Parasitic Wasps Should Help Control California Mealybug

September 21, 1999

An "exotic" parasitic wasp may hold the key to controlling the pink hibiscus mealybug that attacks more than 200 plants, including fruits, vegetables and ornamentals. This week, federal and state agriculture officials will release the parasitic wasps into areas around Calexico, CA, and El Centro, CA.

"We are confident that this biological control method will help prevent the pink hibiscus mealybug from economically damaging U.S. agriculture," says Richard L. Dunkle, deputy administrator for plant protection and quarantine at USDA's Animal and Plant Health Inspection Service.

Natural enemies of the mealybug, the microscopic, stingless wasps, native to China and Egypt, lay eggs inside the body of the mealybug. The eggs hatch into maggot-like larvae that kill the mealybug by feeding on its internal organs. The wasps have controlled successfully pink hibiscus mealybug in Egypt, India, China, Australia, Hawaii and most recently the Caribbean.

Economic losses from the mealybug in the Caribbean have been substantial, exceeding $3.5 million a year in Grenada and $18 million a year in Trinidad and Tobago. If no action was taken in the United States, says USDA, annual damages could reach $750 million from the mealybug.