Rhabdiopteryx hamulata

The genus Rhabdiopteryx is currently represented in Slovakia by three species: R. acuminata Klapálek 1905, R. navicula Theischinger 1974 and an alpine species, R. neglecta (Albarda 1889). Distribution of these species is very well analyzed and documented (Krno 2004b), however, for many years the questions of occurrence of R. harperi Vinçon & Murányi, 2009 and R. hamulata have remained. The former species is still not confirmed in Slovakia, but we expect it may occur in eastern Slovakia in the Bukovské Mountains. Krno (2000) and Šporka (2003) suggested the latter species occurs in the Dunaj River basin in Slovakia, but this has not been confirmed, and its occurrence in the Danube River was considered doubtful by Ujhelyi (1975). In 2009, we found the first confirmed Slovakian records of larvae and adults of R. hamulata in two upland to submontane brooks in the Hron River basin in southern Slovakia (Fig. 5). Globally, this species has a disjunct population in Bulgaria (Braasch & Joost 1975), and is also known from Macedonia (Ikonomov 1986) and Hungary (Kovacs & Murányi 2008). The species is categorized as vulnerable and the Slovakian populations represent the known northern boundary of its distribution in Europe. The species occurs in the Pannonian ecoregion, but borders the Carpathian ecoregion. Larvae have a speckled appearance with spots forming a transverse row on each abdominal segment, and the subgenital plates of larvae are incised inward at the distal end of the body (Fig. 3).

Larval specimens were abundant in Podlužianka brook, but less common in collections from Sikenica brook in the Štiavnica Mountains. These 4 th order streams are characterized by neovolcanic basins, high fluctuations of flow in spring and autumn and a summer temperature maximum in excess of 20˚ C. Both brooks flow through Pannonic oak-hornbeam forest. In this biotope we recorded Alnus glutinosa, Ulmus minor, Acer campestre, Fraxinus excelsior and Rubus fruticosus among the floral components. Larvae were frequently associated with submerged roots with entrained leaf packs and streaming detritus. During our examination of larvae, the digestive tracts of 26 specimens were analyzed and the species appears to be a complete detritophage. Larvae were found primarily in the meta and hyporhithral zones, as in Hungary, Bulgaria and Macedonia (Kovacs & Murányi 2008; Tyufekchieva et al. 2013). The species is known from submontane and mountain streams (Újhelyi 1975; Kovacs & Murányi 2008) from localities outside of Slovakia, but in Slovakia the species occurs in upland to submontane streams.

Material examined. Slovakia, Štiavnické vrchy Mts, Podlužianka:1. (N48°18´06.2´´ E18°37´32.9´´), 215m a.s.l., 11.3.2009, 25L, 1♀, 2♂, coll. I. Krno, leg. et det. M. Žiak; 2. (N48°18´14.8´´ E18°37´57.4´´), 153m a.s.l., 11.3.2009, 4L, coll. I. Krno, leg. et det. M. Žiak; Slovakia, Štiavnické vrchy Mts, Sikenica: (N48°18´14.8´´ E18°37´57.4´´), 153m a.s.l., 12.3.2009, 1L, coll. leg. et det I. Krno.