Spiders in Western Washington: Identification, Prevention, and Treatment
Anyone who has lived in Washington knows Spiders are frequent visitors of our homes, offices, and gardens. They are a type of Arachnid, meaning they use 8 legs to move around. Spiders can also spin strands of silk in order to create webs, allowing them to take cover in out of reach areas. These silk threads enable Spiders to fly along the breeze like tiny, creepy Mary Poppins. That being said, Spiders are almost entirely beneficial. They feed on a wide variety of insects and other annoying or harmful critters, such as mites.
Table of Contents
The Hobo Spider
The Hobo Spider is a kind of House Spider, or formally, the “Aggressive House Spider.” It’s important to note that this name does not accurately describe the behavior of this species. This spider is a member of the Agelenidae family or Funnel-Web Spiders. The Hobo Spider creates a funnel-like web (as the family name suggests) in dark, moist places where it waits at the mouth of the funnel for prey.
Europe introduced many species of Hobo Spider to the United States. We have three species here in the Pacific Northwest, none of which are native. The most common of these species is fairly large. Females are usually less than 1 inch in body length, not including their legs. The Hobo Spider can and will travel long distances. They are fast runners and can cover 15 to 20 inches per second.
Males and females are most common in the fall, however, you can find them around at any time of the year. Females lay their eggs in spherical silken sacs, near the web on walls or other structures. This occurs in the fall, and eggs hatch the following spring. Female spiders die once they have laid their eggs. These spiders generally have a 2 year life cycle, although some females can live for over 3 years. Additionally, Hobo Spiders can live for several months without food or water.
Wolf Spiders
People usually fear Wolf Spiders because of their quick movements and larger size. Unlike Hobo Spiders, Wolf Spiders do not wait in a web for their prey to get caught. They are ground hunting Spiders, so you will find them in fields or on the forest floor. Although they do not weave webs, Wolf Spiders can spin silk and will do so in order to create egg sacs to carry.
Species found in Washington State range from ⅕ to 1 inch long, legs not included. Each of their legs ends in a 3-clawed foot, allowing them to grip and climb objects easily. They are typically brown or dark brown in color.
Wolf Spiders are nocturnal and hunt during the night. In the Fall, you may find them in house plants, basements, or garages. They do bite, but only when provoked, and are not aggressive. Like most species of spiders in Washington, they are pretty shy and avoid people.
Orb Weavers
Another common species during the Fall is the Orb Weaver. Orb Weavers spin their webs in large spaces, such as between pillars, across gates or paths, or between branches. Their wide, organized webs often have a small hole in the center where the Spider sits, waiting for prey. It is most likely that you will find them around the exterior light fixtures of your home where pests gather (such as moths or other insects). You’ve probably walked through a few of these webs before.
You can identify this Spider by its large, globe-like abdomen, which is often patterned with stripes of black, brown, orange, or yellow. The most common Orb Weaver in Western Washington has a white cross on its back. They are about ¾ to 1 inch in size, not including their legs.
This species is rarely found indoors, however they may make their way in by accident. They are non-aggressive and generally fearful, darting away when their web is disturbed or torn down. While they can be especially numerous September through October, they provide protection against insects, and are pretty much harmless.
Jumping Spiders
This family of tiny and cute looking Spiders is vast. Washington is home to many different species that range in color and size. It is not uncommon for them to be brightly colored, iridescent, or patterned. However, more abundant species are neutrally colored so that they can better blend in with natural backgrounds.
These little Spiders are quick and have great eyesight. They can hunt during the day, and capture prey by utilizing the element of surprise to pounce when it is least expected. Interestingly, Jumping Spiders do not spin webs. However, they are capable of creating silken strands and will use them to lower themselves onto unsuspecting prey. They will also spin silken pouches to shelter themselves overnight.
A fun fact about this type of Spider: it can move forward, backwards, sideways, and can spin around without moving forwards!
Harvestmen
Also known as Daddy-Long-Legs, these are not technically spiders, but are extremely common in this area, and worth mentioning. Harvestmen are arachnids (like Spiders). However, they cannot spin silk strands, and instead hunt tiny insects and feed on plant material. They do not have fangs, but use their small claw-like mouthparts to eat. These mouthparts cannot penetrate human skin, so they are totally harmless and overall beneficial creatures.
A Note About Black Widows and the Brown Recluse
We occasionally have individuals contact us because they are afraid that they have encountered one of these Spiders. We want to make it clear that the Black Widow is very rare on the Western side of the mountains, as they don’t thrive in the conditions. They can usually be found in dark, tucked away places. Female Black Widows are nocturnal and timid in nature. They are not aggressive, and will typically withstand significant disturbances before biting as a defensive measure. While Black Widow bites can certainly be serious, they are seldom fatal. Only the female is poisonous.
Brown Recluse spiders are not native to the state of Washington. As of 2017, only 2 specimens have been found in Washington, and they were imported. Brown Recluses are more frequently found in the South Eastern U.S.
Treatment
Due to the nature of Spiders, treatment can take time to be effective. Arachnids generally have tough exoskeletons, so a perimeter spray will not instantly kill them (unless they are hit directly). They’re able to walk right over any materials we put down, and rarely mind doing so. Consider also that Spiders are not social, and do not clean themselves like other animals do. This means that they won’t interact with our materials, making residual treatments mostly ineffective.
Instead, a perimeter spray for general pests will help eliminate food sources. Our treatment for Spiders includes a web sweep to remove any webs or egg sacs that have allowed the Spiders to grow in numbers. Regular web sweeps are crucial to controlling the population. We also always recommend cutting back any vegetation from around your home. At least 10 to 12 inches between the sides of the structure and any vegetation will prevent insect and Spider activity by eliminating harborage points.
To stop creepy-crawlies from getting into your home, check access points such as doors or windows for potential gaps. Seal weak points with caulk, and invest in door sweeps and screens to prevent critters from making their way inside.
Remember, Spiders are a beneficial and abundant part of the Pacific Northwest. It is impossible to get rid of every Spider around your home, and in fact, keeping some around will help stop other insects from infesting.
Prevention
Stopping an infestation before it starts is tricky, but we know better than anyone what methods to use. We offer a maintenance service to help with all kinds of pests, including Spiders. All Pest Protection is a quarterly maintenance service aimed to prevent infestations of general pests such as Ants, Rodents, Wasps, Spiders, and other insects. We come out on a 3-month rotation to provide an exterior perimeter spray where the home and foundation meet, spot treat around doors and windows for activity, sweep reachable webs and Spider egg sacs, and maintain Rodent Bait Stations (secured, locked, black plastic boxes) on the exterior of the home to mitigate outside Rodent populations.
All Pest Protection (APP) also can include various warranties for general pests, which are established after the Initial Inspection and Treatment. Once you get started, each quarterly service is only $109 before tax. Should your house be overrun by Fleas, Bees, or Spiders, or any of the pests eligible under your warranty, all you would have to do is give us a call. We’ll dispatch a Technician to complete a pest-specific treatment at no cost to you under your APP Warranty.
Sources
Ambrose, Kevin. “The Wolf Spider Is Autumn’s Most Frightening Home Intruder.” The Washington Post, WP Company, 3 Oct. 2018, https://www.washingtonpost.com/weather/2018/10/02/wolf-spider-is-autumns-most-frightening-home-intruder/.
Antonelli, Arthur L. Pest Management Study Manual for Pest Control Professionals. Washington State University Extension, 2016.
Boriyo, Hawii. “How to Identify a Wolf Spider.” OSU Extension Service, Oregon State University Extension Service, 19 July 2018, https://extension.oregonstate.edu/pests-weeds-diseases/insects/how-identify-wolf-spider
Bush, Michael R, et al. “Common Spiders of Washington.” Washington State University Extension, Sept. 2018, pp. 1–15., https://pacificalandscapesseattle.com/wp-content/uploads/Pacifica-Landscapes-Resource-Documents-Common-Spiders-of-Washington.pdf.
About the Authors
This article was created and edited in collaboration with multiple licensed pest control technicians, experts, researchers, and authors.
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