L. Forró szerk.: Miscellanea Zoologica Hungarica 10. 1995 (Budapest, 1995)

Hutter, G.; Moog, O.: First record of Acentrella sinaica Bogoescu, 1931 in Austria (Insecta: Ephemeroptera: Baetidae)

Distribution Acentrella sinaica is distributed throughout the middle and the south of Europe (Sartori 1988) and thus far recorded from Romania (Bogoescu 1931), Italy (Belfiore 1983), southern France (Müller-Liebenau 1974), Belgium (Müller-Liebenau 1980), Switzerland (Riederer 1981), former Czechoslovakia (Soldan 1978) and Poland (Kalmer 1967). Adam (1990) also mentions the Iberian peninsula as a part of its range. Habitat A. sinaica is found in rapidly flowing water of the meta- to hyporhithral class (Sowa 1980, Studemann etal. 1992). According to Bogoescu and Tabacuru (1957) the larvae live in streams with high flow velocities, where they dwell beneath stones and woody debris. Sartori describes A. sinaica as a specialist for disturbed environmental conditions since they were found in Switzerland (Sarine, Epagny) below a power plant. This account is very similar to a find by Thomas (in Müller-Liebenau 1974) from Southern France. The published accounts so far were all at elevations of 400-940 meters. Kamler (1967) reported on the species distribution in the Polish portion of the Tatra mountains. He found A. sinaica to be a frequent member of the benthic community at 680 m, less common at 770 m, and represented by a single specimen at 940 m, in sandy and stony substrates. Studemann et al. (1992) reported a distribution between 600 and 800 m. The collection site in the Taurach river, just upstream from its confluence with the River Mur, strongly corresponds in terms of substrates and current velocities to previously reported sites where A. sinaica was collected. However, the elevation of 1200 m above sea level is by far the highest reported so far. Development According to Grandi (1960) the species produces only one generation per year. In the middle and lower metarhithral systems the larval stage lasts from April to August and in the upper and middle hyporhithral systems from April to September (Sowa 1980). Studemann et al. (1992) describe A sinaica as having univoltine summer cycle (larval development, growth and hatching during summer; overwintering as eggs). The Taurach river was sampled in three seasons (March, July and November 1993) and A. sinaica was found only in the summer collections, suggesting that it is a summer species. Associations A. sinaica is a typical representative of the rheophilic community. Devan (1984) describes a community with Rhithrogena hercynia and Baetis alpinus. Müller-Liebenau (1969) reports an association with Baetis alpinus, Rhithrogena semicolorata, Epeorus assimilis and Electrogena lateralis. According to Kownacka (1971) A. sinaica appears together with Baetis scambus, Epeorus sylvicola and Rhithrogena loyolea from 780-900 m elevation. In the Taurach river, Baetis alpinus and Rhithrogena semicolorata (Gr.) are the dominant mayfly species of the community. A complete list of the species collected in the Taurach river is given in Table 1.