Field life-tables and key mortality factors ofAchaea janata Linn on castor

Abstract

Field life-tables and key mortality factors of castor semilooper Achaea janata L. were studied on castor for the year 1985-86 and 1986-87. There were 4 regular overlapping generations during both the years. The parasitization of Achaea janata larvae in early instars (I-III instar) by parasite Microplitis maculipennis (Sziepligetis) was 1,34, 4,41, 22·02 and 43·70% in first, second, third and fourth generation respectively during 1985-86. Similarly, the parasitization by same parasite was 44'12, 61'46 and 65·55% during second, third and fourth generation respectively in the year 1986-87. Key mortality factors and separate budget for each generations were prepared.