Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 3, 2004
Publication Date: January 1, 2005
Citation: Zhang, A., Amalin, D. 2005. Sex pheromone of the female pink hibiscus mealybug, maconellicoccus hirsutus: biological activity evaluation.. Environmental Entomology. 34(2):264-270.
Interpretive Summary: The pink hibiscus mealybug (PHM) causes severe economic problems throughout the world. It is a highly polyphagous pest and has been found on a wide range of 215 genera of unrelated plant hosts. PHM attacks many agricultural crops, vegetable crops, forest trees, and many species of ornamental plants. Potential losses of $750 million per year in the USA have been estimated if the insect cannot be controlled. We have conducted the biological activity evaluation of the identified sex pheromone in three locations in Key Biscayne, Florida. The results indicated that synthetic pheromone on a rubber septum was highly attractive to male PHMs in the field conditions. With the recent arrival of this invasive species on California and Florida as well as in Mexico and Central America, timely detection of the PHM infestation is of top priority for the biological control efforts of this pest. The synthetic pheromone would provide a much more economical, convenient, and useful detection and monitoring tool. Relatively high concentration of pheromone repels males away from the source, indicating that mating disruption could be a successful management strategy for this pest. In addition, parasitoids were not lured to the synthetic pheromone source and a relatively low number of these natural enemies was caught in the sticky traps, suggesting that mating disruption would not impede, on the contrary, it would facilitate biological control eradication programs currently underway in the Caribbean region, California, and Florida.
The synthetic sex pheromone of the pink hibiscus mealybug, Maconellicoccus hirsutus, was evaluated in the field bioassays. In a period of 27 weeks, >90,000 males were captured on sticky traps in the three locations in Key Biscayne, Florida. Our experimental results demonstrated that a laboratory-prepared (R)-lavandulyl (S)-2-methylbutanoate and (R)-maconelliyl (S)-2-methylbutanoate blend in a ratio of 1 : 5 on a rubber septum was highly attractive to males at concentration as low as 0.1 micro-gram per trap. Male M. hirsutus captures were not significantly different from traps baited with 1 or 10 micro-gram doses, but 0.1 and 100 micro-gram doses captured significantly fewer males. The enantiomers of the natural pheromone antagonized attraction. The alcohols, which could be detected in virgin female's volatiles, also exhibited repulsive effect. Rubber septum lures baited with 1 and 10 micro-gram doses of the synthetic pheromone remained activity for at least 21 weeks under field conditions. Monitoring of adult flight activity with 1 micro-gram dose of synthetic pheromone indicated there were multiple generations during the tested period.