The Western Black Widow (Latrodectus hesperus) is a native and common spider species throughout much of Wyoming. This arachnid is well-established in the region, particularly in warmer, lower-elevation areas of the state. While its presence is widespread, the black widow is naturally shy and generally avoids human contact. Understanding how to identify this species and where it lives can help people coexist safely with this venomous resident.
Confirming the Western Black Widow in Wyoming
The female Western Black Widow is the most recognizable specimen, distinguished by her size and markings. An adult female typically measures about one-half inch in body length, excluding the legs, and presents a glossy, spherical black abdomen. Her defining feature is a vibrant red or orange hourglass-shaped mark found on the underside of her abdomen.
This distinct marking can sometimes appear as two separate red triangles or a faded shape, but the overall black, bulbous body remains a consistent identifier. The male black widow is significantly smaller, roughly half the size of the female, and is tan or beige with lighter striping on its abdomen. Only the female possesses fangs and venom potent enough to pose a risk to humans; the male is considered harmless.
Typical Habitats and Geographic Distribution
The Western Black Widow is found outdoors across Wyoming in areas where shelter and prey are abundant. They prefer dark, dry, and undisturbed locations close to the ground, spinning messy, irregular webs in crevices and protected corners. Outdoor habitats include woodpiles, under rocks, in sheds, and within the protective spaces of outbuildings.
These spiders also inhabit human-made structures, moving into basements, crawl spaces, and cluttered garages, especially when seeking refuge from changing weather. They are more prevalent in the central and eastern portions of the state, which have lower elevations and more temperate conditions compared to the high-altitude mountain ranges. Finding one often indicates a nearby food source.
Bite Symptoms and Prevention Strategies
A bite from a female black widow is a defensive action, typically occurring when the spider is accidentally squeezed or disturbed. The venom contains alpha-latrotoxin, a neurotoxin that affects the nervous system. An initial bite may feel like a slight pinprick or go unnoticed entirely.
Within 30 to 40 minutes, symptoms begin to develop, starting with localized pain, redness, and minor swelling at the bite site. This pain quickly spreads, causing strong muscle cramping and stiffness in the abdomen, back, and chest. Severe reactions can include nausea, vomiting, headache, and profuse sweating, requiring immediate medical attention. While a black widow bite can make a person very ill, fatalities are extremely rare, particularly for healthy adults.
Precautions can prevent nearly all black widow encounters. Always wear thick gloves when gardening, moving woodpiles, or working in cluttered areas like sheds and basements. Shake out shoes, clothing, and blankets that have been left in garages or other storage spaces before use. Reducing clutter around the home’s foundation and keeping woodpiles away from the structure will eliminate preferred nesting sites.