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<Author> Keiji YASUDA ; Hajime SUGIE ; R. R. HEATH |
The synthetic sex pheromone, (Z)-3-dodecenyl (E)-2-butenoate, was attractive to male sweet-potato weevils, Cylas formicarius (FABRICIUS), in a sweet-potato field in Okinawa, Japan. A rubber dispenser impregnated with 1 mg of synthetic sex pheromone remained attractive for more than one month. The activity of the synthetic sex pheromone was not inhibited by addition of up to 10% of the E, E-isomer of the sex pheromone. Pheromone traps on the ground captured more males than those set above the ground. Most of the males were seen to approach the traps by walking. More males were captured when they were released downwind of the trap than when released from the upwind or other sides. The number of males caught in the pheromone trap increased between 1500 and 1900, and a large peak was observed between 1800 and 2000. The number of trapped males decreased gradually thereafter and decreased rapidly after sunrise. |
