Submitted to: Entomological News
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/29/2001
Publication Date: N/A
Interpretive Summary: The gypsy moth is a serious defoliator of forest and shade trees. One of the natural enemies that has been imported into North America to help control the gypsy moth is a Braconid wasp, Cotesia melanoscela, that has a number of attributes that indicate that it would be a good candidate for augmentative release against the gypsy moth. Unfortunately, this wasp is itself attacked by a large number of hyperparasitoids that drastically reduces its potential for gypsy moth control. A thorough understanding of the makeup of the hyperparasitoid complex attaching C. melanoscela is needed to develop release protocols that will facilitate its escape from its hyperparasitoid complex. The present paper reports on aspects of the biology of some 20 species of hyperparasitoids active in Maryland against C. melanoscela. Since little is known about the biology of most of these species, results give useful insights on the nature of hyperparasite complexes in general as well as insights into the preferred methods of releasing C. melanoscela in particular. Results should be useful to agencies contemplating the release of C. melanoscela as well as to general studies of parasitoid release into an environment rampant with hyperparasitoids.
Technical Abstract: The hyperparasitoid complex of Cotesia melanoscela, a primary parasitoid of the gypsy moth, was characterized over one yearly cycle (March 1986 through March 1987) in the three geographic provinces of Maryland: the coastal plain, the Piedmont Plateau, and the Appalachian Mountains. Aspects of this study have been previously reported. The present paper presents additional biological information derived from this data set, including the preferences of the hyperparasitoid species for height in tree, for attacking hidden versus exposed cocoons, observed sex ratios and, for the gregarious species, the numbers of individuals emerging per cocoon. Additionally, we compare and contrast the relative abundance and periodicity of the specific hyperparasitoids at the three Maryland locations with results reported in previously published studies from regions farther north.