Hobo Spider

Eratigena agrestis

Classification

Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Araneomorphae
Family: Agelenidae
Subfamily: Ageleninae
Genus: Eratigena
Species: agrestis

Pronunciation

How to pronounce Eratigena agrestis: /ɛˈræ.tɪˌdʒiː.nə əˈɡrɛs.tɪs/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Summary

Eratigena agrestis, or hobo spider, is a funnel-web spider originally from Europe that has expanded its range into North America. It is characterized by its brown color, herringbone abdominal pattern, and construction of funnel-shaped webs. Despite its notoriety, it is generally non-aggressive and not considered medically significant.

Physical Characteristics

Female: 11-15 mm; Male: 8-11 mm. Brown coloration with subdued earth shades, herringbone pattern on abdomen, lack of colored bands on legs, distinct chevron patterns on abdomen, light stripe on the sternum.

Identification Tips

Identification is best done through microscopic examination of the epigynum and palpal bulb. Look for the absence of colored bands and distinct chevron patterns on the abdomen. A light stripe runs down the middle of the sternum, distinguishing it from other Eratigena species.

Habitat

Prefers fields, flower beds, wood piles, and dark corners of basements. Often found in areas where it can construct a funnel web.

Distribution

Originally from Europe, now found throughout the Pacific Northwest, Great Basin, and parts of western North America. Documented in various U.S. states including Colorado, Montana, and Wyoming.

Diet

Primarily feeds on insects and other spiders, using its funnel web to catch prey.

Life Cycle

Females produce one to four egg cases in late fall. Spiderlings emerge in the spring. Males are often found searching for mates in late summer.

Reproduction

Males search for females by signaling at the entrance of the funnel web. After mating, males typically leave to find other females.

Ecosystem Role

As a predator of insects, it plays a role in controlling pest populations.

Cultural Significance

Commonly misidentified as a hazardous species, which has fueled public fears despite lack of evidence for significant medical threat.

Health Concerns

Previous claims of venom causing medical issues have been largely debunked, and it is not considered a significant threat to human health.

Collecting Methods

Hand collection
Using a sweep net

Preservation Methods

Ethanol preservation
Dry preservation

Evolution

Previously classified under the genus Tegenaria until the reclassification to Eratigena in 2013.

Similar Taxa

Misconceptions

Commonly believed to be aggressive and venomous; the name 'aggressive house spider' is misused. 'Agrestis' means 'rural' or 'field' in Latin, not 'aggressive'.