HABITAT DISTRIBUTION, LIFE HISTORY AND BEHAVIOR OF TETRAGNATHA SPIDER SPECIES IN THE GREAT SMOKY MOUNTAINS NATIONAL PARK

Abstract

Habitat distribution patterns of five species of Tetragnatha Latreille 1804 were studied by analyzing 1163 one-hour samples collected at 17 focal sites representing 16 major biotic communities (habitats) in the Great Smoky Mountains National Park. Tetragnatha versicolor Walckenaer 1841 is a habitat generalist, being common over a wide range of elevations (520-1755 m) and in 10 of the 16 habitats, including seven forest habitats as well as wetland, high grass bald, and grassland habitats. Te- tragnatha laboriosa Hentz 1850 is virtually restricted to non-wetland grassy habitats, T. elongata Wal- ckenaer 1805 to streams, T. viridis Walckenaer 1841 to hemlock trees, and T. straminea Emerton 1884 to non-forested wetlands (marshes). Microhabitat segregation exists in the high grass bald community between T. versicolor (prefers trees and shrubs) and T. laboriosa (prefers herbs). Size frequency histograms of seasonal samples of T. straminea specimens indicate that this species has a one-year life cycle with six post-emergent instars, and that most individuals overwinter in the antepenultimate instar and mature and mate in May and June. Tetragnatha straminea is able to capture prey with or without using a web and adopts stick-like cryptic postures in three different contexts.