Influence of PGRs on the Longevity and Reproduction Potential of the Mustard Aphid, Lipaphis erysimi (Kaltenhach)

Nine PGRs (2,4-D, IBA, IAA, coumarin, chlorogenic acid, gibberellic acid, alar B-9, maleic hydrazide and cytokinine) belonging to four major classes of plant growth hormones (auxins, gibberellins, abscissins and kinins) were investigated for their influence on the longevity and on the reproductive potential of mustard aphid, Lipaphis erysimi (Kaltenbach). The leaf surface treatment with three concentrations (64, 256, 1024 ppm and control) was given to L. erysimi. The findings revealed that auxins (IAA, IBA and 2,4-D) and kinin (cytokinine) adversely affected the longevity and reproductive potential, and the reduction was concentration dependent. The maximum inhibitory effect was noticed in the treatment of indole-3-acetic acid, where about 50% shortening of the longevity was observed even at the lowest concentration of 64 ppm. Although, gibberellins (GA₃, alar B-9 and maleic hydrazide) and abscissins (coumarin and chlorogenic acid) suppressed the longevity as well as reproductive potential upto 256 ppm concentration but with increase, in concentration not much inhibitory effect was observed.