Keywords: Galleria, Maladera affinis, entomo-pathogenic fungi, survey

Entomo-pathogenic fungi Metarhizium anisopliae (Metsch.) Sorokin was applied by different application method to manage white grubs at Gopalchok eco-site, Mangalpur, Chitwan during winter season of 2004/05. A field experiment was conducted based on households (HHs) survey (N=30) to assess the efficacy of fungus in managing the target white grub species. HHs survey showed low economic status, mainly due to large family size (4.93), poor soil management and soil insect-pests: white grubs, cutworms, corn borer and cricket along with continuous maize based farming system. Farmer’s negligence to pest management resulted severity of white grubs. They were in favor of biological control but interestingly lacked knowledge on IPM, and proper pesticides use. The agro-vets shared information on pest management with the farmers. The field experiment consisted of five treatments: broadcasting of fungus, furrow application of fungus, maize seed inoculated with fungus, fungus aqueous solution drenching and control without fungus application in RCBD with four replications in the severely infested field identified through survey. Observations: before, after 3 months and after 5 months of application were recorded on white grub population, Galleria infection, white grub infection, soil characteristics, maize yield, and records of different species of grubs. Fungus assessment before treatment showed natural occurrence of the native fungus in the field. Among the treatments, furrow application method showed significant (p<0.01) increase in Galleria infection to 58.75% after three months compared to control (0%) that demonstrated the efficacy of fungal propagules of high quality. Furrow method was effective in reducing white grub population as indicated by sampling after 3 months and significant reduction (85%) compared to control (50%) after five months. Better stability of fungus was found under cool and dry environment of winter, where white grubs infection rate was significantly (p<0.01) increased after 3 and 5 months of fungus applications with higher infection rate on furrow application (40.82%) followed by fungus aqueous suspension drenching (20.78%), compared to control (2.08%), which ensures greater chance of causing epizootics in coming season and supports results on white grubs (dominant species, Maladera affinis (Blanchard) population reduction. This study revealed that furrow application of fungus and drenching of fungal aqueous solution after thirty days of sowing would be effective strategy for managing white grubs. The success of bio-control depends on pest life cycle, application methods and prevailing weather conditions, for which comprehensive study for many seasons along with cost effective local resources for fungus mass production and supports from research and development organizations are needed.