Increased Reproduction of Pea Aphids on Broad Beans Treated with 2, 4-D1

Abstract

Sufficient concentrations of 2,4-D dimethyl amine to cause only slight and transitory symptoms on broad beans, markedly increased the reproductive rate of pea aphids, Macrosiphum pisi (Harris), on such treated plants. Longevity of aphid adults, and growth rate of grasshopper nymphs, Melanoplus bivittatus (Say), appeared unaffected. Most notable changes in growth terminals, where aphid development is greatest, occurred in the free amino nitrogen fraction. Increased free amounts of alanine, aspartic acid, serine, and glutathione were especially evident.