I’m not actually referring to sexually transmitted diseases in the title of this post, although pollinators can be vectors for diseases in flowers. I’ll save that for a future post. Today, I want to talk about crab spiders!
If you suffer from Arachnophobia, you are missing out on some of nature’s coolest predators. (Also, if you suffer from Arachnophobia, I’m sorry about the photo above…and the ones below…and future photos with spiders in them. I think that covers all the bases.) People have a natural attraction toward predators…they love the large mammalian and avian carnivores. But for some reason, they become very alarmed in the presence of our little arachnid friends. I can’t say I understand it, although I do try to be sympathetic.
Crab spiders are members of the family Thomisidae. They are featured in my post today because of their interesting methods for catching prey. Most crab spiders do not build the webs you may associate with other members their order (Araneae). They are called “sit and wait” or “ambush” predators because of their propensity toward hiding and leaping out to grab unsuspecting prey items.
Many, although not all, crab spiders like to do their sitting and waiting on flowers (well, wouldn’t you?). One species in particular (Misumena vatia) is known for its ability to gradually shift its colouration until it matches its flower post perfectly. This generally happens over the period of a couple days.
This species is much faster at changing from yellow to white than the reverse because it must build yellow pigment, but to turn white, all it has to do is excrete it. Ah, isn’t biology fascinating?
In the future, vegetarian spiders and common penguin misconceptions!