Unruh has released several promising natural enemies of the apple ermine moth in Washington.
In large numbers, ermine moth caterpillars can munch the leaves off an apple tree in about 6 weeks.
We're hoping the wasps will suppress ermine moths on backyard trees and in abandoned orchards in western Washington," says Unruh.
In the early 1980s, the apple ermine moth was established in the Pacific Northwest area of the U.
The parasitoids of the apple ermine moth and their parasitism rates were determined through collection and rearing of pupae in 4 geographic regions from 1988 to 1991.
A total of 12,863 apple ermine moth pupae were collected from cultivated orchards at 5 sites in mid Jun, 1990-1991.
Parasitoids of the apple ermine moth pupae were evaluated from 20 different collections from 16 sites of 4 geographical regions in 3 countries (Table 1).
When apple ermine moth was classified for habitat types such as natural, abandoned, and cultivated habitats, there was a significant difference in mean total parasitism rates among the habitat types ([chi square] = 7.
Similarly host plant effects also could be possible factors affecting levels of parasitism rate by the parasitoid of apple ermine moth.