Persistence of cabbage butterfly Pieris brassicae granulosis virus (PBGV) under soil ecosystem of Himachal Pradesh.

摘要

The excessive and injudicious use of chemical pesticides for insect control in agriculture, led to development of resistance against pesticides. Therefore alternative, viz. biological pesticides such as microbial agents (bacteria and viruses) is of paramount importance. The fate of these microbes in the environment especially in the soil is a matter of great concern and needs to be investigated as the residual inoculums persisting in the soil ecosystem are important for disease epidemic in the next season. The studies on soil persistence of a local strain of granulovirus of Pieris brassicae Linnaeus isolated from dry temperate region of Himachal Pradesh under laboratory conditions revealed that at room temperature the virus was active up to 7 months with 99 per cent reduction in its activity. Under refrigerated condition, however, virus was active even after 10 months of inoculation with 60.50 per cent reduction in its activity. These findings are of significance with reference to temperate region (where the winter temperature is below 0 degrees C for about 5 months) as the virus would continue to persist in soil for longer duration and can cause virosis in insects for sustainable management of the pest in the coming seasons.