title: Web orientation and prey resources for web-building spiders in eastern hemlock.
abstract: We examined the arthropod community on eastern hemlock, Tsuga canadensis (L.) Carr, in the context of its role in providing potential prey items for hemlock-associated web-weaving spiders. Using sticky traps simulating spider webs, we evaluated what prey items are available to web-weaving  spiders in eastern hemlock based on web orientation (horizontal versus vertical) and cardinal direction. We found that the overwhelming majority (>70%) of prey items available to spiders in hemlock canopies were Diptera. Psocoptera, Hymenoptera, and Hemiptera comprised most of the remaining  potential prey. A significant direction × orientation interaction, and greater trap capture in some direction-orientation combinations, suggests that spiders might locate their webs in eastern hemlock canopies for thermoregulatory purposes, ultimately optimizing prey capture. We also  evaluated these findings in the context of hemlock infestation by the invasive hemlock woolly adelgid, Adelges tsugae Annand. The adelgid is a sedentary insect with a mobile crawler stage that provides a readily available, easily obtained food source for predators in hemlock canopies. However,  an abundance of alternative prey will affect within canopy spider distribution and the potential intensity with which spiders consume these prey. Understanding the response of spiders to potential prey availability is essential to understanding the trophic interactions involving these predators  and their potential for influencing herbivore populations.
authors.affiliation: University of Kentucky, Department of Entomology, S-225 Ag Science North, Lexington, KY 40546-0091, USA.
authors.forename: Rachael E
authors.initials: RE
authors.lastname: Mallis
authors.forename: Lynne K
authors.initials: LK
authors.lastname: Rieske
mesh_terms: D000818:Animals; D001181:Arthropods / Q000254:growth & development; D058448:Biota; D017753:Ecosystem; D020387:Food Chain; D006430:Hemiptera / Q000254:growth & development; D007629:Kentucky; D010572:Pest Control, Biological; D011235:Predatory Behavior; D013112:Spiders / Q000502:physiology*; D014197:Trees; D028225:Tsuga / Q000254:growth & development*