The mealybug Maconellicoccus hirsutus (Green) has extended its range throughout the Caribbean region since it was first detected in Grenada in 1994, and has recently been detected in Southern California, Mexico, and Central America. Laboratory and field experiments using virgin females were conducted on St. Croix, U.S. Virgin Islands, to determine if females attract males with pheromones. Virgin females isolated in gelatin capsules attracted on average one male to each capsule over a period of 18 h in the laboratory compared with gelatin capsules without females. Adhesive traps baited with virgin 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 unbaited traps. Virgin females attracted more males than controls at 0–10 m from infested hibiscus, but were capable of attracting males at 50 m distance from an infestation. The attractiveness of virgin females to flying males strongly suggests the involvement of a female-produced sex pheromone. Isolation and synthesis of such a sex pheromone would provide a valuable tool for population monitoring and control of this invasive pest.