The common name crab spiders brings to mind an arachnid with a round body surrounded by four pairs of legs. It’s a physical description that mimics the look of a crab. That initial visual serves as a generally good descriptive starting point for three North American spider families that have crab spider as a common name.
A microscopic examination of all the body parts is necessary for identification of many crab spider species. This less formal identification guide uses crab spider pictures as the second best tool for spider identification help.
Depending on the source, the family Thomisidae consists of around one hundred and thirty species, divided into at least ten genera. Because their range extends across the entire United States, species from three of the genera:
Many individual flower crab spiders across the three families share a similar body color pattern, i.e., white or yellow bodies with red stripes or green stripes. Therefore, it’s important to note that crab spider identification for these three genera relies primarily on eye pattern. Having a good macro lens for the camera is all it takes to start the identification process.
The name flower spider formally applies to the Goldenrod Crab Spider (Misumena vatia). Females are typically three times larger and consequently receive more noticed than the male.
The top picture highlights the spider’s eye characteristics. Normally when viewed from the front and top angle, all eight eyes will show up. The picture at the top of this section shows a top down view of the entire spider body, with all eight eyes appearing.
The Green Crab spider, another species in the genus, is also known for the more oblong shape of the abdomen. It is fairly common east of the Rocky Mountains.
Picture two, the Whitebanded Crab Spider (Misumenoides formosipes) highlights the fact that color name does not always apply. The eye pattern from a front and top view shows six eyes.
Mecaphesa go by the common name Hairy Crab Spiders. While over two dozen species have been documented in North America, the majority of species live in warmer climates. They somewhat resemble the white banded crab spiders, however their bodies are hairy. From a front and top picture of the spider, six eyes appear.
It’s called the Northern Crab Spider (Mecaphesa asperata). However with the exception of the Desert Southwest and lower Rocky Mountain states, it’s a very wide ranging species.
A hairy green body covered with distinct markings on face, cephalothorax and abdomen make it fairly easy to identify.
The existence of the California crab spider (Mecaphesa californica) also explains the existence of so many crab spider species. They tend to inhabit small, regional ranges.
Rows of spots down the abdomen are good field ID clues for the Desert Crab Spider (Mecaphesa deserti).
Two species from two different genera also have colorful bodies. Diaea livens, a California crab spider species, also sports a green head. Misumenops bellulus is a Florida species.