Behaviour and population dynamics of shoot gall maker (Betousa stylophora Swinhoe) on aonla (Emblica officinalis Geartn) in south-west Haryana

The study on behaviour and population dynamics of Betousa stylophora Swinhoe on aonla was carried out at CCSHAU, Regional Research Station, Bawal for two years 2012–14. The shoot gall maker Betousa stylophora (Lepidoptera: Thyrididae) was recorded as an important pest of aonla. The fresh gall formation was observed from July to November. The mean twig infestation was recorded maximum (40.0%) in variety NA-10 followed by Chakaiya (34.0%) during the study period. The minimum twig infestation was recorded (13.5%) in seedling (Desi). Average number of galls were recorded highest in NA-10 (4.6 galls/twig) followed by Chakaiya (4.1 galls/twig) which were significantly higher from all the varieties. The minimum number of galls 2.0 galls/twig were recorded in the seedling. During the study rainfall was found to be the overriding factor in determining the infestation with the highest correlation coefficient (r= 0.645 and r= 0.742). The minimum temperature showed a significant positive correlation (r= 0.563 and r= 0.537) with infestation during 2012–13 and 2013–14 respectively.