author(s)
Rakhshan and Md. Equbal Ahmad

abstract
The present seasonal study of Aphis craccivora Koch and its predator Cheilomenes sexmaculata (Fabricius) was carried out in two years on two most common vegetables (Phaseolus sinensis and Lablab purpureus) under agroclimatic condition. The activity of aphids was recorded from August to January (5-6 months) and September to March (6-7 months) on P. sinensis and L. purpureus respectively. However, the activity of predators was observed from September to January (4 months) and October to March (5-6 months) on P. sinensis and L. purpureus respectively. Generally, the appearance of predator was observed on A. craccivora after 2-4 weeks (26-27 ºC; 56-57% RH) on P. sinensis and after 5-6 weeks (19-22 ºC; 50-60% RH) on L. purpureus. The early appearance of both aphids and its predators on P. sinensis was observed probably due to suitability of host plants. Thus, the appearance and population buildup of aphids and predator were observed host plants and temperature/humidity dependent. This study shows that host plants as well as whether parameter (temperature, relative humidity, rainfall, wind and sunshine hours) greatly influenced the aphid predator interaction. Thus, both the biotic and abiotic factors have equal role in regulating population of A. craccivora and C. sexmaculata in agro-ecosystem. Therefore, for effective management of pest and conservation of natural enemies requires a thorough understanding of their ecology.