Lure of Sex May Confuse a Weevil

Romance could turn deadly for amorous pecan weevils. Scientists with the Agricultural Research Service and Oklahoma State University have--for the first time--identified the weevil’s chemical sex attractant, or pheromone.

This could lead to a commercial pheromone that pecan growers would deploy to monitor weevil populations or to disrupt weevil mating. Prospective mates either couldn’t find each other or would be lured to doom in traps. In lab and field studies, a synthetic version of the male weevil’s pheromone attracted 80 percent of females.

Chemical insecticide sprays are now the main recourse for protecting pecan orchards.

Unchecked, the weevils chew on young pecan nuts, ruining their marketability. In late summer, female weevils bore into nuts to lay eggs. Soon, larvae hatch, drop to the ground and burrow into the soil. Two to three years later they emerge as adults, feed and mate.

University scientists are awaiting results of large-scale field tests of the synthetic attractant in orchards this past summer.

ARS is considering patenting the use of the weevil pheromone.

Scientific contact: Paul Hedin, USDA-ARS, Crop Science Research Laboratory, Mississippi State, Miss., (601) 323-2230.