Pacific Northwest Spider Identification -Complete Guide

Introduction

The Pacific Northwest is home to a diverse range of spider species, each with its own unique characteristics and behaviors. While many people may fear spiders, it is important to understand their role in the ecosystem and to be able to identify them for safety purposes. In this article, we will explore the common types of Pacific Northwest spiders and provide tips for identifying them based on appearance, habitat, web structure, behavior, diet, and venom.

Common Types of Pacific Northwest Spiders

The Pacific Northwest is home to a variety of spider species, including the black widow, hobo spider, wolf spider, and orb-weaver spider. The black widow is easily recognizable by its shiny black body and red hourglass marking on its abdomen. The hobo spider is brown with chevron markings on its abdomen and is known for its aggressive behavior. The wolf spider is large and hairy with distinctive eye patterns on its head. The orb-weaver spider is known for its intricate webs and can be identified by its round body shape.

To identify these spiders, it is important to pay attention to their physical characteristics such as body shape, coloration, and markings. For example, the black widow’s hourglass marking is a key identifier, while the hobo spider’s chevron markings are unique to that species.

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Rarely Found Spider Species


The Pacific Northwest is also home to some rare spider species, such as the coastal giant salamander spider. This spider is only found along the coast of Oregon and Washington and is known for its large size and unique appearance. Another rare spider species found in the region is the red-legged purseweb spider, which builds its web inside a silk-lined burrow.

Identifying Pacific Northwest Spiders by Appearance

To identify spiders based on appearance, it is helpful to understand their anatomy and terminology. Spiders have two main body parts: the cephalothorax (head and thorax) and the abdomen. They also have eight legs and multiple eyes.

When identifying spiders based on appearance, it is important to pay attention to their body shape, coloration, markings, and leg length. For example, wolf spiders have long legs and distinctive eye patterns on their head.

Identifying Pacific Northwest Spiders by Habitat

Spiders in the Pacific Northwest can be found in a variety of habitats, including forests, fields, and wetlands. Some species prefer to live in dark, damp areas while others prefer sunny, dry environments.

To identify spiders based on habitat, it is important to pay attention to where they are found. For example, the hobo spider is often found in basements and crawl spaces, while the orb-weaver spider is commonly found in gardens and wooded areas.

Identifying Pacific Northwest Spiders by Web Structure

Spiders create a variety of web types and structures depending on their species and habitat. Some spiders create orb webs while others create funnel webs or sheet webs.

To identify spiders based on web structure and prevent spider webs outside the house, it is important to pay attention to the shape and location of the web. For example, orb-weaver spiders create circular webs while funnel-web spiders create funnel-shaped webs.

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Identifying Pacific Northwest Spiders by Behavior

Spiders exhibit a variety of behaviors and movement patterns depending on their species and habitat. Some spiders are aggressive while others are more docile.

To identify spiders based on behavior, it is important to pay attention to how they move and react to their environment. For example, wolf spiders are fast runners while black widows tend to stay in one place.

Identifying Pacific Northwest Spiders by Diet

Spiders have a diverse range of diets and prey preferences depending on their species and habitat. Some spiders feed on insects while others feed on other spiders or even small vertebrates.

To identify spiders based on diet, it is important to pay attention to what they are eating or what they have caught in their webs. For example, orb-weaver spiders typically feed on insects caught in their webs.

Identifying Pacific Northwest Spiders by Venom

Some spider species in the Pacific Northwest are venomous and can cause harm to humans if bitten. It is important to be able to identify these species for safety purposes.

To identify venomous spiders, it is important to pay attention to their physical characteristics and behavior. For example, the black widow has a distinctive hourglass marking on its abdomen and is known for its venomous bite.

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Tips for Safely Handling Pacific Northwest Spiders

If you encounter a spider in the Pacific Northwest, it is important to handle it safely to avoid bites or injuries. It is recommended to wear gloves and use a container to capture the spider before releasing it outside.

It is also important to avoid disturbing spider webs or nests as this can cause the spider to become aggressive and potentially bite.

Resources for Further Research on Pacific Northwest Spiders

For those interested in learning more about Pacific Northwest spiders, there are a variety of resources available. Books such as “Spiders of the Pacific Northwest” by R.J. Adams and “The Spiders of Washington” by David D. Pollock provide detailed information on spider identification and behavior.

Websites such as BugGuide.net and SpiderID.com also offer resources for identifying spiders based on appearance, habitat, and behavior.

Threats to Spider Species in the Pacific Northwest


Human activities such as habitat destruction and pesticide use are major threats to spider populations in the Pacific Northwest. Climate change is also having an impact on spider diversity, as changes in temperature and precipitation patterns can affect their habitat and food sources. Invasive species such as the European gypsy moth can also have a negative impact on spider populations by reducing their prey.

FAQs

What is the most common spider in the Pacific Northwest?

The most common spider in the Pacific Northwest is the hobo spider (Tegenaria agrestis). It is also known as the aggressive house spider or funnel weaver.

What kind of spiders are in Washington state?

Washington state is home to a variety of spiders, including hobo spiders, black widows, wolf spiders, orb weavers, jumping spiders, and cellar spiders, among others.

What is the largest spider in Washington?

The largest spider in Washington is the Giant House Spider (Eratigena atrica), which can have a leg span of up to 3 inches (7.5 cm). However, it is not venomous to humans and is not considered a threat.

Conclusion

Identifying Pacific Northwest spiders can be a fascinating and rewarding experience. By understanding their physical characteristics, habitat preferences, web structures, behaviors, diets, and venomous species, we can appreciate their role in the ecosystem and ensure our safety when encountering them.

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