Search

Laricobius nigrinus Fender (Coleoptera: Derodontidae) is a specialist predator of the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), native to the Pacific Northwest. It has been introduced into the eastern United States for biological control of exotic hemlock woolly adelgid populations that threaten native hemlock. The possible role of olfactory cues in host finding by this predator has received little study. We used gas chromatography–electroantennographic detection (GC-EAD) to test adult L. nigrinus olfactory sensitivity to volatiles from foliage of both adelgid-infested and uninfested eastern hemlock [Tsuga canadensis (L.) Carriere] and western hemlock [Tsuga heterophylla (Raf.) Sarg.], and two hemlock woolly adelgid nonhost species (eastern white pine, Pinus strobus L., and western white pine, Pinus monticola Douglas ex D. Don). Adelgid infestation did not alter L. nigrinus EAD response profiles to volatiles from either hemlock species. In total, antennal preparations...

Understanding the seasonal phenology of an insect pest in a specific geographic region is essential for optimizing the timing of management actions or research activities. We examined the phenology of hemlock woolly adelgid, Adelges tsugae Annand, near the southern limit of the range of eastern hemlock, Tsuga canadensis (L.) Carriere, in the Appalachians of northern Georgia, where adelgid phenology has not been previously reported. Adelges tsugae- infested hemlock trees were visited at various sites from 2004 - 2007. Two hemlock twigs were collected from each of 3 hemlock trees per site, except during the final 3 months of sampling when 1 twig was collected from each of 3 trees per site. Progrediens adults initiated oviposition by midMay, 2 - 4 weeks earlier than has been reported for more northern parts of the adelgid range. Sistens eggs were present until late-June (2006) or early-July (2004 - 2005). After aestivation, sistens nymphs resumed development by early October. Sistens adults were first found ...