|Koch, M. - COLORADO STATE UNIV|
|Peairs, F. - COLORADO STATE UNIV|
Submitted to: Journal of Agricultural and Urban Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 7, 2004
Publication Date: April 1, 2004
Citation: Armstrong, J.S., Koch, M.D., Peairs, F.B. 2004. Artificially infesting sunflower Helianthus annus L. field plots with sunflower stem weevil Cylindrocopturus adspersus (Leconte) (Coleoptera: Curculionidae) to evaluate insecticidial control. Journal of Agricultural and Urban Entomology. 21:71-74. Interpretive Summary: The sunflower stem weevil reduces sunflower yield on the Central Great Plains by boring into the base of the stalk, which ultimately causes the plant to lodge before it can be harvested. As with any insect pest, the densities vary by location and year, retarding the development and evaluation of control strategies. This experiment evaluated an artificial infestation technique that provides a consistent sunflower stem weevil population for evaluation of control strategies. The technique accelerated the evaluation of effective management strategies for sunflower stem weevils, which in turn provided producers with options for control of sunflower stem weevils.
Technical Abstract: An artificial infestation technique was evaluated for the sunflower stem weevil Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae) infesting sunflower Helianthus annuus L. to encourage consistent populations so that management strategies could be developed and evaluated. Sunflower stalks from the previous years crop were dissected to estimate the density of sunflower stem weevil larvae used to infest sunflowers test plots within and outside of enclosures. The results indicated that a native population of weevils increased the non-enclosed infestations, but that both techniques (enclosed versus non-enclosed) were very efficient in creating a consistent infestation. Insecticide treatments were used to create a gradient for evaluation and proved that carbofuran injected into the seed-furrow at planting, provided very effective control of the sunflower stem weevil. These results indicate that sunflower stem weevils can be manipulated to encourage consistent infestations, which can literally save years and effort in research, and that the management technique of injecting carbofuran in the seed furrow at planting provides a management option that could prevent millions of dollars of loss from sunflowers infested with sunflower stem weevil.