Oviposition by the banded sunflower moth (Lepidoptera: Cochylidae) in response to constituents of the bracts and leaves of Helianthus annuus
Barker, J.F.
Sunflower bracts that develop around the outer edge of the disk of a sunflower head have been reported to be the primary oviposition site for the banded sunflower moth, Cochylis hospes Walsingham, Experiments were conducted with the natural bract substrate, sunflower leaves, an artificial substrate, and sunflower extracts to look for the presence of chemical components or physical properties of bract and leaf parts that stimulated oviposition by the banded sunflower moth. In choice experiments with intact sunflower bracts or leaves, C. hospes oviposited on either sunflower part with about equal frequency. The moths oviposited on an artificial substrate of floral foam but they preferred the natural substrate over the artificial substrate in a ratio of 8.8:1. The moisture content of the artificial substrate significantly influenced oviposition. Extracts of sunflower bracts or leaves prepared with water or hexane significantly stimulated oviposition over that on the control. Bract extracts prepared with ether did not show significant activity. Results of this study indicated that the leaves and bracts of sunflower contain a combination of contact chemicals, volatiles, and moisture that enhanced, in varying degrees oviposition by the banded sunflower moth.
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