Tegenaria agrestis, known in the United States as the Hobo Spider, is native to Europe but is now well established in the Pacific Northwest of the United States and spreading eastward (Baird and Stoltz 2002). Hobo Spiders are medium-sized brown spiders that build funnel webs and resemble many other agelinid spiders. Beginning in the late 1980s, the claim was made that this spider was responsible for necrotic skin lesions seen in the Pacific Northwest that had previously been attributed (without justification) to the Brown Recluse (Loxosceles reclusa) (Vest 1987a,b; Vest et al. 1996), although the Brown Recluse (the bites of which can indeed produce necrotic skin lesions) is absent from or extremely rare in the Pacific Northwest (Vetter 2008). Although Brown Recluses clearly cannot be responsible for the symptoms in question in this region, the claim that Hobo Spider bites are instead responsible has been seriously challenged (Binford 2001; Vetter and Isbister 2004, 2008; Gaver-Wainwright et al. 2011), although this question may not yet be fully resolved. Many serious conditions having nothing to do with spiders can produce necrotic skin lesions. For example, methicillin-resistant Staphylococcus aureus (MRSA) bacterial infections are a potentially very serious cause of skin and soft tissue injury and are often presented by patients as spider bites. Suchard (2011) found that the great majority of patients seeking medical attention for a "spider bite" were actually suffering from skin and soft-tissue infections. Misdiagnosis as "spider bite" can lead to delayed or inappropriate treatment (Vetter and Isbister 2008).
The Hobo Spider is one of two European agelinid spiders that became established in the Pacific Northwest of the United States early in the 20th century. The first of the two aliens to be noted, the Giant House Spider (T. duellica) has been considered harmless in both its native range and in North America. In Europe, the Hobo Spider, like the Giant House Spider, has been considered medically benign and, as noted above, recent investigations have suggested that despite repeated assertions that Hobo Spiders in North America are not so benign, it now appears likely that in fact North American Hobo Spiders are generally as harmless as those from European populations. Both the Hobo Spider and Giant House Spider have expanded their ranges and occur together in some areas, although the Giant House Spider is still mainly restricted to the Pacific Northwest west of the Cascades (Vetter et al. 2003).
Hobo spiders are native to western Europe and were introduced to the Pacific Northwest region of the United States (accidentally, most likely through the Port of Seattle) as well as southern portions of British Columbia, sometime before the 1930s. This spider has since spread as far south as Nevada and as far east as Montana and Wyoming.
Biogeographic Regions: nearctic (Introduced ); palearctic (Native )
Regularity: Regularly occurring
Type of Residency: Year-round
Hobo spiders have long legs (a characteristic of funnel-web spiders), which have fine hairs and are uniform in color. They usually have a brown cephalothorax with diffuse, indistinct darker brown markings on the legs and abdomen. The underside of the abdomen has a characteristic yellow marking with no spots, distinguishing it from other Tegenaria species. Male hobo spiders share the enlarged pedipalps found in many other spider species; examination of male pedipalps and female epigynum, requiring magnification, is required for sexual identification. Physical variation among individuals tends to be quite high, with a large range of colors and sizes recorded. Size ranges from 6-18 mm with an average length of 12 mm. Females are typically larger than males.
Range length: 6 to 18 mm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry ; venomous
Sexual Dimorphism: female larger
- Vetter, R. 2006. "Hobo Spider Management Guide" (On-line). Accessed February 02, 2012 at http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7488.html.
- Vetter, R., A. Antonelli. 2002. "How to identify (or misidentify) the hobo spider" (On-line). Accessed February 03, 2012 at http://pep.wsu.edu/pdf/PLS116_1.pdf.
- Vetter, R., A. Antonelli. 2012. "How to identify (or misidentify) the hobo spider" (On-line). Accessed September 06, 2012 at http://pep.wsu.edu/pdf/PLS116_1.pdf.
Native European populations of hobo spiders prefer to nest outdoors and typically do not live near humans. North American populations, however, are regularly found nesting near humans, often near, and sometimes in, houses. They also nest under rocks and other objects in yards or gardens. Recently, hobo spiders have been found nesting in rural habitats in the United States.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: savanna or grassland
Other Habitat Features: urban ; suburban ; agricultural
Hobo spiders prey on any insect species that becomes tangled in their webs. No information regarding specific prey is available at this time.
Animal Foods: insects
Primary Diet: carnivore (Insectivore )
Hobo spiders prey on small to moderate sized insects such as ants, beetles, and flies that are caught in their webs (often located inside houses, under rocks, or sometimes in clumps of grass outdoors), controlling the populations of these species. Hobo spiders are themselves prey, particularly for giant house spiders, with lower population sizes of the first significantly correlated to higher populations of the second. Food competitors include crab spiders (Philodromus and Xysticus sp.), wolf spiders (Pardosa sp.), and other web-building spiders, including orb web weavers (Family Araneidae). There is currently no information available regarding parasites of hobo spiders.
Insects such as praying mantises and black and yellow dauber wasps, as well as other spider species such as flower crab spiders, giant house spiders and American house spiders are known to prey on hobo spiders.
- American house spider (Achaearanea tepidariorum)
- Praying mantis (Mantis religiosa)
- Flower crab spider (Misumena vatia)
- Black and yellow dauber wasp (Scelifron caementarium)
- Giant house spider (Tegenaria gigantea)
Life History and Behavior
These spiders perceive their environments using three main receptors: mechanoreceptors, chemoreceptors, and photoreceptors. Mechanoreceptors are the most important sensory channel and consist of a number of very sensitive hairs located on the legs. The legs also house a number of sensilla that detect small air pressure changes. Chemoreceptors can also be found in hairs, usually on the legs and pedipalps, and are known as "taste hairs". These hairs are used to detect prey suitability as well as during courtship when males uses these receptors to follow pheromones laid down by females. Photoreceptors are found in the eyes of spiders, providing them with basic visual information, though images are unfocused due to the small size of their lenses.
Communication Channels: visual ; tactile ; chemical
Other Communication Modes: pheromones ; scent marks ; vibrations
Perception Channels: visual ; tactile ; vibrations ; chemical
- Foelix, R. 1982. Biology of Spiders. Cambridge, Massachusetts and London, England: Harvard University Press.
Hobo spider eggs hatch in late spring to early summer, having been laid the previous fall. This species has three distinct stages of life with molting occurring between each stage: small juvenile, medium-sized immature and adult. Lifespan is greatly influenced by climate, with warmer, coastal populations completing their life cycle in a year and inland populations tending to follow a three year life cycle.
Populations of hobo spiders found in coastal or warmer climates have a life cycle averaging one year. Inland populations tend to be more long-lived, with a lifespan of up to three years. Most individuals die shortly after mating, however females occasionally live through the winter after mating.
Status: wild: 1 to 3 years.
Males use their pedipalps to insert sperm into the female’s epigynum where fertilization takes place. Males die shortly after mating and females die shortly after laying egg cases. It is reasonable to assume that only one mate is taken in the life-span of the spider as members of the species die shortly after breeding.
Mating System: monogamous
Mating takes place in late summer to early fall. Females are largely stationary in the web while males wander in search of mates. Females produce one to four egg cases, each of which can contain 100 or more eggs. The egg cases are deposited and attached to the undersides of rocks, wood, or other structures and are composed of layers of silk mixed with dirt and debris. After eggs are laid, the female usually dies, though there are some cases of females overwintering into another breeding season. Eggs gestate through the winter, hatching the following year.
Breeding interval: Once in life-span (1-3 years)
Breeding season: Mid-July to August
Range number of offspring: 100 to 400.
Average gestation period: 6 months.
Range age at sexual or reproductive maturity (female): 3 to 36 months.
Range age at sexual or reproductive maturity (male): 3 to 36 months.
Key Reproductive Features: semelparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous
Males provide no parental investment after copulation. Females place egg cases in secure spots after laying but usually die before hatching takes place.
Parental Investment: no parental involvement; precocial
Molecular Biology and Genetics
Barcode data: Tegenaria agrestis
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Tegenaria agrestis
Public Records: 23
Specimens with Barcodes: 25
Species With Barcodes: 1
This species is not listed in any database as being endangered or having any special conservation status.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
National NatureServe Conservation Status
Rounded National Status Rank: NNA - Not Applicable
Relevance to Humans and Ecosystems
There is great debate as to the toxicity of hobo spider venom to humans. Venom of the North American populations of this species has been suspected to cause fairly severe necrotic wounds (necrotic araneism) at injection sites, with some evidence that the venom causes comparable effects to that of brown recluse spiders, while European populations have not been considered to be dangerously venomous to humans. This species is notoriously difficult to identify, however, and some recent studies indicate that the necrotic effects attributable to hobo spider venom represent a case of mistaken identity.
Negative Impacts: injures humans (bites or stings, venomous ); household pest
- 2001. "Necrotic Arachnidism -- Pacific Northwest, 1988-1996" (On-line). Accessed February 01, 2012 at http://www.cdc.gov/mmwr/preview/mmwrhtml/00042059.htm.
- Bennett, R., R. Vetter. 2004. An approach to spider bites. Erroneous attribution of dermonecrotic lesions to brown recluse or hobo spider bites in Canada.. Can Fam Physician, 50/1: 1098-1101. Accessed February 02, 2012 at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2214648/.
Since hobo spiders often live near or inside houses, they can often aid in getting rid of pest insects that share the same habitat.
Positive Impacts: controls pest population
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