Ábrahám Levente (szerk.): Válogatott tanulmányok 15. - Natura Somogyiensis 31. / Miscellanea 15. (Kaposvár, 2018)
Purger J. J.: First occurrence of Rosalia longicorn Rosalia alpina (Linnaeus, 1758) int he valley of the Drava River (Hungary)
42 Natura Somogyiensis with Ainus glutinosa and Fraxinus excelsior (Alno-Padion, Alnion incanae, Salicion albae) (Szmorad 2014) and 91F0 - Riparian mixed forests of Quercus robur, Ulmus laevis and U. minor, Fraxinus excelsior or F. angustifolia, along the great rivers) (Király & Szmorad 2014). Results and discussion During field work along the Old-Drava side arm one male specimen of Rosalia longi- corn was found in the edge of the alluvial forest on 1st July 2016. This rare Natura 2000 species was recorded near Lóka-sarok locality (N45°58’5.07”, E17°2r40.31”), cca. 60 m to the northwest from the B733 border stone. Rosalia longicorn was observed on a leaf of dewberry (Rubus caesius L.) shrub, 30-40 cm above moist ground. Photographs were taken from 1 m distance without disturbing the animal (Fig. 1). Rosalia longicorn has been considered as a montane species, associated with beech (Fagus sylvatica) in Central Europe, whereas in southern Europe this species has often been reported from lowlands, and its host spectrum is broader (Cizek et al. 2009). According to FIegyessy and Merkl (2014) it is a characteristic species of beech forests, though in Hungary it rarely occurs in other mixed forest communities with beech. Its larvae develop during several (2-4) years in dead trunks and their host plants can also be trees other than beech, e.g. hornbeam (Carpinus betulus), field maple (Acer campestre), sycamore (A. pseudoplatanus), Norway maple (A. platanoides), common ash (Fraxinus excelsior), narrow-leaved ash (F. angustifolia ssp. danubialis), wich elm (Ulmus glabra) and lime species (Tilia spp.) (Hegyessy & Merkl 2014). Adult male individuals of Rosalia longicorn emerge from the tree in June (one week earlier than females) and they are very active during hot summer days (Hegyessy & Merkl 2014). The mobility of this species and dispersal up to 1.6 km is reported by Drag et al. (2011). The male individual of Rosalia longicorn observed in the Drava valley was more than 30 km distance from its previously known occurrences in Hungary (Fig. 2.) and Croatia (Katusic et al. 2017), therefore it probably could not come from these areas. Cizek et al. (2009) suggest that Rosalia longicorn spreads into Central European lowland forests along large rivers, and that the spectra of hosts and habitats exploited are wider than generally thought. The forests in the area along the Drava River belonging to Danube-Drava National Park contain a lot of fallen trunks of various tree species which are potential hosts of Rosalia longicorn, therefore these habitats can be considered as suitable for their colonisation. Acknowledgement: Mobility for the research was facilitated by Danube-Drava National Park Directorate (project: LIFE 13/Nat/HU000388 Life Old-Drava).
