Population dynamics of major insect pests of Teasle Gourd (Momordica subangulata Blume. Subsp. Renigera) and study the reaction of different genotypes against Fruit fly infestation

The present investigation was carried out at of AICRP on Vegetable Crops, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, Nadia to study the seasonal incidence of important insect pests of Teasle gourd and its correlation with different weather parameters alongside, eighteen genotypes were subjected for screening against the fruit fly infestation during the summer season of 2018 and 2019. The highest population of Red pumpkin beetle (1.41 adult/plant), epilachna beetle (2.0 adult/plant) were recorded during second week of July while highest population of pumpkin caterpillar (2.9 larva/plant) was recorded during the end of June and higher fruit damage due to fruit fly infestation (57.75% fruit damage) and subsequent higher maggot population (12.53 maggot/fruit) was recorded during the third week of July. Minimum relative humidity plays a significant role in population development of red pumpkin beetle (r = 0.578), epilachna beetle (r = 0.822) and maggot population (r = 0.923) while maximum relative humidity is highly significant relation with epilachna beetle (r = 0.728) and maggot (r = 0.833) population and the minimum temperature have significant relation with red pumpkin beetle (r = 0.624) and pumpkin caterpillar (r = 0.698) population build up. Fruit fly incidence was significantly lower in case BCTG-1 (15.7%) and BCTG-13 (18.3%) compared to highly susceptible one BCTG-10 (76.2%). Genotypes with lower fruit fly infestation had low larval numbers in the fruits, and there was a highly negative correlation (r = 0.96) between percentage fruit infestation and ascorbic acid content (r = -0.896) and total sugar (r = -0.977) in fruit.