Flight Patterns of Lygaeus equestris (Heteroptera) in Spring and Autumn with Special Reference to the Influence of Weather

The seasonal and diurnal flight periodicity of Lygaeus equestris (L.) during its preand posthibernation migrations is described. Weather effects on flight periodicity are (1) long-term affecting the ontogenetic development of the bug and thus the recruitment of individuals ready to migrate and (2) immediate causing inhibition or release of flight behaviour of the potential migrants. The criteria sunshine and low wind speeds provide a reliable prediction about when flight occurs, presupposing potential migrants are present in the population. The significance of these criteria is discussed in relation to microclimatic conditions, the behaviour of the bugs before take-off, body temperature thresholds for take-off, and flight speed. It is concluded that knowledge of the factors regulating flight periodicity is important for understanding the population dynamics of L. equestris.