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

Querco-Carpinetum croaticum that covers the hilly parts of Slavonia but also reaches the foots of mountain massifs. These species belong to the boreal - Eurasian type of fauna (Olsufjev 1977). On the other hand, males of Atylotus loewianus which have also been collected at the same station belong to the group of Mediterranean species (Olsufjev 1977) and they have been collected only on the southern parts of the rolling area around Lake Borovik. Male specimens of the boreal-Eurasian species Hybomitra ciureai, Haematopota subcylindrica and Tabanus sudeticus were also collected in the periodically inundated belts of the rivers Drava and Sava. Another boreal-Eurasian species Hybomitra bimaculata, was collected in the oak woods out of the reach of floodwaters. In the region of Gorski Kotar, the rainiest part of Croatia, males of Philipomyia aprica and Tabanus bromius were collected at an altitude of 845 m in the woods consisting of firs and beeches of the assotiation Abieti-Fagetum illyricum. Several males of Tabanus bromius were also collected at the altitude of 1400 m. Males of Dasyrhamphis anthracinus, Philipomyia aprica and Philipomyia graeca were caught while they were hovering. It is known that males hover exclusively to attract the females with empty spermathecae and undeveloped eggs (Gilbert 1984). The hovering of males on clearings in woods is their habitual behaviour before mating (Mcmahon and Gaugler 1993). Males of Tabanus bishopii and Tabanus rufidens hover over wood paths, attack and dart ahead and then fly from side to side trying to catch the passing females (Matsumura 1984). Identical behaviour of horse-flies was observed in the mornings and in late afternoons only with Dasyrhamphis anthracinus, Philipomyia aprica and Philipomyia graeca. It is asserted that the larger facets on the upper surface of the eyes allow the perceiving of small fast objects and they mediate in the capture of the females in flight (Downes 1969). Other males were mainly collected while they were alighting on a red car, or while they were feeding on Paliurus spina christi. Some males were also caught on the humid soil of forest paths. The hovering of Dasyrhamphis anthracinus, Philipomyia aprica and Philipomyia graeca in the mornings and towards evenings is in keeping with the fact that the mating of horse-flies mostly takes place during sunrise and sunset (Chvála 1988). Males usually appear earlier than the females and they die immediately after mating (Chvála et al. 1972). This fact has been established for the males of Chrysops caecutiens when the sample collected on 31st May contained only 3 males and no females, and for those of Atylotus loewianus collected on 5th August 1994, when 73 specimens were caught at the station in Borovik, out of which 45 were males dominating with 61.64% over the females in the early period of this species season. There were only 5 males and 58 females in the sample of Atylotus loewianus that was collected at the same station on 16th August. At this occasion males were represented with only 8.62% in the collected sample. Males of Dasyrhamphis anthracinus were also more numerous than the females in the sample collected on 30th May 1995 and 4th June 1996 on the station near Baasinska jezera. Males were also in the majority in the sample of Philipomyia aprica collected on 17th July in Gorski Kotar. These results support the assertion that males appear earlier than the females and that they die immediately after mating. The analysis of the collected sample regarding the number of females shows that males are mostly represented in larger numbers at the beginning of the activity period of their species. Since the males and females of most species copulate only once, the females disperse after the copulation and avoid the males (Mcmahon and Gaugler 1993). The analysis of the sample of Tabanus glaucopis collected at the station in Senj on 24th July 1995 shows that there are 14 males and 14 females. Identical results were obtained with Tabanus shannonellus collected in Bol on the island of Brae on 23rd August 1994 and at the station in Kotlenice on 27th July