Pupal Development Research Articles

The dual Ras Association (RA) Domains of Drosophila Canoe have differential roles in linking cell junctions to the cytoskeleton during morphogenesis.

During development cells must change shape and move without disrupting dynamic tissue architecture. This requires robust linkage of cell-cell adherens junctions to the force-generating actomyosin cytoskeleton. Drosophila Canoe and mammalian Afadin play key roles. One central task for the field is defining mechanisms by which upstream inputs from Ras-family GTPases regulate Canoe/Afadin. They are unusual in sharing two tandem Ras-association (RA) domains, which, when deleted, virtually eliminate Canoe function. Work in vitro suggested RA1 and RA2 differ in GTPase affinity, but their individual functions in vivo remain unknown. Combining bioinformatic and biochemical approaches, we find that both RA1 and RA2 bind to active Rap1 with similar affinities, and their conserved N-terminal extensions enhance binding. We created Drosophila canoe mutants to test RA1 and RA2 function in vivo. Despite their similar affinities for Rap1, RA1 and RA2 play strikingly different roles. Deleting RA1 virtually eliminates Canoe function, while mutants lacking RA2 are viable and fertile but have defects in junctional reinforcement in embryos and during pupal eye development. These data significantly expand our understanding of regulation of adherens junction:cytoskeletal linkage.

A large reverse-genetic screen identifies numerous regulators of testis nascent myotube collective cell migration and collective organ sculpting.

Collective cell migration is critical for morphogenesis, homeostasis, and wound healing. During development migrating mesenchymal cells form tissues that shape some of the body's organs. We have developed a powerful model for examining this, exploring how Drosophila testis nascent myotubes migrate onto the testis during pupal development, forming the muscles that ensheath it and also creating its characteristic spiral shape. To define genes that regulate this process, we have carried out RNAseq to define the genes expressed in myotubes during migration. Using this dataset, we curated a list of 131 ligands, receptors and cytoskeletal regulators, including all Rho-family GTPase GAPs and GEFs, as candidates. We then used the GAL4/UAS system to express 279 shRNAs targeting these genes, using the muscle specific driver dMef2>GAL4, and examined the adult testis. We identified 29 genes with diverse roles in testis morphogenesis. Some have phenotypes consistent with defects in collective cell migration, while others alter testis shape in different ways, revealing some of the underlying logic of testis morphogenesis. We followed up one of these genes in more detail-that encoding the Rho-family GEF dPix. dPix knockdown leads to a drastic reduction in migration and a substantial loss of muscle coverage. Our data suggest different isoforms of dPix play distinct roles in this process, reveal a role for its protein partner Git. We also explore whether cdc42 activity regulation or cell adhesion are among the dPix mechanisms of action. Together, our RNAseq dataset and genetic analysis will provide an important resource for the community to explore cell migration and organ morphogenesis.

Assessment of larvicidal, growth-suppressing, and developmentaltering bioefficacy of Ageratum houstonianum against Aedes aegypti (L.).

Aedes aegypti is a major vector responsible for spreading dengue, chikungunya, yellow fever, and Zika viruses worldwide. These illnesses have increased globally due to climate and environmental changes. Vector control and management are the principal tactics for combating mosquitoes-borne diseases in the absence of an effective vaccine. The study aimed to ascertain bioactivities of Ageratum houstonianum leaf acetone extract (AhLAE) against Aedes aegypti. Bioefficacy of AhLAE was tested against fourth instar larvae (L4) of Ae. aegypti using standard WHO protocol. The mortality, growth, and development of larvae, pupae and adults were recorded after exposure to the extract. The AhLAE showed larvicidal activity against L4 with LC50 and LC90 values of 401.88 and 691.24 mg/L, respectively. The mortality of the larvae further increased on subsequent days. The AhLAE caused a significant reduction in pupae formation and adult emergence. It also increased the larval duration of L4 and development duration of the pupa formed from the treated L4, indicating its growth-suppressing effects. The impact of the AhLAE was dose-dependent; high concentrations caused reduction in survival and growth of L4. Consequently, the L4-pupal and L4-adult growth indexes decreased. Additionally, the AhLAE induced developmental anomalies in the form of larva-pupa (L-P) intermediates. The study found that the AhLAE exhibited larvicidal, growth-suppressing, and development-altering activities against Ae. aegypti. The findings suggest the potential of AhALE as a natural insecticidal agent for controlling mosquitoes.

Parasitic behaviour and developmental morphology of Anastatus japonicus reared on the factitious host Antheraea pernyi.

The egg parasitoid Anastatus japonicus is a key natural enemy in the biological control of various agricultural and forestry pests. It is particularly used against the brown marmorated stink bug Halyomorpha halys and the emerging defoliator pest Caligula japonica in East Asia. It has been proved that the eggs of Antheraea pernyi can be used as a factitious host for the mass production of A. japonicus. This study systematically documented the parasitic behaviour and developmental morphology exhibited by A. japonicus on the eggs of A. pernyi. The parasitic behaviour of A. japonicus encompassed ten steps including searching, antennation, locating, digging, probing, detecting, oviposition, host-feeding, grooming, and resting. Oviposition, in particular, was observed to occur in three stages, with the parasitoids releasing eggs during the second stage when the body remained relatively static. Among all the steps of parasitic behaviour, probing accounted for the longest time, constituting 33.1% of the whole time. It was followed by digging (19.3%), oviposition (18.5%), antennation (9.6%), detecting (7.4%), and the remaining steps, each occupying less than 5.0% of the total event time. The pre-emergence of adult A. japonicus involves four stages: egg (0 to 2nd day), larva (3rd to 9th day), pre-pupa (10th to 13th day), pupa (14th to 22nd day), and subsequent development into an adult. Typically, it takes 25.60 ± 0.30 days to develop from an egg to an adult at 25℃. This information increases the understanding of the biology of A. japonicus and may provide a reference for optimising reproductive devices.

Juvenile responses to immune challenges are not carried through to subsequent life stages in an insect

Environmental variability can significantly impact individual survival and reproduction. Meanwhile, high population densities can lead to resource scarcity and increased exposure to parasites and pathogens. Studies with insects can offer valuable insights into eco-immunology, allowing us to explore the connections between these variables. Here we use the moth Anticarsia gemmatalis to examine how increases in population density and immunological challenge during the larval stage shape its investment in immune defence and reproduction. Larvae reared at a high population density exhibited greater lytic activity against bacteria compared to those reared at low density, whilst bacterial challenge (i.e. bacteria-immersed needles) also increased lytic activity. There was no interaction between the variables population density and bacterial challenge, indicating that these are independent. Surprisingly, neither increase in lytic activity carried through to activity in prepupal haemolymph. Rearing of larvae at a high density delayed pupation and decreased pupal weight. The immunological stimulus did not significantly influence pupal development. Lower population density as a larva resulted in greater adult weight, but did not significantly influence lytic activity in the eggs or the number of eggs laid. Negative correlations were found between lytic activity in the eggs and the number of eggs, as well as between adult weight and the number of eggs. Overall, this study demonstrates that high population density and immune challenge trigger increased lytic activity in caterpillars, but this effect is transient, not persisting into later stages. The trade-offs observed, such as delayed pupation and reduced prepupal weights under high density, suggest a balancing act between immune investment and developmental aspects. The findings hint at a short-term adaptive response rather than a sustained strategy. The implications of delayed pupation and smaller adult moths could influence the moth's life history strategy, impacting its role in the ecosystem. Further research tracking larval immune investment and subsequent reproductive success will unveil the evolutionary dynamics of this relationship in changing environments.

Effects of Global Climate Warming on the Biological Characteristics of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae).

Spodoptera frugiperda (J.E. Smith) is a significant economic pest that has recently invaded Africa and Asia. However, much of the information regarding its ecological capabilities in these newly invaded environments remains largely unknown. In this study, the life history traits of the fall armyworm under conditions of increased temperature, different photoperiods, and varying humidity levels were systematically evaluated. Among 43 studies, a total of 20 studies were included in the analysis by passing the screening criteria, and random-effects meta-analysis, fixed-effects meta-analysis, and meta-regression were conducted. It has been found that with the increase in temperature above 20 °C, various physiological indicators of the fall armyworm are significantly enhanced. When the temperature reaches 32 °C, the physiological activities of S. frugiperda are at their highest point. As the temperature increases, the duration of each developmental stage of the fall armyworm decreases significantly, accompanied by an increase in oviposition quantity and period in females. Additionally, the pupal development time is shortened, which leads to an increase in the lifespan of the adult moth. Using temperature and relative humidity as environmental variables, the optimal survival conditions for each insect state of the fall armyworm were calculated. These findings can assist in predicting the population dynamics of the fall armyworm and in formulating appropriate and practical management strategies.

Are weapon allometries steeper in major or minor males? A meta-analysis

Abstract Competition for mates can drive the evolution of exaggerated weaponry and male dimorphism associated with alternative reproductive tactics. In terrestrial arthropods, male dimorphism is often detected as non-linear allometries, where the scaling relationship between weapon size and body size differs in intercept and/or slope between morphs. Understanding the patterns of non-linear allometries is important as it can provide insights into threshold evolution and the strength of selection experienced by each morph. Numerous studies in male-dimorphic arthropods have reported that allometric slopes of weapons are shallower in large “major” males compared to small “minor” males. Because this pattern is common among beetles that undergo complete metamorphosis (holometabolous), researchers have hypothesized that the slope change reflects resource depletion during pupal development. However, no comprehensive survey has examined the generality of this trend. We systematically searched the literature for reports of weapon allometries in male dimorphic species and conducted a phylogenetically controlled meta-analysis to explore the factors influencing the difference in slopes between morphs. Our search identified 59 effect sizes from 19 studies, 50 species, and 5 orders of terrestrial arthropods. We found strong evidence that metamorphosis type influences the patterns of weapon allometries. Slopes were significantly steeper in minor males compared to major males in holometabolous species, but there was no difference in slopes between morphs in hemimetabolous species (i.e. those that undergo incomplete or no metamorphosis). These results support the hypothesis that holometabolous species face a resource ceiling during pupal development that limits the exaggeration of weapon size.

The transcription factor RUNT-like regulates pupal cuticle development via promoting a pupal cuticle protein transcription.

Holometabolous insects undergo morphological remodeling from larvae to pupae and to adults with typical changes in the cuticle; however, the mechanism is unclear. Using the lepidopteran agricultural insect Helicoverpa armigera, cotton bollworm, as a model, we revealed that the transcription factor RUNT-like (encoded by Runt-like) regulates the development of the pupal cuticle via promoting a pupal cuticle protein gene (HaPcp) expression. The HaPcp was highly expressed in the epidermis and wing during metamorphosis and was found being involved in pupal cuticle development by RNA interference (RNAi) analysis in larvae. Runt-like was also strongly upregulated in the epidermis and wing during metamorphosis. Knockdown of Runt-like produced similar phenomena, a failure of abdomen yellow envelope and wing formation, to those following HaPcp knockdown. The insect molting hormone 20-hydroxyecdysonen (20E) upregulated HaPcp transcription via RUNT-like. 20E upregulated Runt-like transcription via nuclear receptor EcR and the transcription factor FOXO. Together, RUNT-like and HaPCP are involved in pupal cuticle development during metamorphosis under 20E regulation.

The Effect of Soil Type and Moisture on the Development of Forensically Important Megaselia scalaris and Dohrniphora cornuta (Diptera: Phoridae).

Necrophagous phorid flies are common insects found on buried corpses, and their developmental data play a crucial role in estimating the post-burial interval (PBI). This study aimed to investigate the effects of soil type and moisture content on some life cycle parameters of two forensically important insects, Megaselia scalaris (Loew, 1866) and Dohrniphora cornuta (Bigot, 1857) (Diptera: Phoridae). Larval and pupal survival, development time, and larval body length of M. scalaris and D. cornuta were observed in three different soil types (loamy sand, sandy loam A, and sandy loam B) with six moisture contents (0%, 20%, 40%, 60%, 80%, and 100%). The results indicated that soil types, soil moisture, and their interaction significantly influenced the growth and development of both species, with moisture being the most influential factor. In each soil, 20% and 40% moisture contents were more suitable for their growth and development. Both the development time and maximum larval body length were significantly different among soil types and moisture contents. The larval period of both species lasted the longest in all soils with 0% moisture content. Additionally, a regression analysis of the relationship between larval body length and development time was performed at different moisture contents in three soils. This study expanded our knowledge of the factors that influence the development of necrophagous insects and provided some reference data for applications of M. scalaris and D. cornuta in PBI estimation.

A long noncoding RNA at the cortex locus controls adaptive coloration in butterflies

Evolutionary variation in the wing pigmentation of butterflies and moths offers striking examples of adaptation by crypsis and mimicry. The cortex locus has been independently mapped as the locus controlling color polymorphisms in 15 lepidopteran species, suggesting that it acts as a genomic hotspot for the diversification of wing patterns, but functional validation through protein-coding knockouts has proven difficult to obtain. Our study unveils the role of a long noncoding RNA (lncRNA) which we name ivory, transcribed from the cortex locus, in modulating color patterning in butterflies. Strikingly, ivory expression prefigures most melanic patterns during pupal development, suggesting an early developmental role in specifying scale identity. To test this, we generated CRISPR mosaic knock-outs in five nymphalid butterfly species and show that ivory mutagenesis yields transformations of dark pigmented scales into white or light-colored scales. Genotyping of Vanessa cardui germline mutants associates these phenotypes to small on-target deletions at the conserved first exon of ivory. In contrast, cortex germline mutant butterflies with confirmed null alleles lack any wing phenotype and exclude a color patterning role for this adjacent gene. Overall, these results show that a lncRNA gene acts as a master switch of color pattern specification and played key roles in the adaptive diversification of wing patterns in butterflies.

Bot fly parasitism in mantled howler monkeys (Alouatta palliata): General patterns and climate influences.

Parasitism is a strong selective pressure, and its study is crucial for predicting the persistence of host species. Mantled howler monkeys are infected by the larvae of the bot fly Cuterebra baeri. This parasitosis produces myiasis and may have negative impacts on host health, although systematic information on the dynamics of this host-parasite relationship is very limited. Currently, all available information on infection patterns of C. baeri comes from a single mantled howler monkey population (Barro Colorado Island, Panama). Therefore, in this study we describe temporal variation in infection patterns for a newly mantled howler monkey population and analyze the relationship between climate and infection likelihood. We assessed the presence of C. baeri nodules in 17 adult individuals in Los Tuxtlas for 10 months through direct observation and compiled data on ambient temperature and rainfall. Most subjects had nodules during the study and there were no differences between sexes in the number of nodules. Nodules were usually located in the neck. Prevalence and abundance of nodules peaked thrice during the study (February, April, and September), a pattern that was very similar to that of parasitism intensity (February, April, and August). Incidence closely tracked these peaks, increasing before and decreasing after them. The likelihood of nodule appearance increased when both mean and minimum temperature decreased in the 24-21 prior days to nodule appearance. It also increased with decreased rainfall in the 5-2 prior days to nodule appearance. Although only three of the eight analyzed climate variables had a significant effect on parasitosis, these results suggest that climate may affect pupal development and the access of larvae to hosts. Besides contributing data on C. baeri parasitism for a new mantled howler monkey population, our study provides novel information on the influence of environmental factors on the dynamics of host-parasite systems.

Pastoral grasses and legumes as potential host plants for fall armyworm Spodoptera frugiperda (J.E. Smith) development.

AbstractThe fall armyworm, Spodopterafrugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is a highly polyphagous, migratory pest native to the tropical and subtropical region of Americas. Grass crops particularly corn have been most heavily impacted since S. frugiperda invaded Australia in 2020. In northern Western Australia, S. frugiperda is primarily a problem in dry season (May to October) crops when there are abundant host plants available in monocultures. During the wet season (November to April) it is not known what host plants may support larval growth and development. Accordingly, this present study undertook a no-choice feeding bioassay to assess larval and pupal development on several grasses and legumes that are present over the wet season in northern Western Australia to evaluate their potential as suitable host plants for S. frugiperda. Maize (control) and sorghum were the most suitable hosts for S. frugiperda development as they supported greater larval and pupal survival, heavier larvae and pupae, and shorter development period. Following maize and sorghum, pastoral grasses, particularly blue grass, and a weedy grass, barnyard grass, had comparable effects on larval and pupal development. Legume pastures (Cavalcade, butterfly pea, and siratro) were unsuitable hosts in this bioassay as very few larvae completed their development to adults. This study demonstrates the potential for rangeland pasture grasses and weedy grasses as wet season host plants for S. frugiperda. They provide the necessary green bridge for S. frugiperda populations to survive. It is recommended that pastoralists monitor their grass forage for S. frugiperda and consider management if significant reductions in biomass are detected.

Chitin synthase genes of Aedes albopictus and their effects on development of pupae.

The invasive species Aedes albopictus is a major vector of several arboviruses. The global spread of this species seriously threatens human health. Insecticide resistance is an increasing problem worldwide that limits the efficacy of mosquito control. As the major structural component of cuticles, chitin is indispensable to insects. Chitin synthase (CHS) is the enzyme that catalyzes the biosynthesis of chitin at the final step. In this study, two CHS genes of Aedesalbopictus (AaCHS1 and AaCHS2) were identified and their basic characteristics were evaluated via bioinformatics analysis. The highest abundance of AaCHS1 transcripts was detected in pupae, whereas that of AaCHS2 transcripts was detected in females; the highest expression levels of AaCHS1 and AaCHS2 were found in the epidermis and the midgut of pupae, respectively. The survival and emergence rates of pupae were significantly reduced after the injection of double-stranded RNA of AaCHS1 or AaCHS2, indicating that both AaCHS1 and AaCHS2 play crucial roles in the pupal development. In addition, the chitin content of pupae was obviously decreased after the suppression of AaCHS1expression by RNA interference (RNAi) treatment. This influence of the RNAi treatment was further supported by the reduced chitin thickness and weakened chitin fluorescence signal in the new cuticle. The midgut of pupae presented a reduced intensity of the chitin fluorescence signal along with RNAi treatment specific to AaCHS2 expression. The results of this study indicate that CHS genes may be suitable as molecular targets used for controlling mosquitoes.

A Countermeasure Strategy against Peramine Developed by Chilesia rudis in the Endophyte-Ryegrass-Herbivore Model.

Exploitation of the symbiotic relationship between endophytic fungi and ryegrass is a crucial technique for reducing the incidence of insect pests. This is primarily due to the production of alkaloids, such as peramine, by the fungi. This alkaloid has been reported as both a deterrent and toxic to a variety of insects. However, insects have developed various strategies to counteract plant defenses. One of the most studied methods is their ability to sequester toxic compounds from plants. In this study, we examined the feeding preferences and adaptation to peramine in Chilesia rudis, a native Chilean larva. Using a no-choice assay, we assessed larval feeding preferences and mass gain on seven experimental lines and two commercial cultivars of endophyte-infected and non-infected ryegrass. Pupal development time and adult performance were evaluated post-assay. Additionally, we measured peramine content in larval carcasses, feces, and ryegrass leaves. Jumbo was the most preferred cultivar with 32 mm2 of leaf tissues consumed. The longest pupal development time was observed in L161 and ALTO AR1, both at 28 days. Wing length in adults was greatest in the Jumbo and L163 cultivars, measuring 1.25 cm and 1.32 cm, respectively. Peramine concentrations were detected in the bodies of C. rudis. In conclusion, this larva can adapt to endophyte-infected ryegrass and develop counter-adaptation mechanisms to mitigate the effects of peramine.

Antenna development, function and its direct or indirect impact on physiology and behaviour of Drosophila melanogaster

AbstractSensory mechanotransduction is the process of deciphering physical stimuli into neural electrical receptor potentials, essential to Drosophila, the fruit fly. Nearly every aspect of an adult Drosophila intricate behavioural repertoire that involves the senses of proprioception, hearing, touch, olfaction, balancing and graviception. Mechanotransduction are mediated by a wide variety of specialized sensilla and sensory neurons that comprise the antenna. The eye and antenna of Drosophila melanogaster are derived from a cluster of approximately 23 cells that are set aside during embryonic development and are constantly divided during the three larval stages, organizing into an epithelial sac known as the eye‐antennal imaginal disc. During late larval and pupal development, the forward lobe of this epithelium, known as the antennal disc, gives rise to the antenna (an organized tripartite structure), whereas the posterior lobe, known as the eye disc, gives rise to the eye. The development of the antenna is a complex and intricate process that relies on the interplay of numerous genes. Each gene involved contributes to the regulatory network that governs the formation, differentiation, and patterning of specific structures within the antenna, ensuring its proper functionality. Thus, aberrant expression or mutation of any gene results in a faulty antenna. The defectiveness appears in terms of antennal structure leading to loss of function including defective behaviour found in an organism. A similar kind of structure–function relation of hearing with a behavioural defect has been reported in vertebrates. Some of the behavioural defects associated with genes are conserved in both vertebrates and Drosophila. Thus, a behavioural assay is an adaptable approach to studying the functionality of various genes associated with the antennae. Here a crucial relationship is established between the genetic regulation of mechanosensory neurons and an organism's behaviour. The current review summarizes antennae development, function and several methods used to study the mechanosensory behaviour associated with Drosophila antennae.

Influence of Soil Type and Moisture on Pupal Development of Chrysomya rufifacies (Macquart) at Two Different Temperatures.

The present study investigates the developmental process of Chrysomya rufifacies (Macquart) pupae and their dependency on soil composition, moisture levels, and temperature changes. This research holds implications for forensic and veterinary applications, providing crucial insights for estimating minimum postmortem intervals and managing myiasis-causing flies in diverse environments. Specifically, the study explores the impact of five moisture content levels in loam and sandy soils (0%, 20%, 40%, 60%, and 80%) on the pupal development of Ch. rufifacies under two distinct constant temperature regimes (24 ± 1 °C and 30 ± 1 °C). A significant correlation was observed between soil type and temperature regarding the time required to complete the pupal stages; however, moisture had no significant impact. Larvae exhibited varying survival rates across the two temperatures and five moisture levels in the two types of soils, particularly under extremely lower moisture conditions (0%) at 30 ± 1 °C, failing to progress to the pupariation stage. Additionally, growth parameters such as pupal length and width of the fully formed puparia were significantly impacted by temperature, soil type, and moisture level. Adult head width was systematically measured across different moisture levels and soil types, revealing distinct temperature-dependent responses. Furthermore, a sex-specific analysis highlighted that female Ch. rufifacies consistently displayed larger head widths and higher emergence rates compared to their male counterparts. This research enhances our understanding of the intricate interrelationship among three environmental variables: soil type, moisture level, and temperature, elucidating their collective impact on the pupation processes of dipterans.

Intrapuparial stage aging and PMI estimation based on the developmental transcriptomes of forensically important Aldrichina grahami (Diptera: Calliphoridae) gene expression

BackgroundThe expression profiles of differentially expressed genes (DEGs) during pupal development have been demonstrated to be vital in age estimation of forensic entomological study. Here, using forensically important Aldrichina grahami (Diptera: Calliphoridae), we aimed to explore the potential of intrapuparial stage aging and postmortem interval (PMI) estimation based on characterization of successive developmental transcriptomes and gene expression patterns. MethodsWe collected A. grahami pupae at 11 successive intrapuparial stages at 20 °C and used the RNA-seq technique to build the transcriptome profiles of their intrapuparial stages. The DEGs were identified during the different intrapuparial stages using comparative transcriptome analysis. The selected marker DEGs were classified and clustered for intrapuparial stage aging and PMI estimation and then further verified for transcriptome data validation. Ultimately, we categorized the overall gene expression levels as the dependent variable and the age of intrapuparial A. grahami as the independent variable to conduct nonlinear regression analysis. ResultsWe redefined the intrapuparial stages of A. grahami into five key successive substages (I, II, III, IV, and V), based on the overall gene expression patterns during pupal development. We screened 99 specific time-dependent expressed genes (stage-specific DEGs) to determine the different intrapuparial stages based on comparison of the gene expression levels during the 11 developmental intrapuparial stages of A. grahami. We observed that 55 DEGs showed persistent upregulation during the development of intrapuparial A. grahami. We then selected four DEGs (act79b, act88f, up and ninac) which presented consistent upregulation using RT-qPCR (quantitative real-time PCR) analysis, along with consideration of the maximum fold changes during the pupal development. We conducted nonlinear regression analysis to simulate the calculations of the relationships between the expression levels of the four selected DEGs and the developmental time of intrapuparial A. grahami and constructed fitting curves. The curves demonstrated that act79b and ninac showed continuous relatively increasing levels. ConclusionsThis study redefined the intrapuparial stages of A. grahami based on expression profiles of developmental transcriptomes for the first time. The stage-specific DEGs and those with consistent tendencies of expression were found to have potential in age estimation of intrapuparial A. grahami and could be supplementary to a more accurate prediction of PMI.

Development and Thermal Requirements of Abaris basistriata (Coleoptera: Carabidae) Under Laboratory Conditions

The carabid beetle Abaris basistriata (Coleoptera: Carabidae) is noteworthy for its predatory capabilities and its generalist function in the habitat. This study aimed to assess the influence of different temperatures on the development of A. basistriata and determine its thermal requirements. The insect was fed with larvae of Tenebrio molitor (Coleoptera: Tenebrionidae) and maintained at 18, 22, 25, and 28 ± 1 °C, 70 ± 10 % relative humidity, and 14-hour photoperiod. There were significant differences in the development time of stages and instars of A. basistriata as a function of temperature. Threshold temperatures for egg, larva, pupa, and preimaginal development were 10.68, 11.32, 12.67, and 11.73 °C, respectively. The thermal constants were 82.41, 264.83, 84.57, and 664.89 degree-days, respectively. The highest number of A. basistriata individuals reached the adult stage in the shortest time of development at 28 °C, where 70 % of survival was recorded. This finding suggests that 28 °C is the most favorable temperature for rearing this carabid species under laboratory conditions.

Drosophila medulla neuroblast termination via apoptosis, differentiation, and gliogenic switch is scheduled by the depletion of the neuroepithelial stem cell pool.

The brain is consisted of diverse neurons arising from a limited number of neural stem cells. Drosophila neural stem cells called neuroblasts (NBs) produces specific neural lineages of various lineage sizes depending on their location in the brain. In the Drosophila visual processing centre - the optic lobes (OLs), medulla NBs derived from the neuroepithelium (NE) give rise to neurons and glia cells of the medulla cortex. The timing and the mechanisms responsible for the cessation of medulla NBs are so far not known. In this study, we show that the termination of medulla NBs during early pupal development is determined by the exhaustion of the NE stem cell pool. Hence, altering NE-NB transition during larval neurogenesis disrupts the timely termination of medulla NBs. Medulla NBs terminate neurogenesis via a combination of apoptosis, terminal symmetric division via Prospero, and a switch to gliogenesis via Glial Cell Missing (Gcm); however, these processes occur independently of each other. We also show that temporal progression of the medulla NBs is mostly not required for their termination. As the Drosophila OL shares a similar mode of division with mammalian neurogenesis, understanding when and how these progenitors cease proliferation during development can have important implications for mammalian brain size determination and regulation of its overall function.

INFLUENCE OF ALUMINUM OXIDE NANOPARTICLES ON BIOLOGICAL FEATURES AND HOST HEMOCYTES OF Galleria mellonella L. (Lepidoptera: Pyralidae) WITH ITS ENDOPARASITOID Pimpla turionellae L. (Hymenoptera: Ichneumonidae)

Nanoparticles (NPs) are released directly or indirectly into nature with increased production and consumption, and their effects on insects, which occupy a large place in the ecosystem, are of interest. There is also interest in the potentially toxic effects of NPs applied to hive pests on parasitoids, or honey bees, and host-parasitoid relationships. The influence of aluminum oxide (Al2O3) NPs on the biological features of the hive pest Galleria mellonella, total counts of hemocyte, and hemocyte types; as well as on the biological features of the endoparasitoid Pimpla turionellae were investigated. The data obtained revealed that Al2O3 NPs caused a decrease in the larval, pupal, and adult development time of G. mellonella. The immature developmental time of P. turionellae was reduced. It was also demonstrated that Al2O3 NPs decreased the total counts of hemocytes in G. mellonella larvae; granulocyte, spherulocyte, oenocytoid, and prohemocyte counts decreased at all NP concentrations, while plasmatocyte counts increased. The data showed that Al2O3 NPs affected the biological properties of the hive pest model organism G. mellonella and indirectly affected its endoparasitoid P. turionellae. In addition, NPs showed a suppressive effect on cellular immune system responses, decreasing hemocyte counts. Our study results suggest that especially honey bees, honeycomb pests, and parasitoids may be negatively affected by NPs, which have increased in recent years as environmental pollutants, and that NPs may have insecticidal effects.