Host preference and performance of cabbage aphid Brevicoryne brassicae L. (Homoptera: Aphididae) on four different brassica species

Host preference and performance of cabbage aphid Brevicoryne brassicae were studied on seven brassica varieties under Greenhouse. Nymphs, apterous and alate aphids were significantly different on day three and day 15 among tested varieties. Higher total number of aphids per plant was recorded on Brassica carinata and lower on Brassica oleracea. Alates of B. brassicae preferred more to feed and reproduce on B. carinata varieties than the other tested varieties. Developmental and reproduction periods, fecundity and longevity of B. brassicae were significantly different among tested varieties. Shortest and longest developmental period were recorded on Holeta-1 (6.4 days) and Kale (8.9 days), respectively. The aphid had the highest fecundity on B. niger (79.5 nymphs/adult) and the lowest on cabbage (62.4 nymphs/adult).The reproductive rate, intrinsic rate of increase, generation time, doubling time of B. brassicae were significantly different among tested varieties. The intrinsic rate of increase of B. brassicae was 0.337, 0.310, 0.286, 0.276, 0.262, 0.250 and 0.239 days-1 on Holeta-1, Yellow Dodola, Axana, Blinda, B. niger, Cabbage, and kale respectively. Varieties of B. carinata were more suitable for cabbage aphid feeding and reproduction than the other tested varieties. Key words: B. brassicae, reproduction, development, intrinsic rate of increase, fecundity, Ethiopian mustard.