SEASONAL ABUNDANCE AND NATURAL PARASITIZATION OF GALL FLY (TRIOZA FLETCHERI MINOR CRAWFORD) ON ARJUNA PLANTATION IN SEEMANCHAL REGION OF BIHAR INDIA

The psyllid, Trioza fletcheri minor Crawford is one of the most significant gall-forming insect pests infesting the leaves of Terminalia arjuna.The non-chemical management of T. fletcheri, presents a significant challenge in Tasar culture due to the need to ensure the safety of the Tasar silkworm.The present study, conducted in the arjuna host plantation garden at the Advance Centre on Sericulture, Kishanganj, from February to July 2024, identified T. fletcheri as the primary pest of T. arjuna.The pest first emerged in early March and persisting until August, with a peak population of 162.60 flies per trap in early July (27 th standard week).This coincided with the highest foliar damage (74.80%) in mid-July (28 th standard week).Correlation analysis revealed significant positive associations between gall fly populations, foliar damage, and both minimum temperature (r = 0.716**) and relative humidity (r = 0.670**).Natural parasitization of T. fletcheri by chalcid wasps initiated in May, peaking at 48.38% in July (28 th standard week), with parasitization positively correlated with gall fly population (r = 0.863**) and foliar damage (r = 0.883**).Parasitization was also significantly associated with relative humidity (r = 0.761**), while non-significant relationships were observed with maximum temperature, minimum temperature and rainfall.Biotic and abiotic factors collectively accounted for 85 percent (R) of the overall variation observed in the gall fly population.This study highlights the impact of weather conditions on pest and parasitization dynamics in T. arjuna.