Arizona is home to a variety of tarantula species, a natural part of the state’s diverse ecosystem. These large, hairy spiders thrive in the warm, arid conditions found across much of the region. While their appearance can be intimidating, they pose little threat to humans and are an interesting component of the local wildlife.
Common Arizona Tarantulas
Arizona hosts approximately 30 different tarantula species. Among the most recognized is the Arizona Blonde tarantula, scientifically known as Aphonopelma chalcodes, also referred to as the Western Desert tarantula or Desert Blonde tarantula. This species is named for the light-colored hairs that cover its carapace, contrasting with its often dark legs and abdomen. Arizona Blonde tarantulas can reach a body length of about 2 to 3.8 inches, with females typically being larger than males.
Another notable species is the Texas Brown tarantula (Aphonopelma hentzi), which, despite its name, is frequently found in Arizona. These spiders are dark brown, featuring lighter brown hairs on their heads and abdomens. The Grand Canyon Black tarantula (Aphonopelma marxi) is also present, characterized by its predominantly black body with reddish-brown hairs on its abdomen. A newly identified species, Aphonopelma jacobii, was recently discovered in the cooler, forested areas of the Chiricahua Mountains.
These tarantulas inhabit dry, well-drained soils, preferring desert scrublands, grasslands, and rocky areas. Most species are burrow dwellers, digging their own burrows or occupying abandoned ones. These burrows provide shelter from extreme temperatures and predators, and some species, like the Arizona Blonde, line their burrow entrances with silk to detect prey. Some species may also be found in natural crevices, under rocks, or in agricultural fields.
Encountering Arizona Tarantulas
Tarantulas are docile and not aggressive unless provoked. Their primary defense mechanism involves flicking urticating hairs from their abdomen using their hind legs. These tiny, barbed hairs can cause irritation upon contact with skin or mucous membranes, and can even temporarily impair vision if they enter the eyes. If this initial defense is unsuccessful, a tarantula may bite as a last resort.
While all tarantulas possess venom, the venom of Arizona species is mild and not dangerous to humans. A tarantula bite is often compared to a bee sting, causing localized pain, swelling, and redness. Serious reactions are uncommon, though individuals can experience an allergic response. Cleaning the bite area with soap and water is recommended.
Tarantulas are nocturnal, hiding in their burrows during the day. Encounters are most likely during the late summer and fall, particularly from late August through October. This period is known as the “wandering season,” when mature male tarantulas leave their burrows in search of mates. They can often be seen crossing roads or venturing into yards during this time. If a tarantula is encountered, it is best to observe it from a distance, avoid provoking it, and under no circumstances attempt to handle it.