Microhabitat identity of two species of sheet-web spiders: field experimental demonstration.

Descriptive studies reveal that web-site characteristics of two sympatric species of sheet-web spiders, Linyphia triangularis and L. tenuipalpis are similar, even though their body sizes and web sizes are significantly different. The hypothesis of identical web-sites were tested by a species exchange experiment in the field. Here the residence times of adult females of each species released in webs of the other species were compared to the residence times of other females released in own species' webs. As there was no differences between the species-exchange series and the control series, the experimental results supported the conclusions of the descriptive studies. The utility of testing habitat parameter differences experimentally, and the significance of the results to the ecology of the species, in particular to their interspecific interactions, are discussed.