S. Mahunka szerk.: Folia Entomologica Hungarica 56. (Budapest, 1995)

rate in a sample of Trechus obtusus. These rates exhibit the high variability within certain species (Den Boer 1970). The state of wings may be genetically fixed or depends on environmental factors (Aukema 1986). A good example is the case of the frequent species, Calathus melanocephalus which was captured in nearly all light traps, but always in quite low individual number. 4. However, if a certain specimen is long winged (macropterous), it does not mean that the the carabid is able to fly in all seasons, because the ability of flight depends from the actual condition of wing muscle, too (Carter 1976, Den Boer et al. 1980). Consequently, the catches of light traps indicate the state of development of the wing moving apparatus, too. This is in positive correlation with flying of the individuals captured by light trap (Liebherr 1986). The development of wing muscles depends on many factors, and it changes either in time or in space (e.g. Van Schaick Zillesen and Brunsting 1984, Desender 1985, Nelemans 1987). It seems that the state of the wing moving apparatus is the main limiting factor of the flight of ground beetles. This statement is proved by the results of investigations of Geipel and Kegel (1989) in Germany, where there were only 18 specimens with fully developed wing muscles among cca. 400 of a sample. 5. The weather is unfavourable. The weather conditions (especially air temperature) can play important role in forming the flight patterns of carabids (Pausch 1979, Van Huizen 1979). Under unfavourable wheater conditions the flight activity of a species may change (it may be limited only on a single night or may be totally absent). This hypothesis is confirmed by the captures of Trichocellus placidus, too. The main nocturnal flight activity of this species falls between September and October in Hungary, with a higher proportion of catches in the first decade of October (Kádár and Szél, unpublished data). Since in this period the air temperature at night only seldom reaches the necessary lower threshold value of flight (Van Huizen 1979), therefore, the catches of this species display a highly discontinuous pattern, i.e. the catches are limited to a few days of the aforementioned months. Acknowledgements - We wish to express our thanks to D. N. Fedorenko and R. Sciaky who kindly helped us in the determination of Dyschirius lucidus and Harpalus subsinuatus. This study was supported by the Hungarian National Scientific Research Fund (OTKA No. T5404). REFERENCES Adis, J. (1982): Zur Besiedlung zentralamazonischer Überschwemmungswälder (VárzeaGebiet) durch Carabiden (Coleoptera). - Arch. Hydrobiol. 95: 3-15. Aukema, B. (1986): Winglength determination in relation to dispersal by flight in two wing dimorphic species of Calathus Bonelli (Coleoptera, Carabidae). In: Den Boer, P. J., Luff, M. L., Mossakowski, D. and Weber, F. (eds): Carabid Beetles, their Adaptations and Dynamics, Gustav Fischer, Stuttgart, pp. 91-99. Baehr, M. (1986): Parophonus australicus sp. n., first record of Selenophorina from Australia (Coleoptera, Carabidae, Harpalinae). - Mitt. Münch. Ent. Ges. 76: 67-70. Boiteau, G. (1983): Activity and distribution of Carabidae, Arachnida, and Staphylinidae in New Brunswick potato fields. - Can. Ent. 115: 1023-1030.