Comparisons of boll weevil (Coleoptera: Curculionidae) pheromone traps with and without kill strips

Authors: Suh, Charles; Armstrong, John; Spurgeon, Dale; Duke, Sara

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2008
Publication Date: 2/1/2009
Citation: Suh, C.P., Armstrong, J.S., Spurgeon, D.W., Duke, S.E. 2009. Comparisons of boll weevil (Coleoptera: Curculionidae) pheromone traps with and without kill strips. Journal of Economic Entomology. 102:183-186.

Interpretive Summary: Boll weevil eradication programs rely heavily on insect traps to detect and monitor weevil populations. These traps are typically equipped with an insecticide-impregnated device (kill strip) to kill captured insects. Despite their widespread use in eradication programs, the effectiveness and benefits associated with the use of kill strips have not been extensively studied. We examined the influences of kill strips on weevil captures and trap servicing, and determined if kill strips reduce the incidence of weevil predation and trap obstruction (e.g., spider webbing). The use of kill strips had no influence on weevil captures and did not simplify trap servicing, although their use did result in a small reduction in weevil predation and trap obstruction. In light of these findings, the use of kill strips is likely unnecessary in eradication programs, but may be a consideration in situations when trap numbers are reduced and chronic problems with weevil predation or trap obstruction exist.

Technical Abstract: Boll weevil, Anthonomus grandis Boheman, eradication programs typically equip pheromone traps with an insecticide-impregnated kill strip. These strips are intended to kill captured insects, thereby simplifying trap servicing and reducing the loss of weevils from predation and escape. However, the effectiveness of kill strips has not been extensively evaluated. We examined the influences of kill strips on weevil captures, trap servicing, and the incidences of weevil predation and trap obstruction (e.g., by spider webs). Evaluations were conducted weekly during three different production periods (pre- to early, late-, and post-season) of cotton, Gossypium hirsutum L., to represent different environmental conditions and weevil population levels. Within each period, mean weekly captures of weevils in traps with and without kill strips were statistically similar. On average, traps with kill strips took 9 sec longer to service than traps without kill strips, but statistical differences were only detected during the late-season period. Overall, the mean weekly proportion of traps with evidence of weevil predation or trap obstruction was significantly lower for traps with kill strips (0.25) than for traps without kill strips (0.37). However, this reduction in the frequency of weevil predation or trap obstruction was too small to produce a corresponding increase in the numbers of weevils captured. In light of these findings, the use of kill strips is likely unnecessary in eradication programs, but may be a consideration in situations when trap numbers are reduced and chronic problems with weevil predation or trap obstruction exist.