L. Forró szerk.: Miscellanea Zoologica Hungarica 13. 2000 (Budapest, 2000)

Kovács, T., Ambrus, A.; Juhász, P.: New Hungarian mayfly (Ephemeroptera) species arising from collectings of larvae II.

pseudorivulorum (on 6 occasions); Raptobaetopus tenellus, Heptagenia sulphurea, Ephemerella ignita (on 5 occasions); Baetis fuscatus, Heptagenia coerulans, Heptagenia longicauda, Ephemera lineata (on 4 occasions). Family Caenidae Brachycercus europaeus Kluge, 1991 (syn. B. pallidus auct.) Könnend: Route No. 86, Rába, XN20, 18.08.1998, 5, A. Ambrus, T. Kovács — Molnaszecsó'd: Road to Döröske, Rába, XN21, 18.08.1998, 4, A. Ambrus, T. Kovács — Rábahídvég: Route No. 8, Rába, XN31, 18.08.1998, 3, A. Ambrus, T. Kovács — Rum: Route No. 87, Rába, XN42, 18.08.1998, 2, A. Ambrus, T. Kovács. This species is widespread in Poland (Sowa 1975), Lithuania and Russia to the Ural Mountains (Kluge 1991). The specimens were collected on the slowly flowing sections of River Rába, near the shore, on muddy, sandy, sediment covered bottom. Most often the following species were found at the same sampling points: Isonychia ignota, Heptagenia coerulans (on 4 occasions); Heptagenia flava, Oligoneuriella keffermuellerae, Oligoneuriella pallida, Ephemerella ignita, Cercobrachys minutus (on 3 occasions). Discussion Due to its geographical distribution the occurrence of Baetis tricolor was expected in Hungary. This species was recorded in 10 UTM quadrats altogether at 11 localities from the following rivers: Fekete-Körös, Maros, Rába, Tisza, Sebes-Körös. Brachycercus europaeus was not found formerly within the Carpathian Basin. During our collecting trips this species was found at 4 sampling points in four different UTM quadrats on the Rába section between Körmend and Rum. At present this is the most south-western border of its area. Several species that are rare at European level were found at the same sampling points: Isonychia ignota, Heptagenia coerulans, Oligoneuriella keffermuellerae, Cercobrachys minutus. The occurrence of the latter species together with the closely related Brachycercus europeus at the same sampling points was discussed by Kluge (1991) (Russia: Baskiria, River Belaja). The two species were recovered in Hungary in identical habitats. The results of collecting activities of aquatic larvae carried out during the past years (Kovács et al. 1998, 1999) and the data presented here indicate and emphasise the importance of Tisza river and Rába, as in both of these water bodies 9 new Ephemeroptera species for Hungary were found. Acknowledgements We are grateful for the generous help of Adam Gazaczow, Nikita Ju. Kluge and Tomás Soldán.