S. Mahunka szerk.: Folia Entomologica Hungarica 64. (Budapest, 2003)

plate of male R. thienemanni is broadening to half of the length, then slightly tapering with concave sides, and apex is truncate (see Fig. 2 in Zwick 1972). The postgenital plate of female R. hamulata is slightly broadening to half of the length, then strongly tapering with concave sides, and apex is arcuately emarginate (Fig. 5). The postgenital plate of female R. thienemanni is nearly parallel-sided to half of the length (or slightly narrowing), then tapering with concave sides, and apex is arcuate (see Fig. 6 in Zwick 1972). Újhelyi (1975) revealed that the species lives in the mountain streams, not in the Danube. This is confirmed by our results. Despite a number of samplings only one larva was found in the Lengyendi-patak. Larvae were found twice in the Nagy-patak, but these were probably drifted down from the Monostor-patak. Therefore, the Monostor-patak is considered as typical habitat, where the species is detected from the first finding ( 1995) to the present days. The habitat is characterized as follows. The studied reaches are on the southern edge of the foothills, 270 m above sea level. The bedrock is andésite. The stream often dries out in the middle of the summer but there is water again in the middle of the autumn (in the case of R. thienemanni, Dumont (1984) also reports drying-outrunning water). The spring of the stream is at about 600 m, where water is always present, with many Diura bicaudata (Kovács et al. 2002). The reach (about 50 m long), where most of the larvae were found, is not forested, and the stream is rich in microhabitats, with widening, slowing, then narrowing and fast-running stretches. The streambed is also variable, covered by mud, gravel, pebbles and larger stones. Fontinalis antipyretica is abundant; this moss was reported also by Újhelyi (1975). The larvae of R. hamulata were taken from pebbles, stones, Fontinalis and submerged twigs and leaves. Following the period of egg-laying this reach of the stream frequently dries out, and water appears again in the autumn only. Eggs probably survive the dry period in the moist clumps of Fontinalis. The first larvae were found in November, when they were 3.3-5.2 mm long. Starting from this date, larvae were collected until the middle of April (the date of the last observation was 16 April). According to Hungarian data (including Újhelyi'

s ones) the time, when the species is on the wing, lasts from 11 March till 26 April. Swarming period of Brachyptera risi, the second species of Taeniopterygidae inhabiting the Monostor-patak starts a few weeks later. Merely two adult female R. hamulata were found in the field: one of them was flying, while the other was hidden in a bark crevice of a tree standing near the stream. Újhelyi (1975) listed the species of Plecoptera collected together with adults of R. hamulata along the Nagy-Vasfazék-patak, and all other stonefly species liv-