Change in the photic reaction due to DDT in the grain weevil, Sitophilus granarius (L.) (Coleoptera: Curculionidae)

Abstract

Exposure of Sitophilus granarius (L.) to lethal doses of DDT produced a change in photic orientation from the normal photonegative toward photopositive. The extent and time of occurrence of this change after exposure depended somewhat on the dosage. The change was reversible in survivors and is shown to be due to an actively maintained orientation. As long as efficient locomotion was possible DDT did not adversely affect the ability to discriminate and orient to light. The survival value of the change in photic reaction is discussed.