Genetic Diversity and Identification of Palearctic Black Flies in the Subgenus Wilhelmia (Diptera: Simuliidae)

Abstract

Accurate species identifications are the essential first step in understanding the medical, economic, and ecological importance of black flies. The utility of DNA barcoding based on cytochrome c oxidase subunit 1 (COI) sequences was evaluated for identifying six common species of Palearctic black flies in the subgenus Wilhelmia, including several that are virulent pests. Chromosomally identified larvae from Turkey and Germany and COI sequences in GenBank were analyzed. Intraspecific genetic divergence was 0.7-3.5% (mean 1.6%), whereas interspecific genetic divergence was 2.7-16.9%. On the basis of COI barcodes, the six nominal species of Simulium (Wilhelmia) were clustered in three distinct clades with high levels of genetic divergence, using maximum likelihood and Bayesian analyses. All specimens of Simulium equinum (L.), Simulium pseudequinum Séguy, and Simulium paraequinum Puri were correctly identified. However, >75% of identifications were ambiguous for Simulium lineatum (Meigen) and Simulium turgaicum Rubtsov (Meigen) because of overlapping intra- and interspecific divergence of the two species and Simulium balcanicum (Enderlein), all three of which are chromosomally similar and nearly isomorphic. Phylogenetic evaluation showed that S. balcanicum, S. equinum, S. pseudequinum, and S. paraequinum were monophyletic, with high bootstrap and posterior probability values, but it also showed that S. lineatum and S. turgaicum were paraphyletic, each clustering in two distinct groups, suggesting the presence of cryptic taxa. Although DNA barcoding provided a partial means of identification and indications of additional biodiversity, other molecular markers are needed to clarify the limits of all pest species of the subgenus Wilhelmia.

Molecular detection of Dirofilaria spp. and host blood-meal identification in the Simulium turgaicum complex (Diptera: Simuliidae) in the Aras River Basin, northwestern Iran

“…We recently showed with detailed morphological and molecular studies that S. turgaicum comprises three well-supported lineages in Iran [ 9 ]. The divergence within S. turgaicum has previously been shown by other researchers, as well [ 16 – 18 ].…”

Overview of Zoonotic Diseases in Turkey: The One Health Concept and Future Threats

“…The growing understanding of the links between environmental disturbances and disease may require an extension of the "One Medicine" concept to include not only animal and human health, but planetary health as well (319). Particularly, global warming affects the behaviors of vector arthropods and causes a generation of aggressive insect populations as seen in simuliids (435) or biting midges (439). Similarly, ticks cause a global challenge (20,48,459,469,470).…”

“…Black flies can also cause multideaths of animals, which are seen suddenly, particularly in cattle due to simulotoxicosis and toxic shock (434). In Turkey, some Simulium species have been reported, which showed pest characteristics and caused outbreaks (432,433,435,436). In contrast, in a study that was performed for molecular detection of blood-feeding preferences of Simulium species in Central Kizilirmak Basin of Turkey, Onchocerca sp and Leucocytozoon sp were detected in the samples of Simulium spp.…”

Phylogeography of Simulium Subgenus Wilhelmia (Diptera: Simuliidae)—Insights From Balkan Populations

“…The Palearctic subgenus Wilhelmia Enderlein belongs to the Simulium Latreille genus and includes species that are considered significant and widespread pests of humans and livestock (Crosskey 1990, Werner and Adler 2005, Sarıözkan et al 2014, Inci et al 2017). At present, 31 extant species of Wilhelmia are described.…”

“…The identification of morphologically similar species with molecular tools also proved to be equally successful. In the majority of studies, DNA barcoding using the mitochondrial cytochrome c oxidase subunit I (COI) gene is often used to reveal the cryptic diversity of black flies (Hernández-Triana et al 2012, Pramual and Nanork 2012, Conflitti et al 2013, Sriphirom et al 2014, Inci et al 2017).…”