Spiders in New Mexico – A Guide to the Most Common Species

New Mexico is home to a fascinating diversity of spider species. From tiny jumping spiders to large tarantulas, these eight-legged creatures can be found across the state. While some spiders get a bad reputation, most are harmless and play an important role in controlling insect populations. This article will spotlight the most common spiders found in New Mexico and provide tips on identification.

The Most Common Spiders in New Mexico

1. Wolf Spiders

Wolf spiders are one of the most common spiders in New Mexico. With over 100 species found in North America there is great variation in size, coloration and habitat preference. However, some features allow for easy identification of these ground-dwelling hunters. Wolf spiders have a brown grey or black body with subtle markings on the abdomen. They have eight eyes arranged in three rows. Unlike other spiders, wolf spiders do not build a web to catch prey. Instead, they actively hunt on the ground, relying on excellent eyesight to track down insects and other small invertebrates.

Some of the most frequently encountered wolf spiders in New Mexico include the Carolina wolf spider (Hogna carolinensis), which can grow over 1 inch long and the desert wolf spider (Lycosa santrita) a smaller tan species found in arid regions of the state. Wolf spiders often take refuge in burrows during the day and may be seen wandering at night, especially in the summer when males go searching for mates. While their size and fast speed can be alarming, wolf spider bites are not medically significant for humans.

2. Jumping Spiders

With their large forward-facing eyes, jumping spiders are daytime hunters that rely on stealth and lightning-fast pounces to capture prey. New Mexico is home to many jumping spider species, but a few commonly encountered ones include the daring jumping spider (Phidippus audax), the Arizona jumping spider (Pelegrina arizonensis), and the Apache jumping spider (Phidippus apacheanus). Jumping spiders have a compact body about 1⁄4 to 1⁄2 inch long, with short, stout legs. They are often brightly colored, with iridescent mouthparts. Unlike other spiders, jumping spiders do not build a web for catching food. Instead, they will patiently stalk their prey before leaping great distances to attack. Jumping spiders may frequently be spotted on walls, fences or vegetation during the day. Despite their namesake ability, they are not considered dangerous to humans.

3. Orbweaver Spiders

Orbweaver spiders are responsible for building the stunning circular webs often found in gardens, fields and forests. There are hundreds of orbweaver species, but some commonly encountered ones in New Mexico include the black and yellow garden spider (Argiope aurantia), the banded garden spider (Argiope trifasciata), the marbled orbweaver (Araneus marmoreus), and the arrowhead orbweaver (Verrucosa arenata). Most orbweavers have elongated abdomens and brightly colored or patterned bodies that may help camouflage them at the center of their webs. The webs have a distinctive spiral shape and often a zigzagged stabilimentum running through the center. Orbweavers tend to be harmless to humans, although the spiky abdomen of the arrowhead orbweaver can inflict a minor sting if handled.

4. Cellar Spiders

Cellar spiders, also called daddy longlegs spiders, are very common around human dwellings in New Mexico. They build messy-looking webs in corners, windows, basements and other undisturbed locations. Two frequently encountered species are the longbodied cellar spider (Pholcus phalangioides) and the marbled cellar spider (Psilochorus pullulus). Both have small gray or brown bodies less than 1⁄2 inch long, with disproportionately long, spindly legs up to 3 inches long. Despite their name, cellar spiders do not have venom dangerous to people. In fact, they help control pest populations by feeding on insects like cockroaches, mosquitoes and clothes moths that also inhabit homes. While startling due to their erratic movements, cellar spiders pose no threat if left alone.

5. Cobweb Spiders

Cobweb spiders encompass several spider families that construct messy, sheet-like webs in undisturbed indoor and outdoor locations. In New Mexico, the most commonly encountered cobweb spiders are the southern black widow (Latrodectus mactans), the western black widow (Latrodectus hesperus), and the brown widow (Latrodectus geometricus). The adult female black widows are shiny black all over, except for a reddish hourglass marking on their round abdomens. Brown widows may have variable white, brown and black mottling. All widow spiders have neurotoxic venom that can cause severe reactions in some individuals. However, they are not aggressive and only bite when threatened. Bites can be avoided by carefully inspecting before sticking hands in dark places outside. Other cobweb spiders like the common house spider (Parasteatoda tepidariorum) are harmless.

6. Tarantulas

The deserts and grasslands of New Mexico are home to several species of large, hairy tarantulas. Some that may be encountered in the state include the Oklahoma brown tarantula (Aphonopelma hentzi), the Mexican redknee tarantula (Brachypelma hamorii), the Texas tan tarantula (Aphonopelma anax), and the Arizona blond tarantula (Aphonopelma chalcodes). They often emerge after rains or in summer to mate. Male tarantulas leave their burrows in search of females. Despite their intimidating size and appearance, most tarantulas native to the U.S. have relatively mild venom and are docile if left alone. Bites may occur from accidental contact or when spiders are handled roughly. While painful, the venom usually just causes localized swelling and irritation in humans.

7. Sac Spiders

One of the most common spiders found inside New Mexico homes is the yellow sac spider (Cheiracanthium inclusum). As their name suggests, yellow sac spiders construct silken retreats or sacs in out-of-the-way corners in basements, sheds and other locations. The spiders emerge at night to hunt for prey. They have pale yellow bodies about 1⁄4 inch long, with slightly darker yellow legs. Bites may occur if trapped between skin and clothing. The venom can produce minor skin irritation, pain and redness in humans. Controlling insects that yellow sac spiders feed on can discourage them from entering homes.

Safe Spider Practices

• Learn how to identify venomous spiders in your area, while remembering that most spiders are harmless.

• Avoid disturbing or handling spiders when possible. Never grab them barehanded.

• Keep structures and yards tidy, sealing cracks and crevices that provide entry points to spiders.

• Remove spider egg sacs and webs when found inside the home.

• Wear gloves, long sleeves and pants when working in crawl spaces or cleaning neglected areas.

• Shake out clothing, towels, bedding and shoes before use if they’ve been left on floors.

• Have severe spider bites treated promptly by a medical professional.

While spiders often get a bad reputation, most play an important role as predators of pest insects. Understanding the common species in New Mexico and practicing caution around venomous varieties can allow us to coexist with these fascinating creatures. A little knowledge and vigilance goes a long way in preventing spider surprises!