Types of Spiders in Wyoming and How to Identify Them

Wyoming is home to a wide variety of spiders, though only a handful are commonly noticed. Most are harmless and lead quiet lives in grasslands, sagebrush, forests, and even homes. Understanding the main types of spiders in Wyoming helps you appreciate these arachnids and identify the few that need caution.

What are the main spider families found in Wyoming?

Several spider families thrive in Wyoming's semi-arid climate and varied habitats. The most frequently encountered include wolf spiders (Lycosidae), jumping spiders (Salticidae), orbweavers (Araneidae), funnel weavers (Agelenidae), crab spiders (Thomisidae), ground spiders (Gnaphosidae), cellar spiders (Pholcidae), and cobweb spiders (Theridiidae). Each family has distinct identification features and behaviors that make them recognizable with a little practice.

How can you identify common Wyoming spiders?

Identification features such as eye arrangement, body shape, web type, and hunting behavior are key. For example, wolf spiders have a distinctive eye pattern with four small eyes in a row, two large forward-facing eyes, and two more on top. Jumping spiders have a similar large front pair but a flattened face and an alert, jerky movement. Orbweavers build classic spiral webs, while funnel weavers create sheet-like webs with a tubular retreat. Crab spiders hold their legs out to the sides like a crab and often sit on flowers.

Wolf Spiders: The Ground Hunters

Wolf spiders are among the most common types of spiders in Wyoming. They are robust, hairy, and brown to gray, often with a Union Jack-like marking on the cephalothorax. They do not build webs to catch prey; instead, they hunt actively on the ground, especially at night. Females carry egg sacs attached to spinnerets and later carry spiderlings on their backs. You might spot them by flashlight in sagebrush or near ponds, their eyes shining greenish. They can bite if handled but are not dangerous.

Jumping Spiders: The Curious Stalkers

Jumping spiders are small, compact, and often brightly colored or iridescent. They have excellent vision and will turn to look at you. They hunt during the day, stalking prey and leaping several times their body length. In Wyoming, look for them on sunny rocks, fences, and garden plants. Their courtship dances, involving raised legs and rhythmic movements, are a delight to observe.

Orbweavers: Master Web Builders

Orbweavers are the architects of the classic circular web. In Wyoming, species like the cat-faced spider (Araneus gemmoides) are common in late summer and fall. They are large, with bulbous abdomens often patterned with bumps or spots. Their webs are strung between shrubs, grasses, or porch eaves. At dawn, dew makes these webs visible—a perfect time for photography. Orbweavers are harmless and beneficial.

Funnel Weavers: The Sheet Web Specialists

Funnel weavers, including the common grass spider, build horizontal, sheet-like webs with a funnel at one end. The spider waits inside the funnel, rushing out when vibrations signal prey. These webs are conspicuous on dewy mornings across lawns and fields. Funnel weavers are fast but shy, retreating into the funnel when approached.

Crab Spiders: The Ambush Predators

Crab spiders are small to medium, with flattened bodies and long front legs held out to the sides. They do not build webs; instead, they sit motionless on flowers, waiting to grab visiting insects. Many can change color over days to match their flower, from white to yellow. In Wyoming, look for them on goldenrod, sunflowers, and rabbitbrush in late summer.

Cobweb Spiders and the Western Black Widow

The cobweb spider family includes the only medically significant spider in Wyoming: the western black widow (Latrodectus hesperus). Females are shiny black with a red hourglass on the underside of the abdomen. They are reclusive, building irregular webs in dark, undisturbed places like woodpiles, rodent burrows, and outbuildings. Bites are rare and occur mainly when the spider is pressed against skin. Other cobweb spiders in the family, like the common house spider, are harmless and often found in corners of homes.

Where do Wyoming spiders live?

Spider habitats in Wyoming range from alpine meadows to shortgrass prairie. Moisture-loving species like fishing spiders (Dolomedes) live near streams and ponds. Ground spiders and wolf spiders dominate dry, open areas. Jumping spiders and crab spiders prefer sunny spots with vegetation. Funnel weavers like grassy fields, while orbweavers need structures to anchor webs. Knowing the habitat helps narrow identification.

When is the best time to observe spiders in Wyoming?

Spiders are active from spring through fall, but late summer and early autumn are peak observation times. Many species mature in August and September, increasing their size and visibility. Morning dew reveals webs, and cool nights make ground hunters easier to spot with a flashlight. Winter is mostly quiet, though a few species remain active indoors.

Table: Quick Comparison of Common Wyoming Spider Families

Practical tips for spider watching in Wyoming

Bring a hand lens or camera with macro capability. Move slowly to avoid startling spiders. Early morning is best for webs; evening flashlight walks reveal eye shine. Wear gloves when reaching into woodpiles or rock crevices where a black widow might hide. Observe without disturbing—spiders play vital roles in controlling insects. Keep a field notebook to record date, habitat, and identification features. With patience, each outing reveals new types of spiders in Wyoming and deepens your connection to the landscape.