House spiders are familiar indoor inhabitants, and their longevity often sparks curiosity. Understanding their typical lifespan helps clarify their natural history within homes.
Understanding House Spider Lifespans
The lifespan of house spiders varies, though most common species generally live for about one to two years. Some species may live for longer, depending on various factors. Their life cycle includes stages from eggs, which hatch into spiderlings, to adult spiders.
Spiderlings resemble miniature adults and undergo several molts as they grow. While many spiders complete their life cycle within a year or two, some can have extended lifespans. This variability is influenced by specific conditions and species differences.
Factors Affecting Spider Longevity
Several factors influence a house spider’s lifespan. The availability of food and water is important; spiders are carnivores, feeding on insects like flies and moths. While they can survive for 30 to 60 days without food, water is crucial for their survival, as they drink from dew drops or condensation.
Temperature and humidity also play a role. Spiders are ectothermic, meaning their body temperature is regulated by their surroundings. Warm and humid conditions can extend their lifespan, while extreme heat or very low humidity can cause desiccation. Conversely, colder temperatures can slow their metabolism, potentially prolonging life by conserving energy.
Predation from wasps and other spiders affects longevity. Female spiders often live longer than males, as males tend to have shorter lives, sometimes dying after mating. Exposure to pesticides can shorten a spider’s life, causing direct mortality or impairing behaviors like web-building and foraging.
Lifespans of Common Household Species
The American house spider (Parasteatoda tepidariorum), a common cobweb weaver, typically lives for about one year, though some individuals may survive up to two. These spiders are often brownish-gray with a high, rounded abdomen and irregular webs.
Cellar spiders (family Pholcidae), commonly known as “daddy longlegs” due to their very long, thin legs, can live for two to three years in indoor environments. They construct loose, messy webs, often in corners of rooms or basements. Females can produce multiple egg sacs.
The hobo spider (Eratigena agrestis), characterized by its brown color and a V-shaped pattern on its abdomen, generally lives for one to three years. These funnel-web spiders are more commonly found outdoors in fields but can sometimes enter homes.
Jumping spiders (family Salticidae), recognized by their large front eyes and agile, pouncing movements, typically live from six months to two years in the wild. However, under controlled conditions, some can live up to three years. These spiders do not build webs for catching prey but use silk for shelter.
Separating Fact from Fiction
Common beliefs about house spiders and their lifespans are often inaccurate. One misconception is that releasing a “house spider” outdoors is beneficial; however, many are adapted to indoor conditions and may not survive outside, especially in harsh weather. They are not equipped for colder temperatures or lack of shelter outdoors.
Another myth suggests spiders use plumbing to enter homes, but they typically get stuck in sinks or bathtubs while seeking water. Most house spiders are not dangerous to humans and will only bite if they feel threatened, posing little risk. Spiders do not spread disease and can be helpful by preying on household pests like flies and mosquitoes.