The function of the zig-zag structure, known as a stabilimentum,
is unknown. The stabilimentum is not sticky, and therefore does not
directly function in the capture of prey. It does, however, reflect
strongly in the UV portion of the spectrum. This has led to some
speculation that, perhaps, the stabilimentum might serve to attract insects,
thereby increasing the chances of them becoming trapped in the sticky portions
of the web.
In this study, we used colored dyes to manipulate
the color and UV reflectance of the stabilimenta of 150 webs. Each
web was followed for five days, during which time the number of insects
and the type of insects captured in the webs were recorded. In addition,
data were collected on the abdomen size (all subjects were female) of the
resident spider and the overall length of the stabilimentum. Lastly,
data were collected on the number of males present. The data will
be analyzed to determine whether stabilimentum color influenced capture
rate or the kinds of insects captured. |
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