Constructions of life table for Cabbage butterfly (Pieris brassicae Linn.) on different hosts under natural conditions.

Abstract

The lab experiment entitled “Constructions of life table for Cabbage butterfly (Pieris brassicae Linn.) under natural conditions” was conducted during Rabi season 2022- at the Department of Entomology, College of Agriculture, Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut-250110 (U.P.). Cabbage butterfly (Pieris brassicae Linn.) required 37 and 34 days to complete its life cycle on the Cabbage butterfly on Cabbage in the month of January and March respectively and 41 days for the same on the Nasturtium in the month of March. There was an initial drop in survivorship (lx) followed by an intermittent steady decline with the long pauses till the formation of adult. A sharp decline in survivorship was observed at adult stage which persisted till the end of generation under all the conditions studied. From the data obtained from stage specific life table, the highest apparent mortality 57.14 per cent was recorded in the pupal stage of Pieris brassicae Linn. on Nasturtium. The summation of all the k-values, the highest value of 0.91 was recorded on Nasturtium host while the lowest value was 0.12 on Cabbage in the month of March. The data obtained from life and fertility table exhibited highest potential fecundity, net reproductive rate (R0), intrinsic rate of increase (r), finite rate of increase (λ), annual rate of increase (ARI) on Cabbage in the month of March, while the lowest values were noted on Nasturtium. However, the Mean length of generation was found to be the highest in case of Nasturtium and lowest on Cabbage in March. The parameters assumed intermediate values in case of Pieris brassicae Linn. on Cabbage in the month of January. The above studies clearly revealed that, the growth of the Cabbage butterfly was at the highest on Cabbage in the month of March followed by that on the same host in the month of January. On the contrary, Nasturtium proved to serve as a fairly good source of nectar and served as an oviposition site but did not support the healthy growth of the Cabbage butterfly