RAJAN SALALIA AND ARVIND ISHER

The populations of mustard aphid and its natural enemies on Brassica napus c.v RSPN 25 was assessed during rabi 2008–09 at the Research farm of the Division of Plant Breeding and Genetics, FOA, SKUAST – Jammu (J&K), India. The incidence of Lipaphis erysimi on Brassica napus c.v RSPN 25 began from December and continued till harvesting stage i.e. March. Initially the alate forms were noticed on the crop and subsequently apterous adults and nymphs appeared in large numbers, its density gradually increased from December and attained peak during inflorescence and pod formation stage during February–March. The seven spotted lady bird beetle, Cocinella septempunctata (Linn.) also appeared as a varacious feeder during February–March. The synchronized occurrence of both prey and predator reflect the dependence of the Coccinellid on aphid for its survival.