Development Of Immature Stages Research Articles

Naturally Abscised Fruitlets as a Potential Breeding Resource for Early Spring Buildup of Medfly Populations in Temperate Regions

The Mediterranean fruit fly (medfly), Ceratitis capitata, is considered one of the most destructive fruit pests worldwide. Female medflies prefer to lay eggs in ripening, ripe, or overripe fruits. In deciduous orchards of temperate regions, fruitlets (juvenile fruits) of early cultivars could represent the earliest spring resource with a potential host function for medflies. However, little is known about the medfly female’s ability to ovipositing and complete breeding in fruitlets. To clarify the possible role of fruitlets, the suitability of key-host fruitlets for the oviposition of medflies and the further development of immature stages were examined in laboratory conditions and an attempt was made to assess the degree of infection of fruitlets collected in the field. Additionally, the development of the overwintering medfly population and the putative use of fruitlets as a resource for early population growth were simulated using the PESTonFARM model optimized to reflect specific features of medfly biology and behavior. Our laboratory data demonstrate that nectarine and pear fruitlets can support the full development of medfly offspring. However, no medfly pupae were obtained from a sample of 14,000 fruitlets collected at the farm. The simulation showed that the sample number needed to detect with at least 95% certainty rare cases of medfly pupae or adults emerging from infected fruitlets is several tens of thousands, which is several times more than the actual number of fruitlets used in our study. Our research suggests that the fruitlets of some cultivated fruit species can potentially constitute a viable food resource for the development of the earliest generation of spring medflies, with implications for medfly Integrated Pest Management (IPM).

Native range host-specificity and impact studies of Osphilia tenuipes Fairmaire (Coleoptera, Curculionidae): a potential biocontrol agent for Kalanchoe delagoensis (Crassulaceae) in Australia

ABSTRACT Kalanchoe delagoensis Eckl. & J.Zeyh. (Crassulaceae, mother-of-millions) is a plant endemic to Madagascar which was introduced to, and became invasive in, Australia. The stem-boring weevil Osphilia tenuipes Fairmaire (Coleoptera, Curculionidae) is a natural enemy of K. delagoensis in Madagascar. A laboratory culture of this insect was established from field collections in the south of Madagascar, and its potential as a biocontrol agent for Australia was assessed under natural field conditions in Madagascar. The host range of O. tenuipes (open and closed multiple-choice tests, and a multi-generational trial) was examined with seven Kalanchoe spp. and one Echeveria sp. These trials demonstrated that O. tenuipes was oligophagous. However, oviposition and development of immature stages through to adults were recorded on two species of interest for Australia, Kalanchoe spathulata DC. and Kalanchoe blossfeldiana Poelln (Crassulaceae). The multi-generational trials showed that O. tenuipes completed five generations on K. spathulata and K. blossfeldiana. Emergence and survival of adults on controls (K. delagoensis) and the three species tested were significantly different. Osphilia tenuipes adult weights were not significantly different (for species and generations). Adult survival after 30 days was significantly higheron K. delagoensis compared to K. blossfeldiana and K. spathulata. The weevil significantly reduced the numbers of phyllodes and bulbils and overall plant biomass of K. delagoensis. It was evident that O. tenuipes is a damaging, oligophagous insect with significant promise as a potential biocontrol agent for K. delagoensis in Australia.

Lethal and Sublethal Effects of Cyromazine on the Biology of Musca domestica Based on the Age-Stage, Two-Sex Life Table Theory.

Cyromazine is a triazine insect growth regulator insecticide that is recommended for control of Musca domestica worldwide. Cyromazine is highly effective in causing mortality of M. domestica; however, some aspects of its lethal and sublethal effects on the biology of M. domestica are still unknown. The present study explored lethal and sublethal effects on several biological traits and population parameters of M. domestica. Concentration-response bioassays of cyromazine against third-instar larvae of M. domestica exhibited sublethal and lethal effects from concentrations of 0.03 (LC10), 0.06 (LC25), and 0.14 (LC50) μg/g of a larval medium. Exposure of M. domestica larvae to these concentrations resulted in reduced fecundity, survival, longevity and oviposition period, and delayed development of immature stages (i.e., egg hatch time and larval and pupal durations) in the upcoming generation of M. domestica. The values of population parameters such as intrinsic rate of increase, finite rate of increase, net reproductive rate, age-specific survival rate and fecundity, and age-stage life expectancy and reproductive value, analyzed using the age-stage and two-sex life table theory, were significantly reduced in a concentration-dependent manner in comparison with the control group. In conclusion, the study highlights the significant effects of cyromazine on the biology of M. domestica that could help suppress its population in cases of severe infestations.

Larval morphology and temperature-dependent development models of Fannia pusio (Wiedemann): A forensic indicator with expanding distribution

Fannia pusio (Wiedemann) is originally from tropical and subtropical regions of the Americas, where it has repeatedly been collected from both animal carrion and human cadavers. This species is expanding its distributional range, and it has been introduced to Africa, Asia, Australia, Oceania, and Europe. Newly introduced species may be confused with native species of local arthropod necrophagous assemblages, which from a forensic entomology perspective may impact the accuracy of post-mortem interval (PMI) estimations based on insect evidence. In this work we aim to raise awareness among forensic entomologists of the potential benefits and risks associated with the expanding range of F. pusio. Morphology of all larval instars is documented with a combination of light, confocal laser scanning and scanning electron microscopy. Characters allowing identification from other forensically important Fanniidae are listed. Thermal requirements for the development of immature stages of F. pusio were examined under nine ambient temperatures. Models describing changes in larval body length over time were produced for eight different temperatures. The thermal summation constant (k) and developmental zero (Tmin) were calculated for six developmental events: hatching, first ecdysis, second ecdysis, wandering, pupariation, and eclosion.

Impacts of gamma radiation, as hygiene physical control agent, on population growth of Tribolium castaneum (coleoptera: Tenebrionidae) in wheat flour

Traditional control agents are usually inconvenient for managing Tribolium castaneum especially in sensitive stored products such as milled flour where those agents may cause its spoilage or have detrimental effects on health of consumers. Gamma radiation of Cobalt-60 may be hygiene, safe and effective physical control agent for controlling T. castaneum that low gamma radiation doses can save physicochemical aspects of milled wheat flour. Therefore, effects of low doses (0, 10, 30, 50, 70 and 90 Gy) of gamma radiation were examined on survivability, development, formation and normality of developmental stages of rust red flour beetles (larvae and pupae) and on emergence and mortality of adults. Furthermore, their direct and consequent sterilizing effect on adults was also concerned. Irradiated larvae with gamma radiation doses 70–90 Gy reduced larvae numbers up to 100%. A dose of 70 Gy was also sufficient to cause completely inhibition for next pupal development, while a dose of 50 Gy was sufficient to cause completely inhibition for consequent adult emergence. Although, 67.41–81.02% of emerged adults from irradiated pupae with radiation doses 70–90 Gy were dead or deformed, gamma radiation dose of 90 Gy was sufficient to cause complete sterility for healthy emerged adults. Irradiating adult populations with doses ranged between 50 and 90 Gy reduced adult population growth 75.00–87.50%. A dose of 30 Gy was considered as effective and economic dose for reducing 94.41–99.50% of progeny production of irradiated adults. Thus, gamma radiation dose of 90 Gy may be optimal dose to reduce the pest population and prevent the pest recovery, by killing and inhibiting development of immature stages and causing complete sterility of mature stage.

Effects of elevated temperatures on the development of immature stages of Anopheles gambiae (s.l.) mosquitoes.

This study investigated the effects of temperature on the development of the immature stages of Anopheles gambiae (s.l.) mosquitoes. Mosquito eggs were obtained from laboratory established colonies and reared under eight temperature regimes (25, 28, 30, 32, 34, 36, 38 and 40°C), and 80 ± 10% relative humidity. Larvae were checked daily for development to the next stage and for mortality. Pupation success, number of adults produced and sex ratio of the newly emerged adults were recorded. Larval survival was monitored every 24h, and data were analysed using Kaplan-Meier survival analysis. Analysis of variance was used where data followed normal distribution, and a Kruskal-Wallis test where data were not normally distributed. Larval and pupal measurements were log-transformed and analysed using ordinary least square regression with robust standard errors. Increasing the temperature from 25 to 36°C decreased the development time by 10.57days. Larval survival (X2 (6) = 5353.12, p < 0.001) and the number of adults produced (X2 (5) = 28.16, p < 0.001) decreased with increasing temperature. Increasing temperatures also resulted in significantly smaller larvae and pupae (p < 0.001). At higher temperatures, disproportionately more male than female mosquitoes were produced. Increased temperature affected different developmental stages in the life cycle of An. gambiae (s.l.) mosquitoes, from larval to adult emergence. This study contributes to the knowledge on the relationship between temperature and Anopheles mosquitoes and provides useful information for modelling vector population dynamics in the light of climate change.

Characterized Gene Repertoires and Functional Gene Reference for Forensic Entomology: Genomic and Developmental Transcriptomic Analysis of Aldrichina grahami (Diptera: Calliphoridae).

Many flies of Diptera are common entomological evidence employed in forensic investigation. Exploring the existence of inter- and intra-species genomic differences of forensically relevant insects is of great importance. Aldrichina grahami is a common blow fly species of forensic importance. The present study characterized the gene repertoires of A. grahami, and provides insights into issues related to forensic entomology, such as necrophagous behavior, gene family features, and developmental patterns. Gene families were clustered and classified according to their function in different aspects of the necrophagous lifestyle, generating several gene repertoires. The genes under positive selection pressure and evolutionary changes were screen and identified. Moreover, genes that exhibited potential prediction value in the post mortem interval (PMI) estimation and development of immature stages were subjected to analysis based on the developmental transcriptome. Related insect species were compared at the genomic level to reveal the genes associated with necrophagous behaviors. The expression of selected genes in separated repositories was verified using qPCR. This work was conducted using a high-quality chromosome-level genome assembly of A. grahami and its developmental transcriptome. The findings will facilitate future research on A. grahami and the other forensically important species.

Functional and numerical responses of the predatory mite Amblyseius aerialis (Acari: Phytoseiidae) to Aceria guerreronis (Acari: Eriophyidae)

The coconut mite, Aceria guerreronis Keifer, is one of the main pests of the coconut tree (Cocos nucifera L.) worldwide. Its control is mainly based on the use of acaricides. However, due to the habitat of this pest mite, which is protected by fruit bracts that act as a physical barrier, chemical control is often inefficient. Thus, natural enemies have been studied as an alternative to acaricides. We evaluated the functional and numerical responses of Amblyseius aerialis (Muma) to increasing densities of A. guerreronis (40, 80, 160, 240 and 360) and additionally the oviposition rates of the phytoseiid A. aerialis over 11 days on different food sources: coconut pollen, A. guerreronis and a mix of pollen and A. guerreronis. Our results showed that Amblyseius aerialis showed a type III functional response, where prey consumption increasing as the density of A. guerreronis increased, with a maximum consumption of up to 175 prey per predator. All the prey densities allowed female oviposition. The number of eggs laid by A. aerialis increased with increasing prey density and stabilized between 240 and 360 A. guerreronis individuals, with an average oviposition of 1.7 eggs/female. Furthermore, our results showed that all the food sources (coconut pollen, A. guerreronis and a mix of pollen and A. guerreronis) supported oviposition. The mean oviposition was approximately 1.5 eggs/female on all the food sources. Our study suggests that A. aerialis can be effective in the biological control of A. guerreronis. However, further studies are needed to investigate whether A. aerialis can explore the habitat of A. guerreronis and if that prey can support the development of immature stages and the reproduction of A. aerialis.

Oviposition of Culicoides insignis (Diptera: Ceratopogonidae) under laboratory conditions with notes on the developmental life history traits of its immature stages

BackgroundCulicoides insignis is a confirmed vector of bluetongue virus (BTV) throughout the American tropics and a possible vector of epizootic hemorrhagic disease virus (EHDV) in Florida. Despite its importance, fundamental information on the biology and ecology of this vector species is lacking. In this study, we examined the oviposition of C. insignis under laboratory conditions, monitored the development of immature stages and attempted colonization of this species.MethodsLive C. insignis females were collected from the field using CDC-UV-LED traps, allowed to blood-feed on live chicken and given various natural substrates for oviposition in two-choice assays. The eggs deposited were transferred to 0.3% agar slants, and the hatched larvae were provided a diet of Panagrellus redivivus Linnaeus nematodes and the development of all immature stages was monitored.ResultsCulicoides insignis females exhibited an overall oviposition preference for dishes containing mud from their larval habitat as gravid females deposited a significantly higher number of eggs on these dishes (35.3 eggs/female) than on controls (17.7 eggs/female). The ovipositing females also deposited a higher percentage of eggs on substrates with habitat mud and other organically enriched muds (≥ 75.2%) compared to controls (31.0%). The larvae developed successfully to adulthood on the nematode diet, exhibiting high overall larval survival rates (85.0%). Sex ratios of the F1 generation were male biased, approximately 3:1 (male:female). Captive mating could not be induced in the F1 adults.ConclusionsMud from the larval habitat and other organically enriched muds provide strong oviposition cues to C. insignis under laboratory conditions. Further studies will be needed to identify the key biotic/abiotic factors influencing midge oviposition in the field. The agar/nematode method is effective for the rearing of C. insignis larvae. However, further studies will be needed to address the issue of male-biased sex ratios in the progeny and to examine the mating habits/cues of C. insignis in nature, which may provide clues towards inducing captive mating in the F1 adults.Graphical abstract

Developmental Temperature Affects Life-History Traits and Heat Tolerance in the Aphid Parasitoid Aphidius colemani.

Simple SummaryIndividual insects can experience different temperatures across their lives. In consequence, development of immature stages can take place at temperatures contrasting with those that the adult will encounter. In order to study the adaptation of organisms to warm environments, it is interesting to establish the links between developmental temperature and responses of the adult generation, in terms of physiology, morphology, and behavior. We exposed the parasitoid Aphidius colemani to three temperatures during larval development (10, 20, or 28 °C). We then measured the responses of adult parasitoids regarding their traits (physiology, morphology) and their tolerance to high temperatures. Mass, lipid reserves, survival, and heat tolerance of adults were affected by the rearing temperature regime. This means that, overall, developmental temperatures may affect how insects respond to a given temperature once they are adults, which may consequently influence the ability of parasitoids to control their aphid hosts. These results are important in the context of biological control in hot environments, such as the Maghreb, where this species of parasitoid is used in mass release techniques to control aphids in various crops.Developmental temperature plays important roles in the expression of insect traits through thermal developmental plasticity. We exposed the aphid parasitoid Aphidius colemani to different temperature regimes (10, 20, or 28 °C) throughout larval development and studied the expression of morphological and physiological traits indicator of fitness and heat tolerance in the adult. We showed that the mass decreased and the surface to volume ratio of parasitoids increased with the development temperature. Water content was not affected by rearing temperature, but parasitoids accumulated more lipids when reared at 20 °C. Egg content was not affected by developmental temperature, but adult survival was better for parasitoids reared at 20 °C. Finally, parasitoids developed at 20 °C showed the highest heat stupor threshold, whereas parasitoids developed at 28 °C showed the highest heat coma threshold (better heat tolerance CTmax1 and CTmax2, respectively), therefore only partly supporting the beneficial acclimation hypothesis. From a fundamental point of view, our study highlights the role of thermal plasticity (adaptive or not) on the expression of different life history traits in insects and the possible correlations that exist between these traits. From an applied perspective, these results are important in the context of biological control through mass release techniques of parasitoids in hot environments.

Bionomics of predatory butterfly, apefly (Spalgis epius) (Lepidoptera: Lycaenidae) on mealybug, Paracoccus marginatus (Hemiptera: Pseudococcidae) in Mulberry

Apefly, Spalgis epius (Westwood) (Lepidoptera: Lycaenidae) is a small phytophagous butterfly. The larvae feed on the bugs of Pseudococcidae, Hemiptera. In the present study, the development of immature stages and life cycle of this predatory butterfly was observed on Paracoccus marginatus (Williams and Granara de Willink) (Hemiptera: Pseudococcidae) in mulberry under laboratory conditions. The collected eggs have been stored in the laboratory at 40-80% Relative Humidity and 25-30 °C. The eggs had been disk-shaped and greenish-blue in colour, sculptured and each top and bottom compacted with micropylar despair withinside the top and hatched in 3.2 ± 0.15 days. It beneath is going 4 larval instars and the entire larval duration lasts 12.99 ± 0.01 days. The top surface of the larval body turned completely evolved with a wax coating. The mold on the hard dorsal side of the pupa resembled the face of a monkey structure. The prepupal larva reduced in size and the surface of the body turned dull black colour. The duration of the pupal period was recorded as 10.07 ± 0.03 days. The overall duration from egg to adult emergence was observed as 30.64 ± 0.31 days. In adults, the patch is larger in females than that in males. The information of the development and life cycle of S. epius on natural/ factitious hosts on numerous crops is advantageous to develop and standardize the mass culturing techniques for exploration of this capability species for predation of mealybugs.

Performance of two species of whiteflies is unaffected by glucosinolate profile in Brassica plants.

While plant glucosinolates are known to impart resistance to many insects, their role in the interactions between plants and many phloem-feeding insects such as whiteflies are poorly understood. The whitefly Bemisia tabaci complex comprises many cryptic species that differ in the ability to utilize Brassica plants. However, whether Brassica plants-specific traits such as glucosinolates determine differences of whiteflies in colonizing Brassica plants remains in question. We first observed performance of two whitefly species MEAM1 and Asia II 3, which differ obviously in their ability to colonize Brassica plants, on four cultivars of three Brassica species that vary in glucosinolate profile. We found that the life history characteristics of each of the two whitefly species seems to be only marginally affected by cultivar. We next used wild-type Arabidopsis plants and mutants defective in glucosinolate biosynthesis or hydrolysis to explore the effects of glucosinolates on the whitefly. We found that fecundity and development of immature stages of neither of the two whitefly species differ significantly between wild-type and mutants. The data suggest that glucosinolates may have little effect on the oviposition by adults and the survival and development of immature stages of MEAM1 and Asia II 3 whiteflies. The marked differences in colonizing Brassica crops between the two whitefly species are likely due to plant traits other than glucosinolates. © 2021 Society of Chemical Industry.

Progeny fitness determines the performance of the parasitoid Therophilus javanus, a prospective biocontrol agent against the legume pod borer

Therophilus javanus (Bhat & Gupta) is an exotic larval endoparasitoid newly imported from Asia into Africa as a classical biological control agent against the pod borer Maruca vitrata (Fabricius). The parasitoid preference for the five larval instars of M. vitrata and their influence on progeny sex ratio were assessed together with the impact of larval host age at the time of oviposition on development time, mother longevity and offspring production. In a choice situation, female parasitoids preferred to oviposit in the first three larval instars. The development of immature stages of the parasitoid was observed inside three-day-old hosts, whereby the first two larval instars of T. javanus completed their development as endoparasites and the third larval instar as ectoparasite. The development time was faster when first larval instars (two- and three-day-old) of the host caterpillars were parasitized compared to second larval instar (four-day-old). The highest proportion of daughters (0.51) was observed when females were provided with four-day-old hosts. The lowest intrinsic rate of increase (r) (0.21 ± 0.01), the lowest rate of increase (λ) (1.23 ± 0.01), and the lowest net reproductive rate (Ro) (35.93 ± 6.51) were recorded on four-day-old hosts. These results are discussed in the light of optimizing mass rearing and release strategies.

Thermal Requirements and Population Viability of Chrysodeixis includens (Lepidoptera: Noctuidae).

Development, mortality, fecundity, and longevity of soybean looper Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae, Plusiinae) were examined at six constant temperatures (18, 22, 25, 28, 32, and 36∘C) under laboratory conditions. This set range comprises temperatures observed at soybean- and cotton-producing regions during the growing season. Complete development from egg to adult was observed from 18 to 32∘C. Linear and nonlinear models were fitted to the data to estimate thermal constants and bioclimatic thresholds. Although the development of immature stages of C. includens can be expected across broader temperature ranges, this species is meant to complete the whole cycle and recover from low densities between 19.7 and 30.0∘C. The best fitness is achieved at 25.4∘C. The results can be used to parameterize phenological or mathematical models to forecast the occurrence of different stages of C. includens in the field and help optimize the efforts to control this insect-pest.

Biological performance of the predatory mite Neoseiulus barkeri Hughes (Phytoseiidae): a candidate for controlling of three mite species infesting grape trees

The life history and predation rate of Neoseiulus barkeri (Phytoseiidae) feeding on Colomerus vitis (Eriophyidae), Tetranychus urticae (Tetranychidae) and Brevipalpus lewisi (Tenuipalpidae) were determined in the laboratory at constant temperatures of 25, 30 and 35 °C, relative humidity of 50 ± 5 % and a photoperiod of 16:8 h (light:dark). Within the temperature range studied, the increase of temperature from 25-35 °C led to a shortened development period and an increased total predation rate and reproduction. Survival during immature stages development surpassed 94 % at all the temperatures from 25 to 35 °C. The highest fecundity (59.50, 48.25 and 35.30 eggs per female) was recorded at 35 °C, while the minimum (40.25, 31.00 and 20.50 eggs per female) was at 25 °C when N. barkeri fed on C. vitis, T. urticae and B. lewisi, respectively. It is demonstrated in the life table parameters that when the predatory mite N. barkeri is fed on C. vitis, the highest reproduction rates (rm = 0.195, 0.210 and 0.232 females/female/day) are obtained, while feeding on B. lewisi gave the minimum of reproduction rates (rm = 0.095, 0.105 and 0.115) at 25 °C, 30 °C and 35 °C, respectively. The population of N. barkeri multiplied 20.45, 22.63 and 24.89 times in a generation time of 16.80, 14.75 and 12.50 days when fed on C. vitis at the same temperatures mentioned above, respectively, while N. barkeri multiplied 10.70, 12.88 and 14.36 times in a generation time of 23.20, 21.11 and 18.08 days when fed on B. lewisi at the same temperatures, respectively. This shows that N. barkeri is a promising control agent for C. vitis, T. urticae and B. lewisi on grape trees.

Development of immature stages of Heteronychus arator rugifrons (Fairmaire, 1871) (Coleoptera: Dynastidae), a major crop pest in Madagascar

Adults (black beetles), and to a lesser extent, larvae (white grubs), of Heteronychus arator rugifrons (Fairmaire) are major crop pests of cereals—particularly upland rice—in the central highlands of the island of Madagascar. Since the biology of this endemic subspecies is far less well understood than that of the African black beetle Heteronychus arator F., we undertook laboratory studies to determine the developmental durations of its immature stages at two temperatures, with measurements taken (body length and weight of all stages/instars, head capsule width of all larval instars). The mean immature stage development period was significantly shorter at 25°C (160.8 ± 11.60 d) than at 18°C (251.4 ± 11.93 d), mainly due to shorter egg incubation, L1 instar and pupal periods. Some morphological traits of immature stages confirmed that H. arator rugifrons is a distinct subspecies from H. arator. In particular, head capsule width was homogenous among larval instars, irrespective of the rearing temperature, with no overlap across instars. Head capsule width range was 1.04–1.52 for L1, 1.72–2.36 for L2, and 2.40–3.48 for L3. This information should be helpful in studies of population dynamics and economic threshold calculations with a view to management of this pest.

An alternative protocol for rearing of stable fly, Stomoxys calcitrans (Diptera: Muscidae) under laboratory conditions

Stomoxys calcitrans is widely adopted in experiments due to their relevance in animal health. Nevertheless, the rearing of S. calcitrans under laboratory conditions is still a challenge. In this manuscript, we show a new method for rearing the immature stages of S. calcitrans using plant material as only substrate source and sterilized sand for pupae to mimic their natural environment in order to maintain the colonies in the laboratory and for other biological tests. For this purpose, 65 eggs were collected from the colony established in the laboratory and placed into Petri dishes (80 × 15 mm) containing 50 grams of a mixture of alfalfa hay (100 g) and distilled water (200 ml), in a controlled environment (27 ± 1 °C and 70 ± 5 % UR), and the experiment was repeated six times. The mean number of days for egg hatching was 1.4 (± 0.5), the larval period from L1 to L3 was 11.33 days (± 1.75) and the pupal period was 5.83 days (± 0.51). The complete cycle from egg to adult was 18.66 days (± 2.06). The mean larval survival rate, pupation rate, and emergence rate (pupa to adult) were 91.03 % (± 3.14), 88.71 % (± 3.17), and 91.13 % (± 3.0), respectively. The results obtained in the present work indicated that the use of a larval substrate with alfalfa hay allowed the development of immature stages of S. calcitrans in laboratory, which has been demonstrated by the good percentages of larval development, pupation, and adult emergence.

The effect of host species on the development of immature stages and biological aspects of the larval parasitoid, Bracon hebetor Say [Hymenoptera: Braconidae] adults

Present research was conducted to study the effect of the host species on the developmental duration of the immature stages of the larval parasitoid, Bracon hebetor and on the biological aspects of the adults of the parasitoid when reared on three different hosts: the great wax moth Galleria mollonella, the Mediterranean flour moth Ephestia kuehniella and the fig moth Ephestia cautella. The results showed that the species of host had a significant effect on some development of the immature stages of the parasite, B. hebetor, as the longest period of the pupa duration on the G. mellonella host was 7.37 days, while the shortest period of the pupa duration on the E. kuehniella host was 4.87 days. The results indicated that there was a significant difference in the period of development from egg to adult of the parasite when reared on host G. mellonella and host E. kuehniella, which amounted to 12.97 and 10.07 days, respectively, on the one hand, and between host E. cautella and host E. kuehniella on the other hand were 11.93 and 10.07 days, respectively. The results also showed that the highest value of the percentage of eggs hatching was 86.60% on the host G. mellonella, while it was 53.7 and 67.80% on the hosts E. kuehniella and E. cautella, respectively.

Scatopsidae (Diptera) reared from graminoid plants in the Czech Republic, with description of a new species of Swammerdamella

Abstract Ten species of Scatopsidae (Diptera) have been reared from tussocks of 7 species of Cyperaceae, 2 species of Juncaceae, 4 species of Poaceae and from dead specimens of 1 species of Typhaceae gathered in meadow, boggy meadow, alder forest and shores of a pond and a montane brook from 3 localities in the Czech Silesia (Czech Republic). One of them, Swammerdamella jindrichi Haenni sp. n. is described as new. Information is given for the first time on the sites of development of immature stages for several species, notably of genera Ferneiella and Thripomorpha.

Development of an Alternative Low-Cost Larval Diet for Mass Rearing of Aedes aegypti Mosquitoes.

Background Aedes aegypti is a major vector of arboviruses that may be controlled on an area-wide basis, using novel approaches such as Sterile Insect Technique (SIT) and Incompatible Insect Technique (IIT). Larval diet is a critical factor to be considered in mass rearing of Aedes mosquitoes for SIT and IIT programs. Therefore, the current study is aimed at evaluating the effects of two novel diets developed from dry fish powder on the growth and development of immature stages and adult fitness-related characteristics of Ae. aegypti in Sri Lanka. Method Three batches of the first instar Ae. aegypti larva, each containing 250 larvae, were exposed to three different larval diets as standard dry fish powder (D1), dry fish powder meal and brewer's yeast (D2), and International Atomic Energy Agency- (IAEA-) recommended diet (D3), separately. Morphometric and developmental parameters of the 4th instar larvae, pupae, and adult mosquitoes reared under different dietary treatments were measured. The entire experimental setup was replicated thrice. A General Linear Model (GLM) in the form of two-way ANOVA was used for the statistical analysis. Results Significant diet-based variations were observed in the head length, head width, thoracic length, thoracic width, abdominal length, abdominal width, and total length (F2,87 > 4.811; P < 0.05) of Ae. aegypti larvae. The highest pupation success and the larval size were observed from the larvae fed the D2 diet, while the lowest was reported from D1. All adult morphometric parameters of adult male and female Ae. aegypti mosquitoes also denoted significant dietary variations, reporting the best-sized adults from the D2 diet (F2,87 > 3.54; P < 0.05). Further, significantly higher fecundity and male longevity were also shown by the adult Ae. aegypti (F2,6 > 7.897; P < 0.01) mosquitoes reared under diet D2. Conclusion Based on all the growth and developmental parameters, the D2 diet tends to perform similar to the IAEA-recommended diet in mass rearing of Ae. aegypti mosquitoes, while being more inexpensive. Therefore, larval diet D2 could be suggested as the ideal diet for mass rearing of Ae. aegypti for IIT and SIT-based vector control in Sri Lanka.