Clavigralla spp. damage pods and seeds of pigeon pea, cowpea, and other pulse crops, but egg parasitoids in the genus Gryon are effective natural enemies. Extracts of neem, Azadirachta indica A. Juss., were tested against both pest and parasitoid, to determine if this common botanical insecticide was effective as an antifeedant and compatible with natural or potential augmentative biological control. Fifth instar C. scutellaris (Westwood) were exposed to green beans dipped in various concentrations of aqueous, methanolic, and hexane extracts. Feeding was monitored by staining for salivary deposits on outer and inner pod walls and the seeds. All concentrations tested (1.25 – 5%) produced significant reduction of feeding activity compared with the controls; a concentration effect was evident with hexane extracts. Gryon fulviventre (Crawford) successfully parasitized neem-dipped eggs, although the duration of antennation during oviposition was significantly extended. Dipping eggs in aqueous neem solution after exposure to parasitoids did not affect emergence, longevity or sex ratio of progeny. Newly emerged adults were initially repelled by honey mixed with aqueous neem extract, but day-6 survivorship did not differ among adults fed neem-laced honey and controls. Neem is an effective antifeedant for pod bugs, and appears to be compatible with the major natural enemy.
Species 1: Heteroptera Coreidae Clavigralla scutellaris
Species 2: Hymenoptera Scelionidae Gryon fulviventre
Keywords: neem, pigeonpea
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