Spatiotemporal variability of horsefly abundance and richness in northwestern Patagonia

Horseflies (Diptera: Tabanidae) are a nuisance to humans and livestock in many regions around the world including Patagonia, Argentina. Although in this region there are no records of Tabanidae species as vectors of disease-causing microorganisms to livestock, it is suspected that they are disease vectors in other Ar-gentinean regions adjacent to Patagonia. There are several studies on the taxonomy and morphology of Tabanidae in Patagonia, but little is known on their ecology and behavior in this region. An initial assess-ment was conducted aimed at describing the fluctuations in horsefly populations/activity throughout the flight season and among different locations in northwestern Patagonia using Nzi traps. Four species were captured throughout the sampling season totalling 483 individuals and most individuals (87 %) belonged to the species Dasybasis antilope Brèthes. Species phenology, abundance and composition were strongly in-fluenced by site characteristics (e.g. vegetation, livestock) and less clearly by ambient temperature. The current study is an initial contribution toward understanding spatiotemporal fluctuations in horsefly popula-tions and activity in the Argentinean Patagonia.