Effect of formulations and dispensers on attractiveness of virelure to the tobacco budworm

Formulations of virelure, the synthetic sex pheromone of the tobacco budworm,Heliothis virescens (F.), were developed, bioassayed in traps in field cages, and used in traps to survey populations in plant hosts. Virelure (10 mg) laminated between thin sheets of vinyl polymer plastic was attractive to male moths for 21 days, and attractiveness did not regress appreciably for the first 7 days. Another dispenser was an 8 × 30-mm cigarette filter encased in a glass shell vial. A mixture of 10 l (Z)-11-hexadecenal and 0.5 l (Z)-9-tetradecenal, the pheromone components, formulated with wheat germ oil andd-alpha tocopherol (91) in 0.5 ml CH₂Cl₂ (WGOE) was still attractive to males after 5 days. Cottonseed oil, polyethylene glycol 600 distearate (peg-600-d), and peg-6000-d also inhibited excessive vaporization and oxidation of virelure. Virelure (21.25 l) formulated on filters with WGOE and used as bait (replaced weekly) in survey traps caught 27,263 males in 1975; analysis of catches each day for 7-day periods showed that most males were caught within 3 days after baiting, and attractiveness regressed considerably during the last 3–4 days of each week. Four ratios of virelure components were tested as bait (20 mg) in saucer-type pheromone traps, and the 161 ratio caught significantly more male moths than ratios of 241, 321, or 401.Lepidoptera Noctuidae.In cooperation with the Texas Agricultural Experiment Station, Texas A & M University, College Station 77843.This paper reports the results of research only. Mention of a pesticide in this paper does not constitute a recommendation for use by the USDA nor does it imply registration under FIFRA as amended. Also, mention of a commercial or a proprietary product in this paper does not constitute an endorsement by the USDA.