Substrate preference in a colonial orb-weaver

FLORENCIA FERNÁNDEZ CAMPÓN; SUSAN RIECHERT

Lexington, Kentucky, USA

Congreso; American Arachnological Society Meeting; 2000

Adult females of _Parawixia bistriata_ basically exhibit two distinct morphs characterized by brown and yellow opisthosomes. When dispersin from the colony and becoming solitary, females can be either found on leaves or on trunks or branches of tress. In the field, the yellow morph was only found on leaves, specifically bell9ow or inside groups of leaves glued with silk. The brown morph, however, did not show a significant substrate association. We tested for individual preference for the different substrates in a mark and reciprocal release experiemtn on trunk versus leaf substrates and recorded the substrate they were found on days 3 and 5 follwowing the release. (All but one yellow spider was found on leaves on the last day of the experiment. Four of the 7 brown morph spiders released on leaves were found on leaves, and the remaining 3 were found on branches (with no leaves). Half of the brown spiders released on trunks (3/6) were found on either a branch with no leaves or trunk, and the other half were found on leaves. These results indicate that females of the yellow morph exhibit a marked preference for leaves as a substrate whereas individuals of the brown morph do not seem to prefer a particular substrate.