Vol. 10, Special Issue 10 (2021)

Author(s):
MP Sruthi, S Raguraman, N Chitra and RK Balaji

Abstract:
Field surveys were carried out in six village blocks three in Coimbatore and three in Tiruppur districts of Tamil Nadu viz., Karamadai, Kinathukadavu, Pollachi South, Udumalaipettai, Pongalur, and Tiruppur. The diversity study was conducted across two seasons in three vegetable crops: bhendi, brinjal, and cowpea, at the vegetative stage, reproductive stage, and harvesting stage. The roving survey was covered in a plot area of 10×5 m² and was conducted in five randomly selected plants from five different plots. The collected data was combined and the Species percent, relative abundance, diversity indices such as Shannon-Weiner Index, Simpson's Index, Margalef Index, and Species Evenness Index were calculated and represented graphically. Cheilomenes sexmaculata (39%) was the most abundant species in every location because of its diverse prey preferences, followed by Coccinella transversalis (22%), Illeis indica (21%), Propylea spp. (5%), and Brumoides suturalis (5%). C. sexmaculata was found to act as an aphidophagous and coccidophagous predator. The surrounding vegetation was found to influence the abundance of coccinellids. From this study, we analysed that diversity indices fluctuated according to the season, crop stages, and locations. In the second season, which extends from May to August 2021, we found a greater number of coccinellids than in the first (January-April, 2021). This study suggests that coccinellids are the reliable biological source to contain the soft bodies insects in vegetables such as bhendi, brinjal and cowpea.