The Permanent and Cumulative Effect of Tepa-Induced Sterility in Male Japanese Beetles1

Abstract

The permanence of the chemosterilant effect of tepa on male Popillia japonica Newman was investigated in 2 experiments. In the first, tepa-treated male beetles were confined with virgin female beetles, eggs were collected at various intervals, and sterility was determined for successive periods. In the second, successive groups of females were paired with a group of treated males and the fertility of eggs deposited by the females determined. In neither study was there evidence of a decline in sterility or indication that the tepa-induced sterility of the male was not permanent. When male beetles were topically treated with consecutive daily increments of tepa, the fertility of eggs obtained from paired females indicated that the effects of the additive doses were cumulative.