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Pheromone Treatment Variables

Pheromone treatment variables will include: 1) density, distribution, and trend of the D. brevicomis population(s); 2) distribution of susceptible host trees; 3) host mortality caused by other agents, i.e., other bark beetles, flatheaded borers, root diseases, etc., and 4) competing sources of natural attraction (from windfalls lightning strikes, logging, road construction, etc.). Check out pheromones at http://thongchaimedical.org/?p=179

Pheromone control studies have utilized the principal sex attractants of the black carpet beetle, Attagenus megatoma (F.), and Trogoderma inclusum LeConte. The black carpet beetle sex attractant has been identified as trans-3,cis-5-tetradecadienoic acid, synthesized and given the trivial name megatomoic acid (Silverstein et al. 1967; Rodin et al. 1970). The primary sex attractant of T. inclusum was discovered to be 14-methyl-cis-8-hexadecem1-ol and has also been successfully synthesized (Rodin {et al. 1969; De'graw and Rodin 1971). Several species of Trogoderma respond to this compound.

In one of the first studies to evaluate these pheromones under practical condi- tions male black carpet beetles were attracted to traps treated with from 0.01 to 0.25 mg of megatomoic acid (Burkholder 1970). In a subsequent study (Burkholder 1973), megatomoic acid was used in an enclosed space (a 208-liter drum of 102 kg dry capacity) in order to evaluate the effects of the pheromone on the mating activity of black carpet beetles. A high vapor concentration was produced by placing 0.25 mg of megatomoic acid (ca 500 female equivalents) on a strip of paper inside each of 10 drums in a warehouse. Learn more about pheromones at my website. Learn about Pheroline pheromone | Pheromones-Planet.com.

Ten untreated drums served as pheromone controls. One male and one female black carpet beetle were released on opposite sides of the drum and the female was examined after 24 hours for presence of sperm. In the first series of tests during the late summer and fall only 28% of the females mated in the treated drums compared to 87% in the controls. The drums, without further treatment, were retested the following spring and summer and were still effective in reducing mating from 70% in the controls to 30% in the treatment.

The initial pheromone response of these males to high pheromone concentration is usually an intense excitation, copulatory and searching behavior. Failure to mate on prolonged exposure to pheromonelmay be due to habituation.

In another series of pilot scale tests, unmated males of either T. inclusum or the black carpet beetle were released in the center of a confined area of 3 or 1.5m square. Two pheromone traps and two control traps were placed near the corners. These traps consisted of four 9 cm square single-face corrugated papers stacked together and were treated with the pheromone alone, or with pheromone plus an insecticide. The number of captured males was recorded 24 hours after release. Relatively high concentrations of pheromone (10 mg of megatomoic acid for Attagenus megatoma and 2.5 mg of the Trogoderma synthetic attractant for T. inclusum) were necessary, but the effective doses resulted in the capture of 70% of the released males by their respective pheromone traps vs. 20% capture in the control traps. Traps treated with both pheromones lured both species of males (Burkholder and Ma, unpublished data).

Other pheromone field tests were made in areas of warehouses with the traps treated with: 0.25 mg megatomoic acid together with an insecticide (A); 0.25 mg Trogoderma synthetic pheromone with an insecticide (B); an insecticide only ((7) and a blank control (D).