Skip to main content
ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sunflower and Plant Biology Research » Research » Publications at this Location » Publication #162801
Title: ISOLATION OF THE DITERPENOIDS, ENT-KAURAN-16A-OL AND ENT-ATISAN-16A-OL, FROM SUNFLOWERS, AS OVIPOSITION STIMULANTS FOR THE BANDED SUNFLOWER MOTH, COCHYLIS HOSPES

Author
item MORRIS, BRUCE - NORTH DAKOTA STATE UNIV.
item FOSTER, STEPHEN - NORTH DAKOTA STATE UNIV.
item Grugel, Sharon
item Charlet, Laurence

Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2004
Publication Date: 1/1/2005
Citation: Morris, B.D., Foster, S.P., Grugel, S.R., Charlet, L.D. 2005. Isolation of the diterpenoids, ent-kauran-16a-ol and ent-atisan-16a-ol, from sunflowers, as oviposition stimulants for the banded sunflower moth, Cochylis hospes. Journal of Chemical Ecology. 31(1):89-102.

Interpretive Summary: The banded sunflower moth is endemic to North America and is widespread in areas where wild or cultivated sunflowers are present. The larvae of this insect are restricted to feeding on sunflower. In the northern Great Plains, the largest sunflower-growing region in North America, it is an important pest of cultivated sunflower. Females oviposit preferentially on pre-bloom sunflower heads. The resulting larvae feed on the disk flowers and seeds, causing losses in seed production. This paper describes the isolation and identification of two terpenoid alcohols from the sunflower head that stimulate oviposition by banded sunflower moth. It is likely that these chemicals are key components in host selection by female moths. Identification of these compounds responsible for the chemical oviposition stimulation of banded sunflower moths on sunflowers, could be useful for studying differences in host preference between cultivars. The results could ultimately aid breeding programs to determine lines with resistance to the banded sunflower moth, through selecting for low production of these compounds.

Technical Abstract: Two diterpenoid alcohols, ent-kauran-16a-ol (1) and ent-atisan-16a-ol (2), were isolated from pre-bloom (R3 stage) sunflower heads as oviposition stimulants for the banded sunflower moth, Cochylis hospes. Fractionation of a sunflower head extract, by normal-phase flash column chromatography, resulted in an early eluting fraction exhibiting significant activity in an egg-laying bioassay. Compounds 1 and 2, along with ent-trachyloban-19-oic acid (3) and ent-kaur-16-en-19-oic acid (4), were isolated as the major components of this fraction and identified by their NMR and mass spectra. The purified compounds were individually tested for ovipositional activity in dose-response bioassays. In these bioassays, compounds 1 and 2 gave a linear dose response, with increasing numbers of eggs laid as the dosage of either increased. Compounds 3 and 4 failed to elicit significant egg-laying at any of the dosages tested. A factorial design bioassay, using compounds 1 and 2, showed that 1 was relatively more stimulatory than 2, but that there was no synergistic effect on oviposition when the two compounds were combined.