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

Table 1 (continued) 1931 1988 2001 1998-2002 Heteroptera: Gerromorpha Mesovelia furcata MULSANT et REY, 1852 + + + + Microvelia reticulata (BURMEISTER, 1835) + + + + Aquarius pallidum pallidum (FABRICIUS, 1194) + + + + Gerris argentatus SCHUMMEL, 1832 + + + + Gerris odontogaster (Z^TTERSTEUY, 1828) + + + + Gerris thoracicus SCHUMMEL, 1832 + + + + Hydrometra gracilentum HORVÁTH, 1899 + + + Hebrus pusillus pusillus (FALLÉN, 1807) + + + Hebrus ruficeps THOMSON, 1871 + + + Microvelia buenoi DRAKE, 1920 + + Gerris lacustris (LINNAEUS, 1758) + + + Gerris asper (FlEBER, 1860) + Hydrometra stagnorum (LINNAEUS, 1758) + Velia caprai caprai TAMANINI, 1947 + Limnoporus rufoscutellatus (LATREILLE, 1807) + Micro velia pygmaea (DUFOUR, 1833) + Gerromorpha species number 9 10 11 13 Total species number 28 26 25 31 THE HETEROPTERA FAUNA OF THE LAKE Table 1 consists of species lists from four periods of collectings. The species names of the old lists are given according to recent validity. The number of aquatic species varied between 14 and 19. Most aquatic species were found by HORVÁTH between 1927 and 1930. Ten species were collected in all sampling periods. These species are common in Hungarian still waters. Two of the species collected only once (Micronecta minutissima, Notonecta lutea) are particularly rare in the country. Of particular interest is that Micronecta griseola was common between 1927 and 1930 in Lake Balaton. It disappeared later, but we found it again in 2004. These data were revealed after the recent sampling period, so the species is not listed in the table.