Submitted to: Proceedings of the National Academy of Sciences (PNAS)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2004
Publication Date: 7/1/2004
Citation: Zhang, A., Shirali, S., Oliver, J.E., Klun, J.A., Aldrich, J.R., Amalin, D., Serrano, M., Lapointe, S., Franqui, R., Meyerdirk, D.E. 2004. Sex pheromone of the pink hibiscus mealybug, maconellicoccus hirsutus,contains an unusual cyclobutanoid monoterpene. Proceedings of the National Academy of Sciences. 101(26):9601-9606.
Interpretive Summary: The pink hibiscus mealybug (PHM) is an extremely polyphagous insect that feeds on a wide range of host plants and inflicts severe damage throughout much of the world. The insects inject toxic saliva into the host plant, which leads to malformed fruit, leaves, and shoots, stunting of plant growth, and eventually plant death. This exotic insect pest has been spreading through the Caribbean region since its detection on the island of Grenada in 1994. The PHM has now spread to Southern California, Mexico, Central America and, most recently, to Florida in 2002. Agricultural crops in the United States expected to be at greatest economic risk to PHM invasion include ornamentals, vegetable crops, citrus, grapes, and avocados. Potential losses of $750 million per year have been estimated if the insect cannot be controlled. To date, only live virgin females have been used in traps to lure nearby males. Limited availability of live virgin females and environmental factors restrict this application. We have discovered, identified, and synthesized two new chemical compounds that together constitute the female sex pheromone of PHM. This synthetic pheromone will provide a much more economical, convenient, and useful survey tool for PHM population monitoring to facilitate eradication programs, and sex attractant-baited traps will also be useful in the study of seasonal life history of PHM. Furthermore, the pheromone will enable the future development of mass trapping, attract-and-kill, and mating disruption technologies for the growers to manage this pest.
Technical Abstract: Two new compounds that together constitute the female sex pheromone of the pink hibiscus mealybug (PHM), Maconellicoccus hirsutus, were isolated, identified, and synthesized. They are (2R)-2-isopropenyl-5-methyl-4-hexenyl (2S)-2-methylbutanoate [common name is (2R)-lavandulol (2S)-2-methylbutanoate)] and [(1R)-2,2-dimethyl-3-(1-methylethylidene)cyclobutyl]methyl (2S)-2-methylbutanoate (which we refer as (1R)-maconelliol (2S)-2-methylbutanoate). Maconelliol is a novel cyclobutanoid monoterpene, and its structure has been established by enantioselective synthesis from precursors of known structure and configuration. A 1 : 5 synthetic mixture of the two RS esters (1 mg/rubber septum) proved to be a potent attractant in field bioassays. The pheromone component, maconelliol 2-methylbutanoate, represents a heretofore undescribed natural product.