Development of Lipaphis erysimi on Brassica genotypes.

摘要

Studies were conducted to determine the biological development of the mustard aphid (Lipaphis erysimi) and the resistance of 8 Brassica genotypes (DLSC-2, JMM-927, Purple Mutant, RH-9501, RH-7846, RK-9501, T-27 and BSH-1). New nymphs, aged 10-12 h, obtained from the stock culture were released individually on plant parts of the test genotypes in Petri dishes. The leaves were changed every 24 h and nymphs were transferred to fresh leaves with the help of a camel hair brush. Observations on nymphal period, reproductive period, adult longevity, natality per female, natality per female per day and total lifespan were recorded. Results showed that the nymphal period of mustard aphid on leaves of the Brassica genotypes varied from 7.73 to 9.26 days. The minimum nymphal period was recorded on the susceptible control BSH-1, while the longer nymphal period was recorded on DLSC-2. The maximum reproductive period was found on BSH-1, while he reproductive period recorded on DLSC-2 was comparatively lower. The adult longevity was significantly longer on BSH-1. Maximum natality per female was observed on BSH-1, which differed significantly in the remaining 7 genotypes. Similarly, maximum natality per female per day was observed on BSH-1, but differed significantly from the rest of the genotypes. The total lifespan of mustard aphid varied from 24.30 to 28.90 days. The longest total mustard aphid lifespan was recorded on BSH-1. Based on the growth and development of mustard aphid on the 8 genotypes, DLSC-2, T-27 and RK-9501 were less suitable for the development of mustard aphid.