Age-Stage, Two-Sex Life Table of the Mustard Aphid, Lipaphis erysimi (Kaltenbach) on Cabbage and Cauliflower under Laboratory and Field Conditions

Mustard aphid, vernacularly known as turnip aphid, Lipaphis erysimi, is a serious pest of vegetable Brassicas in India. Design of new pest management strategies depends on the life-table parameters. However, life table of L. erysimi was poorly studied under field conditions. The present study aims at constructing life tables of L. erysimi on cabbage and cauliflower under field conditions. The field population had the shortest nymphal duration, viz. 4.31 ± 0.48 and 4.33 ± 0.62 days on cauliflower and cabbage, respectively. The biotic potential of aphid on cauliflower and cabbage in the field was 2.71 × 10⁵³ and 3.49 × 10⁴⁹, which was much better than the corresponding values in the laboratory (2.86 × 10³⁸ and 2.27 × 10³⁸). The population parameters varied between two rearing conditions, viz. r and λ, was significantly superior under field conditions; however, the R₀, GRR and T were superior under laboratory conditions. On cauliflower and cabbage, the population of L. erysimi doubles in 1.75 and 1.74 days, respectively, whereas in a laboratory conditions, it took 2.24 and 2.47 days. S_xj of L. erysimi varied across developmental stages. The expected longevity of L. erysimi on cauliflower at age zero (e₀) was 12.84 and 7.90 days under laboratory and field conditions, respectively.