Sac Spider (Trachelas spp.)

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

Updated: 2/3/2014; Authored By Staff Writer; Content ©www.InsectIdentification.org

Sac Spider

Sac Spiders should be a good incentive to keep up with the laundry. They like to hide in the clothes and will bite their way out if they have to.

When it comes to catching prey, Sac Spiders are predatory hunters, not web weavers. They use their spider silk to weave tent-like sacs between leaves or on tree trunks for retreats though. Sac Spiders are fast runners. They may appear tan, yellowish or even slightly greenish. Only 8 native species inhabit North America.

The group of various Sac Spiders are known to deliver painful bites to humans. These spiders are not outright aggressive, but if threatened, they bite defensively. Because they are wanderers, they sometimes rest in a pile of clothes (clean or dirty) that have been left on the floor. When someone moves it, or puts on something from the pile, the Sac Spider may get trapped between the clothing and the person's skin and bite him/her to escape.

Like all spiders (except Cribellate Orbweavers), they produce a venom designed to immobilize their insect prey. While their venom is not seriously dangerous like a Brown Recluse's or Black Widow's, Sac Spider bites are slow to heal. It is not uncommon for the bite area to get infected as victims frequently scratch or touch it.

Basic Information

Common Name: Sac Spider

Scientific Name: Trachelas spp.

Category: Spider

General Identification

Size (Adult; Length): 5mm to 8mm (0.20in to 0.31in)

Identifying Colors: red; brown; tan; green; yellow

Additional Descriptors: biting, venomous

Taxonomic Hierarchy

Kingdom: Animalia

Phylum: Arthropoda

Class: Arachnida

Order: Araneae

Family: Corinnidae

Genus: Trachelas

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 Sac 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

Images Gallery for the Sac Spider

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