Comparison of Feeding and Olfactory Behaviors Between Laboratory-Reared and Overwintered Native Boll Weevils (Coleoptera: Curculionidae)

Major differences in the feeding and olfactory behaviors of laboratory-reared and overwintered native boll weevils, Anthonomus grandis grandis Boheman, were observed. Both number of feeding punctures and damaged anthers in cotton squares (flower buds) were at least 1.5 times lower for overwintered weevils than for a laboratory-reared strain. However, overwintered females damaged a greater number of anthers with each feeding attempt (>2.5-fold). Similar to what was observed for cotton squares, decreases in the number of feeding punctures for overwintered weevils were also noted for artificial food formulations. Ingestion rates for overwintered weevils were from 1.2- to 2-fold lower for a water extract of cotton squares with and without added sucrose. However, ingestion was significantly higher (>5-fold) for overwintered weevils on a per-puncture basis; i.e., overwintered weevils appeared to ingest higher quantities of water-soluble plant material per feeding attempt. Olfactory behavior also differed significantly; overwintered weevils were 14.4–28.8% more responsive to the volatiles of cotton squares in choice olfactory studies.