Abstract

The flight activity was compared for the Blue-tailed Damselfly Ischnura elegans, the Azure Damselfly and the Emerald Damselfly Lestes sponsa Coenagrion puella at an exposed pond and a sheltered pond at Rimac, Saltfleetby National Nature reserve, Lincolnshire in July and August 1998. Meteorological conditions (air temperature, light intensity, cloud cover, relative humidity, wind speed and wind direction) were investigated concurrently in relation to flight activity of the three species. Flight activity of all three increased with rising air temperature, light intensity and declining cloud cover. These factors appear to be the main ones that exert control on day to day variation in flight activity of these three species. Their relative importance varies from species to species, which is most likely to be due to the nature of the exoskeletons (which influences the rate of solar radiation absorption), size (which influences rate of warming and power requirements) and behaviour. Only Coenagrion puella showed any relationship between mating activity (tandem wheel flight) and meteorological conditions.