SREL Reprint #2390

Relationship of habitat age to phenology among ground-dwelling Linyphiidae (Araneae) in the southeastern United States

Michael L. Draney1 and D.A. Crossley, Jr.2

1Department of Biology, P.O. Box 30001, New Mexico State University, Las Cruces, New Mexico 88003 USA
2Institute of Ecology, University of Georgia, Athens, Georgia 30602 USA

Abstract: Ground-dwelling Linyphiidae from eight South Carolina inner coastal plain habitats were sampled for one year using pitfall traps. Habitats formed an age gradient, from a field disturbed yearly and pine stands aged 5, 25 and 40 years, to xeric, mesic and hydric hardwoods (50-75 years) and an old-growth forest (200 years). Sixteen of the 55 trapped species were represented in sufficient numbers (n adults ≥ number of sampling periods, 26) to examine patterns of correlation between phenology and habitat distribution. Half of the species are multivoltine, characterized by adults present throughout the year, continuous reproduction, and overlapping generations. Adult abundance of these species peaked during spring through autumn. Other species were univoltine, with adults present briefly, indicating synchronous reproduction and non-overlapping generations. Adult abundance of these species always peaked during winter months. This study examines relationships between observed voltinism patterns and characteristic habitat (distribution among the habitats) among the 16 most abundant species. Species from older habitats tend to be univoltine, whereas species inhabiting more recently disturbed habitats were more likely to be multivoltine. Stenochronous winter reproduction (univoltines) probably increases survivorship by limiting individuals' exposure to the harsh conditions of the southeastern summer during vulnerable periods of immaturity and reproduction. This phenological specialization appears optimal in this region except in frequently disturbed habitats, where rapid multivoltine reproduction is most advantageous.

SREL Reprint #2390

Draney, M.L. and D.A. Crossley, Jr. 1999. Relationship of habitat age to phenology among ground-dwelling Linyphiidae (Araneae) in the southeastern United States. pp. 211-216 In: XIV International Congress of Arachnology, The Journal of Arachnology, Chicago, IL.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).