Attraction of males by virgin females of the mealybug Maconellicoccus hirsutus (Hemiptera : Pseudococcidae)

The mealybug Maconellicoccus hirsutus (Green) has extended its range throug hout the Caribbean region since it was first detected in Grenada in 1991, a nd has recently been detected in Southern California, Mexico, and Central A merica. Laboratory and field experiments using virgin females were conducte d on St. Croix, U.S. Virgin Islands, to determine if females attract males with pheromones. Virgin females isolated in gelatin capsules attracted on a verage one male to each capsule over a period of 18 h in the laboratory com pared with gelatin capsules without females. Adhesive traps baited with vir gin females and placed on hibiscus, Hibiscus rosa-sinensis L.,in the field, captured more males at all three study localities on St. Croix than did un baited traps. Virgin females attracted more males than controls at 0-10 m f rom infested hibiscus, but were capable of attracting males at 50 m distanc e from an infestation. The attractiveness of virgin females to flying males strongly suggests the involvement of a female-produced sex pheromone. Isol ation and synthesis of such a sea pheromone would provide a valuable tool f or population monitoring and control of this invasive pest.