Diversity and abundance of some insect fauna in Bhawal and Madhupur Sal forests of Bangladesh

The abundance and diversity of insect fauna were studied from two deciduous sal forests of Bhawal and Madhupur located at central part of Bangladesh. A total of 544 individuals of insects of 61 species belonging to 54 genera, 33 families and 11 orders have been identified with Hymenoptera (31%) as the dominant order in species richness followed by Coleoptera (13%), Orthoptera (11%), Diptera (10%), Hemiptera (8%), Lepidoptera (8%), Odonata (8%), Homoptera (3%), Isoptera (3%), Neuroptera (3%) and Dictyoptera (2%). Bhawal scores higher Shannon-Weaver diversity index (Hʹ=3.725) compared to Madhupur (Hʹ=3.340). The Bhawal Sal Forest with the collected 341 (63%) insects and identified 53 (59%) species belonging to 10 orders was found more diverse in species richness than the Madhupur Sal Forest with 37(41%) species belonging to 11 orders identified from the collected 203 (37%) insect samples. Insects of the order Neuroptera were not recorded from Bhawal. Off the 61 species, 29(48%) species were common in both the forests, 24(39%) species were exclusive to Bhawal and eight (13%) species were exclusive to the Madhupur Sal Forest. Apis cerana of Hymenoptera was identified as the dominant species having 9% of the identified samples followed by dipteran species Musca domestica with 6% of the samples. Among the insect species 30 (49%) species were found playing beneficial role as biological control agents, predators, pollinators, honey producers and also organic debris recycler. On the other hand, 31(51%) species were found to be harmful causing damage to forest vegetation as well as human and wildlife at variable degrees. J. Biodivers. Conserv. Bioresour. Manag. 2021, 7(1): 11-24

Nuclear transport genes recurrently duplicate by means of RNA intermediates in Drosophila but not in other insects

Background The nuclear transport machinery is involved in a well-known male meiotic drive system in Drosophila. Fast gene evolution and gene duplications have been major underlying mechanisms in the evolution of meiotic drive systems, and this might include some nuclear transport genes in Drosophila. So, using a comprehensive, detailed phylogenomic study, we examined 51 insect genomes for the duplication of the same nuclear transport genes. Results We find that most of the nuclear transport duplications in Drosophila are of a few classes of nuclear transport genes, RNA mediated and fast evolving. We also retrieve many pseudogenes for the Ran gene. Some of the duplicates are relatively young and likely contributing to the turnover expected for genes under strong but changing selective pressures. These duplications are potentially revealing what features of nuclear transport are under selection. Unlike in flies, we find only a few duplications when we study the Drosophila duplicated nuclear transport genes in dipteran species outside of Drosophila, and none in other insects. Conclusions These findings strengthen the hypothesis that nuclear transport gene duplicates in Drosophila evolve either as drivers or suppressors of meiotic drive systems or as other male-specific adaptations circumscribed to flies and involving a handful of nuclear transport functions.

Characterization of Glycoside Hydrolase Families 13 and 31 Reveals Expansion and Diversification of α-Amylase Genes in the Phlebotomine Lutzomyia longipalpis and Modulation of Sandfly Glycosidase Activities by Leishmania Infection

Sugar-rich food sources are essential for sandflies to meet their energy demands, achieving more prolonged survival. The digestion of carbohydrates from food is mainly realized by glycoside hydrolases (GH). To identify genes coding for α-glycosidases and α-amylases belonging to Glycoside Hydrolase Family 13 (GH13) and Glycoside Hydrolase Family 31 (GH31) in Lutzomyia longipalpis, we performed an HMMER search against its genome using known sequences from other dipteran species. The sequences retrieved were classified based on BLASTP best hit, analysis of conserved regions by alignment with sequences of proteins with known structure, and phylogenetic analysis comparing with orthologous proteins from other dipteran species. Using RT-PCR analysis, we evaluated the expression of GH13 and GH31 genes, in the gut and rest of the body of females, in four different conditions: non-fed, sugar-fed, blood-fed, and Leishmania mexicana infected females. L. longipalpis has GH13/31 genes that code for enzymes involved in various aspects of sugar metabolism, as carbohydrate digestion, storage, and mobilization of glycogen reserves, proteins involved in transport, control of N-glycosylation quality, as well as others with a putative function in the regulation of myogenesis. These proteins are representatives of GH13 and GH31 families, and their roles seem to be conserved. Most of the enzymes seem to be active with conserved consense sequences, including the expected catalytic residues. α-amylases also demonstrated the presence of calcium and chloride binding sites. L. longipalpis genome shows an expansion in the α-amylase gene family, with two clusters. In contrast, a retraction in the number of α-glucosidases occurred. The expansion of α-amylases is probably related to the specialization of these proteins for different substrates or inhibitors, which might correlate with the higher diversity of plant foods available in the natural habitat of L. longipalpis. The expression of α-glucosidase genes is higher in blood-fed females, suggesting their role in blood digestion. Besides that, in blood-fed females infected with the parasite Leishmania mexicana, these genes were also modulated. Glycoside Hydrolases from families 13 and 31 are essential for the metabolism of L. longipalpis, and GH13 enzymes seem to be involved in the interaction between sandflies and Leishmania.

The hAT-family transposable element, hopper, from Bactrocera dorsalis is a functional vector for insect germline transformation

Background The hopper hAT-family transposable element isolated from the Oriental fruit fly, Bactrocera dorsalis, is distantly related to both the Drosophila hobo element and the Activator element from maize. The original 3120 bp hopperBd-Kah element isolated from the Kahuku wild-type strain was highly degenerate and appeared to have a mutated transposase and terminal sequences, while a second 3131 bp element, hopperBd-we, isolated from a white eye mutant strain had an intact transposase reading frame and terminal sequences consistent with function. Results The hopperBd-we element was tested for function by its ability to mediate germline transformation in two dipteran species other than B. dorsalis. This was achieved by creating a binary vector/helper transformation system by linking the hopperBd-we transposase reading frame to a D. melanogaster hsp70 promoter for a heat-inducible transposase helper plasmid, and creating vectors marked with the D. melanogaster mini-white+ or polyubiquitin-regulated DsRed fluorescent protein markers. Conclusions Both vectors were successfully used to transform D. melanogaster, and the DsRed vector was also used to transform the Caribbean fruit fly, Anastrepha suspensa, indicating a wide range of hopper function in dipteran species and, potentially, non-dipteran species. This vector provides a new tool for insect genetic modification for both functional genomic analysis and the control of insect populations.

Order Diptera as a model in the studies of insect immunity: a review

Order Diptera is the most important group of animals when it comes to insect immunity research. The largest share of experimental data in the group falls on the genus Drosophila - a model species with a number of advantages. Other crucial representatives are those of the mosquito group, as they are vectors of a number of infectious diseases infecting higher vertebrates and humans. As representatives of the genera, Anopheles, Aedes and Culex are very significant model organisms. In total, more than 40 dipteran species are being actively studied as models in various aspects related to immunity. Together with the representatives of the order Lepidoptera, they are the major source of the knowledge gained so far on the defense mechanisms in insects. The current review demonstrates that the studies conducted on dipteran species concern all existing mechanisms of immune defense, namely antimicrobial peptides, signalingpathways, pathogen recognition, the different types of hemocytes, antiviral and other immune responses (phagocytosis, nodulation, melanization and encapsulation).

Diversity of Public Health and Forensic Important Flies Using Three Measures of Hill Numbers in Iran

Introduction: Dipteran species (flies) are one of the most important insects within the public health and forensic fields. Previous studies have shown that flies play an important role in transmitting the diseases and also estimating the time of death, but their diversity by new methods has been less studied. Methods: Dipteran specimens were collected from rabbit carcasses during spring and summer 2019 and then identified. We used the three measures of Hill numbers (q=0,1,2) to compare the species diversity between the seasons. The analysis was performed with an R package (iNEXT) that provided in 2014. Results: During the present study, 12 dipteran species were collected on rabbit carcasses. L. cuprina and M. stabulans were recorded only from the remains of rabbits in summer. The analysis with iNEXT software showed that species richness (q = 0) in spring is lower than summer and this difference was significant. While, the value of Shannon and Simpson diversity index (q = 1, 2) in summer was lower than in spring. Shannon index value was not significantly different between the seasons, as its confidence intervals almost completely overlapped, but a significant difference in Simpson index was detected between the seasons. Conclusion: We conclude that Ch. albiceps, L. sericata and C.vicina are more frequent flies in the study area and dipteran species are more diverse in spring. The current study provided a database in the field of public health and forensic entomology that could be useful for estimating minimum postmortem intervals and also in vector control programs.

The diverging evolutionary history of opsin genes in Diptera

Opsin receptors mediate the visual process in animals and their evolutionary history can provide precious hints on the ecological factors that underpin their diversification. Here we mined the genomes of more than 60 Dipteran species and reconstructed the evolution of their opsin genes in a phylogenetic framework. Our phylogenies indicate that dipterans possess an ancestral set of five core opsins which have undergone several lineage-specific events including an independent expansion of low wavelength opsins in flies and mosquitoes and numerous family specific duplications and losses. Molecular evolutionary studies indicate that gene turnover rate, overall mutation rate, and site-specific selective pressure are higher in Anopheles than in Drosophila; we found signs of positive selection in both lineages, including events possibly associated with their peculiar behaviour. Our findings indicate an extremely variable pattern of opsin evolution in dipterans, showcasing how two similarly aged radiations - Anopheles and Drosophila - can be characterized by contrasting dynamics in the evolution of this gene family.

Dipteran diversity and succession pattern on carcass of rabbits treated with opium dross: Implication in forensic medicine

Keshavarz D, Rassi Y, Oshaghi MA, Azizi K, Rafizadeh S, Shahriarinamadi M. 2020. Dipteran diversity and succession pattern on carcass of rabbits treated with opium: Implication in forensic medicine. Biodiversitas 21: 3135-3141. The present study aimed to investigate the effect of opium on the succession pattern and diversity of Diptera on rabbit carcasses. In the present experimental study, dipteran species were collected from rabbit carcasses during the decay process. During this study, two replicates were performed, and four rabbits were used in each. Rabbits divided equally into two groups. In the first group, animals were received 25 mg opium dross orally via a gastric tube and then gradually increased the dose to 100 mg/case/day, while the second group were used as controls and received distilled water. The most frequent species on both carcass types were Chrysomya albiceps (26.2%), Lucilia sericata (15.9%), and Musca domestica (13.9%). Diversity analysis indicates high species richness on untreated carcasses (Shannon: 2.1; Margalef: 1.7). However, a significant difference was not detected for the Shannon index between the treated and untreated carcasses (P: 0.56). The taxa similarity values for sampling intervals ranged from 0.20-0.46 for both untreated and treated carcasses. Permutation analysis showed that successional patterns of dipteran species were similar between opium dross-treated and untreated carcasses. Therefore, in the case of opioid (opium) abused cadaver, this substance could not have an effect on the PMI estimation based on the pattern of succession. But it seems that the PMI should be corrected when the estimate is based on larval growth rate.