Guide to Black and White Spiders Found in Utah

Black and White Spiders Found in Utah

Utah is home to a diverse variety of spider species. Among the most recognizable are black and white spiders, which are found throughout the state. While the majority of Utah's spiders are harmless, there are a few venomous species that can pose a danger to humans through their bites. This article covers some of the most common black and white spiders found in Utah, how to identify them, which ones can bite, and what to do if you get bitten.

Orb Weavers

Orb weaver spiders are some of the most common black and white spiders in Utah. There are over 170 orb weaver species in North America. They get their name from the intricate, circular webs they construct for catching prey. Distinguished by their round, bulbous abdomens, orb weavers have a variety of patterns and colors but are frequently black and yellow or black and white.

Marbled Orb Weaver

The marbled orb weaver (Araneus marmoreus) is a large spider found throughout Utah. Females have a black and white striped or mottled pattern on their rotund abdomens. They build horizontal webs low in vegetation to catch flying insects. Their venom is considered harmless to humans.

Banded Garden Spider

Also called the banded orb weaver, this spider (Argiope trifasciata) has distinct white and black zebra striped legs. Females can grow over 1 inch long. Their webs are orb shaped with a signature zig-zag pattern through the center. They're commonly found in fields and gardens statewide. Their bites cause only mild pain to humans.

Black and Yellow Garden Spider

Named for their contrasting colors, these spiders (Argiope aurantia) are chunky, reaching over 1 inch in body length. They construct vertical orb webs in vegetation. A distinctive line of zig-zags decoration sits at the center. Though sizable, their venom is not considered medically significant.

Jumping Spiders

There are around 50 species of jumping spiders in Utah. Compared to other spiders, jumping spiders have excellent vision and can leap distances up to 50 times their size. They come in varied colors and patterns from solid black to striped black and white.

Bold Jumper

Easily identified by the 4 large spikes on its abdomen, the bold jumper (Phidippus audax) is the most commonly encountered jumping spider. They have a black body with a pattern of white, gray, orange, or red. The males are showy with large palps used to transfer sperm. Jumping spiders have a mild venom that rarely affects people.

Whitebanded Jumping Spider

As the name suggests, whitebanded jumpers have characteristic white bands around their legs and abdomen bordering a primarily black body. They have 4 pairs of eyes, with the front pair large and forward facing. Though small, around 1⁄4 inch long, they can bite in self-defense but are harmless to humans.

Wolf Spiders

Wolf spiders are named for their active hunting behaviors. Ranging from small to large in size, most wolf spiders in Utah have a mottled gray and black camouflage pattern on their bodies. They have good eyesight and do not use webs to capture prey.

Carolina Wolf Spider

Carolina wolf spiders (Hogna carolinensis) are big, around 1.5 inches long. Females are especially wooly with gray and black camouflaging stripes. Instead of building webs, they roam open habitats hunting insects and other invertebrates on foot. They occasionally find their way indoors. Though large in size, their venom causes only mild reactions in humans.

Rabid Wolf Spider

Named for their quick, erratic movements, rabid wolf spiders (Rabidosa rabida) have a black and white striped pattern on their abdomen. They do not spin webs. Females carry egg sacs attached to their spinnerets. They prefer to dwell in leaf litter in wooded areas but may wander into buildings. While they can bite in defense, symptoms are generally no worse than pain and redness.

Cobweb Spiders

Several kinds of cobweb spiders live in Utah and construct messy, tangled webs in dark corners of sheds, garages, and homes. Most are some variation of black, white, and yellow in color. They have a venom that's toxic to insects but harmless to people.

Barn Spider

Also called the common house spider, barn spiders (Parasteatoda tepidariorum) are small with a legspan up to 1⁄2 inch long. Their abdomens show variable patterns of white, brown, and black. Their messy webs catch flies, moths, mosquitoes, and other small insects. They're found worldwide around buildings. Their bite may cause mild pain.

Cellar Spider

Named for their favorite haunts in basements and cellars, these spiders (Pholcus phalangioides) are skinny and spindly with very long legs relative to their small bodies. They are pale gray to brown and hang upside down in flimsy, chaotic webs. Though startling if they land on you, these spiders are harmless to humans.

Venomous Black and White Spiders

Western Widow Spider

Closely related to the black widow, western widows (Latrodectus hesperus) are found throughout Utah. The female's rounded black abdomen has a red hourglass shape on the underside, which can range from vivid to faint. They build messy, tough webs. The neurotoxic venom can cause muscle cramps, abdominal pain, and sweating if bitten. Seek medical care if bitten.

Brown Recluse Spider

While not confirmed to live in Utah, brown recluse spiders may potentially exist in the southern portion of the state. Identifiable by the dark brown violin shape on their bodies, recluses are shy and bite only when threatened. The hemotoxic venom destroys cell membranes and can cause severe wounds. Seek emergency care if bitten.

What to Do if Bitten by a Spider

Most spider bites do not require any specific first aid or medical intervention, but here are some tips:

• Clean the bite area with mild soap and water.
• Apply a cool compress to relieve swelling and pain.
• Avoid scratching or picking at the bite as it heals.
• Watch for signs of infection like increasing redness or pus.
• Take over-the-counter pain medicine as needed for discomfort.
• See a doctor for bites by potentially venomous spiders like widows or recluses.

With sensible precautions, the beautiful and fascinating black and white spiders found throughout Utah can be safely appreciated!

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.