Welcome to this brief introduction to Washington spiders. As with most states, knowledge regarding the totality of the Washington spider population relies on the few experts who perform common search tasks such as shaking the conifer tree limbs and sweeping grassy areas with nets in search of the spider species not seen by most Washington residents.
Even with those limitations, the average spider enthusiast can still find around two hundred species by paying close attention to their surroundings. In some instances, such as the presence of the giant house spider sitting, sometimes unwelcomely in a corner of the room, they are easy to spot. In other instances, such as the presence of funnel weaver spiders in the lawn, only the dew on the grass indicates their presence via their water drop enhanced webs.
This introduction focuses on the more common types of spiders visible to residents and it starts with the jumping spiders. A hefty chunk of the fifty or so species found in the state can easily be found in the back yard. Some, such as the bold jumping spider, can wander indoors. Most live around the local plant live where they tend to walk around looking for prey. Many of the adults can be easy to identify because of their distinctive body colors and patterns.
Like most things in life, there’s an ID catch. Many juvenile jumping spiders go through physical phases as they emerge into adulthood. The juvenile Johnson’s Jumper in the video is a good example. BugGuide provides a series of pictures showing six different phases juveniles might take prior to assuming their noticeably red body color.
Because the camera’s macro lens was placed about three inches away from the spider, it’s reasonable to assume that the spider saw it’s reflection in the lens. The rubbing and showing of the fangs is a behavior noted in a few other videos associated with questions about jumping spider behavior. Is the spider marveling with it’s first instance of self-recognition or is the spider going into a semi-defensive posture after seeing what looks to be another spider’s territorial encroachment? Hard to say. Either way, taking videos of jumping spiders can be fairly easy and fun because they appear to be amenable to a camera lens.
The video also provides an example of how a tech savvy couple of generations have helped experts learn more about spider populations. For example, a recent article, Spiders feeding on vertebrates is more common and widespread than previously thought,
geographically and taxonomically (2022. Journal of Arachnology 50:121–134) used pictures from the internet as part of the data to research the topic. They being by noting,
According to a recent global literature survey, a total of 39 out of the 129 known spider families (~30%) contain species capable of capturing vertebrate prey. The finding that the percentage of spider families engaged in
vertebrate predation is so high is novel.
Of course, the emergence of AI and it’s ability to create pictures on demand could skew future research with spider-vertebrate prey photos or videos. Nonetheless, the presence of first and second generation internet technology has helped with improving our understanding of spider behavior.
Switching back to jumping spider identification, a handful of adult jumping spiders have brown bodies, differentiated by white markings that serve as the best ID clues. The included two pictures show the Bronze jumping spider and the Oak jumping spider.
Male Bronze jumpers have a distinct brown body with white stripe on the abdomen.
Even without the distinct body patterns, the white mustache of Oak jumping spiders serves as the best ID clue.
Because they live around residential areas, the Zebra jumping spiders, one of the more than a dozen non-native species that now make their home in Washington, are also easy to find and identify.
Common Washington Spiders
A handful of spider families tend to live around residential areas, and for various reasons they can be easily seen and identified. Visitors interested in learning more about the spiders in this section can press the green spiders button for additional information.
Despite the discussions about the dangers of the Hobo spider, Long-legged sac spider, Brown recluse and Black widow spiders, arachnologist Rod Crawford, consistently makes the media rounds in the Seattle area assuring residents that, with very few exceptions, spiders of medical importance don’t inhabit the western part of the state.
The picture shows a Long-legged sac spider (C. inclusum) it’s more common in western Washington and is more likely to be found inside homes and buildings. Researchers have noted it’s painful, albeit non-life threatening bite.
Along with the Giant house spider, the Hobo spider shares the fact of being non-native species that raise hackles because they are funnel weaving spiders that enjoy living indoors rather than in the yard.
The funnel weaving family extends to more than one genera, and funnel weavers use a variety of habitats, such as the grass and bushes around the home as their home base. One of the most common, the Western Funnel Weaver, is pictured. They can grow fairly large and the red coloration at the top of the abdomen is a good ID clue.
Wolf spiders also roam residential grounds and often somewhat resemble funnel weavers at first glance. With few exceptions, identifying wolf spiders can be challenging. The name thin-legged Wolf Spider adopts a physical feature of the spider. However, a few wolf spider genera are well known for thin legs. Genera differences boil down to more distinct physical features on the spiders, such as number of hairs on the legs. This is tentatively identified as a Thin-legged wolf spider.
Orbweaving spiders are another family that are easy to find and identify because they often build their orb shaped webs at eye level and remain stationary in them until an unsuspecting insect is caught in the sticky web. Washington hosts about twenty five species in genera that range from A to Z. The Cross Garden Spider (Araneus diadematus) is a highly urbanized non-native species. While body color ranges along a brown shade spectrum, the cross like marks on the abdomen help with identification.
Three different Zygiella species can be found in Washington. Identifying them using body patterns can be challenging. The same Rod Crawford mentioned above also helps on Bugguide, “Which species can’t be told from color alone. Z. x-notata and Z. atrica occur in urbanized habitats, the former on buildings and the latter on trees. Z. dispar is found in natural forest.” Size wise, they tend to be a bit smaller than the average Araneus species.
Rural areas of Washington offer great opportunities to learn about spider diversity in the state. The Orbweaver category is no exception.
Marbled orbweavers are much more common on the East Coast. Many know them as the bright orange or yellow spiders. In northern areas across the United States, including Washington, they can have very muted body colors like the specimen in the picture.
Moving down the common species ranks, outdoor enthusiasts might want to keep an eye out for Aculepeira packardi during the summer hiking season. They can be found in mountain meadows. Beginners could easily mistake it for the Western Spotted Orbweaver. The rounded shape on the abdominal pattern is a good place to start a physically based ID.
Stretch spiders, genus Tetragnatha, rank as the most diverse and common of the state’s Long-jawed orbweavers. One look at the picture explains the name. Unlike the members of the larger orb weaver family, stretch spiders can often be found lounging on a leave on a sunny day. Up to ten different species have been documented in the state.
A few species that go by the name crab spiders also can be found at eye level around yard. They can have circular abdomens, a good ID clue for the flower crab spiders. They can also have thinner bodies such as the slender crab spider (part of the running spiders group) in the picture.
Closely related to the spiders, about two dozen harvestmen species also live in the state. Six legs and one body part serve as basic ID clues. The European harvestman (Phalangium opilio) might be the easiest to find. They are fairly large in size and tend to sit still on leaves waiting for prey.