Hobo (Eratigena agrestis)

The Hobo spider is different from the Australian funnel-web, even though they both belong to the funnel-web spider group. With various scientific names like Philoica agrestis and Tegenaria rhaetica, these spiders can be found in Europe, Central Asia, and North America. Here, you’ll discover more interesting facts about them!

Scientific Classification

• Family: Agelenidae
• Genus: Eratigena
• Scientific name: Eratigena agrestis

Physical Description and Identification

Adults

• Size: Females are 0.43 – 0.59 inches (1.1 – 1.5 cm), while the smaller males measure 0.31 – 0.43 inches (0.8 – 1.1 cm). The leg span is 2.54-5.08 inches (6.4-12.9 cm).
• Color: They have an overall brown body. Identifying these spiders can be difficult since they look closely similar to other ‘brown’ spiders.
• Other Characteristic Features: The abdomen is oblong with a chevron pattern running through the center. Sexual dimorphism is visible in these spiders. In males, the palps are similar to boxing gloves, while in females, it does not appear so swollen. Males even have smaller abdomens than their female counterparts.

Eggs

The female hobo spider lays eggs during September that go on to hatch the following spring. The mother produces about four sacs in her lifetime containing 100 eggs each, which she attaches to the bottom of an object or the surface nearby.

Spiderlings

Juvenile spiders emerge around June, and they go through several molting phases before reaching adulthood. It takes around one or two months to attain complete maturity.

The Web

They build trampoline-shaped horizontal webs close to woodpiles, and brick walls, where the spider shelters, waiting for its prey to arrive.

Are Hobo Spiders Venomous?

Yes, Hobo spiders are venomous. However, their venom is not considered highly toxic to humans. Earlier theories suggest that necrosis or skin death could be an effect of the hobo spider bite, but the 2017 reports refute this fact and do not include this species under the list of most venomous spiders.

Can Hobo Spiders Bite?

Yes, Hobo spiders can bite. While they aren’t typically aggressive, they might bite if they feel threatened or cornered. Their bite goes unnoticed initially, but in 15 minutes, the victim could sense numbness and pain in the affected area. It may eventually turn red, harden, and become swollen. In the case of severity, the area could turn black after a fluid discharge. However, no fatality has been recorded.

Photo Credit: Kyron Basu

Photo Credit: Kyron Basu

Ecological Importance and Behavior of Hobo spider

Hobo spiders are integral to their ecosystems. They help control insect populations, as they primarily feed on small insects caught in their funnel-shaped webs. These webs are strategically constructed close to ground level in dark and moist areas, such as woodpiles and brick walls. By preying on insects, they maintain a balance within their habitat, indirectly supporting plant life and soil health.

Natural Predator: These spiders face threats from larger predators, notably other bigger spiders and ants. These natural checks and balances contribute to the predator-prey dynamics that Hobo spiders are part of, ensuring no single species dominates the ecological niche.

Prey-Predator Dynamics: In the wild, the Hobo spider is both a predator and prey, which places it firmly within the intricate food web. Their diet consists mainly of insects, which they capture with precision in their webs. The survival strategies of Hobo spiders, from the design of their webs to their swift hunting techniques, highlight their role as effective predators. 

Relationship with Humans: Although Hobo spiders are venomous, their bites are not fatal to humans. Misunderstandings have arisen from their resemblance to more dangerous spiders, such as the brown recluse. However, they generally avoid human contact and only bite when they feel threatened. 

Quick Facts

Did You Know

• French scientist and civil servant Baron Charles Athanase Walckenaer described this species for the first time in 1802 as Aranea agrestis. Later, in 1841, he transferred it to the Tegenaria genus, and finally, it became a part of the Eratigena genus.
• Its brown body makes it closely similar to the brown recluse, though the latter is distinguished by a violin-shaped marking on top of its abdomen.

In summary, by understanding the Hobo spider’s behavior, we gain a deeper appreciation for these often-misunderstood creatures and their place in our world.