EFFECTS OF THE CHEMOSTERILANT THIOTEPA ON THE SEXUPARAE AND SEXUALES OF THE PEA APHID, ACYRTHOSIPHON PISUM (HOMOPTERA: APHIDIDAE)

Abstract

Several chemosterilants have been tested against insects (Borkovec 1966). As a result, a total or partial sterility and decrease in fecundity have been noticed in several insects. Amongst Aphididae, Brevicoryne brassicae L., Myzus persicae Sulzer, Aphis fabae Scop., Macrosiphum euphorbiae Thomas, and Acyrthosiphon pisum (Harris) have been tested to determine the effects of chemosterilants like tepa, thiotepa, and metepa (Bonnemaison 1966; Bhalla and Robinson 1966, 1968; Chawla et al. 1973, 1974; Sharma et al. 1980; Steffan and Stüben 1976). In all previous work, either viviparae or their nymphal instars were the object of chemosterilant treatment and up to 95% reduction in fecundity was observed. Nothing to date has been described on the effect of chemosterilants on the sexuparae or sexuales of Aphididae. To continue with the results obtained by Sharma and Thériault (1980) and Sharma et al. (1980) on the viviparae, this paper describes the effects of 0.5% thiotepa [Tris (1-aziridinyl) phosphine sulphide] on sexuparae of the pea aphid, Acyrthosiphon pisum (Harris), and their progeny.