ON THE DENSITY AND COMPOSITION OF NATURAL ENEMIES OF CABBAGE INFESTING APHIDS FROM MANIPUR

Field populations of Brevicoryne brassicae, Myzus persicae and Lipaphi s erysimi infesting cabbage were monitored continously for two crop se asons along with a dozen natural enemies comprising of 5 species of Sy rphids, 3 species of Coccinellids and 4 species of Aphidiid parasitoid s. The population data showed significant high positive relation betwe en pests and predators/parasitoids. Their period of occurrence also sy nchronised with that of aphids indicating that the natural populations of cabbage aphids being regulated predominantly by predators and to a limited extent by parasitoids and other abiotic factors.