Incidence of major insect pests and its natural enemies of Cabbage (Brassica oleracea var. capitata) under Polyhouse conditions

Abstract

The major insect pests of cabbage crop during rabi, 2021-22 were aphids, leaf webber, diamondback moth and tobacco caterpillar. Although the incidence of semilooper, painted bugs were noticed, it was low. The peak infestation of aphids was seen in last week of November (48th SMW) while that of the lepidopteran pests (leaf webber, DBM and tobacco caterpillar) occurred in January (4th, 4th 2nd SMW, respectively). The mean population of Coccinellids, syrphids and spiders were 0.45, 1.10 and 0.69 respectively under polyhouse conditions. Correlation studies revealed that aphids alone showed significant negative correlation with morning temperature and significant positive correlation with evening temperature while all the lepidopteran pests showed non-significant negative and positive correlations, respectively. All the three natural enemies (coccinellids, syrphids and spiders) showed significant negative correlation with morning temperature and significant positive correlation with evening temperature.