On Sept. 30, a team of forestry professionals from the Colorado Department of Agriculture, City of Boulder and CU-Boulder released parasitic wasps on East Campus. The wasps target and kill emerald ash borer, the highly destructive tree pest that poses a serious threat to urban forests and has been found on campus. Ìý
The tiny, stingless wasps are not attracted to people or pets. Their release has been approved by officials from the U.S. Department of Agriculture as a biocontrol measure to suppress emerald ash borer populations in the city and prevent further spread.
The wasp species, which is highly specific to parasitizing emerald ash borer over other insects, was discovered in Asia, where emerald ash borer originated. The females lay eggs inside emerald ash borer larvae hidden under the bark of ash trees. The growing parasitoid larvae ultimately kill their hosts before they mature.
The wasp was brought to the United States and, after extensive evaluation, is being laboratory-reared by the USDA for release in states impacted by emerald ash borer. Since 2007, wasps have been released in 17 of 24 states where emerald ash borer has been confirmed.
Emerald ash borer, a non-native pest responsible for the deaths of millions of ash trees and billions of dollars in costs, was first confirmed in Boulder in Sept. 2013, but to date has not been detected elsewhere in Colorado. Ash species comprise an estimated 15-20 percent of all trees in Colorado’s urban and community forests.
More information about the USDA’s Emerald Ash Borer Biocontrol Program can be found at .
More information about emerald ash borer in Colorado, including the current quarantine in Boulder County and surrounding areas, can be found at .