Third Symposium on Hemlock Woolly Adelgid in the Eastern United States

While the emphasis of this symposium is the hemlock woolly adelgid (HWA), there are presentations on a closely related insect, the balsam woolly adelgid (BWA) and on an insect frequently found infesting the same trees as HWA, the elongate hemlock scale (EHS). The conference begins with a discussion of the foundation of our science and the challenges of adelgid systematics. Other sessions will discuss economic and ecological impacts, survey and detection, research and technology development, and management. The final presentation will provide a discussion of where we are now and where do we need to go in the research and development of HWA. ELONGATE HEMLOCK SCALE (FIORINIA EXTERNA) Elongate hemlock scale (EHS) was first reported in 1908 on Long Island, NY (Sasscer 1912). It was introduced from Japan, where densities are much lower than those reported in this country. There are at least 57 host species noted in Connecticut by McClure and Fergione (1977) and McClure (1979), including species of hemlock, cedar, fir, pine, spruce, and yew. The scale is found only on undersides of needles, but the damage is visible from above. EHS is found from North Carolina northward to southern New England and westward to Ohio. The damage includes yellow banding on top of needles and premature needle drop. Concurrent infestations of scales and adelgids hasten hemlock decline, and hemlock borer or Armillaria root rot may attack weakened trees. Presentations on EHS at this symposium will cover classical biological control; natural enemies in the southern Appalachians; management with entomopathogenic fungi; effects of systemic insecticides, a growth regulator, and oil on EHS and associated natural enemies; and reproductive success, mass release and recovery of Cybocephalus sp. on EHS. BALSAM WOOLLY ADELGID: ADELGES PICEAE AND HEMLOCK WOOLLY ADELGID: A. TSUGAE (HOMOPTERA: ADELGIDAE) It is interesting to compare the initial significance and spread of hemlock woolly adelgid (HWA) and balsam woolly adelgid (BWA). BWA was found in natural stands of balsam fir in 1908 and in Fraser fir of the southern Appalachians in 1955. Severe mortality was immediately apparent. HWA was found on ornamental eastern hemlock in 1952 or ‘54 in Richmond,