An overview of lady beetles in relation to their potential as biological controls for hemlock woolly adelgid

Abstract

More than 63 species of lady beetles (Coleoptera: Coccinellidae) have been collected in China from hemlock infested with hemlock woolly adelgid, Adelges tsugae. The lady beetle species that seem most useful for biological control are in the genus/subgenus Scymnus (Neopullus), namely S. camptodromus, S. sinuanodulus, and S. ningshanensis. The geographic range of these lady beetles is limited to one or two provinces. Only five lady beetles were found in Japan; however, it has been surveyed there less intensively. Review of the life history of lady beetles and their prey indicates that lady beetles have been less effective for biological control of aphids than of scales. Because the generational period for adelgids is closer to that of scales than aphids, it is hypothesized that lady beetles that prey on adelgids will be more effective than those that prey on aphids. Introducing biological controls faces problems of climate-matching and often, time is required for agents to become adapted to the new environment.

Citation

Yu, Gouyue; Montgomery, Michael E. 2008. An overview of lady beetles in relation to their potential as biological controls for hemlock woolly adelgid. In: Onken, Brad; Reardon, Richard, comps. Fourth Symposium on hemlock woolly adelgid in the eastern United States; 2008 February 12-14; Hartford, CT. FHTET 2008-01. Morgantown, WV: U.S. Forest Service, Forest Health Technology Enterprise Team: 19-28.