Biology of the Yellowmargined Leaf Beetle (Coleoptera: Chrysomelidae) on Crucifers

Abstract

Multi-generation survivorship, developmental biology, fecundity, and adult longevity of the yellowmargined leaf beetle, Microtheca ochroloma Stål, were studied in the laboratory on cabbage, Brassica oleracea var. capitata L., collard, B. oleracea var. acephala L., mustard, B. juncea Cosson, turnip, B. rapa L., and radish, Raphanus sativus L. Host plant significantly affected multi-generation survivorship; survivorship was 0% on cabbage but >70% on the other hosts when tests were terminated in the fourth generation. Duration of development of life stages and total duration of development from oviposition to adult emergence did not vary significantly with host at 20°C. The latter averaged 27 d among hosts. Development averaged 7.8 d for eggs, 10 d for the four larval instars, 3 d for prepupae, and 5.6 d for pupae. Fecundity and adult longevity were significantly affected by host plant. Egg numbers per female were significantly higher on turnip than on collard but did not differ significantly among cabbage, mustard and radish. Sex did not affect longevity, but beetles lived significantly longer on radish than cabbage, collard, mustard, or turnip.