The Ecology of Insect Parasites and Predators

Abstract

The Study Of parasitic and predatory insects has recently become more urgent because of difficulties in preventing serious crop damage and damage to stored products by insects of various kinds. With the discovery of modern insecticides it was expected by the optimists that problems of pest control were now soluble if not yet solved. Tests had shown the very high toxicity of these substances to insects, few of which could survive insecticide application in the field. The short-term effect was beneficial, with a satisfactory reduction of damage. Some pests, however, like the codling moth on apple trees, remained numerous enough to cause economic damage even when frequent insecticide sprays were used. Other pests, like the red spider mites, seemed in fact to be more serious where insecticide was used than without it.