Earlier this summer parasitic wasps that attack the emerald ash borer were released in Jefferson County as a pilot program to establish natural enemies of this exotic pest in Iowa.
The second release site in Iowa's pilot program will be at Mount Hosmer City Park in Lansing, Iowa (Allamakee County) during the week of August 1, 2016.
As with the earlier release near Fairfield, two species of Asian parasitic wasps will be released so they can seek and destroy EAB in infested trees. See the Iowa State University Extension and Outreach Yard & Garden news release from July 28, 2016 for information on the release process.
Parasitic wasps are not available to homeowners for the protection of individual landscape trees. The expected outcome of the biological control effort is to SUPPRESS the pest population within infested areas, not to keep beetles from attacking individual trees. The wasps are successful in suppression only in areas where the pest is already established in moderately large numbers.
The best possible outcome of releasing the wasps is that it will slow the spread of the emerald ash borers from infested areas into uninfested areas. It will not stop the all beetles from attacking ash trees.
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