Ambush

When they think of spiders most people think of webs. Charlotte and scary spider movies have helped to reinforce the link between spiders and webs in the public consciousnesses. However not all spiders spin elaborate webs to catch their prey. The goldenrod crab spider is a good example. The goldenrod crab uses camouflage to ambush its prey. It is able to change its color between white and yellow so that it can blend in to a flower where it can wait for prey. When the skipper comes in to the flower to collect nectar and/or pollen the spider attacks, injecting its prey with a paralyzing venom. 

Goldenrod Crab Spider

One of the new things that I have begun to photograph in the last couple of years are spiders. I find spiders extremely fascinating. Like other predators they are diverse in their prey and how they hunt. This affects the habitat where different species live. When most people think of spider they think of them spinning webs but there are many types of spiders that do very little spinning. The goldenrod crab spider is a good example of this.   

 The goldenrod crab spider typically only spins webs during mating and egg laying. They hunt by ambushing their prey. The goldenrod crab has the ability to change its color between white and yellow. They change color to blend in to the flower that they are sitting on. This camouflage helps them to sneak up and ambush their prey. The prey typically consists of pollinating insects which the crab injects with venom and sucks out all of the body fluids, as in the first photo. They are often found in their yellow form on goldenrod flowers, because goldenrod attracts many insects.

 Female goldenrod crab spiders (top) are all one color, either yellow or white, except for the two red stripes that run down their abdomen. Male goldenrod crabs (second and third photo) have a dark thorax. Their front two pair of legs are also dark. The abdomen and back legs look similar to those of the female. The big difference between the sexes is size. The female spider is at least three times larger then the male. This is true of many spider species. This last shot gives you a perspective of just how small the male goldenrod crab is.

Along Came a Spider

The goldenrod crab spider gets its name from its ability to change yellow. It uses this camouflage to hide on yellow goldenrod flowers and ambush butterflies, bees and other nectar eating insects that visit the flower looking for food. Since goldenrod is not always available it can also wait on other color plants, in this case thistle, in its white form.
Since this type of spider does not spin a web they must rely on their ambush ability. This spider has caught a skipper butterfly. The spider will grab its prey with its front legs and then inject it with its venom. Once the prey has become immobilized it will suck out all of the bodily fluids. This goldenrod crab is a female. You can tell the difference because males have a brown thorax with a white abdomen where the female is entirely one color, other then the red stripes. Females are also about three times larger which makes mating very dangerous for the males.

Circle of Life

When most people think about spiders they think of webs, but there are actually quite a few spiders that hunt for prey with out the use of a web. The goldenrod crab spider, for instance, catches its prey by waiting on a flower and ambushing nectar eating insects as they come to feed. The goldenrod crab spider has the ability to change its color from white to yellow to light green so that it can match the color and blend in to the flower from which it is hunting from.

Despite the fact that it is on a purple thistle flower, they can not turn purple so she had no camouflage, this goldenrod crab spider was able to catch this European skipper with her long crab-like, front legs. Once its in her grip then she grabs a hold of the prey with her powerful jaws, leaving her legs free. You can tell that this is a female because of her size. Even though she is smaller then this small European skipper the male goldenrod crab spider is one half to one third as large. I took these photographs up at Voyager National Park last summer.

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