Biological control of Eucalyptus gall wasp, Leptocybe invasa Fisher & La Salle (Hymenoptera: Eulophidae) by its native parasitiods

Abstract

Utilization of native parasitoids viz. Megastigmus dharwadicus Narendran and Vastrad (Hymenoptera: Torymidae) and Aprostocetus gala
Walker (Hymenoptera: Eulophidae) for biological control of eucalyptus gall wasp, Leptocybe invasa Fisher and LaSalle (Hymenoptera: Eulophidae) is reported. Two native parasitoids multiplied in the greenhouse were released in a severely affected eucalyptus plantation spread over an area of 1000 ha. A total of 14,000 heavily parasitized galled seedlings, 1400 M. dharwadicus and 300 A. gala were distributed over a period of six months. The per cent parasitization by these native parasitoids was ascertained before distribution of galled seedlings. Though there was a gradual increase in per cent parasitization, the reduction in gall incidence was not evident up to three months. However, drastic reduction in gall incidence and pest emergence accompanied by very high per cent parasitization was evident within eight months. Post release evaluation conducted during June 2011 and May 2012 indicated the successful control of the pest.