SAVE PARASITES AND MICROBES OF CUTWORMS, AGROTIS SEGETUM (SCHIFF) PEST OF POTATO IN SHIMLA HILLS.

摘要

To explore the natural parasites and microbes associated with cutworm (Agrotis segetum), extensive survey were conducted during 2008 and 2009 main crop season at medium altitude hills of Himachal Pradesh. Three potential parasites viz. Macrocentrus collaris Spinola, Parisepsia carbonaria Panz and Ichneunioti spp. and two different cultures of Bacillus spp. were reared/ isolated from caterpillar of A. segetum. M. collaris was found active from 14th MW (30th March to 5th April) till 22nd MW (25-31st May) and dominant parasite on cutworm in potato field of Shimla. The parasitization by M collaris to cutworm ranged from 16.66 to28.57 per cent (average 20.08 per cent) during 2008. Highest parasitization of M.collaris in 3rd instars larvae was recorded on16th MW (28.57 per cent). The second parasite, P. carbonaria was observed from 15th MW (6-12 April) until 22nd MW (25-31 May) on cutworm and caused 7.69 to 22.22% parasitization. The average parasitism was 13.22%. Ichneumons sp. was found active from April to May and the average parasitism by it was recorded as 3.97% on cutworm. The microbe Bacillus spp. was observed from 14th MW (30th March to 5tth April) till 22nd MW (25-31st May) and caused 7.69 to 16.66% mortality. The average mortality was 11.59%. M.collaris was predominant parasite on cutworm and contributed nearby twenty per cent of the total mortality. Total mortality due to three parasites and microbes on cutworms in Shimla hills were 46.525%.