Common Spiders in Las Vegas

Spiders are a diverse and abundant group of animals in the desert surrounding Las Vegas. Recognizable by their eight legs, two body segments, and spinnerets (which produce silk for webs), spiders differ from other invertebrates as they lack wings and antennae. Most spiders are harmless, but a few can be harmful to humans. The Mojave Desert hosts a multitude of spider species, too many to list comprehensively. This article highlights some of the most common, conspicuous, and interesting species found in the area.

Common Spiders in Las Vegas

Crab Spiders (Infraorder Araneomorphae, Family Thomisidae) are known for their crab-like appearance, with two front legs that are longer than the others. They are typically small, measuring around 5-10 mm, and come in various colors, often matching the flowers or surfaces they inhabit. These spiders do not build webs but are ambush predators, relying on their camouflage to catch prey.

Desert Tarantula (Aphonopelma chalcodes) (Infraorder Mygalomorphae, Family Theraphosidae) is a large, hairy spider that can grow up to 10 cm in body length. They are typically brown or black and are often found in burrows in the ground. Despite their intimidating appearance, they are generally harmless to humans and are known for their gentle nature.

Funnel-Weaver Spiders (Infraorder Araneomorphae, Family Agelenidae) create dense, funnel-shaped webs in vegetation or under rocks. These medium-sized spiders are usually brown or gray, with a body length of about 1-2 cm. They are fast runners and use their webs to capture prey, waiting at the narrow end of the funnel to ambush insects that become ensnared.

Garden Spiders (Infraorder Araneomorphae, Family Araneidae) are orb-weavers known for their large, intricate webs. They vary in size but are generally around 1-2 cm in body length. Their coloration can range from bright yellows and reds to more subdued browns and blacks. Garden spiders are commonly found in gardens and forests, where they help control insect populations.

Mojave Tarantula (Aphonopelma mojave) (Infraorder Mygalomorphae, Family Theraphosidae) is another large tarantula species native to the Mojave Desert. Similar in size to the Desert Tarantula, they can reach up to 10 cm in body length. These spiders are usually darker in color, often a deep brown or black, and are also ground-dwellers, preferring burrows for protection and hunting.

Trashline Orbweavers (Cyclosa spp.) (Infraorder Araneomorphae, Family Araneidae) are small orb-weaving spiders, typically around 5-10 mm in length. They are known for the unique feature of placing debris and prey remnants in a line across their webs, which serves as camouflage. These spiders are usually brown or gray and can be found in gardens, forests, and grasslands.

Violin Spiders (Recluse Spiders) (Infraorder Araneomorphae, Family Sicariidae) are medium-sized spiders known for the violin-shaped marking on their back. They range in size from 6-20 mm and are usually brown. These spiders are notorious for their venomous bite, which can cause serious necrotic lesions. They prefer dark, undisturbed areas such as woodpiles, basements, and closets.

Widow Spiders (Black Widow) (Infraorder Araneomorphae, Family Theridiidae) are easily recognized by the shiny black body and red hourglass marking on the underside of females. These spiders are about 1-1.5 cm in body length and are known for their potent venom. They are typically found in dark, sheltered areas such as garages, sheds, and woodpiles.

Wolf Spiders (Infraorder Araneomorphae, Family Lycosidae) are robust, fast-moving spiders that do not build webs. They are medium to large in size, ranging from 1-3 cm in body length, and are usually brown or gray with distinctive markings. These spiders are ground-dwellers and can often be seen hunting at night or during the day.

Las Vegas is home to many more spider species, each playing a crucial role in the ecosystem by controlling insect populations. While encountering a spider may be unsettling, understanding their behaviors and characteristics can help appreciate their importance and reduce unwarranted fear.