Banded sunflower moths (BSFM) are known to attack sunflower heads pre-bloom, whereas sunflower moths (SFM) are known to attack sunflower heads only post-bloom. The factors underlying this differential selection of sunflower heads were investigated. In choice bioassays in small arenas, female BSFM showed strong ovipositional preferences to pre-bloom, over post-bloom, heads. While chemicals from the bracts and leaves are important in host selection, the pre-bloom head preference of BSFM females was due predominantly to textural changes on the outer surface of the outer bracts of the head; there was no significant difference in oviposition by females to extracts of the bracts from the different head stages. In the choice bioassays, female SFM did not oviposit on pre-bloom heads, but did so on the post-bloom heads. Again, chemicals from leaves and bracts (pre- and post-bloom) influence host selection in this moth, but specificity towards the post-bloom head appears to be due to the textural change resulting from the open head, as well as from chemicals on the pollen (as previously shown).
Species 1: Lepidoptera Tortricidae Cochylis hospes (banded sunflower moth)
Species 2: Lepidoptera Pyralidae Homoeosoma electellum (sunflower moth)
Keywords: oviposition behavior, hostplant selection
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA