Host selection, development, survival, and reproduction of turnip aphid (Homoptera: Aphididae) on green and red cabbage varieties.

Host selection, development, survival, and reproduction of the turnip aphid, Lipaphis erysimi (Kaltenbach), on selected green and red cabbage varieties, Brassicae oleracea L. variety capitata, were studied in the laboratory. Although numbers of alate L. erysimi on different varieties varied generally, more alate adults and nymphs were observed on green than on red varieties on day 3; whereas, these differences were not so significant on day 15. There were no significant differences in alate adults on all six varieties on day 15. Numbers of nymphs and apterous adults of L. erysimi varied among the varieties. When mean numbers of those aphids on green varieties were compared with those on red varieties, the green varieties had more nymphs and apterous adults than those on the red varieties. Developmental durations of L. erysimi nymphs also varied among all varieties, and the nymphs fed on green varieties developed longer than those fed on red varieties. Adult longevities on these cabbage varieties were not significantly different; whereas, the adult fecundities were. Survival rates of L. erysimi varied greatly among all varieties, but there are no significant differences between the green and red varieties. Factors that might affect aphid host selection, growth, longevity, fecundity, and survivorship were discussed.