Diurnal behaviour of <Emphasis Type="Italic">Cephalcia lariciphila</Emphasis> (Hymenoptera: Pamphiliidae): relation to climatic factors and significance for monitoring

Adults of Cephalcia lariciphila emerge and start their activity at Vetrny Jenikov village (Czech Republic) during mid-April. First specimens were collected from Malaise traps at the same time as from emergence traps. Last specimens flew at the beginning of May or even the beginning of June. Adult occurrence typically lasted about 20 (–30) days. One Malaise trap and five yellow sticky boards were placed on three plots, and sawflies were collected at 1 hour intervals in two two-day periods. The variables with the best explanatory power for activity of imagos were temperature in interaction with humidity. Sawflies were most active at 16°C with 20% air humidity and numbers caught decreased steeply up to 0°C and 80% air humidity. The daily flight activity began at 10 a.m. and ended after 5 p.m. Both methods, the Malaise traps and the yellow sticky boards, should be used in forest practices from the middle of April.