Abstract
The effect of temperature on the key parameters of the functional response of larvae of the damselfly I. elegans (van der Linden) was investigated in the laboratory. The attack coefficient, a, increases in a sigmoid manner with temperature while the handling time, Th, declines logarithmically from 5-16.degree. C, after which it remains constant. The life history of Ischnura is described. Growth begins in late March or early April and stops at the end of Sept. or beginning of Oct. each year. From field temperature measurements, the onset and termination of growth revolve around a temperature of 8.degree. C. This temperature corresponds to the temperature in the laboratory experiments at which the attack coefficient begins to increase markedly. Mathematical models of long-lived arthropod predators are discussed.