High Levels of Diversity in Anopheles Subgenus Kerteszia Revealed by Species Delimitation Analyses

Abstract

The Anopheles subgenus Kerteszia is a poorly understood group of mosquitoes that includes several species of medical importance. Although there are currently twelve recognized species in the subgenus, previous studies have shown that this is likely to be an underestimate of species diversity. Here, we undertake a baseline study of species delimitation using the barcode region of the mtDNA COI gene to explore species diversity among a geographically and taxonomically diverse range of Kerteszia specimens. Beginning with 10 of 12 morphologically identified Kerteszia species spanning eight countries, species delimitation analyses indicated a high degree of cryptic diversity. Overall, our analyses found support for at least 28 species clusters within the subgenus Kerteszia. The most diverse taxon was Anopheles neivai, a known malaria vector, with eight species clusters. Five other species taxa showed strong signatures of species complex structure, among them Anopheles bellator, which is also considered a malaria vector. There was some evidence for species structure within An. homunculus, although the results were equivocal across delimitation analyses. The current study, therefore, suggests that species diversity within the subgenus Kerteszia has been grossly underestimated. Further work will be required to build on this molecular characterization of species diversity and will rely on genomic level approaches and additional morphological data to test these species hypotheses.

The insupportable validity of mosquito subspecies (Diptera: Culicidae) and their exclusion from culicid classification

“…They reviewed the options for retaining subspecies and for practical reasons advocated that biological classification "should emphasise species and reduce the use of subspecies to avoid preserving arbitrary partitions of continuous variation". They also aptly noted that many binomial taxa represent species complexes rather than individual species, which has become increasingly obvious among mosquitoes (see for example the recent discovery of many species complexes in the subgenus of Kerteszia Theobald, 1905e of Anopheles Meigen, 1818 by Bourke et al 2023).…”