The Need for Direct Observation of Behaviour in Studies of Temperature Effects on Light Reactions

Abstract

Many insects which are photopositive at moderate temperatures begin to react photonegatively when they are heated sufficiently. If they are returned to lower temperatures, they become photopositive again. This reversible reaction sometimes prevents injury or death in any environment. In extreme environments, it permits some species to live where they could not survive without it. Consequently, a knowledge of the responses involved and the temperatures at which they occur may help investigators to understand otherwise inexplicable changes in the behaviour, numbers, or distribution of natural populations.