Several species of crab spider can be found in the northeast. Some of these odd-looking species maintain an outdoor habitat in rural or wooded areas, and are rarely spotted indoors. Other crab spiders maintain a regular habitat in residential areas and often wander indoors. Crab spiders get their common name from their ability to crawl from side to side and backwards with as much speed and agility as they can moving forwards, much like a crab. While crab spiders typically have small sized bodies, they are still noticeable, and in some cases, downright large and intimidating due to their long legs and their ability to crawl at a fast speed.
The Bark Crab Spider (Bassaniana versicolor) is a relatively small sized spider that prefers wooded habitats where they hunt insects, but this species is often sighted in backyards and in homes that are located near wooded regions. According to a survey of spider sightings, the bark crab spider was found outdoors 12 times and indoors 16 times. These spiders are not found indoors or outdoors in residential areas often, and their .2 to .3 inch body length does not make them appear intimidating. However, this species’ long legs will make them hard to miss.
Ground crab spiders belonging to the Xysticus genus are encountered by humans frequently in the northeast, as most species of this genus prefer to dwell near plants within backyards. The Thomisidae xysticus species is one of the most commonly encountered crab spiders in Massachusetts, and members of this genus range between .1 to .4 of an inch in body length. One spider survey counted 54 outdoor sightings vs 75 indoor sightings, but luckily these spiders are not dangerous to humans.
Running crab spiders belonging to the Philodromidae genus comprise numerous species which range between .1 to .43 of an inch in body length. These spiders have been spotted 99 times outdoors and 111 times indoors by citizen scientists during the past several years, and as their name suggests, they are very fast, and can often escape humans hoping to squash them when they sneak into homes. Although these spiders will not hesitate to bite, they are harmless and most species are relatively small in size.
Have you ever spotted a spider that could move from side to side?