M. Bodasing et al., The influence of group size on dispersal in the social spider Stegodyphus mimosarum (Araneae, Eresidae), J ARACHNOL, 29(1), 2001, pp. 56-63
The costs and benefits of group living vary with group size, and competitio
n for resources increases with increasing group size. In the social spider,
Stegodyphus mimosarum, individuals attain smaller sizes, and survival is l
ower in larger colonies. In this study we assess whether group size influen
ces the decision to leave a colony-or disperse. Four colony sizes (8, 16, 3
2 and 64) of S. mimosarum were set up under a proportional feeding regime i
n a laboratory experiment. We expected more spiders to leave large colonies
due to intra-group competition. However, there was no significant increase
in the number of spiders leaving with increasing group size. Significantly
more spiders left a colony during spring and when spiders were larger (at
a more advanced stage of development). Variability in access to resources d
oes not promote dispersal, but season and spider sire does influence disper
sal.