to complete larval development, regardless of the concentration tested. Cohorts fed a combination of food types (mixed diets) usually developed better than cohorts fed monotypic diets. Food types that failed to support complete development when fed alone often facilitated development to adulthood when fed in combination with food types containing >1% C20 polyunsaturated fatty acids as total fat, but regardless of essential fatty acid content, algae that produced mucilage and filaments that sank out of the feeding zone were poor quality diets.

Effects of temperature and diet on black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae), development

The black soldier fly, Hermetia illucens, is recognised for its use in a forensic context as a means for estimating the time of colonisation and potentially postmortem interval of decomposing remains. However, little data exist on this species outside of its use in waste management. This study offers a preliminary assessment of the development, and subsequent validation, of H. illucens. Larvae of H. illucens were reared at three temperatures (24.9°C, 27.6°C and 32.2°C) at 55% RH on beef loin muscle, pork loin muscle and a grain-based diet (control). Each of the temperatures and diets were found to significantly (P<0.05) affect all stages of immature growth except for pupation time. Overall, those reared on the pork diet required on average ≈23.1% and ≈139.7% more degree hours to complete larval development than those reared on the beef and grain-based diets, respectively. Larvae reared at 27.6°C and 32.2°C required on average ≈8.7% more degree hours to complete development and had a final larval weight ≈30% greater than larvae reared at 24.9°C. The validity of the laboratory larval length and weight data sets was assessed via estimating the age of field-reared larvae. Grain-diet data lacked accuracy when used to estimate larval age in comparison to estimates made with beef and pork-diet data, which were able to predict larval age for ≈55.6% and ≈88.9% of sampling points, respectively, when length and weight data were used in conjunction. Field-reared larval sizes exceeded the maximum observed under laboratory conditions in almost half of the samples, which reduced estimate accuracy. Future research should develop additional criteria for identifying development of each specific instar, which may aid in improving the accuracy and precision of larval age estimates for this species.

Immature Biology ofNeptis hesione podarces(Lepidoptera: Nymphalidae) in Taiwan, With Discussion on Its Frass Chain Function

Neptis hesione podarces Matsumura (Lepidoptera: Nymphalidae) is a rare nymphalid butterfly in Taiwan. Bionomics and immature morphology of this rare species are given in detail in the present article. Its larvae are monophagous, consuming leaves of a climbing fig Ficus sarmantosa (Moraceae). Seven instars are required to complete larval development. We found that younger larvae of N. h. podarces make frass chains, a behavior that has not been found in other Neptis species. Here we test the antipredator function of this larval behavior and provide details on nest building.

Pseudosuccinea columella: experimental co-infections of juvenile and pre-adult snails with the digeneans Calicophoron daubneyi and Fasciola hepatica.

Experimental co-infections of juvenile and pre-adult Pseudosuccinea columella with Calicophoron daubneyi and Fasciola hepatica (five miracidia of each digenean per snail) were carried out to determine the aptitude of this lymnaeid to ensure complete larval development of the former parasite, the latter or both. Snails infected with F. hepatica were found in the two groups of juveniles, i.e. 1 and 2mm at exposure, and the four groups of pre-adults, i.e. 3-6mm. The highest frequency of F. hepatica, i.e. 37.3%, was noted in the 4mm group. Low frequencies were noted for C. daubneyi and co-infections of both digeneans in the 3, 4 and 5mm groups. Two other groups of P. columella, measuring 3 and 4mm at exposure, were also constituted to study the characteristics of these co-infections. Compared to controls infected only with F. hepatica, the frequency of this digenean infection and the mean number of metacercariae were significantly lower in co-infected snails, while the patent period was significantly shorter. In snails harbouring C. daubneyi only or both digeneans, lower values were noted for prevalence, the patent period and the number of metacercariae. Pre-adult P. columella (3-5mm in shell height at exposure) were able to sustain larval development of C. daubneyi if they were co-infected with the sequence C. daubneyi +F. hepatica. Low values noted for the prevalence of C. daubneyi infection and the number of metacercariae would be in favour of a still incomplete adaptation between the snail population and the miracidial isolate.

Larval descriptions of the family Porcellanidae: A worldwide annotated compilation of the literature (Crustacea, Decapoda).

For most of the family Porcellanidae, which comprises 283 species, larval development remains to be described. Full development has been only described for 52 species, while part of the larval cycle has been described for 45 species. The importance of knowing the complete larval development of a species goes beyond allowing the identification of larval specimens collected in the plankton. Morphological larval data also constitute a support to cladistic techniques used in the establishment of the phylogenetic status (see Hiller et al. 2006, Marco-Herrero et al. 2013). Nevertheless, the literature on the larval development of this family is old and widely dispersed and in many cases it is difficult to collect the available information on a particular taxon. Towards the aim of facilitating future research, all information available on the larval development of porcellanids has been compiled. Following the taxonomic checklist of Porcellanidae proposed by Osawa and McLaughlin (2010), a checklist has been prepared that reflects the current knowledge about larval development of the group including larval stages and the method used to obtain the larvae, together with references. Those species for which the recognised names have been changed according to Osawa and McLaughlin (2010) are indicated.

Complete larval development of Thor amboinensis (De Man, 1888)Decapoda: Thoridae) described from laboratory-reared material and identified by DNA barcoding.

Of the 12 species of Thor described until present date, only three (25%) have their complete larval development known. Present work describes the complete larval development of Thor amboinensis, based on laboratory-reared material. The spent females were identified through the analysis of the partial sequences of the mitochondrial DNA barcode, also used for the reconstruction of the phylogenetic relationships within the recently resurrected and recognized family Thoridae Kingsley, 1879. Eight zoeal stages and one decapodid complete this species larval development. In the genus Thor, the number of zoeal stages varies greatly from two (T. dobkini) to eight (T. amboinensis and T. floridanus). The larvae of T. ambionensis and T. floridanus are readily distinguished from each other by the ornamentation of the ventral margin of the carapace and the pereiopods development. The first zoeal stage of T. amboinensis described by Yang & Okuno (2004) and the one described in present study are very similar. A brief discussion on the morphological characters and on the number of zoeal stages of the genus, as well as of the previous larval descriptions is made. The phylogenetic analysis suggest cryptic speciation for geographical separated populations of T. amboinensis, paraphyly of the genus Eualus, and the reassignment of E. cranchii to a different genus.

Genetic basis of Cry1F resistance in two Brazilian populations of fall armyworm, Spodoptera frugiperda

Large-scale adoption of transgenic crops expressing genes from Bacillus thuringiensis (Bt) imposes high selection pressure for evolution of field-relevant resistance that can reduce pest control efficacy, such as reported for Cry1F maize (Zea mays L.) in populations of fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), of Puerto Rico, Brazil, and the United States. As part of our effort to improve fall armyworm resistance management to Bt crops, here we determined the genetic basis of Cry1F resistance in two S. frugiperda strains originated from field collections in different regions of Brazil and further selected in the laboratory for high levels of resistance to Cry1F maize. Continuous exposure to the TC1507 event for 11 generations resulted in more than 183-fold resistance to Cry1F in the two strains studied, and such a high resistance level enabled the insects to complete larval development on the Bt maize plants. Genetic analyses using concentration-response bioassays with progenies from reciprocal crosses between resistant and susceptible insects indicated that the inheritance of the resistance is autosomal, recessive and without maternal effects. Backcross of the F1 progeny with the parental resistant strains revealed that the resistance in the two selected strains is conferred by a single locus or set of tightly linked loci. These results support some of the assumptions of the strategy in use for fall armyworm resistance management to Bt Cry1F maize, but survival rates of heterozygotes on the Bt plants were higher than 5%, showing that the Cry1F maize does not produce a high dose of the insecticidal protein for S. frugiperda. Additionally, we detected a delay in larval development time that may favor assortative mating of individuals carrying resistance alleles. These findings are consistent with the rapid evolution of Cry1F resistance in certain field populations of fall armyworm. Implications for resistance management of S. frugiperda to Bt maize are discussed.

Morphological descriptions of laboratory reared larvae and post-larvae of the Australian shovel-nosed lobster Thenus australiensis Burton &amp; Davie, 2007 (Decapoda, Scyllaridae)

Complete larval development from newly hatched larvae up to the juvenile stage was successfully achieved in the Australian shovel-nosed lobsterThenus australiensisunder laboratory conditions. The larvae of this species passed through four phyllosoma stages (each stage has a single instar), and developed into the first juvenile stage via a post-larval, nisto stage. The shortest and mean durations from hatching to metamorphosis at a water temperature of 25°C were 32 and 38 days, respectively. Morphologies of body and appendages for all four phyllosoma stages and the nisto stage were described. The phyllosomas were fed exclusively on the jellyfishAurelia auritathroughout their culture. Our results indicate that jellyfish may be a viable diet forT. australiensisphyllosoma’s in culture and may therefore be useful for commercial-scale lobster production.

Differentiation of ovarian development and the evolution of fecundity in rapidly diverging exotic beetle populations.

Fecundity is a fundamental determinant of fitness, yet the proximate developmental and physiological mechanisms that enable its often rapid evolution in natural populations are poorly understood. Here, we investigated two populations of the dung beetle Onthophagus taurus that were established in exotic ranges in the early 1970s. These populations are subject to drastically different levels of resource competition in the field, and have diverged dramatically in female fecundity. Specifically, Western Australian O. taurus experience high levels of resource competition, and exhibit greatly elevated reproductive output compared to beetles from the Eastern US, where resource competition is minimal and female fecundity is low. We compared patterns of ovarian maturation, relative investment into and timing of egg production, and potential trade-offs between ovarian investment and the duration of larval development and adult body size between populations representative of both exotic ranges. We found that the rapid divergence in fecundity between exotic populations is associated with striking differences in several aspects of ovarian development: (1) Western Australian females exhibit accelerated ovarian development, (2) produce more eggs, (3) bigger eggs, and (4) start laying eggs earlier compared to their Eastern US counterparts. At the same time, divergence in ovarian maturation patterns occurred alongside changes in (5) larval developmental time, and (6) adult body size, and (7) mass. Western Australian females take longer to complete larval development and, surprisingly, emerge into smaller yet heavier adults than size-matched Eastern US females. We discuss our results in the context of the evolutionary developmental biology of fecundity in exotic populations.

Dominance of Cry1F resistance in Spodoptera frugiperda (Lepidoptera: Noctuidae) on TC1507 Bt maize in Brazil.

Dominance of resistance has been one of the major parameters affecting the rate of evolution of resistance to Bt crops. High dose is the capacity of Bt crops to kill heterozygous insects and has been an essential component of the most successful strategy to manage resistance to these crops. Experiments were conducted to evaluate directly and indirectly whether the TC1507 event is high dose to Spodoptera frugiperda (JE Smith). About 8% of heterozygote neonate larvae were able to survive, complete larval development and emerge as normal adults on TC1507 leaves, while susceptible larvae could not survive for 5 days. The estimated dominance of resistance was 0.15 ± 0.09 and significantly higher than zero; therefore, the resistance to Cry1F expressed in TC1507 was not completely recessive. A 25-fold dilution of TC1507 maize leaf tissue in an artificial diet was able to cause a maximum mortality of only 37%, with growth inhibition of 82% at 7 days after larval infestation. Resistance to Cry1F in TC1507 maize is incompletely recessive in S. frugiperda. TC1507 maize is not high dose for S. frugiperda. Additional or alternative resistance management strategies, such as the replacement of single-trait Bt maize with pyramided Bt maize, which produces multiple proteins targeting the same insect pests, should be implemented wherever this technology is in use and S. frugiperda is the major pest.

The complete larval development of Ibacus ciliatus from hatching to the nisto and juvenile stages using jellyfish as the sole diet

Phyllosomas of scyllarid lobsters are known to associate with jellyfish in the wild, suggesting that they prey on a wide variety of gelatinous zooplankton species. To investigate the potential of utilizing jellyfish as a diet for Ibacus ciliatus phyllosomas in culture, 22 newly hatched phyllosomas were reared individually and fed with the jellyfish Aurelia aurita and Chrysaora pacifica throughout the rearing period. Of the 18 phyllosomas that survived to stage VII, nine directly metamorphosed into the nisto stage 66.8days (range: 65–70) after hatching. Among them, five nistos successfully molted into the juvenile stage 85.0days (range: 83–87) after hatching. On the other hand, eight of the phyllosomas at stage VII molted through an extra instar. Four metamorphosed into the nisto stage 79.3days (range: 76–82) after hatching; however, these nistos failed to molt into the juvenile stage. Significant differences of the body length between the phyllosomas with and without an extra instar were observed after stage V. The addition of an extra instar in phyllosomas at stage VII may have been caused by the insufficient nutritional conditions during the earlier stages. Complete larval development from hatching to the juvenile stage in I. ciliatus was observed for the first time. Our method of using jellyfish as diet may be useful for improving the aquaculture techniques of I. ciliatus, and other species.Statement of relevancePhyllosoma has been known as a gelatinous zooplankton feeder in the wild. The most important finding in the present paper is that phyllosomas of the scyllarid lobster I. ciliatus can grow into the juvenile stage with feeding on jellyfish. The previous studies have tried to rear I. ciliatus phyllosomas with feeding clams or mussels, and observed that phyllosomas successfully metamorphosed into the nisto stage. However, no one has achieved to obtain the juveniles in culture. We utilized jellyfish as diet for phyllosomas. Consequently, the complete larval development from the newly hatched phyllosoma to the juvenile stages was observed for the first time. Jellyfish has been successfully applied as diet for phyllosoma only in the scyllarid lobster Ibacus novemdentatus until today, so that the present experiment is the second successful achievement. This result suggests that growth and survival rates of scyllarid lobster phyllosoma may be improved by use of jellyfish as diet for phyllosoma in their hatchery.Although the nutrition level of the gelatinous zooplankton has been known to be low, survival and growth rates of phyllosoma which fed on gelatinous zooplankton have been higher than those of phyllosoma which fed on other diet containing much nutrition. Similar results have been obtained in several species of fish. Therefore, we emphasize in this manuscript that the utilization of jellyfish as a nutritional resource for the fish and crustacean aquaculture should be further studied.It is considered that the extra molting may be added under conditions where larvae are unable to obtain sufficient energy reserves for growth and metamorphosis. Such conditions are mainly caused by inadequate nutritional quality; however, there is limited information of the critical timing at which the addition of the extra molting is determined. In our experiments, significant differences of body length between the phyllosomas having an extra molting and the phyllosomas without extra molting were started to be observed during the early stage of phyllosomas. Our results suggest that, in decapod crustaceans, the mortality of decapodid and juvenile stages may be affected by insufficient energy reserves during the early larval stages.

Host Plant Resistance in Cultivated Jute and Its Wild Relatives Towards Jute Hairy CaterpillarSpilosoma obliqua(Lepidoptera: Arctiidae)

The oviposition, feeding behavior, and development of the jute hairy caterpillar Spilosoma obliqua Walker (Lepidoptera: Arctiidae) was studied on one cultivated jute species, Corchorus olitorius L. (‘JRO-204') (Malvales: Malvaceae), and 5 wild jute species, viz., C. tridens L., C. trilocularis L., C. pseudo-olitorius Islam & Zaid, C. aestuans L., and C. fascicularis Lamarck under laboratory conditions with a temperature of 27 ± 2 °C and relative humidity of 80 ± 5%. These host plant species had considerable influence on oviposition, larval feeding behavior, larval survival, larval weight, pupation, pupal weight, and adult emergence. Significant differences were observed in oviposition preference based on numbers of eggs laid by the adults. The mean number of egg clusters differed significantly with 3.6 ± 0.3, 3.0 ± 0.6, 3.3 ± 0.3, 3.0 ± 0.6, 1.0 ± 0.6, and 2.0 ± 1.2 on C. olitorius, C. fascicularis, C. trilocularis, C. pseudo-olitorius, C. tridens, and C. aestuans, respectively. The C. pseudo-olitorius and C. aestuans were less preferred with the lowest mean numbers of eggs per cluster (77.2 ± 8.2 and 75.2 ± 38.8, respectively) compared with 174.0 ± 2.7 on C. olitorius. With respect to feeding preferences, most larvae (53.9 ± 3.4%) preferred C. olitorius as compared with 1.6 ± 0.02% and 7.2 ± 1.5% of larvae feeding on C. aestuans and C. tridens, respectively. Only 2 species, namely C. trilocularis and C. olitorius, supported complete larval development. The growth of 3rd instars indicated a maximum antibiosis effect by C. tridens and C. aestuans on S. obliqua. Total protein content in the host plants had a significant positive correlation with the larval survival, weight, pupation, and adult emergence of S. obliqua, whereas polyphenol oxidase and total phenol were negatively correlated. The effect of wild jute species with higher phenol and peroxidase as host plants manifested adversely on larval development, growth, survival, pupation, and adult emergence, which indicates the antibiosis mechanism of resistance.

The complete larval development of Pagurus maculosus Komai & Imafuku, 1996 (Decapoda, Anomura, Paguridae) reared in the laboratory, and a comparison with sympatric species.

The complete larval development of the hermit crab Pagurus maculosus, is described and illustrated based on specimens reared in the laboratory at 15 °C and 33-35 PSU. Newly hatched larvae invariably passed through a short prezoeal stage (10 minutes to 2 hours), four zoeal stages (each of 7 days,) and one megalopal stage (14 days). Distinct morphological features of each larval stage of the present study are compared with other closely related species in Japanese waters, and we found many differences in morphology and the duration of zoeal stages between them. We mentioned significant diagnostic characters separating this species from other congeners in Japanese waters that include the presence of red-yellowish chromatophores on the maxillipeds. This is the first report of complete larvae development of Pagurus maculosus.

English

aegypti Lin. (Diptera: Culicidae) larvae’s midgut The cashew nut shell liquid (CNSL) has been associated with a number of biological activities. The aim of this study was to evaluate the insecticidal potential caused by CNSL from Anacardium occidentalle L . ( Anacardiaceae ) upon Aedes aegypti and verify histomorphological alterations in the larval midgut. The experiments were carried out using third instar A. aegypti larvae, exposed to CNSL at different concentrations. After 24 h, the larvae were treated and stained with hematoxylin-eosin (HE). Morphometric analyzes were performed on the A. aegypti larvae midgut and registered by photomicroscopy. Anacardic acid was identified in CNSL by high performance liquid chromatography (HPLC) and showed 69% purity. The minimum concentration of CNSL that promoted mortality of A. aegypti larvae (LC 10 ) was 0.01 mg mL -1 ; the LC 90 was 0.139 mg mL -1 and the LC 50 was 0.07 mg mL -1 . Changes in the midgut were severe in larvae treated with CNSL, especially at concentrations of 1.0 to 0.01 mg mL-1; degeneration of the lining, hypersecretion of epithelial cells, increased vacuoles, and separation of the epithelial cells from the basal membrane, and disintegration of the brush border and damage of the peritrophic membrane occurred. CNSL caused damage to the midgut of 3rd instars of A. aegypti by irreversibly disrupting their complete larval development. Key words : Dengue fever, bioinsecticids from plants, morfology of midgut

The complete larval development of Pagurus lanuginosus De Haan, 1849(Decapoda, Anomura, Paguridae) reared in the laboratory, with emphasis on the post-larval stage.

The complete larval development of Pagurus lanuginosus is described and illustrated including the first description of the post-larval stage. Specimens were reared in the laboratory at 15°C and 33.5-35.02 PSU. Newly hatched larvae passed through a short prezoeal stage (10 minutes to 2 hours), four zoeal stages (6, 6, 6, 8 days), and one megalopal stage (10 days). We compared the morphological features of each larval stage with those of the preceding two descriptions on the same species, and found many differences in morphology and the duration between zoeal stages. We concluded that significant diagnostic characters separating this species from other congeners in Japanese waters include the presence of two pairs of yellowish chromatophores on the carapace in the zoeal stages, a translucent body flecked with red chromatophores, and two pairs of red chromatophores on the carapace in the megalopal stage.

Complete larval development of the Monkey River Prawn Macrobrachium lar (Palaemonidae) using a novel greenwater technique.

This study documents the complete larval development of the Monkey River Prawn Macrobrachium lar using a new greenwater rearing technique. Approximately 6,000 larvae were reared for 110 days at an initial stocking density of 1 ind./6 L. Salinity at hatch was 10 ± 2 ppt and progressively increased to 30 ± 2 ppt until decapodids had metamorphosed. Temperature was maintained at 28 ± 0.5°C, pH at 7.8 ± 0.2, DO2 > 6.5 mg/L and NH4+ and NH3 ≤ 1.5 and ≤0.1 ppm respectively throughout the culture period. Larval development was extended and occurred through 13 zoeal stages, with the first decapodid measuring 6.2 ± 0.63 mm in total length observed after 77 days. 5 decapodids in total were produced, and overall survival to this stage was 0.08%. Overall, the pattern of larval growth shares similarities with those of other Macrobrachium spp. that have a prolonged/normal type of development, and it is likely that larvae underwent mark time moulting which contributed to the lengthened development duration. While this study represents a significant breakthrough in efforts to domesticate M. lar, improvement of larval survival rates and decreased time till metamorphosis are required before it can become fully viable for commercial scale aquaculture.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-3-568) contains supplementary material, which is available to authorized users.

Host testing of the parasitoid Cotesia urabae (Austin &amp; Allen, 1989) (Hymenoptera: Braconidae) to assess the risk posed to the New Zealand nolid moth Celama parvitis (Howes, 1917) (Lepidoptera: Nolidae): do host deprivation and experience influence accept

Retrospective host specificity testing of the recently introduced biological control agent Cotesia urabae Austin & Allen, 1989 against Uraba lugens Walker, 1863 was conducted to assess the potential risk posed to the endemic nolid moth Celama parvitis Howes, 1917. The effect that different periods of host deprivation and prior host exposure (‘experience’) had on the parasitoid's readiness to attack a non-target species was examined in a sequence of consecutive no-choice tests. Even though C. urabae was observed to oviposit on C. parvitis in 91% of the no-choice tests, no parasitoids emerged from the 52% of larvae that survived to complete larval development. Host larvae that died during the laboratory rearing were dissected revealing that 63% contained a parasitoid larva, none of which had developed beyond the second instar within the larvae of C. parvitis. These results show a high level of developmental failure of C. urabae within C. parvitis, confirming that it is not a suitable physiological host. Therefore, potential negative impacts of C. urabae on C. parvitis in the wild are likely to be negligible. Significant differences were found in the attack times between parasitoids with different levels of host deprivation, with younger parasitoids taking longer to initiate attack behaviour. Also, it was observed that the lag until first attack decreased significantly after previous experience with the same host in a succession of no-choice tests. These results suggest that host deprivation and experience may play an important role in increasing the responsiveness to non-target species by C. urabae.

Changes in the nutritional composition of captive early-mid stage Panulirus ornatus phyllosoma over ecdysis and larval development

Abstract Elucidation of the key nutritional requirements for complete larval development of the tropical spiny rock lobster, Panulirus ornatus, presents a major challenge for the development of robust commercial aquaculture for this crustacean. As a foundation study in this area, the chemical composition of early–mid stage P. ornatus phyllosoma (Stages I–VI) receiving a novel formulated diet was analysed immediately prior and post-ecdysis to provide insight into the crude nutritional trends during the larval development cycle. From the onset of moulting, cyclical patterns were evident in the proximate composition of phyllosoma, resulting in substantial restructuring between the pre- and post-moult stages of the moult cycle. Proportions of protein, lipid and ash were high at the premoult stage, reflecting growth and nutrient accumulation over the intermoult period, and reduced at the post-moult stage, reflecting the large uptake of water to facilitate subsequent growth. Polar lipid was the dominant lipid class, accounting for > 90% of the total lipid content. Conversely, triacylglycerol concentrations were low (