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United States Department of Agriculture

Agricultural Research Service

Research Project: ECOLOGICALLY BASED MANAGEMENT OF BOLL WEEVILS AND OTHER ROW CROP PESTS UNDER TRANSITION TO BOLL WEEVIL ERADICATION IN TEMPERATE REGIONS

Location: Insect Control and Cotton Disease Research Unit

Title: Evaluation of a new formulation of grandlure for the boll weevil (Coleoptera: Curculionidae)

Authors
item Suh, Charles
item Westbrook, John
item Boratynski, Theodore -
item Cano Rios, Pedro -
item Armstrong, John
item Escarcega, Jesus -
item Campos-Ruelas, Carlos -

Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 11, 2012
Publication Date: January 1, 2013
Citation: Suh, C.P., Westbrook, J.K., Boratynski, T.N., Cano Rios, P., Armstrong, J.S., Escarcega, J.A., Campos-Ruelas, C. 2013. Evaluation of a new formulation of grandlure for the boll weevil (Coleoptera: Curculionidae). Journal of Entomological Science. 48:75-78.

Interpretive Summary: Grandlure, the synthesized pheromone of boll weevils, is comprised of the same four components found in boll weevil pheromone. However, the ratio of the four components in grandlure is considerably different than the component ratio of boll weevil pheromone. Thus, the existing commercial formulation of grandlure may not be the most effective blend for attracting boll weevils to traps. We conducted a trapping study in Mexico and South Texas to compare the attraction of boll weevils to standard grandlure and an experimental formulation of grandlure which matches the component ratio of pheromone produced by boll weevils. No statistical differences in the numbers of captured boll weevils were detected between the two grandlure formulations at any of the evaluation sites. Consequently, boll weevils appeared to be equally attracted to both formulations of grandlure. Considering the increased formulation cost of the experimental grandlure and lack of difference in the numbers of captured boll weevils, we found no justification for altering the existing formulation of grandlure to match the component ratio of pheromone produced by boll weevils.

Technical Abstract: Although grandlure and boll weevil pheromone are comprised of the same four components, the ratio of the four components in grandlure and boll weevil pheromone differ considerably. Thus, the existing grandlure formulation may not be the most effective blend for attracting boll weevils to traps. We conducted a trapping study to compare the attraction of boll weevils to standard grandlure and an experimental formulation of grandlure which matches the component ratio of pheromone produced by boll weevils. Twenty-five to 80 pairs of traps were established at three locations in Mexico (Ojinaga, Durango, and Tamaulipas) and at two locations in South Texas (near Jourdanton and Weslaco). One trap in each pair was baited with standard grandlure and the other trap contained the experimental formulation. Traps were serviced weekly for four to eight weeks and the numbers of weevils captured in each trap were recorded. Statistical differences in the numbers of captured boll weevils were not detected between the two formulations at any of the evaluation sites. Thus, boll weevils appeared to be equally attracted to both formulations of grandlure. Considering the increased formulation cost of the experimental grandlure and lack of difference in the numbers of captured weevils, we found no justification for altering the existing commercial formulation of grandlure. In light of these findings, we suggest research efforts and eradication programs focus on other lure-related issues (e.g., pheromone dose, lure replacement interval, and lure dispenser technologies) to improve the performance of traps in detecting incipient boll weevil populations.

Last Modified: 8/30/2014