Abundance and diversity of insect pests and their natural enemies in Brassica campestris (L.) crop ecosystem

Abstract

For the development of an efficient ecological and biological control strategy that are economically and environmentally sound, it is essential to study the diversity indexes and abundance of insect fauna. In this study we recorded a total number of twelve species of insect pests and twenty four species of natural enemies throughout the cropping season of Brassica campestries during 2019–20 and 2020–21. Among insect pests mustard aphid species (Lipaphis erysimi pseudobrassicae, Myzus persicae) were dominant in both the years with relative abundance of 73.46 and 76.70% respectively. Amongst natural enemies Coccinella septempunctata (14.66 and 16.36%) and Diaeretiella rapae (21.97 and 17.89%) were dominant in both the years respectively. The diversity indexes of insect pests and natural enemies with respect to the Shannon index (H = 0.78, 1.54), Richness (M.I. = 6.34, 7.18), Evenness (J = 0.23, 0.45) was higher during 2020–2021 respectively. This study offer some new insights into the frequency of insect pests and their natural enemies, and may support the idea that sustaining ecosystem health and fostering biodiversity may require an ecological and biological approach to pest management.