Insecticide Hormoligosis1

Abstract

When house crickets, Acheta domesticus (L.), were reared under suboptimum conditions, their growth was increased by certain coneeutrations of most of the 14 pesticides tested. These results are in agreement with the hormoligosis hypothesis, which predicts that subharmful quantities of any stressing agent will be stimulatory to the organism by providing it increased sensitivity to respond to changes in its environment and increased efficiency to develop new or better systems to fit a suboptimum environment. The concentration of these pesticides which was stimulatory was about 1/84 (range of 1/10 to 1100) of the lethal (LD100)dose. This prediction of the action of pesticides on crickets suggests that the hypothesis may be useful as a biological law in understanding and eventually helping control phenomena of biology sllch as “flare back.” Possible mechanisms are suggested.