The horseflies fauna diversity (Diptera: Tabanidae) in the habitats along the Mura river in Međimurje, Croatia

Abstract

From May to September 2022, in the habitats along the Mura River, 1295 horseflies were sampled, classified into two subfamilies, six genera, and 21 species. Seven new records of horseflies were recorded for the first time in the researched area. Newly recorded species are: Tabanus bovinus, Tabanus cordiger, Tabanus sudeticus, Heptatoma pellucens, Haematopota italica, Haematopota scutellata, Haematopota subcylindrica. The species Haematopota pluvialis is the most abundant species, accounting for 60.07% of all sampled horseflies. Tabanus bromius followed with 21.23%, while the other 19 horseflies account for 18.7%. 18 species of horseflies belonged to the boreal-Eurasian type of fauna, two belonged to the Mediterranean type of fauna, i.e. the southern European subtype, while one species belonged to the Afro-Eurasian-arid type of fauna. In the collected sample of horseflies, 33 males classified into 10 species were recorded, while all other collected horseflies were females (1262 specimens) classified into 20 species. The greatest similarity of the horseflies fauna was recorded between the localities Križovec and Goričan, 81.81%. 17 species of horseflies were sampled with a modified Manitoba trap (the so-called canopy trap), and 14 species were sampled with an oil or liquid trap. The largest number of horsefly specimens (59.07%) was sampled in the month of July, while the least horseflies were sampled in September (0.15%). The most abundant species, Tabanus bromius and Haematopota pluvialis, recorded their highest peaks of abundance in July. The longest flight period lasting five months (from May to September) was recorded only for Haematopota pluvialis. Tabanus bromius was represented in all 11 localities, while the species Haematopota pluvialis was represented in 10 localities, as well as the species Chrysops viduatus. Based on the earlier research conducted in 2011 and current research of the horseflies fauna along the Mura river in Međimurje, 22 taxa of horseflies (21 species and 1 subspecies) classified into six genera were identified.