 | Pink Hibiscus Mealybug
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In recent years the pink hibiscus mealybug (Homoptera: Pseudococcidae: Maconellicoccus hirsutus) reached the West Indies from its native region of Africa, and is an impending threat to fruit, vegetables, and ornamentals in the U.S. At the urging of APHIS, about 1 year ago the ICEL entered into an effort to isolate and identify the sex pheromone of M. hirsutus. Late last season this pest was detected in California, even before the expected entry of the pest into Florida, so there is now heightened urgency to identify and synthesize its pheromone. Once PHM females mate they stop releasing sex pheromone; therefore, virgin females are needed for pheromone isolation and identification. To this end, a method was devised to chemically inhibit PHM male development. The chemical formulation and protocol for this technique were supplied to collaborators at the ARS laboratory in St. Croix, Virgin Islands, enabling ~2000 virgin females to be cultured per host pumpkin. Aeration sampling of virgin PHM females was accomplished in quarantine at the ARS facility in Newark, DE, using infested host material shipped from St. Croix. PHM males significantly responded by GC-EAD to a pair of relatively minor compounds in the aeration blends from females. One of these EAD-active compounds has been identified, synthesized, and tested in the field. In the preliminary field tests in the Virgin Islands, the single known synthetic pheromone component attracted wild PHM males at the lowest dose tested (10[g/trap) equivalently to traps baited with 20 live virgin PHM females. At the highest dose tested (10mg/trap), captures of PHM males were significantly inhibited relative to unbaited control traps. Efforts are proceeding to identify the second EAD-active compound and, concurrently, to conduct additional field tests of the known component in the Virgin Islands, the Imperial Valley of California where PHM was detected in 1999, and Puerto Rico. |
