AERIAL DISPERSAL BEHAVIOR OF TWO 
ORB WEAVING SPIDERS 
By Wayne W. Tolbert* 
Graduate Program in Ecology 
University of Tennessee 
Knoxville, Tennessee 37916 
Introduction 
Aerial dispersal, the transport of spiders from place to place by 
wind and/or convection currents, has been recognized as a feature 
of spider behavior since the time of Aristotle (Duffey, 1956). Many 
natural historians and arachnologists have observed and briefly 
commented on this phenomenon (Emerton, 1908; Bristowe, 1939; 
Gertsch, 1949; Nishiki, 1966; and Kaston, 1972), and a few studies 
have been devoted to the environmental conditions associated with 
the general phenomenon of spider dispersal. 
Most studies and observations have been made of mass migra- 
tions of several species of spiders, particularly migrations occur- 
ring during the winter months (Bristowe, 1939). Duffey (1956) 
determined that temperature, population density, and stages of the 
breeding cycle are associated with mass aerial migrations of several 
species of Linyphiidae. Van Wingerden and Vugts (1974) pro- 
duced results similar to Duffey’s for one lingphiid species, Erigone 
artica (White). 
Richter (1970, 1971) has studied in the laboratory some micro- 
climatic factors which influence aerial dispersal in eight species of 
Pardosa wolf spiders. Richter (1970) related the frequency of aero- 
nautic behavior of each species to the abundance and stability and 
that species’ preferred habitat. 
The purposes of this study are to describe the aerial dispersal 
behavior of Argiope trifasciata (Forskal), to compare behavioral 
elements of this species with a sympatric population of the con- 
gener, A. aurantia (Lucas), and to determine, under actual field 
conditions, the major physical parameters which influence these 
behaviors. Factors influencing emergence from the egg sac are 
discussed elsewhere (Tolbert, 1976, in preparation). 
*present address — Science Applications, Inc. 
P. O. Box 843 
Oak Ridge, Tennessee 37830 
Manuscript received by the editor May 27, 1977 
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