The parasitoids of spruce budworm, Choristoneura fumiferana Lederer (Lepidoptera: tortricidae), in Manitoba
Zebrowski, Deirdre A.
The parasitoids of epidemic and endemic spruce budworm populations were studied in eastern Manitoba in the summers of 1994 and 1995. Three sites were established, two in epidemic budworm populations, and one in an endemic budworm population. Sampling of the sites occurred from early May and continued until viable egg masses were no longer found in the collections. Budworm were reared on artificial diet until either a parasitoid or moth emerged. In 1995, a second site was established in the endemic population into which approximately 3000 budworm larvae were released. This site was established in order to collect parasitoids that are present but may not be collected through regular sampling of endemic populations. Earlier studies have suggested that delaying spraying for the spruce budworm until fourth instar can help conserve the parasitoid Apanteles fumiferanae Vier. Examination of day degree accumulation and the related timing of budworm instars in this study suggests that delaying spraying for spruce budworm until early June will help conserve Apanteles fumiferanae Vier. in the study area. (Abstract shortened by UMI.)