Oregon is a state known for its scenic beauty, from its rugged coastline to its lush forests and mountains. However, there is a lesser-known aspect of Oregon’s natural landscape: brown spiders. These eight-legged creatures are not as celebrated as the state’s majestic elk or playful sea otters. However, they are a part of Oregon’s ecosystem, nonetheless.
With the proper awareness, it is possible to coexist with these creatures and appreciate their place in the natural world. So let’s take a closer look at these fascinating arachnids and learn more about what makes them unique.
1. Cat-Faced Spider (Araneus gemmoides)
Araneus gemmoides, also known as the jewel spider or cat-faced spider, is a species of orb-weaver. They can be found thriving in the outdoors of Oregon.
One of the spider’s most striking characteristics is the pair of horn-like projections on its large, round abdomen. They resemble a set of cat ears. Adding to this feline resemblance are two dark-colored dimples on the spider’s stomach. These resemble a pair of cat eyes and contribute to the spider’s common name: the cat-faced spider.
The cat-faced spider comes in a range of shades, from pale to dark brown. Interestingly, female cat-faced spiders can grow up to twice the size of males. Lengths range from 0.2 to 1 inch.
It is common to spot cat-faced spiders near porch lights or outside windows. Here, they can easily prey on flying insects attracted to the light. These areas provide the spiders with a reliable source of food before the winter sets in. During the day, these spiders often sit in the center of their orb-shaped webs. They may be repairing any damage done to the web by the previous night’s activities. They are commonly seen on the sides of buildings, in enclosed spaces, in woods, hiding under leaves, and near lights.
As insectivores, cat-faced spiders primarily feed on other insects and arachnids. However, these spiders can also be cannibalistic, preying on smaller members of their own species.
While cat-faced spiders can give a sharp bite if handled, they typically cannot pierce human skin. Even if they do manage to inject venom, the effects of generally mild. And these spiders are not dangerous to humans.
- Cat-faced spiders are preyed upon by various large insects and other spiders.
- Their lifespan is around one year.
- Female cat-faced spiders typically die soon after laying their eggs.
2. Hobo Spider (Eratigena agrestis)
The hobo spider was accidentally introduced to the United States from Europe. These spiders have successfully adapted to the environment in Oregon and can now be found wherever people live.
Identifying a hobo spider can be challenging as its appearance is similar to many other spider species. The hobo spider typically has a brown body, long legs, and a grayish abdomen with yellowish markings. However, these physical characteristics are also found in other spider species.
The body of a hobo spider can range from 1/4 to 1/2 inch in length. Its leg span can reach up to 1-2 inches, making it a medium-sized spider.
Hobo spiders are reclusive and tend to stay within their funnel-shaped webs. They are not aggressive and are more likely to run and hide than rear up and bite if threatened.
They live in various habitats, but they prefer areas with holes, cracks, or crevices that can support their webs. However, these spiders rarely live above ground level since they are poor climbers.
Hobo spiders build distinctive funnel-shaped webs, which they use to catch insects. These webs are designed to guide prey toward the spider’s hiding place, where it lies in wait. Hobo spiders feed on a variety of insects, including house flies, cockroaches, and ants.
Despite their reputation, hobo spiders are not dangerous to humans. While they do possess venom, it is no more toxic than the venom of most other spider species. Interestingly, the hobo spider was once considered incredibly venomous. However, it has since been taken off the CDC’s list of venomous species.
- The hobo spider prefers moderately dry and warm environments.
- Female hobo spiders eat males after mating.
- Females can live for up to two years, while males typically only live for a few months.
3. Giant House Spider (Eratigena atrica)
Like the hobo spider, the giant house spider was accidentally introduced to Oregon from Europe. They can now be found in many parts of the state.
The giant house spider is part of a group of house spiders that share similar features. These include long legs, dark and hairy bodies, and a preference for living in buildings and homes. Despite their similarities, they are still distinguishable from other spiders.
Adult spiders of this species can have leg spans of up to 4 inches. The giant house spider is typically a muddy brown color, with the legs lacking any distinct banding.
During the autumn, when they reach their maximum size, giant house spiders commonly move indoors. However, they are not typically aggressive toward humans and are more likely to run away rapidly if startled. Giant house spiders inhabit various structures, including rooms, barns, storage sheds, fences, and dark corners.
The giant house spider is a nocturnal predator that mainly feeds on other arthropods. They eat moths, crickets, and flies that are active at night.
Despite its intimidating size and appearance, the giant house spider is not a significant threat to humans.
- They are also called aggressive house spiders because of their aggressive hunting behavior.
- Male spiders die shortly after mating, often resulting in females eating them.
- They have limited visual cells, only allowing them to differentiate between day and night.
4. Giant Crab Spider (Olios giganteus)
One of the largest spiders in North America, the giant crab spider, is a permanent resident of Oregon.
The giant crab spider boasts a covering of tiny hairs that adorn both its body and legs. Its coloring is predominantly a pale brown hue, although it deepens towards the leg tips. An identifying feature of this spider is the black marking on its back, resembling a stretched letter “Y.”
This spider holds the title for one of the largest arachnids in the region. It spans an impressive 2 to 2¼ inches across.
A skilled hunter, this spider actively seeks out its insect prey, relying on its impressive speed to catch them. To avoid detection during the day, it conceals itself by squeezing its flattened body into narrow crevices or cracks. Once night falls, it emerges from hiding to commence its hunting activities.
This versatile spider lives in a range of habitats, including inside deceased saguaro cacti and beneath rocks. They also take up residence in human dwellings.
As effective predators, these spiders play a crucial role in managing insect populations. They prey on a wide range of insects, such as flies, mites, and crickets. In addition to their staple diet, they may occasionally hunt other invertebrates like butterflies, moths, and bees, displaying dietary versatility.
Giant crab spiders are a relatively aggressive species, particularly female spiders carrying an egg sac. Females tend to be highly protective of their offspring and will attack any perceived threat, including humans.
A bite from a giant crab spider can be considerably painful, with a potency that surpasses most other spider bites. It is typically more severe than a bee sting. The venom of this spider can cause a range of symptoms, including nausea, headaches, and localized swelling.
- The giant crab spider has curved legs, providing it with a crab-like appearance.
- This spider species prefers warm and dry climates.
- They are adept at running, climbing, and jumping, enabling them to easily capture their targets.
5. Mouse Spider (Scotophaeus blackwalli)
The mouse spider is indigenous to Europe and some regions of Asia. It has been introduced to a few states in the US, including Oregon.
This spider species has a dark brown carapace and a gray/brown abdomen. The legs of the mouse spider are brown as well. It also has hairs that resemble those of a mouse, from which it derives its common name.
As with most other spiders, females are larger than males, measuring about 0.5 inches. Males typically measure around 0.35 inches.
When it comes to reproduction, the female mouse spider carefully selects a dimly lit location to deposit her eggs. Within this chosen area, she constructs a silken “chamber” around herself. Then, she attaches a thin disc of silk to a flat surface and places her eggs in the center.
To protect the eggs, she envelops them in a thicker layer of silk, measuring approximately 10-12 millimeters in diameter. The number of eggs within this silk cocoon can range from 50 to 130.
The mouse spider typically inhabits burrows located underground, with a preference for areas near rivers and creeks. However, it can also reside in suburban gardens.
The mouse spider occasionally scavenges on deceased insects and other spiders.
Their bite is not dangerous. The venom isn’t particularly potent and does not pose a significant threat to humans or pets.
- The mouse spider is typically spotted indoors and is most commonly observed during May.
- This spider is extremely quick and agile, making it challenging to capture or photograph.
- The mouse spider also lives in Colorado, California, Washington, and Oregon.
6. Western Lynx Spider (Oxyopes scalaris)
The western lynx spider, or Oxyopes scalaris, is a species of lynx spider.
Due to its unique appearance, it is often mistaken for a jumping spider. The spiny-legged lynx spider features eyes that are situated on the top of its head instead of on the sides. Their coloration can range from light to dark brown, with creamy markings on the body. Female western lynx spiders can grow up to 0.3 inches long, while males are typically smaller.
The western lynx spider is a highly skilled daytime predator that actively hunts for prey on the ground. Due to its incredible speed and agility, this spider can be difficult to observe or capture. It jumps rapidly when disturbed.
These spiders typically prefer to inhabit areas with abundant leafy vegetation. They love grassy fields and row crops with plenty of weedy growth.
The western lynx spider is a predator that feeds on various arthropods, including other spiders.
While the venom of the western lynx spider is potent enough to kill its prey, it is not a threat to humans.
- This spider has excellent vision for capturing its prey.
- Western lynx spiders are native to North America.
- They are also called the table grape spider.
The photo featured at the top of this post is © iStock.com/George Inguanez
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