Integrated taxonomy of black flies (Diptera: Simuliidae) reveals unexpected diversity in the most arid ecosystem of Europe

Abstract

The family Simuliidae includes more than 2000 species of black flies worldwide. Their morphological uniformity creates difficulty for species identification, which limits our knowledge of their ecology and vectorial role. We investigated the systematics of black flies in a semi-arid area of the Iberian Peninsula, an ecologically harsh environment for these organisms. Sampling adult black flies in three different habitats (by means of CDC traps) and in avian nest boxes and collecting immature stages in high-salinity rills provided a representative sample of the component species. A combination of approaches, including morphological, chromosomal, and molecular (based on the mitochondrial cytochrome C oxidase subunit I (COI) and internal transcribed spacer 2 (ITS2) genes) revealed five species: four common species (Simulium intermedium, S. petricolum, S. pseudequinum, and S. rubzovianum) and the first European record for S. mellah. Barcoding gap and phylogenetic analyses revealed that ITS2 is a key marker to identify the species, whereas the COI marker does not provide enough resolution to identify some species or infer their phylogenetic relationships. Morphological and chromosomal features are also provided to identify S. mellah unequivocally. Our study highlights the need for integrated studies of black flies in ecologically extreme habitats to increase our knowledge of their distribution, ecology, and potential risks for public health.

Diversity, Distribution and Host Blood Meal Analysis of Adult Black Flies (Diptera: Simuliidae) from Thailand

“…Black flies are very small-sized insects, and many closely related species are morphologically similar or undistinguishable in certain life stages. Therefore, an integrated approach is preferable for correct species identification [3,37]. In this study, three female specimens collected from Loei Province in northeastern Thailand were morphologically identified as the S. siamense complex but were molecularly determined to be S. yvonneae, a species of the same species group (the S. batoense species group), which has been recorded only in Vietnam [2,35].…”

“…Black flies (Diptera: Simuliidae) are small hematophagous insects that can be found in every continent except Antarctica [1]. Up to 2022, there have been 2415 species recorded globally: 2398 living and 17 fossils [2,3]. Approximately 10-20% of these black fly species are pests, and many of these also transmit pathogens to humans and other animals [1].…”