Comparative assessment of mortality of eastern hemlock in biologically-treated areas using spatial analyses

To manage hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), on eastern hemlock, Tsuga canadensis (L.) Carrière, Sasajiscymnus tsugae (Sasaji and McClure) (Coleoptera: Coccinellidae) and Laricobius nigrinus Fender (Coleoptera: Derodontidae) have been released in the southern Appalachians. Recoveries of these two introduced predators from their respective release sites are sporadic, and little is known about their effectiveness. Despite their introduction, hemlock mortality is widespread due to feeding by hemlock woolly adelgid. To assess mortality of eastern hemlock, remotely-sensed digital images from recovery, non-recovery, and control (no releases) sites will be evaluated and percent mortality of hemlock compared using spatial analyses. This study will provide useful information on hemlock mortality in a wider scale which may ultimately help to assess effectiveness of introduced predatory beetles in the southern Appalachians.