Search Results (14)

Diptera comprises more than 154,000 described species, representing approximately 10–12% of insects. Members have successfully colonized all continents and a wide range of habitats. However, higher-level phylogenetic relationships within Diptera have remained ambiguous. Mitochondrial genomes (mitogenomes) have been used as valuable molecular markers for resolving phylogenetic issues. To explore the effect of such markers in solving the higher-level phylogenetic relationship of Diptera, we sequenced and annotated the mitogenomes of 25 species, combined with 180 mitogenomes from 33 superfamilies of dipteran insects to conduct a phylogenetic analysis based on the PCGsrRNA and PCGs12rRNA datasets using IQ-TREE under the partition model. The phylogenetic analysis failed to recover the monophyly of the two suborders Nematocera and Brachycera. Two of six infraorders within the Nematocera—Tipulomorpha and Ptychopteromorpha—were monophyletic. The ancestral Deuterophlebiidae were a strongly supported sister group of all remaining Diptera, but Anisopodidae, as the closest relative of Brachycera, received only weak support. Three of four infraorders within Branchycera—Tabanomorpha, Xylophagomorpha, and Stratiomyomorpha—were, respectively, supported as a monophyletic clade, except Muscomorpha due to the strong long-branch attraction between Cecidomyiidae and Nycteribiidae. The inferred infraordinal relationships followed the topology Tabanomorpha + (Xylophagomorpha + (Stratiomyomorpha + Muscomorpha)). However, the proposed topology lacks strong statistical support, suggesting alternative relationships remain plausible. Based on mitogenome data alone, we infer that Diptera originated earlier than the Late Triassic at 223.43 Mya (95% highest posterior density [HPD] 166.60–272.02 Mya) and the earliest brachyeran Diptera originated in the mid-Jurassic (171.61 Mya). Full article

Background: Asilomorpha, an infraorder of predatory Diptera (Brachycera), is of significant evolutionary interest due to their remarkable ecological diversity, broad size range, and specialized feeding behaviors. However, phylogenetic studies of this group have been limited by sampling challenges. Methods: In this study, we sequenced the complete mitochondrial genomes of two Chinese endemic species, Clephydroneura jiangxiensis (C. jiangxiensis) and Maira xizangensis (M. xizangensis), using whole-genome random sequencing. By integrating these novel data with published sequences from NCBI, we reconstructed the phylogeny of three superfamilies (Asiloidea, Empidoidea, and Nemestrinoidea). Results: Both mitochondrial genomes exhibit the typical 37 genes (13 protein-coding genes, 22 tRNAs, and 2 rRNAs) and display pronounced AT bias. Congruent results from maximum likelihood analysis and Bayesian inference strongly supported the ideas that both new species are placed in Asilidae and that the Asilidae family is monophyletic. However, relationships among the three superfamilies remain unclear. Our results suggest that (1) although Asiloidea and Nemestrinidea are closely related, the potential positioning of Nemestrinoidea as an independent superfamily is worth investigating; and (2) Empidoidea may form a sister group to Asiloidea + Nemestrinidae, though this hypothesis requires further corroboration given the basal position of Hemipenthes hebeiensis (Bombyliidae). Conclusions: These findings highlight the need for expanded taxon sampling, particularly of underrepresented families, to resolve deep-level relationships within Asilomorpha. Clarifying the phylogenetic relationships within Asilomorpha will facilitate future investigations into their evolutionary origins and the evolution of characteristic traits. Full article

(1) Background: Tabanids are one of the most neglected and difficult-to-identify groups within the order Diptera despite their medical–veterinary importance. Since 2010, DNA barcoding has proved to be a promising method for the identification of horseflies in the Old World, but until now it had explored little with regards to Neotropical species. In Mexico, faunal studies continue to be focused on certain regions of the country, which has limited the generation of taxonomic keys. Here, we employed the DNA barcoding approach to contribute to the knowledge of horsefly species in one of the least explored biogeographic provinces in Mexico, the state of Veracruz. (2) Methods: Tabanids were collected at two localities using Malaise traps during two seasons. With a sampling effort of 300 h per trap per site, a total of 22 specimens were collected and identified using taxonomic keys and partial amplification and sequencing of the mitochondrial gene cytochrome c oxidase subunit 1 (COI). (3) Results: Five species of the Tabanus genus were identified through taxonomic keys, and three of these species were confirmed through molecular analyses: T. oculus, T. commixtus, and T. pungens. (4) Conclusions: This is the first contribution of the sequence data of the Tabanidae family for Mexico and demonstrates that DNA barcoding is a vital tool for the recognition of Neotropical species. Full article

Among flying insects, Diptera were the main visitors and colonisers of aquatic and terrestrial habitats in an Alpine glacial floodplain (NE Italy) at 2400 m a.s.l. In all, 4317 dipteran adults were collected using different collection techniques in, on, and out of the water: pond and drift nets, and emergence and Malaise traps, with a different periodicity: biweekly and every three hours for four consecutive days, in early and late summer 2015. Thirty-eight families in all, and 56 species within seven Brachycera families, were identified. Specifically, Chironomidae (36%) within Nematocera and Empidoidea families (23%), and Muscidae (9%) within Brachycera, prevailed. Chironomidae seemed to emerge and fly mainly in late morning–early afternoon, while most Brachycera were more active in late afternoon. Some ecological notes are given for seven Brachycera families, including Muscidae as the predominant family of anthophilous dipterans and the most efficient pollinators in mountain habitats and in the deglaciated areas of the proglacial forelands. Three genera of Muscidae were found as the main representatives of these environments: Thricops Rondani, Spilogona Schnabl, and Phaonia Robineau-Desvoidy). Among these genera, noteworthy was the finding of Spilogona triangulifera (Zetterstedt) as being new to the Italian fauna. Full article

Despite the development of molecular techniques, morphological phylogeny still remains integral in underpinning the relationship between some clades of Calyptratae, especially the ones with fast radiation, such as those in Oestridae (Diptera: Brachycera), yet few synapomorphy has been proposed for adults in this family. Using scanning electron microscopy, we investigated the morphological structure and ultrastructure of the antennae and maxillary palps of adult Oestromyia leporina (Hypodermatinae, Oestridae). One type of trichoid sensillum (Tr), three types of basiconic sensilla (Ba I, Ba II, and Ba III), one type of coeloconic sensillum (Co I), and one type of clavate sensillum (Cl) were found on the antennal postpedicel. Surprisingly, this species has the most complex types of sensilla on the maxillary palps that have been reported in Calyptratae so far, with two types of coeloconic sensilla (Co II and Co III) and two types of mechanoreceptors. We then identified three common characteristics on the arista of Oestridae (Hypodermatinae, Oestrinae, Gasterophilinae and Cuterebrinae) that are potential synapomorphies. These characteristics indicate the value of the morphology of maxillary palps and aristae in taxonomy studies of Calyptratae. Full article

The richest assemblage of the Triassic Diptera has been described from the famous Konservat-Lagerstätte Grès à Voltzia (Upper Buntsandstein) in the northern Vosges Mountains in France, dated as Early Anisian. A re-examination of the holotypes and additional material from the type locality allows for the establishment of Vogerhyphus gen. nov. and erection of the Vogerhyphinae subfam. nov. for Vymrhyphus blagoderovi Krzemiński and Krzemińska, 2003 and Vogerhyphus krzeminskorum sp. nov. (Protorhyphidae), and a new monotypic family Galliidae fam. nov. for Gallia alsatica Krzemiński and Krzemińska, 2003, originally described as Rhagionidae based on its wing venation. Galliidae fam. nov. is characterized by its closed cua cell and long moniliform antenna with 14-segmented flagellum and is hypothesized to belong to the stem-group Brachycera, along with the Late Triassic Prosechamyiidae. The process of brachycerization in the Diptera evolution is briefly discussed. Full article

In equine stables and their surroundings, a large number of insects are present that can be a nuisance to their equine hosts. Previous studies about dipterans transmitting infectious agents to Equidae have largely focused on Nematocera. For the preparation of this systematic review, the existing literature (until February 2022) was systematically screened for various infectious agents transmitted to Equidae via insects of the suborder Brachycera, including Tabanidae, Muscidae, Glossinidae and Hippoboscidae, acting as pests or potential vectors. The PRISMA statement 2020 (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews were followed. The two concepts, Brachycera and Equidae, were combined for the search that was carried out in three languages (English, German and French) using four different search engines. In total, 38 articles investigating Brachycera as vectors for viral, bacterial and parasitic infections or as pests of equids were identified. Only 7 of the 14 investigated pathogens in the 38 reports extracted from the literature were shown to be transmitted by Brachycera. This review clearly shows that further studies are needed to investigate the role of Brachycera as vectors for pathogens relevant to equine health. Full article

Soil faunal communities play key roles in maintaining soil nutrient cycling. Affected by different land-use types, soil environment and soil faunal communities change significantly. However, few studies have focused on the aforementioned observations in coastal zones, which provide suitable habitats for many species of concern. Here, we investigated the changes in soil mesofaunal communities under different land-use types, including cotton fields, jujube trees, ash trees, a saline meadow, and wetlands. The variations in land-use types affected the community composition and diversity of soil mesofauna in the coastal zones. The taxa of soil mesofauna had different responses to land-use types in the coastal zones. Isotomidae was regarded as an indicator taxon of the coastal cropland regions. Entomobryidae was considered to be an indicator taxon of coastal artificial trees. Meanwhile, Onychiuridae and three taxa (Brachycera, Armadillidiidae, and Gammaridae) were indicator taxa of the coastal terrestrial ecosystem and the coastal wetland ecosystem, respectively. Thus, we suggested that specific soil mesofaunal taxa were considered to be appropriate bioindicators for land-use types in the coastal zones. The results of this study were helpful to develop guidelines for coastal biodiversity and ecosystem conservation in the future. Full article

Psilidae (Diptera: Brachycera) is a moderate-sized family currently placed in the superfamily Diopsoidea and contains some destructive agricultural and forestry pests. The systematic position and intrafamilial classification of rust flies are in need of further study, and the available molecular data of Psilidae are still limited. In this study, we present the mitochondrial genomes of 6 Psilidae species (Chamaepsilatestudinaria Wang and Yang, Chyliza bambusae Wang and Yang, Chy. chikuni Wang, Loxocera lunata Wang and Yang, L. planivena Wang and Yang and L. sinica Wang and Yang). Comparative analyses show a conserved genome structure, in terms of gene composition and arrangement, and a highly Adenine plus Thymine biased nucleotide composition of the 6 psilid mitogenomes. Mitochondrial evolutionary rates vary among the 6 species, with species of Chylizinae exhibiting a slower average rate than species of Psilinae. The length, the nucleotide composition, and the copy number of repeat units of the control region are variable among the 6 species, which may offer useful information for phylogenetic and evolutionary studies of Psilidae. Phylogenetic analyses based on 4 mitogenomic datasets (AA, PCG, PCG12RNA, and PCGRNA) support the monophyly of Psilidae, and the sister relationship between Chylizinae and Psilinae, while Diopsoidea is suggested to be non-monophyletic. Our study enlightens the future application of mitogenomic data in the phylogenetic and evolutionary studies of Psilidae, based on denser taxon sampling. Full article

Recent studies on nuclear-encoded mitochondrial genes (N-mt genes) in Drosophila melanogaster have shown a unique pattern of expression for newly duplicated N-mt genes, with many duplicates having a testis-biased expression and playing an essential role in spermatogenesis. In this study, we investigated a newly duplicated N-mt gene—i.e., Cytochrome c oxidase 4-like (COX4L)—in order to understand its function and, consequently, the reason behind its retention in the D. melanogaster genome. The COX4L gene is a duplicate of the Cytochrome c oxidase 4 (COX4) gene of OXPHOS complex IV. While the parental COX4 gene has been found in all eukaryotes, including single-cell eukaryotes such as yeast, we show that COX4L is only present in the Brachycera suborder of Diptera; thus, both genes are present in all Drosophila species, but have significantly different patterns of expression: COX4 is highly expressed in all tissues, while COX4L has a testis-specific expression. To understand the function of this new gene, we first knocked down its expression in the D. melanogaster germline using two different RNAi lines driven by the bam-Gal4 driver; second, we created a knockout strain for this gene using CRISPR-Cas9 technology. Our results showed that knockdown and knockout lines of COX4L produce partial sterility and complete sterility in males, respectively, where a lack of sperm individualization was observed in both cases. Male infertility was prevented by driving COX4L-HA in the germline, but not when driving COX4-HA. In addition, ectopic expression of COX4L in the soma caused embryonic lethality, while overexpression in the germline led to a reduction in male fertility. COX4L-KO mitochondria show reduced membrane potential, providing a plausible explanation for the male sterility observed in these flies. This prominent loss-of-function phenotype, along with its testis-biased expression and its presence in the Drosophila sperm proteome, suggests that COX4L is a paralogous, specialized gene that is assembled in OXPHOS complex IV of male germline cells and/or sperm mitochondria. Full article

Prestomal teeth are cuticular projections on the mouthparts of some fly species that rasp surfaces when feeding. Although prestomal teeth morphology has been reported for several fly species, their material properties have not been investigated. Here we report the morphology, elemental composition, extent of sclerotization, hardness, and elastic modulus of prestomal teeth and relate these findings to feeding habits. Scanning electron microscopy revealed that species categorized as flower visitors have a large labellum with numerous pseudotracheae and lack prestomal teeth, generalist species have these same features but with prestomal teeth, and specialist species that feed on blood or other insects have a smaller labellum with few or no pseudotracheae and relatively large prestomal teeth. Confocal microscopy revealed that prestomal teeth are heavily sclerotized and the labellum contains resilin, an elastomeric protein. Hardness and elastic modulus were explored with nanoindentation and showed that the insectivorous Scathophaga stercoraria had the hardest prestomal teeth and the highest modulus. Energy dispersive x-ray spectroscopy revealed that prestomal teeth had low concentrations of inorganic elements, suggesting that hardness might be partially supplemented by inorganic elements. Our findings indicate that prestomal teeth morphology and material properties relate more to feeding habits than to phylogeny. Full article

Trypanosomes belonging to Trypanosoma theileri group are mammalian blood parasites with keds and horse fly vectors. Our aim is to study to vector specificity of T. theileri trypanosomes. During our bloodsucking Diptera survey, we found a surprisingly high prevalence of T. theileri trypanosomes in mosquitoes (154/4051). Using PCR and gut dissections, we detected trypanosomes of T. theileri group mainly in Aedes mosquitoes, with the highest prevalence in Ae. excrucians (22%), Ae. punctor (21%), and Ae. cantans/annulipes (10%). Moreover, T. theileri group were found in keds and blackflies, which were reported as potential vectors for the first time. The vectorial capacity was confirmed by experimental infections of Ae. aegypti using our isolates from mosquitoes; sand fly Phlebotomus perniciosus supported the development of trypanosomes as well. Infection rates were high in both vectors (47–91% in mosquitoes, 65% in sandflies). Furthermore, metacyclic stages of T. theileri trypanosomes were observed in the gut of infected vectors; these putative infectious forms were found in the urine of Ae. aegypti after a second bloodmeal. On the contrary, Culex pipiens quinquefasciatus was refractory to experimental infections. According to a phylogenetic analysis of the 18S rRNA gene, our trypanosomes belong into three lineages, TthI, ThII, and a lineage referred to as here a putative lineage TthIII. The TthI lineage is transmitted by Brachycera, while TthII and ThIII include trypanosomes from Nematocera. In conclusion, we show that T. theileri trypanosomes have a wide range of potential dipteran vectors, and mosquitoes and, possibly, sandflies serve as important vectors. Full article

A new fossil genus of Bibionidae (Diptera: Bibionomorpha), Burmahesperinus gen. nov., from the mid-Cretaceous Burmese amber, is described and illustrated (type species Burmahesperinus antennatus sp. nov., the other two species included are B. conicus sp. nov. and B. pedicellatus sp. nov.). The new genus is tentatively placed in a new subfamily, Burmahesperininae subfam. nov. of the family Bibionidae. Its possible phylogenetic position is briefly discussed. The new genus, as well as the subfamily, possesses the wing venation similar to the recent genus Hesperinus Walker, 1848, in combination with Brachycera-like modification of both the male and female antenna and the overall habitus typical of fungus gnats (Sciaroidea). Full article

Despite the rising interest in biotic interactions in mountain ecosystems, little is known about high-altitude flower-visiting arthropods. In particular, since the research in these environment can be limited or undermined by harsh conditions and logistical difficulties, it is mandatory to develop effective approaches that maximize possibilities to gather high-quality data. Here we compared two different methods, manual sampling and video observations, to investigate the interactions between the high-mountain arthropod community and flowers of Androsace brevis (Primulaceae), a vulnerable endemic alpine species with a short flowering period occurring in early season. We manually sampled flower-visiting arthropods according to the timed-observations method and recorded their activity on video. We assessed differences and effectiveness of the two approaches to estimate flower-visiting arthropod diversity and to identify potential taxa involved in A. brevis pollination. Both methods proved to be effective and comparable in describing the diversity of flower visitors at a high taxonomic level. However, with manual sampling we were able to obtain a fine taxonomic resolution for sampled arthropods and to evaluate which taxa actually carry A. brevis pollen, while video observations were less invasive and allowed us to assess arthropod behavior and to spot rare taxa. By combining the data obtained with these two approaches we could accurately identify flower-visiting arthropods, characterize their behavior, and hypothesize a role of Hymenoptera Apoidea and Diptera Brachycera in A. brevis pollination. Therefore, we propose integrating the two approaches as a powerful instrument to unravel interactions between flowering plants and associated fauna that can provide crucial information for the conservation of vulnerable environments such as high-mountain ecosystems. Full article