E. F. Knipling

Suppression of Pest Lepidoptera by Releasing Partially Sterile Males A Theoretical Appraisal

Scientists at many institutions are investigating the effects of atomic radiation and chemosterilants on reproduction in Lepidoptera. These insects include some of the most destructive pests of agriculture. The ultimate purpose is to utilize sterilized insects to control populations as is now being done with the screw-worm fly, Cochliomyia hominivorax, and certain tephridid fruit flies. Early attempts to sterilize Lepidoptera and other orders of insects emphasized methods that would assure 100% sterility in the insects intended for release.

The Theoretical Basis for Augmentation of Natural Enemies

Entomophagous parasites and predators developing on their own play a major role in regulating the abundance of insect pests. The total complex of parasites and predators in a pest ecosystem may involve many species, each varying in importance at different times and places. However, even a single well adapted species is capable of reducing the steady density of a pest population. This is clearly indicated by the success that has been achieved by the introduction and establishment of a wide range of parasites and predators for the control of alien pests. DeBach (1971), Clausen (1956), Sailer (1972), and other authorities list several hundred parasites and predators that have given partial to excellent control of insect pests after their introduction and establishment.