Eratigena agrestis (Hobo Spider)

About Eratigena agrestis

Taxonomic Hierarchy

→ Kingdom: Animalia
→ Phylum: Arthropoda
→ Class: Arachnida
→ Order: Araneae
→ Family: Agelenidae
→ Genus: Eratigena
→ Species: Eratigena agrestis

Common Name (Official / AAS)

Hobo Spider

Other Common Names

Funnel Weaver, Aggressive House Spider (incorrect, but commonly used!)

Author

Author of species name: Charles Athanase Walckenaer. First year published: 1802, as Aranea agrestis.

Pronunciation

air-uh-TIH-jen-uh ah-GREZ-tiss

Meaning

Eratigena is an anagram of the genus name Tegenaria (Bolzern et al. 2013). The specific epithet, agrestis, is Latin for “from the fields” or “growing wild.” (The origin of the inaccurate nickname “aggressive house spider” is from a mistaken translation of agrestis.)

Notable Previous Names

Tegenaria agrestis

Identifying Traits of Eratigena agrestis

Size

Body length (excluding legs) of adult female ranges from 10-15 mm; adult males range from 7-10 mm.

Female Primary Colors

Male Primary Colors

Eye diagram of Eratigena agrestis

Eyes

Total of eight eyes. When viewed from the front, two horizontal rows of four; both rows (anterior and posterior) are procurved, meaning they are arched upwards. Eyes are all round and roughly the same size.

Legs

Relatively long and of medium thickness; same color as carapace and without any banding or markings whatsoever. Upon close inspection, thick black spines/hairs are present. Tip of each leg has 3 claws (these are called “tarsal claws”).

Body

Overall a light brown color, with darker brown patterning. Male and female look the same, except for differences in size (plus, the male has enlarged palps, while the female doesn’t). The carapace is pyriform (pear-shaped) and is colored the same as the legs, a light brown color, and has two diffuse, longitudinal dark stripes on it. Abdomen is oval-shaped and mottled with various shades of brown and gray; there is a conspicuous “herringbone” pattern on the top side that runs the full length. This pattern is a series of pale ‘V’ or triangle-shaped markings. Turning the spider over, you should see that the sternum (underside of the cephalothorax) has a solid, pale stripe running down the center of it. If, instead of that, you see pairs of spots on the sides of the sternum, then it is likely one of the other species of Tegenaria or Eratigena (or something else entirely). Really the only 100% accurate way to verify the species of any spider is by examination under a microscope, but an experienced eye can typically identify a hobo spider without that.

Range of Eratigena agrestis

Eratigena agrestis can be found in the following states, provinces and territories across the United States and Canada. Our current understanding of each spider's distribution is drawn from numerous scientific publications and online spider submissions, in order to be as accurate as possible. It is important to remember that spiders do not adhere to the territorial lines decided on by humans, therefore these ranges are subject to change.

Important Range Notes

The hobo spider is native to Europe but was introduced (probably) to Seattle, Washington during the early 1900s and has been gradually expanding its territory ever since (Baird & Stoltz 2002). The small population in the Rouge River area near Pickering, Ontario is a rather new occurrence; maybe specimens were transferred in landscaping mulch brought in from southwestern Canada.

United States

Canada

Additional Information

Habitat

In North America, this species is common in close proximity to man-made structures, but not normally indoors. There are other species of spider that prefer the indoor habitat, and those ones help to keep the hobo spider out: Eratigena atrica and Pholcus phalangioides, especially (both have been witnessed feeding on hobo spiders). The hobo prefers to make its web under low-lying debris on the ground; under rocks, leaf litter, in flower beds, open fields, wood piles, pastures, etc. Wandering males can occasionally stray indoors during mating season.

Web

Constructs a web characteristic of most members of the family Agelenidae: a funnel-shaped retreat with a radiating flat sheet of webbing. Spider typically remains inside the retreat during the day, motionless, unless prey enters the web; at which point, it will then rush out to grab it. At night, the spider may stay perched out on the main sheet of webbing to await prey. It will dart back into the retreat if disturbed.

Season

Mating takes place in the late summer or fall. Males wandering for mates may inadvertently enter homes, especially if a porch light is left on overnight and attracts them to the area. There are often cracks and crevices to squeeze into around entryways.

Food

Prey is any insect or other arthropod that the “hobo spider” is able to subdue.

Lifecycle

Once the male hobo spider reaches sexual maturity, he must leave his web and begin searching for mates. The female remains inside her web and awaits suitors. After mating, the female spider can produce as many as four egg sacs. These are spread about 7-10 days apart typically, as she has to “grow” one batch at a time. Some females produce more than four, but the egg quality and count is lower in the additional sacs. A single egg sac has anywhere from 50-150 individual eggs inside it, sometimes more. Hobo spider egg sacs are unique in that the mother incorporates dirt and debris in between two strong layers of silk that surround the inner “core” of eggs. The resulting egg sac is approximately 8-13mm in diameter and almost perfectly spherical (quite heavy for its size, as well). It is strongly attached to the underside of something near the female’s web, like a rock or some other yard debris. The mother spider will guard them as long as she can, but she will typically die around the time of the first frost (although some females may survive and live another year). Her spiderlings will not emerge from the safety of the sac until the following spring. Some individual offspring will reach maturity by summer, while others will overwinter as immatures and mature the following summer.

Remarks

Pictures of Eratigena agrestis (Hobo Spider)

General

Female Spiders

Male Spiders

Filtering options are grayed out when we do not have pictures for the given perspective. If you are a spider photographer, you can submit pictures of spiders to help fill any voids in our ever expanding library.
  • Eratigena agrestis
  • Sex: Male, FemaleMale, Female
  • Maturity: Adult
  • Attributes: Dorsal
  • City/Region: Krain
  • State: Washington
  • Country: United States
  • Eratigena agrestis
  • Sex: MaleMale
  • Maturity: Adult
  • Attributes: Dorsal, Eyes
  • City/Region: Krain
  • State: Washington
  • Country: United States
  • Eratigena agrestis
  • Sex: MaleMale
  • Maturity: Adult
  • Attributes: Dorsal
  • City/Region: Krain
  • State: Washington
  • Country: United States
  • Eratigena agrestis
  • Sex: MaleMale
  • Maturity: Immature
  • Attributes: Dorsal
  • City/Region: Krain
  • State: Washington
  • Country: United States
  • Eratigena agrestis
  • Sex: MaleMale
  • Maturity: Immature
  • Attributes: Dorsal
  • City/Region: Krain
  • State: Washington
  • Country: United States
  • Eratigena agrestis
  • Sex: MaleMale
  • Maturity: Immature
  • Attributes: Eyes
  • City/Region: Krain
  • State: Washington
  • Country: United States
  • Eratigena agrestis
  • Sex: FemaleFemale
  • Maturity: Adult
  • Attributes: Dorsal, Egg Sacs
  • City/Region: Krain
  • State: Washington
  • Country: United States
  • Eratigena agrestis
  • Sex: FemaleFemale
  • Maturity: Adult
  • Attributes: Egg Sacs, Lateral
  • City/Region: Krain
  • State: Washington
  • Country: United States
  • Eratigena agrestis
  • Attributes: Egg Sacs
  • City/Region: Krain
  • State: Washington
  • Country: United States
  • Eratigena agrestis
  • Sex: FemaleFemale
  • Maturity: Adult
  • Attributes: Eyes
  • City/Region: Krain
  • State: Washington
  • Country: United States
  • Eratigena agrestis
  • Sex: FemaleFemale
  • Maturity: Adult
  • Attributes: Dorsal
  • City/Region: Krain
  • State: Washington
  • Country: United States
  • Eratigena agrestis
  • Sex: MaleMale
  • Maturity: Adult
  • Attributes: Dorsal
  • City/Region: Krain
  • State: Washington
  • Country: United States
  • Eratigena agrestis
  • Sex: FemaleFemale
  • Maturity: Immature
  • Attributes: Dorsal
  • City/Region: Iona Beach, Richmond, British Columbia
  • Country: Canada
  • Eratigena agrestis
  • Attributes: Egg Sacs
  • City/Region: Krain
  • State: Washington
  • Country: United States

References and Further Reading

Various Research Papers

Scientific Diagrams and Keys for Identification

References for the Casual Reader

Species guide last updated: April 29, 2016

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