Assessment of economic injury level and economic threshold level of bud fly (Dasyneura lini Barnes) infesting linseed

A field experiment was conducted in rabi on linseed (var. Neelum) during 2002–03 and 2003–04 to establish relationship between level of bud infestation and seed yield. The results revealed that the economic injury level (EIL) of linseed bud fly (Dasyneura lini Barnes) was found to be 9.80% bud infestation based on the mean findings of field experiments conducted over the period of two years. The economic threshold level (ETL) was worked out as 6.17% bud infestation level. The correlation between per cent bud fly infestation (BFI) and seed yield of linseed was significant and negative having r = −0.9806** and b = −14.31* in the agro-climatic conditions of Ranchi, Jharkhand.