Blackflies (Diptera: Simuliidae) in urban and suburban water courses of the city of Vitoria-Gasteiz (Basque Country, Spain)

Abstract

Simulids or blackflies are a family of Diptera in increasing study in Spain due to their interest as bioindicators of the quality of the aquatic environment and their medical-veterinary impact. Their study is cursory in those Autonomous Regions that constitute the Cantabrian region, and especially in the Basque Country, where there are few studies on their ecology or species description. The immature stages of simulids were sampled during the spring of 2021 in eight water courses located in the urban and suburban areas of the city of Vitoria-Gasteiz (Álava). A total of eight species of blackflies were identified by classical morphology and molecular analysis. From the study of mature larvae (n = 379) and emerged adults (n = 351) in the laboratory, it was estimated that the Simulium (Simulium) ornatum group (S. intermedium, S. ornatum s.l. and S. trifasciatum) accounted for most of the collections, followed by the Wilhelmia subgenus (S. equinum and S. lineatum), S. (Boophthora) erythrocephalum, S. (Eusimulium) rubzovianum and Prosimulium (Prosimulium) tomosvaryi. Simulium ornatum s.l. and S. rubzovianum were captured in most of the water courses, while the remaining species had a more restricted distribution. The species richness in the water courses ranged from one to seven species. The most recurrent fixation substrates by the immature stages were helophytes such as Typha sp. and Scirpus sp. Simulids were more abundant during the first capture period. This study provides the first records of the family Simuliidae for the Basque Country, incorporates color images of interest of the main diagnostic characters of larvae, pupae and adults of the most abundant species recorded, and briefly discusses the results obtained in relation to the unresolved taxonomic status of the group S. ornatum.