Green Nature

Running Crab Spiders

Running Crab Spiders (family Philodromidae) are one of two spider families using the crab spider name.

They are often the forgotton crab spider.

The more colorful crab spiders in the family Thomisidae commonly receive more attention, and they are discussed on another page.

Hunting techniques differentiate the families.

picture of a running crab spiderRunning crab spiders chase prey and crab spiders (flower spiders) perch and wait for prey, typically on flowers and leaves.

Less color variation in running crab spiders correlates nicely with their need for less camouflage when hunting compared to the camouflage needs of flower spiders. The dark bodied spider picture on the left is a male Philodromus-dispar. They are common European spiders, found also in the Pacific Northwest.

picture of a Tibellus sp., running crab spiderThe picture on the left is tentatively identified as Tibellus sp.. The problem with picture identification is the fact that more than a couple of species share a similar general brown and white color pattern.

The Rabid Wolf Spider, for example, looks similar, except it has a lighter color stripe on the top center of the cephalothorax. A very common nursery web spider, Pisaurina mira, also looks similar. It might have a thicker and darker central stripe. Regional variations among the Tibellus sp., Rabid Wolf Spider and Pisaurina makes for identification difficulties.

© 2005-2007. Patricia A. Michaels