Photo Adventures with Curiosity and Learning

August 25, 2007:Miagrammopes How does she capture prey

This morning, I visited my Queenstown Secondary School observatory - expecting to find our juvenile Nephila. She was gone. But I found another twig spider - Miagrammopes. So I watched her some, gently nudged her to watch how she responded and in general, just enjoyed her quite time.

This lady is pure camouflage. Looks like a twig, and most of the time acts like a twig. Here is the context - a small Miagrammpoes holds the strand with her front legs. This maintains tension in the strand and she will release the strand when an insect collides with the strand. The curvature in her front legs, I suppose, is so that her claws are correctly oriented for holding the strand. What fascinates me is that the prey catching process involves many steps. Did each step develop independently or was the sequence of steps somehow preprogrammed into her DNA?


A closer view where the femoral trichobothria (vertical white hairs that act as wind sensors) can be fainly seen.


Here she is almost vertically oriented. Easily seen are the two front legs and one eye. It is surprising that her front leg length almost equals that of her cephalothorax + abdomen.


and closer


She moved away from the vine

aug 25 3834 away

She has reversed orientation and her front legs now point toward the vine. Other legs are more visible.

miagrammopes walking

Another close view where you can barely see the strand held by hew claw (left side of the photo).

Miagrammopes close

Her legs again - this requires a bit of patience and a gentle nudge

Miagrammopes legs

Here I think she is adjusting the tension of her single strand web

Miagrammopes adjust tension

Another close view

Miagrammopes close

Pure camouflage - looking at her dorsal side from below

Miagrammopes twig camouflage

and a closer look

Miagrammopes twig camouflage close

Back to the twig position

Miagrammopes twig

Not great focus but here she is manipulating the single strand. I believe she is increasing the tension (removing slack)

Miagrammopes close

Crawling back to her home position

Miagrammopes crawling home.jpg

Apparently she captures prey by starting with a slack strand of cribellate silk. She gathers the silk into a bundle (shown here) which pulls the strand taut. When an insect collides with the strand, she releases the bundle which apparently helps tangle the prey. A better description is here

Miagrammopes post tension.jpg

A closer view

aug 25 3986 post tension close

Now she reverses her orientation

Miagrammopes reverse


aug 25 3990 reverse close

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This work is licensed under a Creative Commons License.

C. Frank Starmer