Diversity of insect-pests of banana in different agro climatic zones of Assam and ecological interaction of major banana insect pests

Roving survey was conducted in 18 districts of Assam to know the status of insect-pests infesting different cultivars of banana. Survey revealed that banana pseudostem weevil (Odoiporus longicollis), banana rhizome weevil (Cosmopolites sordidus), banana leaf and fruit scarring beetle (Nodostoma viridepennis), aphid (Pentalonia nigronervosa), slug caterpillar (Parasa lepida), banana thrips (Chaetanaphothrips signipennis) and leaf eating caterpillar (Spodoptera litura) were the commonly occurring pests of banana in Assam, irrespective of cultivars. However, O. longicollis, C. sordidus and N. viridipennis were considered as economically important one and were observed in all the districts surveyed. Incidence of insect-pest was more in ‘Jahaji’ cultivar and was less in ‘Bhimkol’. Population of banana pseudostem weevil and banana leaf and fruit scarring beetle increased from the month of March-April with the increase in ambient temperature and reached its minimum during winter months. Population of both the pests exhibited positive correlation with maximum and minimum temperature and, rainfall.