White Crab Spider

This little spider is a real chameleon! Also commonly known as a goldenrod crab spider or a flower crab spider, the white crab spider (Misumena vatia) is one of two known spiders in North America that can actively change their body color from white to yellow and back, depending on the flower on which it is perched. This is not an instantaneous change but occurs over days, not minutes.

The female white crab spider is the chameleon of the species. Her abdomen and cephlothorax can vary between white or yellow and the abdomen may or may not have a red stripe on either side. The occurence of the red stripe is genetically determined, not a function of the immediate surroundings. The legs are plain white or yellow without any markings. The male’s coloration is a different story. He does not look at all like the female with red-brown or brown markings over the entire body and is smaller than the female. (Rather than describe the male in detail right now I will do so when I eventually get a photograph of the male – much easier to visualize.)

Crab spiders hold their legs out on the sides, crablike. The front two pairs are much longer and stronger than the rear pairs. Like a crab, these spiders can walk forward, backward and sideways.

White crab spiders can be found throughout the Northern Hemisphere and are thus classified as a holarctic species. Flowers and shrubs are their habitat. As one of the common names suggests, goldenrod flowers are particularly attractive to white crab spiders.

White crab spiders do not capture prey in a web. Instead they perch atop flowers with their front legs spread open, ready to grab any insect that comes near. Their vision for movement is excellent. The diet of white crab spiders consists mainly of pollinators (bees and moths, for example) or any other unlucky insect that happens to land on the flower where the white crab spider is sitting in wait. Apparently the white crab spider also has a toxin that aids in restraining insects larger than themselves.

White crab spiders live only one year. Males upon maturity find as many mates as possible and then die. Females usually only have one brood a year. The female folds over the tip of a leaf, webs it together to make a little sac and deposits her eggs. Milkweed that is no longer flowering is a favorite nesting site. The female then guards her eggs until she dies at the approach of winter, usually before the eggs hatch. The spiderlings (spider babies) that hatch in the fall overwinter and then mature in the spring or summer to begin the cycle again.

The species name vatia means “bowlegged”. Originally the scientific name for the white crab spider was Araneus vatia which simply translates to “bowlegged spider”. The current scientific name, Misumena vata, means “bowlegged object of hate”, a much less descriptive appellation, unless one considers that many people hate and fear spiders.

This white spider crab was sitting on a self-heal along the Jesse Wright Segment of the North Umpqua Trail in Oregon. These are not particularly good pictures because I did not stop hiking to seriously take photographs. But this little spider is most interesting and still worth a mention.

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