Incidence of green peach aphid, Myzus persicae on Brassica crop and its chemical control in the field

Myzus persicae , green peach aphid is a polyphagous pest infesting a number of economically important agricultural crops. The current research studies were planned to investigate the population dynamics in relation to metrological factors such as, temperature and relative humidity. Our results showed that the population of the aphid remained at its highest point during the second and third week of March corresponding to the maximum temperature and relative humidity ranges of 25, 28, 31 and 63, 57, 51% respectively. Among the insecticides used for their effectiveness against the green peach aphid, chlorpyriphos re- mained highly effective both in recommended field dose and two fold serially diluted dose. The other insecticides were ranked as, lefnuron, lambda cyhalothrin, buprofazin, emamectin benzoate and trichlorfon, respectively after 72 hours post treatment.