Chameleon Crab spiders

Crab spiders are tiny, but indomitable. Life starts for them inside a folded up leaf nest, first created by and then guarded by their mother:

This particular crab spider is the Goldenrod Crab Spider, Misumenia vatia. She is a maximum of 10mm long, and the males are half that size. The babies will hatch in about 3 weeks, after undergoing the first of two molts inside their leaf shelter.

She stands out against the leaf, but once she is on a flower, not so much.

An ambush hunter, this camouflage stands her in good stead when she hides beneath a petal, front legs astride like the claws of her namesake:

Her name actually comes from her ability, unusual among spiders, to walk sideways:

Crab spiders are known for their ability to change color to disguise their presence. This one is whitish.

Although for us it is still easy to see on the pink rose, apparently arthropod vision will see this simply as a dark shape on a dark background. It worked for this one, which caught a hoverfly :

A purplish-blue platycodon flower is too great a challenge, but even un- camouflaged it caught a small fly.

And the one below found a leaf completely covered in newly hatched alder beetle larvae, so camouflage was superfluous, and it gorged itself.

.Their base color is white,

and changing to yellow requires that they secrete yellow pigment, which can take 10-25 days. Changing back to yellow is faster, about 6 days. All this is triggered by them seeing the color of the flowers they want to hunt on. If they are blind, they don’t change color.

They really should be called Chameleon Spiders.

2 thoughts on “Chameleon Crab spiders”

  1. I really like seeing the crab spiders…such great photos! Seems like such a long time that it takes for them to change color.

    Like

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