Survival, Growth, Fecundity, and Behavior of Helicoverpa armigera (Lepidoptera: Noctuidae) on Pigeonpea and Two Wild Cajanus Species

Abstract

Survival, growth, fecundity, and behavior of Helicoverpa armigera (Hübner) were compared on pods of cultivated pigeonpea, Cajanus cajan (L.) Millspaugh, and 2 wild species, C. scarabaeoides. (L.) Thouars, and C. platycarpus (Bentham) van der Maeson. Larval survival was 21% on C. scarabaeoides, 56% on C. platycarpus, and 78% on C. cajan. Pupal survival was high on all 3 Cajanus species. Seven-day-old larvae reared on C. scarabaeoides pods weighed significantly less at 18 d, took longer to pupate and produced significantly smaller pupae than those fed on C. cajan pods. Larval period and weight, and pupal weight when reared on C. platycarpus were intermediate and significantly different from the other 2 species. Differences in pupal duration were not significant between larvae reared on the 3 Cajanus species. Larvae on C. scarabaeoides spent significantly less time feeding and significantly more time off the pod than larvae on the oilier 2 species. Acetone extracts of C. cajan and C. platycarpus pods had a significant feeding stimulant effect on H. armigera larvae, whereas extracts from C. scarabaeoides pods had no effect. Water extract of C. scarabaeoides pods had a significant antifeedant effect though similar extracts from C. cajan and C. platycarpus pods had no effect. Application of these results to resistance breeding programs is discussed.

Cajanus spp., Helicoverpa armigera, trichomes, host plant resistance