S. Mahunka szerk.: Folia Entomologica Hungarica 61. (Budapest, 2000)

The behaviour of some male horse-flies in Croatia (Diptera: Tabanidae) S. Krcmar and J. Mikuska The behaviour of some male horse-flies in Croatia (Diptera: Tabanidae) — The total number of collected (1987-1996) horse-flies was 18,503. Within this sample only 202 (1.09%) specimens were males belonging to 24 species. According to the literature and after the examination of other collections of horse-flies 39 species and 1 subspecies of male horse-flies are in Croatia. Of these 40 taxa of males 17 are linked to the continental areas of Croatia, mostly collected in woods of either oak-trees: QuercoCarpinetum croaticum, Genisto elate-Quercetum roboris and Carpino betuli-Quercetum roboris lypicum or of beeches and firs Abieti-Fagetum illyricum. 16 species are linked to the Mediterranean part of Croatia, mostly collected in complexes of oak-trees and white hornbeams: Querco-Carpinetum orientális croaticum and on the flowers of Paliurus spina christi and Clematis flamula. Males of Chrysops viduatus, Atylotus loewianus, Tabanus autumnalis, Tabanus bromius, Tabanus glaucopis, Tabanus tergestinus and Philipomyia graeca were established in both parts of Croatia. Several males of the species Dasyrhamphis anthracinus and Philipomyia graeca were collected in the morning hours, while they were hovering in the air 1 m above the ground at an air temperature of 22°C. Males of Philipomyia aprica were collected towards evening, while which were hovering at about 1.5 m above the ground at an air temperature of 21°C. Other males were collected on the humid soil of forest paths, while alighting on a red car, or on the flowers of some plants. Key words: Tabanidae, males, Croatia. INTRODUCTION Horse-flies have been incriminated as vectors of vertebrate disease agents for over a century (Foil 1989, Foil et al. 1991). These flies are also considered as major pests of livestock due to blood loss and annoyance (Perich et al. 1986). Most studies on Tabanidae have dealt with the aspects of the biology of adult females, particularly geographical and seasonal distributions, host preference and disease transmission (Smith et al. 1994). This is certainly reflected in the difference in the behaviour between males and females (Solem et al. 1990). The adult males of all Diptera, feed only on carbohydrates (Downes 1958) and since they are not bloodsucking, they are much less known than the females (Smith et al. 1994) and there are a few reliable information about mating of tabanids and about their behaviour related to mating (Matsumura 1984, 1987). The family is characterized by lek-like (Taylor and Smith 1990) aggregations of males at speciesspecific sites and times, where the males engage in a variety of activities as a prelude to mating, including intermittent or continuous hovering (Magnarelli 1985, Gaugler and Schutz 1989) or perching and pursuing (Taylor and Smith 1990). The purpose of this