Hobo spiders, common arachnids often encountered in the Pacific Northwest and increasingly in other Western states, frequently prompt questions about their duration of life. These spiders, scientifically known as Eratigena agrestis, are a type of funnel-web spider that can sometimes find their way into human dwellings. Understanding their typical lifespan and life stages provides insight into these creatures.
Hobo Spider Lifespan
The lifespan of a hobo spider varies depending on its sex, with notable differences between males and females. Male hobo spiders typically live for about one year, often perishing shortly after they mate. Females, however, can survive for several years, sometimes living up to three years or more. This extended lifespan allows females to participate in multiple reproductive cycles.
Adult hobo spiders are most commonly observed during the late summer and early autumn, generally from August through October. During this period, male spiders actively wander in search of mates, increasing their chances of encountering humans.
Life Cycle Stages
A hobo spider’s life unfolds through several distinct developmental stages, starting from an egg and progressing to a mature adult. The life cycle begins in late summer or early autumn when a female hobo spider lays her eggs. She encases these eggs, which can number from 30 to over 100, within a protective silken egg sac. This sac is often hidden in dark, secluded locations.
After an incubation period that typically lasts two to three weeks, the eggs hatch into tiny spiderlings. Spiderlings then disperse from the egg sac. As they grow, spiderlings molt, shedding their exoskeletons to mature into juvenile spiders. This juvenile phase can extend for one to two years, with individuals often overwintering before reaching their final adult form.
Influences on Longevity
Several environmental and biological elements can affect how long an individual hobo spider lives. Local climate and temperature play a part, as colder winters may lead to spiders overwintering, potentially extending their developmental period. Conversely, warmer coastal regions might see a slightly shorter overall life cycle.
The availability of food sources, such as insects and other small arthropods, directly supports a hobo spider’s growth and survival. If prey is scarce, these spiders can scavenge for dead insects, which helps them endure extended periods.
The presence of predators also shapes a hobo spider’s survival. Other spider species, like the giant house spider, along with birds and other animals, can prey on them. Human interactions, including habitat disturbance, sealing entry points into homes, or the use of pesticides, can significantly reduce hobo spider populations. Spiders thrive in undisturbed, damp, and dark environments, and access to such sheltered habitats contributes to their ability to survive and complete their life cycle.
Recognizing a Hobo Spider
Accurately identifying a hobo spider can be challenging, as they share characteristics with many other brown spider species. These medium-sized spiders typically have a body length ranging from 8 to 15 millimeters for males and 9 to 18 millimeters for females, with females generally being larger. Their overall coloration is light to medium brown or tan.
A distinctive chevron-shaped pattern marks their abdomen, though it can be faint. Hobo spiders possess long, slender legs that are uniformly colored, lacking the dark bands or rings found on many similar-looking spiders. Fine, feather-like hairs cover their bodies and legs. They have eight eyes arranged in two straight rows of four. Male hobo spiders can be identified by their enlarged pedipalps, which are appendages near their mouth that resemble boxing gloves.
These spiders construct non-sticky, funnel-shaped webs with a tubular retreat where they wait for prey. Their webs are typically found in low-traffic, dark, and damp areas at ground level, such as basements, crawl spaces, or under rocks and woodpiles. Hobo spiders are not adept climbers, so they are rarely found on smooth vertical surfaces. Due to their similar appearance, hobo spiders are often mistaken for other species, including the brown recluse or giant house spider.