Behind the Scene: Yellow Crab Spider

I was thrilled when I captured this scene, a crap spider and its prey. 



Olympus E-M5, 14-54mm zoom, 1/640th, F7.1, ISO400

What was so cool about this is that my wife and I were on our way south into Montana from Alberta, Canada.  The provincial flower of Alberta is the wild rose!  While I don't believe this is a rose,  the fly might very well have landed expecting the yellow center found on wild roses when in fact the center was a yellow spider in-wait.  Or, at least that is how I envision this all unfolding.



Note the yellow center of a wild rose



For the prior week in the Rockies of Canada it seemed I had my 70-300 zoom on my camera at nearly all times, as the wildlife we saw was big and usually far away.  That included mountain goats, long horned sheep, elk, grizzly bears and black bears. I wasn't prepared for photographing wildlife as small and close as this spider!

Just before crossing the border we stopped at a rest area to use the facilities.  I was walking back to the car and saw a patch of pink flowers blowing in the wind.  The spider seemed like a yellow light flashing back and forth on the flower in the breeze. 

I was surprised that something this small could hold on, not only to the spider but to the flower, because it was very gusty and breezy.  My guess is that this little spider is stronger for its weight than a human.

I grabbed my camera from the back seat of the camera and put on the 14-54mm zoom, which has a reasonable closeup feature.  It was actually quite funny watching me move from left to right trying to follow the spider in the wind.  I took what I thought were hit or miss shots, and I worked quickly as I expected the spider and fly to blow off into the wind at any moment.  Fortunately, I ended up with a good selection of sharp images.

Taken 20 minutes after the spider event.

Update 2013-Feb-28:  I just received and email from the son of one of my fishing buddies that has added more light on the subject.  Thank you Ryan Bridge!

The wasp that the Crab Spider has is a Braconid wasp. They're small in size (maybe 1" average).

They typically are a parasitoid upon caterpillars. A good example is the Tomato Hornworm and the little, white cocoons that people find on them (many people think they're eggs). The female wasp deposits 100's of eggs into the living larva. The eggs hatch and the tiny wasp larva feed on the larva from the inside, often after the larva pupates. In most cases, the pupa is totally consumed from within and the wasp larva build cocoons within the confines of the pupa (inside the cocoon in the case of most moths). They'll over winter if necessary and nearly all 100 or so, will emerge in the Spring as adult wasps. Adult Broconid wasps are predatory and typically feed on caterpillars. They do not build nests or hives, but remain solitary.

Therefore, it's not uncommon for the small wasps to be crawling among the plants and flowers, searching for food. Coming in contact with a Crab Spider and thus, becoming a lunch for that spider, isn't all that rare. Crab Spiders have some of the best camouflage of all spiders, as they will patiently sit and wait for an unsuspecting bug of any kind to get within reach. They commonly feed on pollinators, and use the center of a flower as their "hunting blind". Crab Spiders rarely bite humans, but again are somewhat small and usually go unnoticed due to their size and camouflage.

Hope this helps to explain that pic a little better.

-Ryan Bridge

www.RyanTheBugMan.com.