Anaesthesia and the action of DDT on Anopheles larvae.

Abstract

DR. J. C. JONES1 has reported that “anaesthesia … interferes in some important way with the obtainment of a lethal dose of DDT” by larvae of Anopheles quadrimaculatus Say. If this effect were involved with the metabolic processes of the insect, one might make a case for the intriguing concept of ‘active’ uptake of this poison. If, however, the effect is simply one of producing a lower exposure to the insecticide by decreasing the physical activity of the larvae, it is, obviously, worth no further investigation. On the basis of the following evidence: “…anaesthetized larvae which are drawn about within the [DDT] suspension by cardboard tips are entirely comparable to those left completely quiescent”, Jones ruled out the latter possibility.