Linseed budfly (Dasyneura lini Barnes) having order Diptera and family Cecidomyidae is only national key pest causing more than 40 per cent yield losses in different parts of the India. Budfly was observed causing considerable damage by maggots initially to leaf bud and then to the flower buds of linseed during winter. About 50 per cent of buds were found infested. The damaged bud failed to open. The corolla of infested flowers gets shriveled and their essential organs look emaciated even of the flower open. Due to their feeding, galls were not produced and there was no pod formation.Use of bioinsecticides and biopesticides in Agriculture is a unique production management system which promotes and enhance agro-ecosystem health, including biodiversity, biological cycles and soil biological activity which ultimately minimize the pollution problems caused by conventional insecticides.Due to awareness about the harmful effects of chemical insecticides farmers are diverted towards organic farming.