Phylogenetic relationships of the woodlouse flies (Diptera: Rhinophorinae) and the cluster flies (Diptera: Polleniidae)

Blowfly genomics: current insights, knowledge gaps, and future perspectives

Blowflies (Calliphoridae) form a diverse, species-rich group, yet publicly available genome assemblies are limited to only 16 species, despite recent genomic advances. This knowledge gap extends to mitogenomes and barcode databases, which mainly focus on medically and veterinary-important species. While blowfly phylogenetics has progressed, additional genome sequencing is crucial for various subfamilies, given their diverse life histories. This review presents a quantitative overview of available genetic information for blowflies, highlighting substantial gaps in public databases. DNA barcodes, mitogenomes, and genomes represent only 16.5% (342 species), ∼3% (53 species), and <1% (16 species) of known family diversity, respectively. While 183 genomics-related calliphorid BioProjects are recorded by NCBI, many subfamilies and genera have limited or no genomic representation, impacting studies on identification, systematics, phylogenetics, and evolution. We stress the urgent need for high-quality reference genomes and highlight target species representing all blowfly subfamilies to support a new era of rapid, low-cost genomic research.

Lords of the flies: dipteran migrants are diverse, abundant and ecologically important

Insect migrants are hugely abundant, with recent studies identifying the megadiverse order Diptera as the major component of many migratory assemblages. Despite this, their migratory behaviour has been widely overlooked in favour of more 'charismatic' migrant insects such as butterflies, dragonflies, and moths. Herein we review the available literature on dipteran migration to determine its prevalence, identify key migratory routes and elucidate areas that may prove fruitful for future research. Using 13 lines of evidence to determine migratory behaviour, we determined that species from 60 out of 130 dipteran families show evidence of migration, with Syrphidae fulfilling 12 of these criteria, followed by the Tephritidae with 10. By contrast, 22 families met just two criteria or fewer, underlining the need for more research into the migratory characteristics of these groups. In total, 592 species of Diptera were identified as potentially migratory, making them the most speciose group of insect migrants yet described. Despite this, only 0.5% of dipteran species were found to be migrants, a figure rising to 3% for the Syrphidae, a percentage mirrored by other migratory taxa such as butterflies, noctuid moths, and bats. Research was biased to locations in Europe (49% of publications) and while vast regions remain understudied, our review identified major flyways used by dipteran migrants across all biogeographic realms. Finally, we highlight an unsurpassed level of ecological diversity within dipteran migrants, including ecological roles of huge economic value. Overall, this review highlights how little is known about dipteran migration and how vital their migratory behaviour may be to the health of global ecosystems.

Three new species of Polleniidae (Diptera) from China

Dexopolleniaguangxiensis Liu, Li & Yao, sp. nov., Dexopolleniachongqingensis Liu, Li & Yao, sp. nov. and Xanthotryxushuapingensis Liu, Li & Yao, sp. nov. from the Guangxi Zhuang Autonomous Region and Chongqing are described and illustrated. Keys to species of the genera Dexopollenia and Xanthotryxus from China are provided. Photographs of the habitus and male genitalia of the new species are also provided.

Phylogenomics resolves long-standing questions about the affinities of an endangered Corsican endemic fly

Recent studies on oestroidean Diptera (Brachycera) are providing a comprehensive and nuanced understanding of the evolutionary history of this remarkably diverse clade of holometabolous insects. The Oestroidea, which includes formidable pests such as various blowflies, botflies, and flesh flies that infest livestock, pets and humans, are mostly composed of beneficial species that act as scavengers or parasitoids on various pest insects. In our research, we used genomic methods to elucidate the phylogenetic position of Nesodexia corsicana Villeneuve, 1911 (Diptera: Calliphoridae), a mysterious oestroid species endemic to Corsica and characterized by distinctive morphological features that have puzzled taxonomists for years. Contrary to initial hypotheses, our results place Nesodexia Villeneuve, 1911 within the Calliphoridae subfamily Rhinophorinae, a small lineage of terrestrial isopod parasitoids. Through detailed morphological analysis of adults of both sexes and eggs, we uncovered significant insights consistent with our phylogenomic reconstruction. The unique morphological features of the species, coupled with its restricted and fragmented habitat, highlight its potential conservation importance. We delineated the area of occupancy for N. corsicana and assessed its "threatened" category using specific IUCN Red List criteria. In addition, we mapped the available habitat within its range and determined potential key biodiversity areas (KBA) triggered by N. corsicana. New potential KBAs are only partially covered by the Corsican Regional Park. Finally, we mapped the distribution of habitats on the island to assess the potential distribution of the species beyond its currently known geographic range.

The influence of altitude on the abundance and occurrence of species of the family Calliphoridae (Diptera) in corpses in a Mediterranean area

A carcass is defined as a temporary resource that can support high levels of diversity compared to other resources. The level of diversity often depends on the environmental conditions in which the corpse is found. Calliphoridae (Diptera) are the most important necrophagous insects used in forensic investigations because this family is common, widespread, abundant, and usually the first to colonize a corpse. However, understanding the processes responsible for variation in calliphorid species abundance and richness along gradients in ecology remains a key challenge. In this study, we analyzed the influence of altitude on the abundance and diversity of Calliphoridae species in corpses at three different altitudes (400, 900, and 1500 m a.s.l.) in a mountainous area of southeastern Spain. The results revealed a gradient of decreasing abundance with increasing altitude. An altitudinal substitution of species was observed, with Chrysomya albiceps being found at the lowest altitude and Calliphora vicina at the highest altitude. Seasonal variation was also noted, with Ch. albiceps being the dominant species in the warmer months and C. vicina being the dominant species in winter. Our results confirm the importance of Calliphorids as seasonal, altitudinal, and environmental indicators, given the wide distribution and abundance of this family. This information is of great interest on the interpretation of data in forensic practice.