Ground Crab Spider (Xysticus spp.)

Detailing the physical features, habits, territorial reach and other identifying qualities of the Ground Crab Spider.

Updated: 1/20/2014; Authored By Staff Writer; Content ©www.InsectIdentification.org

Ground Crab Spider

The Ground Crab Spider wanders around until it can pounce on an unsuspecting insect victim.

Crab spiders get their name from the resemblance they share with the crustacean as they walk and when they sit at rest. Their crab-like appearance is linked to the slightly longer sets of front legs than back legs. Ground Crab Spiders are able to walk sideways and backwards as well as forward. Not all spiders can do this.

They sit on flowers and leaves, ambushing their prey as it visits the plant. Butterflies, bees, flies and beetles are all targets. The strong front legs are used to grab the insect and then it is quickly bitten and immobilized.

Males use silk to gently secure females before mating. Females lay fertilized eggs in silken sacs that they guard until spiderlings hatch. The Ground Crab Spider does not weave a web for trapping prey.

Basic Information

Common Name: Ground Crab Spider

Scientific Name: Xysticus spp.

Category: Spider

General Identification

Size (Adult; Length): 3mm to 9mm (0.12in to 0.35in)

Identifying Colors: brown; black; red; tan

Additional Descriptors: crab, mottled, venomous, biting, spiky, spine, hairy

Taxonomic Hierarchy

Kingdom: Animalia

Phylum: Arthropoda

Class: Arachnida

Order: Araneae

Family: Thomisidae

Genus: Xysticus

Species: spp.

Spider Anatomy (Typical)

Graphic showing basic parts of spider anatomy

1

Legs: Spiders have four pairs of legs and these are attached to the cephalothorax.

2

Pedipalps: Small appendages near the mouth used as taste and smell organs.

3

Cephalothorax: Contains eyes, head, mouthparts, and legs.

4

Abdomen: Contains various organs related to digestion, reproduction, and web-making.

5

Spinnerets: Used in the production of spider silk for fashioning webs or catching prey.

NOTE: Unlike insects, spiders have both an endoskeleton (internal) and exoskeleton (external).

Territorial Reach (A-to-Z)

Note: An insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed below as they are driven by environmental factors (such as climate change), available food supplies and mating patterns. Grayed-out selections below indicate that the subject in question has not been reported in that particular territory. U.S. states and Canadian provinces / territories are clickable to their respective bug listings.

Newfoundland and Labrador

Mexico

Territorial Area Map (Visual Reference Guide)

The map below showcases (in red) the states and territories of North America where the Ground Crab Spider may be found (but is not limited to). This sort of data can be useful in seeing concentrations of a particular species over the continent as well as revealing possible migratory patterns over a species' given lifespan. Some species are naturally confined by environment, weather, mating habits, food resources and the like while others see widespread expansion across most, or all, of North America.

Alaska

Hawaii

Prince Edward Is.

Canadian territory of British Columbia graphic

Canadian territory of New Brunswick graphic

Canadian territory of Newfoundland and Labrador graphic

Canadian territory of Saskatchewan graphic

Territory map graphic of the country of Mexico

Contiguous United States shape map layer graphic

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