  A six year field study was conducted from 2001 2002 to 2006 2007 at Punjab
Agricultural University, Ludhiana, India to study the losses in seed yield of
different Brassica species (B. juncea, B. napus, B. carinata, B. rapa and Eruca
sativa) by the infestation of insect pests. The experiment was conducted in two
different sets viz. protected/sprayed and unprotected, in a randomized block
design, with three replications. Data on the infestation of insect pests, and
seed yield were recorded at weekly intervals and at harvest, respectively. The
loss in seed yield, due to mustard aphid and cabbage caterpillar, varied from
6.5 to 26.4 per cent. E. sativa suffered the least loss in seed yield and
harboured the minimum population of mustard aphid (2.1 aphids/plant) and
cabbage caterpillar (2.4 larvae/plant). On the other hand, B. carinata was
highly susceptible to the cabbage caterpillar (26.2 larvae/plant) and suffered
the maximum yield loss (26.4%).
