There are over 40 different types of spiders in Colorado. These fascinating creatures differ significantly in appearance and behavior. While some have stunning patterns that are pleasing to look at, others have dull features.
Regardless of the species, all the spiders in Colorado play vital roles in the ecosystem. These arachnids feed primarily on arthropods, helping check the population of these organisms. For example, spiders in your garden can serve as a natural control for pesky pests.
Many spiders live outdoors in forests, grasslands, and bushes. Others prefer to stay indoors, especially during cold seasons. They prefer damp places that provide adequate moisture and are usually kept away from humans.
Female spiders usually display strong maternal instincts and tend to outlive males. Most female spiders guard their eggs fiercely until they hatch, caring for spiderlings till they learn to fend for themselves.
This guide will teach you everything you need to know about the types of spiders in Colorado. You’ll learn how to identify common spiders in the state along with fun facts about them.
Table of Contents
- Spiders in Colorado
- Western Black Widow
- Eastern Parson Spider
- Texas Brown Tarantula
- Long-bodied Cellar Spider
- Apache Jumping Spider
- Bold Jumping Spider
- Banded Garden Spider
- Northern Yellow Sac Spider
- Woodlouse Spider
- Gray Cross Spider
- Running Crab Spider
- Striped Fishing Spider
- Brown Recluse
- Triangulate Cobweb Spider
- False Black Widow
- Hobo Spider
- Western Lynx Spider
- Red-Spotted Ant Mimic Sac Spider
- Goldenrod Crab Spider
- Common Candy-striped Spider
- Zebra Spider
- Cat-Faced Orb-weaver
- Trapdoor Spider
- European Garden Spider
- Black And Yellow Garden Spider
- Furrow Spider
- American Grass Spiders
- Spitting Spider
- Mouse Spider
- Common House Spider
- Bowl And Doily Spider
- Barn Funnel Weaver
- Spotted Orb-weaver
- Western Spotted Orb-weaver
- Golden Silk Orb-weaver
- Carolina Wolf Spider
- Grand Canyon Black Tarantula
- Asiatic Wall Jumping Spider
- California Flattened Jumping Spider
- Peppered Jumping Spider
- FAQ
- Conclusion
Spiders in Colorado
1. Western Black Widow
- Experience Level: Advanced
- Family: Theridiidae
- Scientific Name: Latrodectus hesperus
- Other Names: Black Widow, Widow Spider
- Adult Size: Up to 0.5 inches
- Lifespan: 1 to 3 years
- Average Price Range: N/A
Black widows are famed for their potent venoms, which, in sufficient doses, can kill a person. Colorado is home to the western black widow. This species is one of three highly venomous black widow species in North America.
Despite the toxicity of this spider’s venom, death from a black widow bite is rare in the US. Prompt treatment contributes to this low mortality. In addition, many black widows don’t inject enough venom to cause death in healthy adults.
Still, the venom of this species is neurotoxic regardless of the volume the spider injects. It can lead to debilitating health consequences like difficulty breathing. See a doctor immediately if you think a black widow has bitten you.
You can identify western black widows by their glossy pitch-black bodies and the unbroken reddish-orange hourglass shape on their bellies. This description is of adult females.
Males are smaller than females and relatively unimportant. Compared to females, they are less venomous and have short lifespans that seem dedicated to mating with females.
You can identify a male western black widow by the orange markings running down the middle of its abdomen and the short, white vertical markings on its sides. Its cephalothorax is black, but the abdomen is brownish. The legs are alternating black and translucent brown bands.
Adult female black widows often consume males after mating, hence the name black widow. However, they are not aggressive towards people.
A western black widow will only bite you in self-defense when it feels threatened. For example, this may happen when you mistakenly press your skin against it, sit on it, or wear clothing harboring it.
This fascinating spider is a carnivorous arachnid that spins tangled webs to trap prey. It feeds primarily on arthropods like small insects and other spiders.
2. Eastern Parson Spider
- Experience Level: Beginner to Intermediate
- Family: Gnaphosidae
- Scientific Name: Herpyllus ecclesiasticus
- Other Names: Parson Spider, Ground Spider, Stealthy Ground Spider
- Adult Size: 0.3 to 0.8 inches
- Lifespan: 1 to 2 years
- Average Price Range: N/A
The eastern parson spider gets its name from the white or grayish pattern on its back. This pattern resembles the neckband clergymen (parsons) wore in the past.
In addition to this pattern, you can identify the eastern parson spider by its hairy dark brown to black body. This arachnid also has two pikes at the end of its abdomen and reddish-brown legs.
The eastern parson spider is nocturnal, and it spends the day resting out of sight. You can find it in woodlands under rocks, rotting logs, or other debris. It also lives in people’s homes or around buildings during cold months.
Unlike most spiders, this species is fierce. It does not attack unprovoked, but it doesn’t hesitate to inflict a painful bite when threatened or backed into a corner. Fortunately, this bite is harmless to most people. But allergic people may experience slightly stronger reactions.
As you might have guessed, this spider is a hunter that doesn’t rely on webs to trap prey. It feeds primarily on arthropods, and it prefers to track and overpower them with its venom. Insects make up the bulk of this arachnid’s diet.
The eastern parson only uses its silk gland to spin webs for its offspring. After laying eggs, this arachnid weaves a protective cocoon around them. Females protect their eggs for as long as possible before they hatch.
This species was originally native to the eastern parts of the US. However, it has spread to all the states, becoming one of the established spiders in Colorado. It appears to be most active between March and June.
3. Texas Brown Tarantula
- Experience Level: Beginner to Intermediate
- Family: Theraphosidae
- Scientific Name: Aphonopelma hentzi
- Other Names: Ordinary Tarantula, Missouri Tarantula, Oklahoma Brown Tarantula
- Adult Size: Up to 2 inches
- Lifespan: 10 to 40 years
- Average Price Range: N/A
The Texas brown tarantula is a giant spider found in Colorado. Due to its intimidating size, many people assume the species inflicts deadly bites or is especially dangerous to handle. But this assumption isn’t correct.
Yes, the Texas brown tarantula inflicts painful bites. But its venom is harmless to humans. If you’re allergic to spiders or spider venom, you may experience stronger reactions.
Texas brown tarantulas are nonaggressive spiders. While they may stand on their hind legs to seem larger when cornered, they typically run from humans and other predators when threatened.
You can find these spiders in Colorado under debris, rocks, or rotting forest logs. These spiders also often live in underground tunnels or burrows other animals have abandoned. Texas brown tarantulas can also build burrows for themselves if need be.
While these spiders like to stay outdoors in hidden places, they sometimes wander into people’s homes. Sadly, these arachnids don’t do well in cold temperatures. So home intrusion is common during cold months.
Female tarantulas can survive for decades, with some living as long as 40 years. This longevity contrasts with males, who usually die about a year after maturity.
You can identify these spiders in Colorado by their large and hairy bodies. They are usually two-toned with mostly dark brown bodies and slightly reddish carapaces.
Texas brown tarantulas are carnivorous, often feeding on insects and other small arthropods. They are efficient predators, injecting prey with venom before consuming them. A single tarantula can catch dozens of insects and small spiders in a day.
4. Long-bodied Cellar Spider
- Experience Level: Beginner to Intermediate
- Family: Pholcidae
- Scientific Name: Pholcus phalangioides
- Other Names: Cellar Spider, Daddy Longlegs, Granddaddy Longlegs, Daddy Longlegger, Carpenter Spider, Skull Spider, House Spider, Vibrating Spider
- Adult Size: Up to 0.4 inches
- Lifespan: 2 years
- Average Price Range: N/A
Cellar spiders are arguably one of the most common spiders in Colorado homes. They are called cellar spiders because you’ll often find them in home cellars. However, these arachnids roam around the house without restricting themselves to cellars.
Also called daddy longlegs, the cellar spider has a bulbous abdomen and 8 thin, long legs. While their bodies are tiny, their legs are often up to 6 times longer than their bodies. This arachnid’s long legs are why many appear larger than they are.
There are several stories about this species. Maybe you’ve heard that daddy longlegs have the deadliest venom of all spiders, only that their fangs can’t penetrate human skin deeply enough to deliver the venom. Fortunately, this is an unfounded myth.
Cellar spiders aren’t particularly venomous. Their bite is not medically significant, so it can’t harm you. You’ll only experience mild itching where the spider bit you at most. Serious allergic reactions are rare. But check with your doctor if you have prolonged symptoms.
Cellar spiders are nonaggressive, and they typically run from humans and predators when threatened. Instead, they reserve their aggressiveness for prey, such as insects and other arthropods.
These arachnids have poor eyesight, but they are good at detecting vibratory signals. As a result, they rely on the webs they spin to trap prey. When an insect gets tangled in these webs, they receive a vibratory signal and quickly gets to consume the prey.
Although you’ll find many of these spiders in Colorado, they are originally from Europe. Over the years, they have established themselves in North America.
Interestingly, cellar spiders weren’t called daddy longlegs until recently. The original daddy longlegs is a spider-like arachnid (harvestmen) from the order Opiliones. The name stuck with cellar spiders because people usually mistook them for the true daddy longlegs.
5. Apache Jumping Spider
- Experience Level: Beginner to Intermediate
- Family: Salticidae
- Scientific Name: Phidippus apacheanus
- Other Names: Apache Jumper
- Adult Size: 0.2 to 0.87 inches
- Lifespan: 1 year
- Average Price Range: N/A
The apache jumping spider is a hunter species. Like other hunting spiders, it doesn’t spin webs to trap prey. Instead, it stalks them before attacking. It then grabs and injects its prey with venom before feasting on them.
Jumping spiders like this species can leap to heights many times their height. That’s why they are called jumping spiders. The apache jumping spider spins a silk thread to use as a dragline when jumping.
The silk thread also acts as a safety line protecting it from injury when a daring jump fails. Jumping spiders typically anchor this dragline to the surface from which they leap off. Besides spinning draglines, these arachnids also spin nests for themselves.
You can identify the apache jumping spider by its hairy body and spiny abdomen. The spider is primarily jet-black, with a sometimes yellow or reddish abdomen and cephalothorax. In addition, you may notice orange blotches on its legs or chelicerae.
The apache jumping spider is not a threatening species. Bites are rare, and the species’ venom is not medically significant to humans. Its bite might hurt though. But if you’re allergic to spider venom, you might experience different symptoms.
As is typical of most spiders, female apache jumping spiders are larger than males.
6. Bold Jumping Spider
- Experience Level: Beginner to Intermediate
- Family: Salticidae
- Scientific Name: Phidippus audax
- Other Names: Daring Jumping Spider, White-spotted Jumper, Bold Jumper
- Adult Size: 0.25 to 0.75 inches
- Lifespan: 1 year
- Average Price Range: N/A
The bold jumper is another type of jumping spider in Colorado. It’s called a bold jumper because it can make pretty daring high jumps, up to 50 times its body size. Few jumping spiders can match this feat.
This arachnid has short, strong back legs that help it make such high jumps. It adjusts the pressure in these legs when making incredible leaps. Like most spider species, female bold jumpers are larger than males.
You can identify the bold jumper by the whitish spots on its black, hairy body. There are 3 spots on the arachnid’s abdomen. These spots fade from yellowish to white as the spider matures from juvenile to adult.
The bold jumper can be hard to tell apart from similar-looking jumping spiders. But observing the fangs of this spider can help. With bold jumpers, the fangs are usually greenish.
Bold jumping spiders are predators that prefer chasing prey instead of waiting for them to wander into webs. They hunt down prey and then use their venom to immobilize their targets. Insects like ants and beetles are common targets.
The venom of this species is great at paralyzing prey, but it is harmless to humans. The spider itself is typically unaggressive towards people. However, it stings when threatened with no escape route. Allergic people may have slightly more discomforting symptoms than non-allergic people.
The bold jumping spider only spins silk to create draglines to support it while jumping. It may also spin a nest for itself.
7. Banded Garden Spider
- Experience Level: Beginner to Intermediate
- Family: Araneidae
- Scientific Name: Argiope trifasciata
- Other Names: Banded Argiope
- Adult Size: 0.59 to 0.98 inches
- Lifespan: 1 year
- Average Price Range: N/A
The banded garden spider has bands all over its body. The legs of this arachnid have alternating dark brown and yellowish-brown rings, except near the cephalothorax. Near the cephalothorax, this arachnid’s legs are a solid yellowish-brown.
The carapace of this species has several silvery hairs, and the abdomen is ovoid. The abdomen has several bands running transversely across it. In addition, the underside has a large, bilaterally symmetrical pattern in the middle.
Banded garden spiders are orb-weaving spiders that spin large, concentric webs. These sticky webs are strong and effective at catching large prey like wasps and grasshoppers. When these webs trap prey, the spiders rush to immobilize and then consume or wrap the prey in silk.
You can find banded garden spiders in areas abundant in shrubs or tall grasses. These arachnids often stay in the center of their webs, waiting for prey. Since they are diurnal, you’re likely to spot them during the day.
If you disturb this arachnid, it will drop from its web’s center and try to escape you. It is nonaggressive, so bites are rare. Even when bites occur, the venom isn’t potent enough to cause you any real harm.
As is typical of spiders, female banded garden spiders are much larger than males. The abdomen is also bigger than the cephalothorax in most banded garden spiders, regardless of sex.
8. Northern Yellow Sac Spider
- Experience Level: Beginner to Intermediate
- Family: Eutichuridae
- Scientific Name: Cheiracanthium mildei
- Other Names: Long-legged Sac Spider
- Adult Size: Up to 0.4 inches
- Lifespan: 1 year
- Average Price Range: N/A
You can identify the northern yellow sac spider by its greenish-yellow to yellowish-tan body. The body has many short hairs and no pattern besides a slightly dark abdominal stripe. In addition, this arachnid’s legs are typically darker than the body, and the mouthparts sometimes appear brownish.
You may encounter northern yellow sac spiders in Colorado homes and offices. These arachnids are nocturnal, so you’ll likely only spot them near wall corners and windowsills at night. Outdoors, you may find them hiding under leaves and debris.
Northern yellow sac spiders do not spin webs to trap prey. Instead, these hunters actively stalk prey before seizing them. Afterward, these arachnids inject their prey with paralyzing venom and feast.
Northern yellow sac spiders spin silk, but only to create protective cocoons for their eggs.
Like most spiders, this species has 8 eyes. However, all the eyes of this spider are of equal size. This feature makes it different from most hunter spiders, which often have a pair of enlarged eyes. The northern yellow sac spider’s eyes are arranged in two rows with two eye pairs each.
Northern yellow sac spiders in Colorado often bite people. People also often mistake them for brown recluses. While they are nowhere as dangerous as brown recluses, these arachnids inflict painful and venomous bites.
The venom of a northern yellow sac spider is not potent enough to kill you or cause lasting problems. But it can cause unpleasant skin irritation and even result in swelling and tiny sores. So be careful around this spider.
9. Woodlouse Spider
- Experience Level: Beginner to Intermediate
- Family: Dysderidae
- Scientific Name: Dysdera crocata
- Other Names: Woodlouse Hunter, Slater Spider, Roly-Poly Hunter, Pillbug Hunter, Long-Fanged Ground Spider, Cell Spider, Sowbug Killer, Sowbug Hunter, Orange Spider
- Adult Size: 0.35 to 0.59 inches
- Lifespan: 3 to 4 years
- Average Price Range: N/A
Woodlouse spiders hardly look like woodlice. Instead, this fascinating species gets nearly all its names from its dietary choices. The woodlouse spider spends plenty of time around woodlice or slaters and feeds primarily on these crustaceans.
You can identify this arachnid by its blood-red or brownish-orange cephalothorax and yellowish-brown abdomen. Its legs are more reddish-brown, especially towards the extremities. Sightings are most common in April and May.
Woodlouse spiders favor damp habitats and avoid staying in open places. So you may find them under rotting logs, rocks, and debris. When temperatures rise, these spiders often enter people’s houses and hide in wall crevices. They usually spin webs over these crevices for protection.
These long-fanged arachnids don’t spin webs to trap prey. Instead, they hunt prey actively and sting them into submission. After paralyzing their prey, the spiders immediately get to work feasting. Woodlice are their primary targets, but these spiders also eat other arthropods.
The venom of the woodlouse spider is harmless to humans. So you don’t need to worry about the spider biting you. If you’re allergic to spider venom, you may experience slightly more serious reactions. But this spider’s bite typically never requires medical attention.
Female woodlouse spiders spin silk cocoons to protect their eggs, which may be about 70 per sac. Unlike most spiders in Colorado, woodlouse spiders have only 6 eyes.
10. Gray Cross Spider
- Experience Level: Beginner to Intermediate
- Family: Araneidae
- Scientific Name: Larinioides sericatus
- Other Names: Bridge Orb-Weaver
- Adult Size: 0.31 to 0.55 inches
- Lifespan: 1 year
- Average Price Range: N/A
The bridge orb-weaver usually lives close to buildings and bridges above light-reflecting water. Although bridge orb-weavers sometimes flock to light sources in numbers, they aren’t social creatures.
In fact, these spiders usually exhibit territorial aggressiveness towards other spiders of their species.
Bridge orb-weavers are carnivores, feeding primarily on insects and other arthropods. Light sources attract prey like insects, so proximity to food may be why these spiders congregate around light sources.
Unlike other orb-weavers, which spin elliptical webs, this species builds circular webs that change in size as it ages. It spins these sticky webs near light sources and uses them to trap prey.
Bridge orb-weavers have strong fangs they use when attacking prey. These fangs can also pierce human skin, but this species’ venom isn’t toxic enough to harm a person. However, you may experience longer skin irritation after a bridge orb-weaver bites you if you’re allergic to spider venom.
You can identify this species by the alternating light and dark rings on its legs. In addition, this orb-weaver has dark markings on its abdomen and several short whitish hairs on its body.
Adult male bridge orb-weavers are larger than females, but they weigh much less. When food is scarce, females may consume male bridge orb-weavers. But this doesn’t happen frequently.
11. Running Crab Spider
- Experience Level: Beginner to Intermediate
- Family: Philodromidae
- Scientific Name: Philodromus spp.
- Other Names: Crab Spiders
- Adult Size: Up to 0.75 inches
- Lifespan: 1 year
- Average Price Range: N/A
Running crab spiders are swift runners and excellent predators. You may have difficulty catching these spiders because of how fast they travel. Unlike most web-spinning spiders, these arachnids do not rely on webs to catch prey.
These hunter spiders enjoy ambushing prey and injecting them with venom. Insects and other small arthropods make up the bulk of their diet. Their cryptic coloration is useful when hunting because insects usually only spot them when it’s too late.
Running crab spiders have flat, mottled brown bodies that create excellent camouflages. These spiders have large front legs, but the second pair is the largest they have. Running crab spiders are shaped like crabs, hence the name.
You can find running crab spiders in humid places abundant in vegetation. They typically stay in coastal areas near streams or rivers. In addition, you may also encounter these spiders in your home.
Don’t panic when you come across running crab spiders in your space. They don’t attack humans unprovoked, and their venom is harmless. However, bites can be painful and result in redness and swelling. In extreme cases, you may experience nausea or vomiting if you’re allergic.
12. Striped Fishing Spider
- Experience Level: Beginner to Intermediate
- Family: Pisauridae
- Scientific Name: Dolomedes scriptus
- Other Names: Fishing Spider
- Adult Size: Less than 1 inch
- Lifespan: 1 year
- Average Price Range: N/A
Striped fishing spiders have adaptations for walking on water. Their feet are covered in water-repellent hair. So you will often find them around water sources, especially fast streams. In addition, you may also find them in coastal forests and woodlands.
This species is a hunter that doesn’t build webs to trap prey. It feeds primarily on crustaceans and aquatic insects it finds by streams. But it also eats other types of arthropods. This opportunistic spider also feeds on non-arthropod prey it can overpower, such as small fish.
The striped fishing spider usually has a tan, brown, or grayish body. It typically has a whitish or tan brown stripe running along the body on each side. In addition, the abdomen bears several alternating white and black W-shaped lines.
The carapace of the striped fishing spider bears a stripe that runs along its middle. The legs of this species are light with several dark markings.
Fishing spiders are not a threat to humans. While their venom can paralyze prey, it is harmless to healthy people. You might experience pain or lingering symptoms if you’re allergic to spider venom. But you won’t need medical attention.
Fishing spiders are often mistaken for wolf spiders. That’s because both species share a close resemblance. One useful way to differentiate them is to observe their nursing behavior. Fishing spiders carry their egg cocoons in their chelicerae. In contrast, wolf spiders carry eggs in spinnerets fixed to their backs.
13. Brown Recluse
- Experience Level: Advanced
- Family: Sicariidae
- Scientific Name: Loxosceles reclusa
- Other Names: Violin Spider, Brown Fiddler, Fiddleback
- Adult Size: 0.24 to 0.8 inches
- Lifespan: 2 to 4 years
- Average Price Range: N/A
The brown recluse is uncommon in Colorado. While it is not an established species in Colorado, you may still encounter it seasonally in some parts of the state. It is a venomous spider that inflicts debilitating bites, often requiring medical attention.
The venom of the brown recluse has cytotoxic properties, causing cells around the bite to die. This effect can result in large ulcers that deepen and become harder to treat. If you suspect this spider has bitten you, see a doctor immediately.
The brown recluse is tan to dark brown. This arachnid’s most defining feature is a violin-shaped pattern on its carapace. Unlike most spiders, it has 6 eyes instead of 8. These eyes are arranged in 3 pairs from which the violin strings extend backward.
The fangs and mouthparts of some brown recluses are reddish-brown and covered with hair. The legs are also hairy, but they lack long spines.
Despite this spider’s reputation as a highly venomous species, it is not aggressive. Brown recluses often run when threatened or they play dead by curling into themselves. Many also simply spin around the same spot until the threat leaves.
Bites typically occur when you mistakenly press your skin against the spider, causing it to sting you in self-defense. On most days, this arachnid only uses its venom to immobilize prey before eating. Flies, mosquitoes, and crickets are its common prey.
14. Triangulate Cobweb Spider
- Experience Level: Beginner to Intermediate
- Family: Theridiidae
- Scientific Name: Steatoda triangulosa
- Other Names: Triangulate Combfoot, Triangulate Bug Spider
- Adult Size: Up to 0.25 inches
- Lifespan: 1 to 3 years
- Average Price Range: N/A
The triangulate cobweb spider belongs to the same family as black widows. So the webs it spins to trap prey are disorganized and non-sticky. But the tangles effectively trap the prey’s legs long enough for the spider to sting them, despite not being sticky.
Insects like flies are common prey for this arachnid. It also consumes other venomous spiders like the brown recluse. But unlike black widows, the venom of the triangulate cobweb spider is not toxic to humans.
You can identify this species by the brown triangulate markings running down the middle of its black abdomen. This two-toned spider also has legs that are alternating brown and black or dark brown bands.
As is typical of most spider species, female triangulate cobweb spiders are larger than males. They also live longer and are the most commonly encountered sex.
15. False Black Widow
- Experience Level: Beginner to Intermediate
- Family: Theridiidae
- Scientific Name: Steatoda grossa
- Other Names: False Widow, Brown House Spider, Dark Comb-Footed Spider, Cupboard Spider
- Adult Size: 0.25 to 0.4 inches
- Lifespan: 1 to 6 years
- Average Price Range: N/A
False black widows resemble true black widows in terms of shape and color. As a result, many people mistake these spiders for true black widows. This resemblance is likely because they belong to the same family as true widows.
You can easily tell both species apart by examining the undersides of their abdomens. False black widows lack the reddish hourglass marking that identifies true black widows. In addition, black variations of false black widows are more purplish than black.
Some false black widows have brown abdomens, which gives away their identity. These arachnids are covered in short hair and bear light markings on their abdomens. Females have bulbous abdomens, while males have smaller and elongated abdomens.
Unlike true black widows, a false black widow’s venom is not medically important. It is effective at paralyzing prey, but it is not strong enough to damage your system. At most, you’ll experience pain or fever that lingers for a few days but no long-term damage.
False black widows spin webs to trap prey. These webs are disorganized and not sticky, but they successfully trap prey. When prey gets caught in their web, false black widow spiders sting it into submission and consume it.
16. Hobo Spider
- Experience Level: Beginner to Intermediate
- Family: Agelenidae
- Scientific Name: Eratigena agrestis
- Other Names: Funnel Weavers, Funnel Web Spiders, Sheet Web Spiders, Ground Spiders
- Adult Size: Up to 0.6 inches
- Lifespan: 1 year
- Average Price Range: N/A
Hobo spiders are difficult to differentiate from many wolf, fishing, and grass spiders in Colorado. This species has chevron or v-shaped patterns pointing towards the head, which is also seen in many fishing spiders.
Unlike wolf and grass spiders, the hobo spider does not have two dark lines behind its eyes that extend to its abdomen. It also lacks the colored bands at the joint between the legs and the body seen in some wolf spiders.
Despite these differences, you often need to hold a hobo spider up close under a magnifying glass to correctly identify it. This requirement is partly because hobo spiders vary greatly in appearance, and even experienced people often get confused.
Hobo spiders were once listed as medically significant. However, evidence collected over the years shows that their venom isn’t harmful to humans. You’ll experience pain and localized swelling when this spider bites you, but the venom doesn’t cause any serious damage.
Hobo spiders are funnel weavers that build funnel-shaped webs to trap prey. While these webs are not sticky, insects and other arthropods often get stuck when they wander into them. Their struggle sends vibratory signals to the hobo spider, which then swoops in to paralyze them with venom.
17. Western Lynx Spider
- Experience Level: Beginner to Intermediate
- Family: Oxyopidae
- Scientific Name: Oxyopes scalaris
- Other Names: Lynx Spider, Foliage Hunter, Grass Lynx Spider
- Adult Size: 0.23 to 0.38 inches
- Lifespan: 1 year
- Average Price Range: N/A
The western lynx spider is a two-toned spider. The body is typically dark brown with several patches of whitish to light brown bristles. In addition, you’ll notice many spaced-out long spines on the legs and fangs of this arachnid.
This species has a small carapace and a relatively long, wide abdomen. Besides the last pair, all the legs are white to tan near the body. The remaining parts of the legs are mostly dark with light bristles.
It is a swift runner capable of impressive leaps. You’re most likely to encounter this arachnid among plants and bushes or on trees, waiting for insects to ambush and eat.
The western lynx spider is a diurnal hunting spider with excellent vision. Unlike most spiders in Colorado, this species does not rely on webs to trap prey. It enjoys the chase and often hunts down insects to inject with venom before eating.
Fortunately, the venom of this spider is not toxic to humans. The spider typically avoids contact with humans. However, bites happen sometimes. You’re unlikely to experience pronounced symptoms if you aren’t allergic to spider venom.
18. Red-Spotted Ant Mimic Sac Spider
- Experience Level: Beginner to Intermediate
- Family: Corinnidae
- Scientific Name: Castianeira descripta
- Other Names: Ant Mimic Spider
- Adult Size: 0.2 to 0.4 inches
- Lifespan: 1 year
- Average Price Range: N/A
The red-spotted ant mimic spider looks like an ant. This is partly due to its natural ant-like shape and color. At first glance, its shiny black body and bulbous, red-spotted abdomen closely resemble those of a true ant.
But this species’ resemblance to ants is also partly intentional. It often walks with its two front legs raised up to mimic a six-legged ant with antennae. The major reason for this mimicry is to get close to real ants, which make up the bulk of its diet.
Like other hunter species, the red-spotted ant mimic spider doesn’t rely on webs to catch prey. Instead, it actively hunts them down and injects them with venom before consuming them. Ants are its main course, but it also feeds on other arthropods.
Inexperienced people may mistake red-spotted ant mimic spiders for black widows. This mistake is because the spider’s red abdominal markings are sometimes misidentified as the red hourglass on black widows.
Fortunately, the red-spotted ant mimic spider isn’t as venomous as black widows. Bites are rare, but you’ll experience pain and localized swelling if it bites you. This species only bites when it is threatened or cornered.
Red-spotted ant-mimic spiders only spin silk to create protective cocoons for their eggs. They also sometimes spin nests for themselves. Until they hatch, females fiercely protect their eggs from potential threats.
19. Goldenrod Crab Spider
- Experience Level: Beginner to Intermediate
- Family: Thomisidae
- Scientific Name: Misumena vatia
- Other Names: Smooth Flower Crab Spider
- Adult Size: 0.125 to 0.75 inches
- Lifespan: 1 year
- Average Price Range: N/A
The goldenrod spider can change its color to match its surroundings. You’ll often find goldenrod spiders in Colorado prairies and flower fields. These arachnids inhabit the flowerheads of white or yellow flowers.
The body of this species is either white or yellow, depending on the color of its flowerhead. Females typically have whitish abdomens with a broad reddish-orange band running down each side. In addition, their first pair of legs have 3 spines.
Female goldenrod spiders have whitish legs and whitish or yellow carapaces. Both sides of this species’ carapace have a black or dark brown band. In contrast, males have greenish-yellow carapaces and partially purple legs.
Goldenrod spiders are hunters that don’t rely on webs to catch prey. They take advantage of their cryptic coloration and ambush insects that come to pollinate flowers. While switching their color to match surrounding flowers often takes time, it helps conceal them from unsuspecting prey.
These arachnids seize prey with their front legs before stinging and feasting on them. Their venom effectively paralyzes prey but is harmless to humans. You’ll feel pain if the fangs pierce your skin, but no more.
20. Common Candy-striped Spider
- Experience Level: Beginner to Intermediate
- Family: Theridiidae
- Scientific Name: Enoplognatha ovata
- Other Names: Candy-striped Spider Complex
- Adult Size: 0.25 inches
- Lifespan: 1 year
- Average Price Range: N/A
The common candy-striped spider was introduced to North America from Europe. It belongs to the same family as black widows, but it is far less venomous. This translucent greenish-yellow spider has two reddish stripes on its cream-colored abdomen.
Candy-striped spiders come in 3 distinct color variations or morphs. The redimita morph has two red to brownish abdominal stripes with a light-colored middle as described above. In many, this light middle has tiny black spots or stripes.
The two reddish stripes are swapped for black spots in the lineata morph. The ovata morph closely lacks a light-colored middle. Instead, the two reddish stripes merge into one wide band. Of all three, the redimita morph is the most widespread in North America.
Female common candy-striped spiders have large, round abdomens. In contrast, the abdomen is more oblong than round in males. Males also generally have smaller abdomens and bodies compared to females.
Candy-striped spiders rely on webs to trap prey. They feed majorly on small insects and spin tangled non-sticky webs to trap them. When their web traps an insect, they inject it with venom before consuming it.
This species’ venom is harmless to humans. In addition, you’ll rarely find the common candy-striped spider within residential buildings. So the chances of being bitten are slim.
21. Zebra Jumping Spider
- Experience Level: Beginner to Intermediate
- Family: Salticidae
- Scientific Name: Salticus scenicus
- Other Names: Zebra Jumper, Zebra Spider
- Adult Size: Up to 0.25 inches
- Lifespan: 1 year
- Average Price Range: N/A
You can identify a zebra spider by the white and black zebra-like patterns all over its body. Black is the base color, while the white stripes are regions covered with tiny white hairs. Sometimes, the ground color is brown instead of black.
The zebra spider is a jumping spider that can leap to impressive heights. Like other jumping spiders, it has strong back legs that aid its jumps. It also spins silk draglines to help it when attempting daring jumps.
Like most spiders, this species has 8 eyes and an abdomen larger than its cephalothorax. They are carnivorous arachnids that feed on insects and other small arthropods. Insects like ants and beetles are frequent prey.
Unlike most spiders, the zebra spider does not use spin webs to catch prey. It is a hunter spider, so it prefers chasing prey and immobilizing them with venom.
The zebra spider rarely bites people. Even if it did, this arachnid’s venom is not medically significant to humans. At most, you’ll experience localized pain but there’s no serious health concern.
Besides spinning draglines for transport, these arachnids spin silk sacs to protect their eggs. Females guard their eggs for as long as possible before they hatch into spiderlings.
22. Cat-Faced Orb-weaver
- Experience Level: Beginner to Intermediate
- Family: Araneidae
- Scientific Name: Araneus gemmoides
- Other Names: Jewel Spider, Cat-faced Spider
- Adult Size: 0.2 to 1 inches
- Lifespan: 1 year
- Average Price Range: N/A
The cat-faced orb-weaver is so named because it resembles a cat’s face when you look at it head-on. When viewed from above, its massive abdomen looks like a diamond or jewel. That’s because the abdomen has several sharp angles resembling diamond edges.
This arachnid comes in several colors, from whitish to orange or dark brown. Its body is also covered with whitish spines, which contribute to its cat-like appearance.
As is typical of orb-weavers, this species spins webs to trap prey. It feeds mostly on insects, although it eats other arthropods too. It detects vibratory signals when its web traps prey and rushes there to inject the prey with venom.
The cat-faced orb-weaver is harmless to humans. Bites are uncommon because the species is nonaggressive, often running when threatened. If you get bitten, expect only mild symptoms like pain and reddening at most. The venom doesn’t cause any damage.
23. Trapdoor Spider
- Experience Level: Beginner to Intermediate
- Family: Halonoproctidae
- Scientific Name: Eucteniza
- Other Names: Mygalomorph Spider, Southwestern Trapdoor Spider
- Adult Size: Up to 1.6 inches
- Lifespan: 5 to 20 years
- Average Price Range: N/A
Trapdoor spiders are not the only spiders in Colorado that live in tunnels. However, they distinguish themselves by covering their burrows with real trapdoors. These trapdoors are made of silk and debris, and they have proper hinges.
You can identify this species by its dark brown to reddish-brown body. The cephalothorax and legs are shiny and uniformly colored. While the cephalothorax is disc-shaped, the abdomen is somewhat bulbous and hairy but roughly equal in size.
The trapdoor spider is a hunter species. So it doesn’t trap prey by spinning webs. Instead, it hunts them down and seizes them with its large fangs. Afterward, it injects them with venom and eats them.
The venom of this arachnid is not medically significant, so it can’t harm you. These spiders are nonaggressive and tend to run when approached. If one stings you, expect nothing beyond mild pain and irritation.
24. European Garden Spider
- Experience Level: Beginner to Intermediate
- Family: Araneidae
- Scientific Name: Araneus diadematus
- Other Names: Cross Spider, Crowned Orb-weaver, Diadem Spider, Cross Orbweaver
- Adult Size: 0.22 to 0.79 inches
- Lifespan: 1 year
- Average Price Range: N/A
The European garden spider has several whitish or yellow dots in the middle of its abdomen. These dots form a cross pattern that is characteristic of the species. The abdomen of this arachnid is bulbous and covered in tiny hairs.
The cephalothorax of this arachnid has longer and thicker hairs. In general, the body of this species has patches of yellow, brown, and grey. The legs are long, thin, and spiny. Females also typically have bigger abdomens than males.
It is easy to mistake this species for a six-eyed spider. While it has 8 eyes, they are so tiny you need to hold them close to see all of them. You can only see some using a magnifying glass.
The European garden spider relies on vibratory signals to trap prey. It weaves circular webs to trap flying prey like gnats and mosquitoes. When its web catches an insect, the spider swoops in to sting and consume it.
You’ll often find the European garden spider hanging upside-down in the middle of its web. This species is nocturnal. In the morning, it dismantles its web and seeks shelter to rest during the day.
The European garden spider’s venom is not of medical significance to humans. While bites are uncommon, you won’t experience more than mild pain and localized inflammation. These symptoms may last longer in people allergic to spider venom.
25. Black And Yellow Garden Spider
- Experience Level: Beginner to Intermediate
- Family: Araneidae
- Scientific Name: Argiope aurantia
- Other Names: Black And Yellow Argiope, Yellow Garden Spider, Zipper Spider, Zigzag Spider, Corn Spider, McKinley Spider, Golden Garden Spider, Steeler Spider
- Adult Size: 0.75 to 1.1 inches
- Lifespan: 1 year
- Average Price Range: N/A
You’ll usually see the black and yellow garden spiders in places teeming with vegetation. These could be forests or dense grasslands. In addition, these beautiful spiders also often spin webs in gardens near people’s homes.
This species’ name comes from the pattern of its abdomen. The middle is black with a few pairs of round yellow spots. While the sides are mostly pale yellow, some parts are a deep yellow surrounded by thin black rings.
The carapace of this spider is grayish and covered with tiny silvery hairs. The legs are also yellow and black, with the half close to the body being more yellowish. The other half of each leg is solid black.
Black and yellow garden spiders weave large, elaborate webs to trap prey. They feed primarily on flying insects and other small arthropods that get stuck in their webs. These include insects like grasshoppers and wasps.
The webs of these arachnids can be over 6 feet wide. These webs often feature a thickened line of silk in the middle known as a stabilimentum. Although the function of this zigzag line is unknown, it’s suspected to dissuade birds from flying through their webs.
You’ll often find black and yellow garden spiders hanging upside-down in the middle of their webs. They tend to run when threatened by people, so bites are rare.
The venom of this species is not toxic to humans. You may experience mild symptoms like pain or itching, but no more. These symptoms may linger for a bit if you’re allergic to spider venom.
26. Furrow Spider
- Experience Level: Beginner to Intermediate
- Family: Araneidae
- Scientific Name: Larinioides cornutus.
- Other Names: Furrow Orb-weaver, Furrow Orb Spider, Foliate Spider
- Adult Size: N/A
- Lifespan: 1 year
- Average Price Range: N/A
Furrow spiders are orb-weaving spiders in Colorado that favor damp or moist environments. You’ll often find them in coastal areas, near streams, ponds, or rivers. In addition, many furrow spiders live in damp places near or inside buildings.
This species is closely related to bridge orb-weavers. However, it has shorter legs and is not as dark as the bridge orb-weaver. The legs are banded and spiny, with the first 2 pairs being longer than the rest.
You can identify a furrow spider by its grayish or tan abdomen and the zigzag pattern running down the middle. This pattern resembles the wavy edge of a leaf or furrows after plowing, hence the spider’s name.
The abdomen is oval and nearly double the size of the cephalothorax. Unlike most orb-weavers, the abdomen of this species is smooth and glossy. This arachnid has a reddish-brown to gray carapace.
Furrow orb-weavers are carnivorous, feeding mostly on insects and other arthropods. They spin large, wheel-like webs to trap their prey. Vibratory signals help them locate prey on the web and attack.
The venom of these spiders has no toxic effect on humans. If one bites you, you’ll experience only mild discomfort or nothing. People allergic to spider venom are much more likely to have mild pain and inflammation than non-allergic people.
While female orb-weaving spiders are bigger than males, the difference is often negligible. They also show little sex-based differences in body pattern, unlike other orb-weaving species.
27. American Grass Spiders
- Experience Level: Beginner to Intermediate
- Family: Agelenidae
- Scientific Name: Agelenopsis
- Other Names: Grass Spiders, Funnel Weavers, Funnel Web Spiders, Sheet Web Spiders, Ground Spiders
- Adult Size: 0.4 to 0.8 inches
- Lifespan: 1 year
- Average Price Range: N/A
You’ll often find American grass spiders in forests or grasslands rich in green vegetation. American grass spiders are sheet-weavers that spin horizontal webs with an upside-down funnel-shaped web under. In most cases, these spiders weave the funnel over their shelter.
There are several species of American grass spiders in Colorado and North America. Unfortunately, these species are usually difficult to tell apart without professional help.
American grass spiders generally have brownish bodies. The abdomen of this species has two prominent broken light stripes bordered by black to dark brown lines. In addition, the posterior ends in two pikes.
The cephalothorax is also brown and usually wider than the abdomen. Unlike the abdomen, it has only one light stripe running down the middle, with a broad black band on each side. These black bands are, in turn, bordered by light stripes.
Many people mistake American grass spiders for wolf or hobo spiders in Colorado. These spiders share many physical qualities and are hard to differentiate. However, you can tell them apart if you closely examine their carapaces.
The other spiders lack the distinct alternating stripes American grass spiders have. Instead, hobo and wolf spiders sport less distinct markings on their carapaces.
American grass spiders feed on arthropods their web catches. These spiders conceal themselves in the funnel-shaped part of their webs and wait for prey to land on the sheet. While their webs aren’t sticky, these arachnids move incredibly fast.
American grass spiders rush to sting prey immediately after detecting vibrations. If you encounter this spider in its nest, you can have fun watching it speed across its web. All you have to do is trigger false vibrations by touching its nest with a stick.
The venom of this spider is harmless to humans, so you have nothing to fear.
28. Spitting Spider
- Experience Level: Beginner to Intermediate
- Family: Scytodidae
- Scientific Name: Scytodes thoracica
- Other Names: Spitting Spider
- Adult Size: 0.15 to 0.25 inches
- Lifespan: Up to 5 years
- Average Price Range: N/A
What makes the spitting spider unique is that it can shoot toxic silk threads from its head. Most spiders in Colorado have only one silk gland on their abdomen. In contrast, the spitting spider has 2 extra silk glands on its head.
The spitting spider is a hunter species, pursuing and subduing prey instead of trapping them in webs. When this arachnid nears its prey, it immediately shoots its toxic silk web at the animal. This toxic silk immobilizes the prey.
The venomous silk this spider ejects is liquid at first, but it quickly solidifies in the air. This arachnid continues spurting out silk threads over the prey until it is completely paralyzed. Afterward, the spider goes over to consume or wrap the prey in silk.
While this silk is harmful to this arachnid’s prey, humans have nothing to worry about. The silk spider’s venom is not of medical importance. In addition, the spider’s fangs cannot penetrate human skin. So there’s no bite risk.
You can easily identify a spitting spider based on appearance. It has a light brown body covered in dark brown markings. In addition, this arachnid’s legs are alternating bands of dark brown and yellowish-brown.
Unlike most spiders in Colorado, the abdomen of the spitting spider is roughly the same size or smaller than the cephalothorax. The abdomen and cephalothorax are typically dome-shaped. It also has 6 eyes, instead of the 8 most spiders have.
29. Mouse Spider
- Experience Level: Beginner to Intermediate
- Family: Gnaphosidae
- Scientific Name: Scotophaeus blackwalli
- Other Names: Mouse Spider, Ground Spider
- Adult Size: Up to 0.5 inches
- Lifespan: 1 to 2 years
- Average Price Range: N/A
The mouse spider has thick, smooth, and shiny hair on its abdomen. This hair is gray and closely resembles the fur of a mouse, hence the spider’s name. Unlike most spiders in Colorado, the abdomen is the same size or slightly smaller than the cephalothorax.
The cephalothorax and legs are brown and hairy. However, the hair on these body parts isn’t as thick or long as the abdominal hair. But all parts of the body have a glistening appearance.
Besides the physical resemblance with mice, this peculiar spider appears to share some behavioral traits with them. For example, it often makes random stops while running, which is how mice often move. It’s possible this behavior influenced the species’ name.
Mouse spiders are nocturnal carnivores. They move swiftly and prefer to hunt prey over trapping them with conventional webs. Like many spiders, they use sticky webs from their spinnerets to subdue their prey.
They often successfully overpower and consume prey many times their size. These arachnids feed primarily on insects and other arthropods, living or dead.
Mouse spiders are from the same family as eastern parson spiders. You can find them in many parts of Colorado. In addition, many mouse spiders live in people’s properties for long periods.
You may see evidence of these spiders in the web-like structures they build in homes they inhabit. These web-like structures are used to protect their eggs, and they weave many layers to offer adequate protection.
There’s no reason to panic if you find a mouse spider in your home. The venom of this species is medically insignificant to humans, so you’re unlikely to suffer serious effects. If you’re allergic, you might experience slightly stronger symptoms.
30. Common House Spider
- Experience Level: Beginner to Intermediate
- Family: Theridiidae
- Scientific Name: Parasteatoda tepidariorum
- Other Names: American House Spider, House Spider
- Adult Size: 0.125 to 0.75 inches
- Lifespan: 1 to 7 years
- Average Price Range: N/A
The common house spider is one of the most encountered spiders in Colorado and most of North America. You’ll find this arachnid in most homes hiding in crevices, windowsills, cellars, and attics.
While they live close to people, they often avoid human contact. Bites are rare, and the venom is a neurotoxin with only mild effects. In cases where bites happen, you may feel localized pain and experience mild swelling.
Bites from female common house spiders are more likely to trigger symptoms. If you’re allergic to spider venom, the pain may last a little longer and come with itching. Regardless, the venom doesn’t cause any serious problems and is medically insignificant.
You’ll usually come across these spiders congregating in close spaces. They build webs with so little spacing that several distinct webs can seem like one. Like other cobweb spiders, this species’ webs are non-sticky and disorganized.
Common house spiders are not hunter spiders. Therefore, they rely on their webs to trap prey for them. These arachnids usually sense when their webs have caught prey and quickly rush towards the scene to attack.
The common house spider has thin light and dark banded legs. Its abdomen is bigger than its body and usually brown with many dark blotches.
Like most spiders, you’re more likely to encounter female common house spiders than males. Females are also larger and live longer than males.
31. Bowl And Doily Spider
- Experience Level: Beginner to Intermediate
- Family: Linyphiidae
- Scientific Name: Frontinella pyramitela
- Other Names: Sheet-weavers
- Adult Size: Up to 0.15 inches
- Lifespan: 1 year
- Average Price Range: N/A
Bowl and doily spiders are named after the type of webs they spin. These arachnids weave bowl-shaped webs with a horizontal sheet (doily) under them. This web is not sticky, but it is effective at catching prey.
These sheet-weavers primarily feed on insects and other arthropods that get caught in their webs. They usually hang around on the sheet below the bowl-shaped web, waiting for an insect to enter the bowl. Immediately after an insect enters, they immobilize it with venom while outside.
The webs of bowl and doily spiders usually span several inches. Adult females typically build these webs, while males only live on them with them.
You have nothing to fear from these spiders. Bites are rare, and the spider generally runs when threatened. In addition, the venom of this spider is not medically significant to humans.
This species has a large, round abdomen many times the size of its cephalothorax. The abdomen and cephalothorax are shiny and black to dark brown. You’ll notice that the abdomen has several white vertical markings on the side.
The markings on the sides of the abdomen resemble inverted commas and curve under the spider. Near the underside, these markings usually become more yellowish. The legs are light brown and sparsely covered in thin bristles.
32. Barn Funnel Weaver
- Experience Level: Beginner to Intermediate
- Family: Araneidae
- Scientific Name: Tegenaria domestica
- Other Names: Drain Spider
- Adult Size: 0.24 to 0.45 inches
- Lifespan: 1 to 7 years
- Average Price Range: N/A
The barn funnel weaver varies in color. You may encounter variants with reddish-brown, gray, or beige bodies. In this species, the legs and cephalothorax usually have stripes. The cephalothorax is flat with two gray or black lines running its length.
The abdomen of the barn funnel weaver is straight and bears gray, brown, and beige markings. This spider is closely related to the hobo spider.
This arachnid is carnivorous, feeding primarily on insects and other small arthropods. It is incredibly fast when escaping predators or attacking prey. Like all funnel weavers, this species is not a hunter spider.
The barn funnel weaver spins large webs to catch prey. It then waits for vibratory signals to alert it when an insect gets stuck on the web. When this happens, the spider swoops down to paralyze the insect with venom before eating.
Barn funnel weavers aren’t aggressive towards people. They typically run away when threatened. While there are no records of bites from this spider, the venom is not considered medically significant. So you’ll be fine even if the spider bites you.
As their name suggests, you’ll usually find these spiders in Colorado barns and sheds. In addition, you may also find them hiding in crevices on doors or walls and under debris. These spiders avoid open spaces and usually run when you point a torch at them.
Like most spiders, female barn funnel weavers outlive males by a significant margin. Life expectancy is greater among those living indoors compared to those outdoors.
33. Spotted Orb-weaver
- Experience Level: Beginner to Intermediate
- Family: Araneidae
- Scientific Name: Neoscona crucifera
- Other Names: Hentz Orb-weaver, Barn Spider
- Adult Size: Up to 0.75 inches
- Lifespan: 1 year
- Average Price Range: N/A
The spotted orb-weaver has a large, roundish abdomen with thick, pointy hair bristles. This abdomen is typically light to dark brown. While the abdomen is covered with small spots, the markings do not create a distinct pattern.
The whole body of this arachnid is covered in short, pointed bristles. The cephalothorax is usually light. However, the part of the legs closest to it is solid reddish-brown. The remaining half of these legs is an alternating black and white or light brown band.
Like all orb-weaving spiders in Colorado, this species spins webs to trap prey. It relies on detecting vibratory signals from its web to know when prey is available. Usually, this prey is an insect or arthropod, which it injects with venom and slowly digests.
The venom of spotted orb-weavers is not medically significant. Since this spider is unaggressive, bites rarely happen. But expect to experience mild pain if you’re bitten. The symptoms quickly disappear, but they may be more pronounced in allergic people.
You’ll sometimes find this species in the same range as the closely related western spotted orb-weaver. Differentiating this species is usually easy. But similarly colored species with faded marks may be harder to differentiate.
34. Western Spotted Orb-weaver
- Experience Level: Beginner to Intermediate
- Family: Araneidae
- Scientific Name: Neoscona oaxacensis
- Other Names: Western Spotted Orb-weaver
- Adult Size: 0.35 to 0.7 inches
- Lifespan: 1 year
- Average Price Range: N/A
The western spotted orb-weaver has several color variants. However, most have dark gray to black bodies. The middle of the cephalothorax has a light gray band in the middle, with a black band on both sides.
The back of the abdomen is black with grayish sides. It is peppered with many whitish spots, and a cream or yellowish pattern runs down the middle. This pattern is typically wider near the waist, and the edges are curvy.
This arachnid’s legs are spiny and mostly black to dark gray near the body. In contrast, the remaining half of each leg alternates between black and cream. Some legs have orange bands near the body.
This species is related to the spotted spider. Both species look different. However, western spotted spiders with unclear abdominal markings can be difficult to differentiate from ordinary spotted orb-weavers.
Western spotted orb-weavers are carnivorous spiders, feeding chiefly on other arthropods. They spin large webs to catch prey and inject them with venom before eating. Insects like flies and gnats are common prey for these spiders.
These spiders are not aggressive towards people, so you have nothing to worry about. They run when threatened, and the venom they inject isn’t toxic enough to cause any harm. If you’re allergic to spider venom, you may experience more discomforting symptoms.
You’re most likely to encounter western spotted orb-weavers in gardens and forests. Many western orb-weavers favor avocado orchards. Like most spiders, females are larger than males.
35. Golden Silk Orb-weaver
- Experience Level: Beginner to Intermediate
- Family: Araneidae
- Scientific Name: Trichonephila clavipes
- Other Names: Banana Spider, Giant Golden Orb-weaver
- Adult Size: 1 to 1.5 inches
- Lifespan: 1 year
- Average Price Range: N/A
The golden silk orb-weaver is a beautiful spider with a long reddish-brown or yellow abdomen. This abdomen is banana-shaped and stippled with many tiny whitish markings. In most variants, the cephalothorax is black with a silvery carapace bearing circular black patterns.
This large arachnid has long yellow legs with black feather-like tufts at the joints. You’ll notice orange or reddish-brown bands after the tufts in some variants. Like most spiders, males of this species are smaller than females.
Male golden silk orb-weavers are about 5 to 6 times smaller than females, so you’ll barely notice them except when they stay in webs with females. They have extremely short lifespans devoted to mating with females.
You’re most likely to encounter golden silk orb-weavers in late summer and fall. If you go hiking through forests or areas abundant in these spiders, you’ll often run into their large, sticky webs. The spiders themselves are unaggressive and often run when threatened.
The golden silk orb-weaver only bites in self-defense when pressed too close to your skin. Like most spiders in Colorado, the venom of this species is harmless to humans. Its bite hurts, but the pain quickly fades.
Banana spiders are carnivorous spiders. They rely on their webs to trap flying insects and arthropods for them to snack on. When an insect gets stuck, it triggers a vibration that alerts the spider to its presence.
36. Carolina Wolf Spider
- Experience Level: Beginner to Intermediate
- Family: Lycosidae
- Scientific Name: Hogna carolinensis
- Other Names: Wolf Spider
- Adult Size: Up to 1.5 inches
- Lifespan: 1 to 2 years
- Average Price Range: N/A
The Carolina wolf spider is the state wolf spider in South Carolina. This brown spider has a bulbous abdomen, which is only slightly bigger than its carapace. Like most wolf spiders, it has a slightly hairy abdomen and carapace.
The carapace of this spider has two dark bands that unite anteriorly. A light stripe runs between both dark bands. In many variants, the center of the abdomen is darker than the rest. The legs have several dark spots.
This species is possibly the largest wolf spider in the US. Females grow well over an inch, while males often reach up to 1 inch in body length. Most male spiders of other species are minute when compared to females.
Like most spiders, the Carolina wolf spider feeds mainly on small insects and other arthropods. It is a hunter species, so it doesn’t catch prey by spinning webs. Instead, it hunts prey on the ground and kills them with venom before eating.
Carolina wolf spiders are unaggressive spiders. If you approach them, their first instinct is to run. They only bite in self-defense. For example, they may sting in response to touch. But you have nothing to fear. Their bites are painful, but their venom is harmless to humans.
Females show solid maternal instincts and are fiercer when carrying their eggs. They spin protective silk cocoons for their eggs, which they carry around. When the eggs hatch, the spiderlings live on their mother’s back for a while before striking out on their own.
37. Grand Canyon Black Tarantula
- Experience Level: Beginner to Intermediate
- Family: Theraphosidae
- Scientific Name: Aphonopelma marxi
- Other Names: Tarantula
- Adult Size: 1 to 1.5 inches
- Lifespan: Up to 30 years
- Average Price Range: N/A
Tarantulas are interesting spiders that may intimidate you at first because of their size and hairiness. Female grand canyon black tarantulas can grow to one and half inches or more in body length and are bigger than males.
This species is typically black or dark brown and covered in thick hair. In most variants, you’ll notice slightly faded gray and brown tufts on the legs and the hind part of the abdomen. It has no specific pattern to speak of.
Bites from this spider can be painful, but it rarely bites unprovoked. The pain often lingers for a while before fading. If you’re allergic to spider venom, the discomfort may last longer. Thankfully, the venom of this spider isn’t enough to cause any health problems.
Like other tarantulas, the grand canyon black tarantula is a hunter. It is nocturnal, often stalking prey and pouncing on them when it’s a few inches close. It kills them with its venom before eating.
The grand canyon black tarantula doesn’t spin conventional webs. It often lives in ground tunnels, so it spins silk covering over the entrance. While they mostly live outdoors, some enter manmade structures to seek shelter from unfavorable weather conditions.
38. Asiatic Wall Jumping Spider
- Experience Level: Beginner to Intermediate
- Family: Salticidae
- Scientific Name: Attulus fasciger
- Other Names: Asian Wall Jumping Spider, Asian Wall Jumper, Mottled Jumping Spider, Mottled Patterned Jumping Spider
- Adult Size: 0.125 to 0.25 inches
- Lifespan: 1 to 2 years
- Average Price Range: N/A
The Asiatic wall jumping spider is originally native to northern and western Asia. Since its introduction to North America, the species has spread and become established in many US states like Colorado.
This arachnid is covered in bristly, multi-toned hairs. It is mostly dark brown to black with whitish many hair bristles. The carapace has rounded sides and light hairs in the middle. While the carapace is studded with 8 eyes, only 6 are clearly visible.
Like other jumping spiders, the Asiatic jumping spider is a hunter. Instead of employing webs, it tracks down prey and injects them with venom. It then consumes its prey on the spot or drags them to its shelter.
The venom of this spider is harmless to humans. The spider itself is nonaggressive. It only attempts biting in self-defense when mishandled. Otherwise, its primary instinct is to run from threats.
This tiny spider spins silk lines to aid it when jumping. It also spins silk sacs for its young and is fiercely protective of them.
You’ll usually come across this spider in buildings during the second quarter of the year. It is attracted to light sources, especially artificial ones. Like spiders, insects are attracted to these light sources and provide ample food.
39. California Flattened Jumping Spider
- Experience Level: Beginner to Intermediate
- Family: Salticidae
- Scientific Name: Platycryptus californicus
- Other Names: California Flattened Jumper
- Adult Size: 0.24 to 0.42 inches
- Lifespan: 1 year
- Average Price Range: N/A
The California flattened jumping spider is a diurnal jumping spider found in Colorado. It is black to dark brown and hairy. On the back, you’ll notice a whitish pattern extending from the carapace to the abdomen. This pattern becomes leaf-like on the abdomen.
This arachnid is a diurnal hunter that stalks prey before attacking. It doesn’t employ webs and relies on subduing and injecting prey with venom on time. If successful, the spider consumes its prey immediately or transports it to a nearby shelter.
California flattened jumping spiders spin strong silk draglines to help them when jumping. They also spin cocoons to keep their eggs before they hatch. These arachnids guard their eggs until they hatch, often carrying them around.
This species doesn’t inject venom strong enough to harm humans. While it is nonaggressive, it will bite if provoked. The bite hurts, but it doesn’t have any lasting effect.
40. Peppered Jumping Spider
- Experience Level: Beginner to Intermediate
- Family: Salticidae
- Scientific Name: Pelegrina galathea
- Other Names: Peppered Jumper
- Adult Size: 0.17 to 0.21 inches
- Lifespan: 1 year
- Average Price Range: N/A
The peppered jumping spider is attracted to grassy plains, prairies, and farmland. This tiny spider enjoys spending time under sunlight.
This species has a dark gray to brown body peppered with white hairy spots. The carapace and abdomen have two white bands on the sides. However, the abdomen is solid brown with white markings, while the carapace is closer to black.
The legs of this species are hairy alternating light and dark rings. Like most spiders, female peppered jumping spiders are larger than males.
Female peppered jumping spiders are also protective of their young. They spin silk cocoons in which they carry their eggs until they hatch. After hatching, spiders often stay with their mother before they can care for themselves.
Peppered jumping spiders feed on insects and other arthropods, but they don’t trap prey with webs. These arachnids hunt down prey and inject them with venom before consuming what they can.
This species is not aggressive towards people. Furthermore, the venom is not medically significant. So you have nothing to fear if you come across it.
Frequently Asked Questions
Still have unanswered questions about the spiders in Colorado? Find the answers you want in this section.
What do spiders in Colorado eat?
Spiders eat other arthropods, regardless of location. Due to their abundance and availability, insects make up the bulk of these arachnids’ food. Flies, mosquitoes, crickets, and ants are common food items.
Spiders also consume other kinds of arthropods, including other spiders. Species living in coastal areas often feed on crustaceans they can subdue. In addition, many fishing spiders feed on non-arthropod prey like fish or slugs.
Do spiders in Colorado have good eyesight?
Yes. But not all spiders in Colorado have the same quality of vision. While some have keen eyesight that helps them spot prey from a distance, others can hardly see at all. Those with poor vision often compensate for this deficiency by using their other senses to detect prey and move around.
Most spiders in Colorado have 8 eyes. But some, like the brown recluse and spitting spider, have only 6. Some of these eyes help spiders see clearly. However, others serve as sharp motion sensors to make navigation easy.
Where can I find spiders in Colorado?
You can find spiders in Colorado almost anywhere. Many spiders live indoors. Although they often stay out of sight, you’ll often become aware of their presence because of the webs they spin. Check your windowsills or crevices in your doors and walls for these arachnids.
Outdoors, you can find spiders anywhere from your garden to forests. Some spiders prefer to live outdoors among trees and tall grasses. These spiders typically spin large webs between twigs or may spend most of their time under rotting logs or rocks.
Are there any poisonous spiders in Colorado?
Yes. The western black widow is the main venomous spider in Colorado. Its venom has neurotoxic properties that can result in significant health problems. It is considered medically significant, so you need to see a doctor for treatment immediately after one bites you.
Although quite rare, there have been sightings of brown recluses in the state. This species has violin-shaped markings on its back and is notorious for causing ulcers. Its venom is cytotoxic, so it kills off cells and tissues in the bite area. Bites from this spider also require urgent medical attention.
Besides widows and brown recluses, spiders in Colorado are generally venomous. The difference is that their venoms aren’t potent enough to harm you. Sometimes you’ll experience mild pain or discomfort if bitten by these spiders. Other times, you’ll feel nothing.
Can a spider bite kill you?
Yes. However, deaths from spider bites are extremely rare. This is thanks to advances in modern medicine and due to the fact that many don’t inject enough venom to cause death.
The western black widow is the only species that injects venom capable of causing death. But most black widows don’t inject venom potent enough to kill you. Still, the only way to be safe is to see a doctor immediately after one bites you.
Bites from black widows are more likely to be fatal in people with weak immune systems, such as children and the elderly. People allergic to spider venom may also suffer from severe allergic reactions or anaphylaxis after being bitten by a black widow.
Are there recluses in Colorado?
Brown recluses in Colorado are rare. There are very few sightings of these venomous spiders in the state.
Are jumping spiders in Colorado?
Yes. There are several types of jumping spiders in Colorado. You’ll find plenty of diversity within this spider family. While sightings of some species are common, others are scarce to come across.
Are tarantulas in Colorado?
Yes. Colorado is home to two main types of tarantulas: the grand canyon tarantula and the Texas brown tarantula. Both species are giant spiders that reach impressive heights when fully erect. As is typical of tarantulas, they are covered in thick long hair.
Are Colorado tarantulas poisonous?
Not really. The tarantulas you’ll encounter in Colorado aren’t dangerous to humans. While their bites can be quite painful, their venom isn’t strong enough to cause any serious damage. The belief that these spiders are poisonous is probably due to their daunting appearance.
Can you keep a pet spider in Colorado?
You can keep pet spiders in Colorado. There are several species in the state, and some are easier to keep than others. If you intend to keep aggressive or highly venomous species, you should keep them in shelters that offer you protection from their bites.
You can have fun keeping many types of spiders, as long as they don’t feel threatened. Squashing them or holding them too tightly can make them bite you. Luckily, you can find some species with bites that don’t hurt at all.
Wrapping up
Spiders are fascinating creatures that some people find intimidating for many reasons, and Colorado is home to dozens of them. But as you’ve seen by now, many spiders in this state aren’t as scary as they seem.
These arachnids help maintain the ecosystem and can be great to have around. They generally mind their business and aren’t aggressive. Except when threatened with no escape, these arthropods rarely bite.
Some people keep spiders as pets because they are both fascinating and low maintenance. If you plan to keep one, you’ll spend much less on it than you would on conventional pets like cats or dogs.
Different spiders have different behaviors, so keep this in mind when interacting with them.