Biology and Biotype of Two Strains of Pea Aphid Acyrthosiphon pisum (Homoptera: Aphididae) on Lentil

Abstract

Four entries of lentil were used to study the life history parameters of two strains of A. pisum under laboratory condition. The entries and the strains were combined factorialy and arranged in CRD with 12 and 15 replications in trial one and two, respectively. Then the data were pooled after assessing the homogeneity of variance. The mean developmental period o f the Debre Zeit (DZ) strain was 8.44 days, the pre-reproductive period was 1.26 days, the reproductive period was 15.91 days and the post reproductive period was 7.07 days. For the Goettingen (GOE) strain the mean values were 8.67, 1.58, 16.04 and 13.26 days, respectively. The peak reproductive rate per female per day and the intrinsic rate o f increase (rm) o f the DZ strain were marginally greater than the corresponding values of the GOE strain. Moreover, the two strains varied in alate production and in realizing their potential fecundity. The rm values on all of the tested entries were positive indicating that the entries were susceptible to both strains.