O. Merkl szerk.: Folia Entomologica Hungarica 66. (Budapest, 2005)

Typical aquatic and semiaquatic habitats and their Heteroptera fauna of the Lake Balaton T. VÁSÁRHELYI

1

* & G. BAKONYI

2 'Department of Zoology, Hungarian Natural History Museum H-l

088 Budapest, Baross u. 13, Hungary. E-mail: vasarhelyi@nhmus.hu department of Zoology and Ecology, Szent István University H-2

100 Gödöllő, Páter K. u. 1, Hungary. E-mail: hakonyi.gabor@mkk.szie.hu Abstract - Faunistic lists of four different surveys made during seven decades on the aquatic and semiaquatic bugs (Heteroptera: Nepomorpha and Gerromorpha) of Lake Balaton are given. All the authors provided presence-absence data. Present authors conducted monitoring between 1984-1986 and 1998-2004, and give a typization of the characteristic habitats around the shallow lake. As for the data of the 1998-2002 collectings, frequency of species occurrence is given, as well as considerations on the efficacy of such samplings. Micronecta griseola HORVÁTH, 1899, once frequent in the lake, was again collected after 70 years of "absence". With 3 figures and 2 tables. Key words - Lake Balaton, Heteroptera, Nepomorpha, Gerromorpha, fauna, habitat, monitoring. INTRODUCTION Lake Balaton is the largest lake in Central Europe, and is prominent from both the touristic as well as the nature protection points of view. As habitats disappear or change partly due to human impact, research efforts are being made to describe, analyse, monitor and save species populations or communities of this lake, too (BÍRÓ 2000). The invertebrate water macrofauna is often neglected by hydrobiologists or ecologists. In case of the aquatic and semiaquatic Heteroptera, however, after the first faunistic list of HORVÁTH (1931), three further papers provided faunistic data allowing considerations on long-term changes and consequences. The degree of similarity of the species lists falls short of expectations (BAKONYI & Corresponding author