Thursday, July 21, 2011

Stalking a goldenrod crab spider in our backyard

We have a couple of really nice articles waiting for posting, John's report on the blood tracking workshop in Ontario and Andy's article on teaching "whoa", but today the readers will have to endure some shots from our backyard.

The other day when I was watering our plants (we grow mainly vegetables for our own consumption and very few flowers), I noticed an odd looking spot on one the rudbeckias. When I looked closer, I realized that it looked like a yellow spider. It was camouflaged perfectly as it had yellow body with a pair of red stripes, exactly the color of the flower. Of course, I had to investigate.

Click on the image to see better how well the goldenrod crab spider is camouflaged - it has the same body color (yellow) and red stripes as the rudbeckia petals have.
As it turned out this is Misumena vatia, also called the goldenrod crab spider, and it is the largest flower spider. According to one of the nature sites: "Crab spiders don't build webs to catch their prey. Instead, they rely on camouflage and ambush. These colourful spiders blend into their surroundings amongst leaves and flowers, where they lie in wait for unsuspecting flies and bees. Some species can even change colour to match the flower they are on."

I watched the spider for the next few days, and snapped two different pictures of the prey it caught.

First the spider caught a small fly.
The next day I saw it ingesting a large fly, which was actually as large as the spider itself.
The spider sat on the same flower for at least three days, and then moved to the next one. Today it was gone. In a strange way I am going to miss it.


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