The banded sunflower moth (Cochylis hospes) is a North American endemic with hosts restricted to the sunflower genus (Helianthus spp.). It is a major pest of sunflower crops in the northern Great Plains, the main area of sunflower cultivation in the U.S.A. Female ovipositional preferences are important for host selection in this species, and the majority of eggs are laid on the bracts of sunflower heads in the pre-bloom stage. The larvae feed on bracts and developing seeds.
Extracts made by immersing sunflower heads in dichloromethane for 60 seconds stimulated oviposition by C. hospes in a bioassay. Bioassay directed fractionations of these extracts on silica gel indicated activity in several fractions. Further silica gel flash column chromatography followed by HPLC allowed the isolation of active compounds. Several of these were diterpenoids, identified by NMR spectroscopy and mass spectrometry, which were also used to indicate the purity of each compound. The pure compounds were then tested in the bioassay to determine relative activities and dose responses for each.
Species 1: Lepidoptera Tortricidae Cochylis hospes (Banded sunflower moth)
Keywords: oviposition, terpenoids
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