Spiders are a vital part of the ecosystem in Greater Tucson, Arizona. Although they might seem daunting to some, these arachnids control insect populations and contribute to maintaining the environmental balance. Here’s a guide to some of the most common spider species you might encounter in Tucson and surrounding areas.
Black Widow (Latrodectus hesperus)
Identification:
- Notable for its shiny black body and the distinctive red hourglass shape on its abdomen.
- Adult females are larger, about 1.5 inches in length.
Habitat:
- Often found in sheltered, quiet areas such as woodpiles, boxes, and in dark corners of garages and basements.
Risk to humans:
- Venomous species. Bites can be painful and medically significant but are rarely fatal with medical attention.
Brown Recluse (Loxosceles reclusa)
Identification:
- Uniformly brown with a dark brown violin shape on their cephalothorax (fused head and thorax).
- About a quarter to half an inch in body size.
Habitat:
- Prefers undisturbed locations such as closets, attics, or storage areas stacked with boxes.
Risk to humans:
- Venomous. Its bite can cause necrotic lesions but is reluctant to bite unless provoked.
Tarantula (Family Theraphosidae)
Identification:
- Large, hairy spiders varying from light tan to dark brown.
- Can reach over 4 inches in leg span.
Habitat:
- Live in burrows in the ground, especially in desert environments.
Risk to humans:
- Non-aggressive and their venom is not dangerous to humans, although their hairs can cause irritation.
Wolf Spider (Family Lycosidae)
Identification:
- Robust, fast-moving spiders that range from 1/2 to 2 inches in length.
- Usually brown or grey with various patterns.
Habitat:
- Often found on the ground in open spaces, where they hunt at night.
Risk to humans:
- Not venomous to humans; can bite if threatened but are generally harmless.
Desert Recluse (Loxosceles deserta)
Identification:
- Similar to the brown recluse, with a violin-shaped mark.
- Smaller than the brown recluse, around 1/3 inch long.
Habitat:
- They thrive in dry desert climates, hiding in undisturbed areas like woodpiles and sheds.
Risk to humans:
- Venomous like the brown recluse but is a shy species that typically avoids interaction.
Funnel Web Spiders (Family Agelenidae)
Identification:
- Not to be confused with the dangerous Australian funnel-web spider.
- They have slender bodies and are typically brownish or greyish.
- Build distinctive horizontal, funnel-like webs to trap prey.
Habitat:
- Common in gardens, near buildings, and in open fields.
Risk to humans:
- Pose little risk to humans; they may bite in defense but are not considered dangerous.
Observing spiders can be a fascinating experience. Just remember, most spiders in Tucson are harmless, and bites are infrequent and typically occur only when a spider is pressed against the skin. If you’re exploring natural spaces or even your home, it pays to be aware of your surroundings and respect the creatures you share the space with. If you believe you’ve been bitten by a venomous spider such as a black widow or any recluse species, seek medical attention immediately.
