Feeding Behavior of First-Stage Tobacco Budworm (Lepidoptera: Noctuidae) on Three Cotton Cultivars

Feeding behavior and histological-histochemical studies of newly hatched tobacco budworm, Heliothis virescens (F.), larvae feeding on cotton Gossypium hirsutum L. revealed that first-stage larvae avoided consuming glands which contains gossypol, a dimeric sesquiterpenoid aldehyde. Between 48 and 72 h of age, larvae molt and then nonselectively consume the glands. Histological studies show that gossypol glands are surrounded by an envelope; histochemical procedures indicate that the envelope contains anthocyanins which differ from gossypol. We suggest that the allelochemics present in these glands act as feeding deterrents or as antifeedant compounds to first-stage larvae.