Accurate identification of spiders like the hobo spider is important for understanding their behavior and presence in living spaces. This article helps distinguish hobo spiders from other species by focusing on their physical attributes, web characteristics, and typical habitats.
Distinctive Physical Characteristics
Hobo spiders (Eratigena agrestis) are light to medium brown. Their body length measures between 7 and 16.5 millimeters, with females larger than males. They possess an oblong abdomen and a cephalothorax (the fused head and thorax) that is also brownish with darker markings.
A notable feature is the presence of a distinctive “herringbone” or “chevron” pattern on their abdomen, though this can be faint and difficult to discern without magnification. Unlike some other spiders, hobo spiders do not have dark bands on their legs, which appear uniformly colored and relatively smooth. Males have enlarged pedipalps, small, leg-like appendages near their mouth, sometimes described as resembling boxing gloves. Hobo spiders have eight eyes arranged in two nearly straight rows.
Web and Habitat Clues
Hobo spiders are known for constructing distinctive funnel webs. These webs are sheet-like with a funnel-shaped retreat at one end, where the spider waits for prey. The webs are not sticky; instead, prey becomes entangled, allowing the spider to emerge and capture it.
These spiders prefer sheltered, dark, and moist environments. Common outdoor habitats include rock and wood piles, tall grass, and cracks in foundations or concrete. Indoors, hobo spiders are found at ground level in basements, crawl spaces, and window wells, as they are not proficient climbers on smooth surfaces. Males often wander indoors during late summer and fall while seeking mates.
Distinguishing from Similar Spiders
Several spider species are often mistaken for hobo spiders due to similar appearances or shared habitats. The giant house spider (Eratigena atrica) is closely related and can be confused with the hobo spider, but giant house spiders are larger and possess dark bands on their legs, which hobo spiders lack. The sternum of a hobo spider has a light stripe down the middle, whereas some other related Eratigena species may have distinct light spots.
Wolf spiders, belonging to the Lycosidae family, are another common look-alike. Wolf spiders are larger and noticeably hairier than hobo spiders, and they have distinct banding on their legs and arrow-shaped patterns on their backs. Crucially, wolf spiders are active hunters that do not build capture webs, unlike hobo spiders which construct funnel webs. Their eye arrangement also differs, with wolf spiders having two large forward-facing eyes and smaller eyes arranged in three rows, while hobo spiders have eight eyes in two rows.
The brown recluse spider is also frequently misidentified as a hobo spider, but these two species have distinct features and geographical distributions. Brown recluse spiders possess a distinctive violin-shaped marking on their cephalothorax and have six eyes arranged in three pairs, whereas hobo spiders lack the violin marking and have eight eyes in two rows. Hobo spiders are primarily found in the Pacific Northwest and Rocky Mountain regions, while brown recluse spiders are found in the south-central United States, making encounters in the same area unlikely. Other funnel weavers, like the barn funnel weaving spider (Tegenaria domestica), also construct similar webs but can be differentiated by subtle markings or reproductive structures.
Safety and Management
When encountering a suspected hobo spider, exercise caution and avoid direct contact. Safe removal methods include using a cup and a piece of paper to trap the spider and then releasing it outdoors. Vacuuming can also effectively remove spiders and their webs.
To reduce spiders entering a home, implement several preventive measures. Sealing cracks and gaps in foundations, around windows, and under doors prevents entry. Reducing clutter in basements, garages, and around the home’s exterior eliminates hiding spots. Managing outdoor vegetation, such as trimming grass near foundations and moving woodpiles away from the house, deters spiders.
While hobo spider bites were once thought to be severe, current scientific understanding indicates they result in only mild pain and redness and are not considered medically significant. Any suspected spider bite should be monitored, and medical attention sought if concerns arise.