Reproductive Biology of Mealybugs (Pseudococcidae) and Practical Applications of their Sex Pheromones in California Nurseries
Traps baited with sex pheromones were used to monitor field populations of longtailed and obscure mealybugs. Lures loaded with 25 microgram doses of racemic pheromones remained effective for at least 3 months. Pheromones could also be combined to make lures that attracted several species simultaneously. The numbers of insects caught in traps was correlated with mealybug abundance, indicating that pheromone traps can be used in place of laborious manual sampling to monitor populations. The efficacy of using pheromone traps to monitor seasonal fluctuations in mealybug popultations was demonstrated.
Obscure, vine, and longtailed mealybugs were shown to reproduce only through sexual reproduction. Copulatory behavior for both sexes was stereotypical across all species. Female and male mealybugs were capable of multiple copulations in a single day and over multiple days. Female reproductive output did not increase with multiple copulations. Male longevity and activity levels were minimally affected by constant exposure to pheromone, and males typically lived 4-5 days after emergence as adults. This better understanding of mealybug reproductive biology has implications for the use of pheromones for monitoring and control of mealybugs.
Several pieces of evidence suggest that the sex pheromone is produced somewhere on the hind pair of legs, probably from translucent pores that are only present on their hind legs of adult females. More males were attracted to body sections of females with the hind pair of legs, and extracts of these legs strongly attracted males. Scanning electron microscopy confirmed the presence of the pores on the hind coxae of adult females. Elucidating the site of pheromone production provides the key baseline data required for studies of the biosynthesis of the irregular terpenoids that comprise the sex pheromones of various species.