Gypsy moth parasites: planned releases for 1998

by John Luhman MDA-Biological Control Program

The Biological Control Program of the Minnesota Department of Agriculture is planning releases of two gypsy moth parasites in 1998: Pimpla disparis, a pupal parasite, and Ooencyrtus kuvanae, an egg parasite. Last summer, over 7,000 disparis were released in nine counties, June through September. About 6,000 Ooencyrtus were released in six counties, August through September. This season we are planning to release at least 20,000 disparis ,May through September, and 10,000 Ooencyrtus, July through September.

Releases of disparis will begin in May at tent caterpillar sites, continue in June and July at whitemarked tussock moth and near gypsy moth trap sites, and end in September at fall webworm sites. We will focus on eastern tent caterpillar sites in southeastern Minnesota in the counties of Winona, Houston, and Fillmore where significant numbers of gypsy moth were trapped last summer. Sites close to the Iowa border will also be targeted where gypsy moth is being trapped. Ooencyrtus will be released mostly near gypsy moth trap sites, especially in the above southeastern counties. This parasite overwinters as an adult, so can be released until October.