Performance of Controlled Release Dispensers for Grandlure, the Pheromone of the Boll Weevil (Coleoptera: Curculionidae)2

Abstract

Comparison of laboratory-measured release rates with boll weevil captures showed that dispensers containing 10 mg of grandlure with a release rate of 10 μg/hr or higher generally produced weevil captures which were at least 50% as high as those with the reference, fresh cigarette filter. Emission rates of ca. 3 μg/hr or lower and amounts of residual grandlure of ≤ 2 mg generally resulted in weevil captures below the 50% threshold. Comparisons of commercial dispenser formulations containing 10 mg of grandlure showed that a Hereon orange plastic laminate (H-OL-T) was most effective in prolonging the release of grandlure in both field and laboratory evaluations. Its emission rate was least affected by temperature changes. Scentry PVC dispensers (S-T-T, S-C-T, S-S-T, and S-YS-T) and the Consep membrane (C-M-T) lost grandlure more rapidly than did the laminate; however, differences in weevil captures were often not significant. Fermone black PVC squares (F-S-T and F-OS-T), AgriSense polymeric rods, (A-50R-T and A-35R-T) and the cigarette filter (CF-T) were less effective in extending the release of grandlure. Dispensers mounted in the capture cylinder lost grandlure more rapidly than did similar dispensers mounted in the cooler trap base. A layer of stickum on one side of flat dispensers to facilitate attachment to the trap resulted in a somewhat lower release rate of grandlure.

Comparisons of Standard and Extended-Life Boll Weevil (Coleoptera: Curculionidae) Pheromone Lures

“…Estimated initial pheromone contents of both standard lures and superlures were somewhat lower than the nominal dosages, but they were still consistent with reports by Leonhardt et al (1990) and Spurgeon et al (1999) for unaged 10-mg grandlure lures. Although the initial pheromone contents of the unaged standard lures did not change in storage during our experiment, the superlure exhibited slight but statistically signiÞcant losses of both pheromone and eugenol.…”

Mutual Interference of Pheromone Traps Within Trap Lines on Captures of Boll Weevils (Coleoptera: Curculionidae)

“…Similarly, when traps of different designs are to be compared for efÞciency in attracting and capturing boll weevils (e.g., Mitchell et al 1978, Dickerson et al 1981, Hardee et al 1996, or when pheromone formulations and dispensers are compared (e.g., Hardee et al 1972, Leonhardt et al 1990, it is desirable to place them as near as possible to one another to ensure that they are sampling from the same area and the same subpopulation of weevils. However, if positional variation is generated from intertrap interference, then traps placed too close together may yield spurious results.…”

Application of Semiochemicals in Integrated Pest Management Programs

“…Semiochemicals are usually non-toxic and do not pose a health risk, but contamination can be a problem if a user handles lures for several different species because crosscontamination of traps can cause reduced trap catches. Current aspects of dispenser designs [96] and controlled release formulations [97] have been reviewed Relative performance of different dispenser types have recently been determined for the pea moth [98], the boll weevil [99,100], the gypsy moth [101], Indian meal moth and almond moth [102], the Mexican rice borer [103], and the Mediterranean fruit fly [104,105].…”