Population dynamics of aphid, Aphis craccivora Koch and their natural enemies in Indian bean

Abstract

A field experiment was conducted during kharif-rabi, 2023-2024 to study the population dynamics of aphid, Aphis craccivora infesting Indian bean at Anand Agricultural University, Anand, Gujarat. The incidence of aphids commenced in the third week of September (39th SMW) and it persisted up to the termination of the crop in the second week of January (2nd SMW). The population of aphid ranged from 5.90 to 41.80 aphids/twig. The highest population was observed during the first week of November (45th SMW). The population of A. craccivora exhibited a highly significant negative correlation with minimum temperature and morning and evening vapour pressures. It also showed significant negative correlation with relative humidity, evening relative humidity and rainfall. The highest population of coccinellids was observed in the second week of December (50th SMW), whereas the highest population of chrysopids was observed in the first week of November (45th SMW). In the case of natural enemies, Coccinellid population exhibited a significant negative correlation with morning vapour pressure and evening vapour pressure. The Chrysopid population had a significant negative correlation with evening vapour pressure.