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Abstract
On eastern hemlock, we found two resident beetles preying on
Adelges tsugae Annand. One is a coccinellid native to Europe,
Scymnus suturalis Thunberg, that also feeds on
Pineus sp. that attack pines. The other is a native derodontid beetle,
Laricobius rubidus LeConte. The seasonal life history of these two species indicates that their effect on
A. tsugae will be more complementary than competitive. The effectiveness of these species may be enhanced by the presence of alternative prey that attack other conifers. Among the many species imported for control of the balsam woolly adelgid, the coccinellid
Aphidecta obliterata (L.) appears to have the best potential for biological control of
A. tsugae. It is important to assess the incumbent population of natural enemies before introducing biological controls, in order to better understand the kind of biological controls that are most suitable and reduce displacement of native species. A multispecies strategy seems the best approach to achieve biological control of
A. tsugae.
Citation
Montgomery, Michael E.; Lyon, Suzanne M. 1995. Natural enemies of adelgids in North America: Their prospect for biological control of
Adelges tsugae (Homoptera: Adelgidae). In: Salom, S.M.; Tigner, T.C.; Reardon, R.C., eds. Proceedings of the first hemlock woolly adelgid review; 1995 October 12; Charlottesville, VA. Morgantown, WV: U.S. Department of Agriculture, Forest Service, Forest Health Technology Enterprise Team: 89-102.
