Goldenrod Crab Spider
or Flower Spider
Goldenrod doesn’t grow on my hill and perhaps that’s why the Goldenrod Crab Spider is so easy to find on the cow parsnip, now that I know what to look for at least. In fact, I didn’t even know it existed until one day I was looking through my attempts to photograph the tiny blossoms of a cow parsnip umbel covered in tiny insects including an immobile moth. I don’t have a macro lens, so it is a challenge to photograph tiny things. Suddenly I noticed what appeared to be a small whitish ball with dark pink side-stripes.
Zooming in, I realized that it was a distinctly crab-like spider with a fly or tiny wasp in its clutches. I suspect that the moth had been a previous meal. Now I look on purpose. A banquet table in full bloom is always covered with insects busily nourishing themselves and among them might very likely be a goldenrod crab spider either waiting patiently with forelegs extended within the flowers for a hapless insect to land or crawl within range, or drinking as if from a large mug tipped for full satisfaction.
The crab spiders can move forward, backwards and sideways just like a crab and can spin webs although the males apparently only do that when the need arises to immobilize a mate, who, as is usual with spiders, would be much larger than him. Later, the female uses her silk-spinning skills to protect her eggs.
If you do find this spider on goldenrod, it would likely be yellow rather than white, as over several days the spider can transfer a pigment to its outer layer to switch between those two colours when it needs to blend into its chosen hunting blind.
Although the spider’s usual method of nourishment is to drink the still-pumping blood and then the liquified body of its paralyzed prey, from the following embedded video from Green Nature, it appears that she also subscribes to the ‘waste-not-want-not’ philosophy. I am impressed by her dexterity.
Bugs of Alberta by John Acorn & Ian Sheldon. Lone Pine, Alberta 2000
The Audubon Society Field Guide to North American Insects and Spiders by Lorus Milne and Margery Milne. Knopf (year unknown – publication page missing)