Studies on Biological Control Host Plant Resistance and Genetic Diversity of Educalyptus Gall Wasp Leptocybe invasa Fisher and La Salle Hymenoptera Eulophidae

Abstract

Investigations on status of gall wasp and its native parasitoids, utilization of native newlineparasitoids to manage gall wasp, exploring the primary host of Megastigmus dharwadicus newlineNarendran and Vastrad, biochemical parameters of different genotypes and molecular genetic newlinediversity of gall wasp and its native parasitoids were carried out in the Department of newlineAgricultural Entomology and Department of Agricultural Biotechnology, College of Agriculture, newlineUAS, Dharwad during 2010-12. newlineQuarterly fixed plot survey conducted in 18 locations of 7 districts revealed the newlinedecrease in gall incidence from I quarter to III quarter while it was absent during fourth newlinequarter. Native parasitoids viz., Megastigmus dharwadicus Narendran and Vastrad was newlinerecorded from all the locations surveyed while Aprostocetus gala Walker from three locations. newlineRoving survey conducted in four states revealed the severe incidence of Eucalyptus gall wasp newlinein Andhra Pradesh, Orissa and Uttarakhand while it was not noticed in Karnataka towards the newlineend of 2011. Activity of native parasitoids was high in Andhra Pradesh (80.00%) and Orissa newline(81.53%) while no parasitoid activity was recorded from Uttarakhand. Augmentative releases newlineof native parasitoids resulted in drastic reduction in gall incidence within 9 months. No fresh newlinegall incidence was noticed one year after last release. Among the native parasitoids M. newlinedharwadcius was the most dominant (90.00%) followed by A. gala (10%). Search for the local newlinehost of M. dharwadicus resulted in identification of 33 parasitoids from 13 plant galls newlinescreened, of which 15 were new records from India. The identity of local host of the native newlineparasitoid, M. dharwadicus remains unresolved. Total phenol was inversely related to the gall newlineincidence which increased with age of the plant. Molecular diversity studies revealed low newlinegenetic diversity among different L. invasa populations indicated the possibility of a single newlineintroduction and revealed the existence of a different Megastigmus sp. in Odisha. newline