In the vast and diverse state of Colorado, there are countless fascinating creatures that call this place home. Among them, spiders play a crucial role in maintaining the delicate balance of the ecosystem. While some may feel a twinge of fear at the sight of these eight-legged creatures, it’s important to remember that most spiders are harmless and even beneficial. This article aims to shed light on the 10 common spider species found in Colorado, offering valuable insights into their habits and how to handle them in case they become a nuisance. From the yellow sac spider to the docile tarantula, each spider is given its moment to shine with vivid descriptions and striking photographs. So, whether you have an unyielding curiosity or just want to arm yourself with knowledge, join us as we explore the captivating world of Colorado’s spiders.
Yellow Sac Spider
Appearance
The Yellow Sac Spider is a small spider with a body length ranging from 5 to 10 millimeters. Its color typically varies from pale yellow to light brown. While males tend to have a lighter coloration, females often exhibit a darker shade. These spiders have eight legs and two palps, which are used for sensing and capturing prey. One interesting feature of the Yellow Sac Spider is its ability to change color depending on its environment. This spider gets its name from its habit of creating a sac-like structure in which it resides.
Habitat
Yellow Sac Spiders can be found in a wide range of habitats, including grasslands, gardens, forests, and even urban areas. They are commonly found in residential homes, where they may hide in dark and undisturbed areas such as basements, attics, and closets. These spiders are known for their ability to adapt to different environments, making them highly adaptable and prevalent.
Behavior
The Yellow Sac Spider is primarily nocturnal, which means it is most active during the night. During the day, it typically hides in its sac or other sheltered locations. As a hunting spider, the Yellow Sac Spider does not build elaborate webs to capture prey. Instead, it actively roams around in search of insects and other spiders. Despite its small size, the Yellow Sac Spider can move quickly. It is also known for its jumping ability, allowing it to pounce on unsuspecting prey.
Dealing with Nuisance
While Yellow Sac Spiders are generally harmless to humans, they may become a nuisance if they enter homes and other structures. If a Yellow Sac Spider infestation is detected, it is recommended to contact a professional pest control service to safely remove the spiders and implement measures to prevent re-infestation. Homeowners can also take steps to minimize the chances of Yellow Sac Spider infestations by sealing cracks and gaps in the home’s exterior, keeping the interior clean and clutter-free, and removing any potential sources of food and shelter for these spiders.
Cellar Spider
Appearance
Cellar Spiders, also known as Daddy Longlegs, are thin-legged arachnids that have a distinctive appearance. They have long, slender bodies and extremely long and delicate legs. The body length of a Cellar Spider ranges from 2 to 10 millimeters, with an average leg span of around 50 millimeters. These spiders are often light brown or gray in color. One notable characteristic of Cellar Spiders is their ability to drop their legs as a defense mechanism, making them appear even more delicate.
Habitat
The name “Cellar Spider” originates from their preference for dark and damp places such as basements, cellars, and crawlspaces. These spiders are commonly found in buildings and structures, where they construct their webs in corners, crevices, and other undisturbed spaces. While they are not exclusively limited to these areas, Cellar Spiders thrive in environments that offer protection and a steady supply of small insects for their prey.
Behavior
Cellar Spiders are active hunters that rely on their webs to catch insects. The design of their irregular and tangled webs allows them to effectively trap flying insects such as gnats and mosquitoes. Unlike many other spiders, Cellar Spiders do not have venom glands and are therefore harmless to humans. When disturbed, they often vibrate their webs, which can create the illusion of movement and scare away potential predators.
Dealing with Nuisance
Cellar Spiders are generally considered beneficial due to their ability to control populations of other insects within homes. However, if their presence becomes overwhelming or people have a fear of spiders, they can be managed by using non-lethal removal methods. This can be done by gently capturing the spider in a glass or a similar container and releasing it outside. It is essential not to kill them, as they play a vital role in maintaining the ecological balance by preying on other pests.
Banded Garden Spider
Appearance
The Banded Garden Spider, also known as the Black and Yellow Garden Spider, is a visually striking arachnid. Females are significantly larger than males, with body lengths ranging from 20 to 30 millimeters. These spiders have a bulbous abdomen, which is patterned with alternating black and yellow bands, giving them their name. Males, on the other hand, are smaller and have a more nondescript brown coloration.
Habitat
Banded Garden Spiders are commonly found in gardens, open fields, and meadows where they can spin their large and impressive circular webs. These spiders prefer areas with abundant vegetation, as it provides them with a steady supply of insects to prey upon. While they might take up residence near human habitation, they are not typically considered household pests.
Behavior
The Banded Garden Spider is an orb-weaver, meaning it constructs intricate, circular webs to capture its prey. These webs are known for their symmetrical design, durability, and strength. The spider waits patiently at the center of its web, feeling the vibrations caused by insects caught in the silk strands. Once prey is detected, the Banded Garden Spider will swiftly move to capture and immobilize it with its venomous bite.
Dealing with Nuisance
Banded Garden Spiders are not considered nuisance pests. On the contrary, they are beneficial in controlling populations of insects such as flies, mosquitoes, and garden pests. Their presence in gardens can be appreciated, as they contribute to maintaining a natural balance. In areas where they may come into close contact with humans, such as doorways or windows, it is best to gently relocate them by gently guiding them onto a leaf or other safe surface and moving them to a more suitable location.
Wolf Spider
Appearance
Wolf Spiders are robust and agile spiders that vary in size, with females being larger than males. Their body length can range from 8 to 35 millimeters, making them one of the larger spider species. They have strong, hairy legs that enable them to move quickly and efficiently. Wolf Spiders typically have a dark brown or gray coloration, often with distinctive markings such as stripes or spots on their body. These markings may help camouflage them in their natural habitat.
Habitat
Wolf Spiders can be found in various habitats, including forests, grasslands, fields, and gardens. Although they are primarily ground-dwelling spiders, they are highly adaptable and can also be found in burrows, under rocks, or even inside homes. Unlike many other spiders, female Wolf Spiders carry their eggs along with them, creating a protective silk cocoon that they attach to their abdomen until the spiderlings hatch.
Behavior
Wolf Spiders are skilled hunters that do not rely on building webs to catch their prey. Instead, they actively chase and capture their meals. These spiders have excellent vision and tactile senses, allowing them to track and pounce on insects with precision. Due to their hunting nature and the ability to adapt to various environments, Wolf Spiders are considered beneficial, as they help control populations of other pests.
Dealing with Nuisance
Wolf Spiders are not considered nuisance pests unless they invade homes or other structures in large numbers. If an infestation is detected, it is recommended to contact a professional pest control service to safely remove the spiders and implement measures to prevent re-infestation. Homeowners can also take steps to reduce the chances of Wolf Spider infestations by sealing cracks and gaps in the home’s exterior, keeping the interior clean and clutter-free, and removing any potential sources of food and shelter for these spiders.
Western Widow Spider
Appearance
The Western Widow Spider, also known as the Black Widow Spider, is a venomous spider that is widely recognized for its distinctive appearance. Females are easily identifiable by their shiny black bodies, round abdomen, and bright red hourglass-shaped marking on the underside of their abdomen. The hourglass marking serves as a warning to potential predators. Males, on the other hand, are smaller, with a light brown coloration and various markings on their abdomen.
Habitat
Western Widow Spiders can be found in a variety of habitats, including dry and arid regions, forests, and urban areas. They are commonly found in undisturbed areas such as woodpiles, debris piles, and rock crevices. These spiders prefer dark and secluded areas, where they can construct their irregular-shaped webs and hide from potential threats.
Behavior
The Western Widow Spider is known for its secretive and reclusive behavior. These spiders are primarily nocturnal, spending their days hiding in their webs or retreats. The female Western Widow Spider is venomous and may bite if threatened or disturbed. Male Western Widow Spiders, however, are harmless and do not possess the same level of toxic venom. The venom of the Western Widow Spider is neurotoxic and can cause severe symptoms in humans if bitten.
Venomous Nature
The venom of the Western Widow Spider contains neurotoxins that affect the nervous system. If bitten by a Western Widow Spider, it is important to seek medical attention immediately. Symptoms of a bite may include severe pain at the bite site, muscle cramps, nausea, difficulty breathing, and in rare cases, can lead to life-threatening complications. Prompt medical intervention is crucial to minimize the effects of the venom and provide appropriate treatment.
Dealing with Bites
If someone is bitten by a Western Widow Spider, it is essential to stay calm and seek medical attention immediately. While waiting for medical help to arrive, it is advised to clean the bite area with soap and water and apply a cold compress to reduce swelling and pain. It is crucial to avoid attempting any home remedies or using potentially dangerous methods to treat the bite. Medical professionals are best equipped to provide the necessary care and administer antivenom if required.
Brown Recluse Spider
Appearance
Brown Recluse Spiders are comparatively smaller spiders, with an average body length of around 6 to 20 millimeters. They are typically light to medium brown in color, with a distinctive violin-shaped marking on their cephalothorax. This marking is what sets them apart and gives them the nickname “fiddleback spider.” Unlike many other spider species, Brown Recluse Spiders have only six eyes instead of eight, arranged in three pairs of two.
Habitat
Brown Recluse Spiders are predominantly found in dry and temperate regions. They prefer undisturbed areas such as attics, basements, closets, and woodpiles. These spiders are reclusive by nature and construct irregular-shaped webs in hidden locations. Brown Recluse Spiders are primarily nocturnal and remain hidden during the day, venturing out at night to hunt for prey.
Behavior
As their name suggests, Brown Recluse Spiders are not aggressive and tend to shy away from human interaction. They prefer to run away or hide rather than bite when threatened. However, if they feel trapped or cornered, they may bite in self-defense. The venom of a Brown Recluse Spider contains cytotoxic and hemotoxic properties, which can lead to localized tissue damage and, in severe cases, systemic reactions.
Venomous Nature
The venom of a Brown Recluse Spider contains enzymes that can destroy cells and tissues, leading to necrotic skin lesions. The initial bite may go unnoticed, but within hours or days, a painful, slow-healing ulcer or necrotic skin lesion may develop. In rare cases, systemic reactions can occur, causing fever, chills, and nausea. If bitten by a Brown Recluse Spider, seeking immediate medical attention is crucial.
Dealing with Bites
If someone is bitten by a Brown Recluse Spider, it is important to seek medical attention immediately. While waiting for medical help to arrive, it is advised to clean the bite area with soap and water and apply a cold compress to reduce swelling and pain. It is crucial to avoid attempting any home remedies or using potentially dangerous methods to treat the bite. Medical professionals are best equipped to provide the necessary care and administer appropriate treatment.
Funnel Web Spider
Appearance
Funnel Web Spiders are a group of spiders that collectively share several physical traits. They have a robust build, with a body length ranging from 10 to 30 millimeters, depending on the species. Funnel Web Spiders are typically brown or grayish in color, enabling them to blend in with their surroundings. The name “Funnel Web Spider” is derived from their distinctive funnel-shaped webs, which act as their primary hunting mechanism.
Habitat
Funnel Web Spiders can be found in a variety of habitats, including forests, grasslands, gardens, and even residential areas. They prefer areas with dense vegetation and soil that allows them to create their funnel-shaped webs. These spiders typically burrow into the ground or hide under rocks or debris, ensuring both protection and easy access for prey to enter their webs.
Behavior
Funnel Web Spiders are ambush predators that rely on their funnel-shaped webs to capture prey. These webs are strategically positioned, with the spider residing at the narrow end, waiting for vibrations created by insects caught in the web. Once prey is detected, the spider quickly rushes out to immobilize and inject it with venom. Funnel Web Spiders can be aggressive if threatened and will bite if they feel endangered.
Dealing with Nuisance
Funnel Web Spiders are generally not considered nuisance pests, as they play a crucial role in controlling populations of insects. However, if their presence becomes overwhelming or poses a threat to human safety, it is recommended to contact a professional pest control service for safe removal. Homeowners can also take preventive measures to minimize the chances of Funnel Web Spider infestations by keeping vegetation trimmed, removing debris and clutter from the yard, and sealing any potential entry points into the home.
Hobo Spider
Appearance
Hobo Spiders are medium-sized spiders, with a body length ranging from 8 to 16 millimeters. They have a brown coloration, with a distinctive pattern on their abdomen consisting of chevron-shaped markings. The legs of a Hobo Spider are long and hairy, enabling them to move quickly. Males and females are similar in appearance, with the females being slightly larger.
Habitat
Hobo Spiders are commonly found in grassy areas, gardens, and urban environments. They prefer undisturbed places such as basements, crawlspaces, and window wells. These spiders construct funnel-shaped webs, which provide them with protection and a means of capturing prey. Hobo Spiders are non-aggressive and tend to retreat if threatened, rather than bite.
Behavior
Hobo Spiders are aptly named for their wandering nature and tendency to hitchhike on goods and objects. Unlike many other spiders, Hobo Spiders do not build elaborate webs to catch prey. Instead, they rely on their speed and agility to chase and capture their meals. While they mostly feed on insects, Hobo Spiders are also known to consume other spiders, adding to their beneficial role in controlling populations of pests.
Dealing with Nuisance
Hobo Spiders are generally considered harmless to humans and are not typically regarded as nuisance pests. However, if their presence becomes overwhelming or causes concern, it is advisable to contact a professional pest control service for safe removal and prevention measures. Homeowners can also take steps to minimize the chances of Hobo Spider infestations by sealing cracks and gaps in the home’s exterior, reducing clutter and vegetation close to the house, and maintaining cleanliness indoors.
Tarantula
Appearance
Tarantulas are among the largest of spiders, with some species reaching body lengths of up to 9 centimeters. They have robust bodies covered in hair, which varies in color from brown to black. Tarantulas have eight legs and two prominent fangs used to capture and immobilize their prey. Contrary to popular belief, tarantulas are typically docile and have a relatively low venom toxicity.
Habitat
Tarantulas can be found in a wide range of habitats, including deserts, grasslands, forests, and even tropical rainforests. They are predominantly ground-dwelling spiders, often constructing burrows or hiding in crevices. Tarantulas are most commonly encountered at night when they become active in their search for food and mates.
Behavior
Tarantulas are slow and deliberate in their movements, known for their calm and docile nature. Despite their fearsome appearance, they are unlikely to bite humans unless provoked or cornered. When threatened, tarantulas may display defensive behaviors such as rearing up on their hind legs, showing their fangs, or flicking urticating hairs from their abdomen, which can cause irritation if they come into contact with the skin or eyes.
Suitability as Pets
Due to their docile nature and relatively low maintenance requirements, tarantulas are popular pets among spider enthusiasts. However, they require appropriate housing, such as a terrarium with proper ventilation and temperature control. Tarantulas are carnivorous and feed primarily on insects. Owning a pet tarantula requires knowledge and understanding of their specific needs, as well as adherence to local regulations regarding exotic pets.
Apache Jumping Spider
Appearance
Apache Jumping Spiders, also known as Bold Jumping Spiders, are small spiders with a body length ranging from 4 to 12 millimeters. They are known for their distinctive coloration, often characterized by a shiny black cephalothorax with white markings and vibrant iridescent colors on their abdomen. Apache Jumping Spiders have eight eyes arranged in three rows, providing them with excellent vision.
Habitat
Apache Jumping Spiders can be found in various habitats, including woodlands, meadows, gardens, and even inside homes. They are agile spiders that are often seen leaping from one location to another, hence their name. These spiders construct small, tubular retreats lined with silk for protection and as a base for hunting.
Behavior
Apache Jumping Spiders are active hunters, known for their impressive vision and ability to accurately judge distances. They use their excellent eyesight to spot and stalk their prey, often performing quick, elaborate dances to communicate with potential mates or intimidate rivals. Despite their small size, Apache Jumping Spiders are skilled hunters and play a significant role in controlling populations of insects in their environment.
Impressive Vision
Apache Jumping Spiders possess one of the best vision systems among spiders. Their large anterior median eyes provide them with acute depth perception and color vision, allowing them to accurately gauge distances and identify potential threats or prey. This impressive vision, coupled with their hunting prowess and agility, makes Apache Jumping Spiders fascinating creatures to observe in their natural habitats.
In conclusion, these ten spider species found in Colorado showcase the diverse and fascinating world of arachnids. While spiders are often misunderstood and feared, they play an important role in the ecosystem by controlling populations of insects. Understanding their appearance, habitat preferences, and behavior can help us appreciate their benefits and coexist peacefully. Whether it’s the elusive presence of the Western Widow Spider or the docile nature of Tarantulas, each species has its unique characteristics that contribute to the intricate tapestry of nature. By respecting their space and taking appropriate measures to deal with them if they become a nuisance, we can continue to live harmoniously with these remarkable creatures.