Abstract
In a preliminary report (Robinson, 1959) it was shown that the plant growth regulator maleic hydrazide (MH) caused both nymphal mortality and reduced fecundity to the pea aphid, Acyrthosiphon pisum (Harris), caged on treated broad bean, Vicia faba L. It was also stated that 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), and 2-methyl-4-chlorophenoxyacetic acid (MCPA), applied by root absorption to broad bean had no effect on adult or nymphal mortality, or fecundity of adult A. pisum, at the rates used.