Arachnids of Columbia County, Oregon

Arachnids are the 8-limbed arthropods, including spiders, scorpions, mites, ticks, and others. With over 500 species of spiders in Oregon not to mention the other families, it would be impossible to include every Columbia County species here. I’ve shown some of the most common and/or interesting arachnids you might find.

List of all arachnids recorded in Columbia County

Yellow Garden Spider columbia county oregon
Yellow Garden Spider – Part of the Orbweaver family, building large round webs with a zigzag pattern in the middle. (photo © codyhenson123)
Cross Orbweaver – Introduced from Europe. Like all Orbweavers it builds a new web every morning after eating the old one. (photo © emmaraven)
Six-spotted Orbweaver – This species builds small webs just 3-4″ across. Found across North America, Europe, and Asia. (photo © edoswalt)
Shamrock Orbweaver oregon columbia county
Shamrock Orbweaver – Color varies but always has white spots. Like other Orbweavers, bite is painful but not dangerous. (photo © Mike Patterson)
Goldenrod Crab Spider columbia county oregon
Goldenrod Crab Spider – The Crab Spider family holds their legs up waiting to ambush prey. Also called “flower spiders” as they wait in flowers. (photo © Mike Patterson)
Oblong Running Spider oregon columbia county
Oblong Running Spider – Part of the Running Crab Spider family, it sits on plants with ambush techniques as well as chasing after prey. (photo © natureguy)
Lynx Spider – Another family of ambush predators that hide in flowers or on leaves or stems. Its bristles may help it hold onto prey. (photo © rojasburke)
Six-spotted Fishing Spider
Six-spotted Fishing Spider – This Nursery Web Spider makes a web for its eggs. It can hunt fish but more often eats insects in or near water. (photo © Chase Lansdale)

Bronze Jumping Spider – Members of the Jumping Spider family are active hunters, seeking out prey and then pouncing on them. (photo © James)
Zebra Jumping Spider – The middle two of its eight eyes are very large, as Jumping Spiders hunt their prey by sight rather than building a web. (photo © Lee Cain)
Johnson's Jumping Spider oregon columbia county
Johnson’s Jumping Spider – One of our largest Jumping Spiders, about 0.4″ long. It can jump up to five times its own body length. (photo © Jim Johnson)
Bold Jumping Spider oregon columbia county
Bold Jumping Spider – Jumping Spiders do have small silk-lined nests on the ground, where they rest at night and take their prey to eat. (photo © danpvdb)
pacific foldingdoor spider oregon columbia county
Pacific Foldingdoor Spider – These Trapdoor Spiders dig a tunnel and then cover it with a plug, springing out when an insect walks over the plug. (photo © Christina Doherty)
woodlouse spider oregon columbia county
Woodlouse Spider – These subterranean spiders (originally from the Mediterranean) use their large jaws to eat woodlice, crickets, and even centipedes. (photo © lohump)
mouse spider oregon columbia county
Mouse Spider – The Mouse Spider is part of the Ground Spider family. They don’t build webs, but hunt down prey and then use silk to entangle and subdue it. (photo © natureguy)

wolf spider oregon columbia county
Wolf Spider (Schizocosa mccooki) – One of many species of the Wolf Spider family, hunters that run along the ground searching for prey. (photo © Ken Chamberlain)
Sierra Dome Spider – Part of the Sheet Web Spider family, this one builds a web in the shape of a dome between the limbs of bushes or trees. (photo © Johannes Riutta)
Giant house spider oregon columbia county
Giant House Spider – Originally from Europe but now in homes in Oregon, it is the largest (1-3″ legspan) spider around. Hides in a funnel on the edge of its flat web. (photo © disciseda)
Long-bodied Cellar Spider oregon columbia county
Long-bodied Cellar Spider – Often mistaken for a Harvestman (Daddy Longlegs), this is a true spider that builds tangle webs in dark places in homes. (photo © rojasburke)
Yellow Sac Spider columbia county oregon
Yellow Sac Spider – Has no web but hides in silk sac, coming out at night to hunt. Often lives in homes and is responsible for human bites, but is not dangerous. (photo © giorege1959)
Common Candy-striped Spider columbia county oregon
Common Candy-striped Spider – Can have 1 or 2 red stripes, or none at all. A Tangle Web Spider that builds cobwebs in corners and empty space. (photo © Grant Bassett)
Common House Spider – The most common Tangle Web species in homes, it would rather run away than bite, though bites are quite painful. (photo © David Anderson)
False Black Widow oregon columbia county
False Black Widow – Another Tangle Web species, bites can cause severe pain and blistering, headache, and nausea, but are not deadly. (photo © Howard Bruner)
Western Black Widow oregon columbia county
Western Black Widow – The red hourglass identifies the only truly dangerous species in our region. It is rarely seen here and prefers drier habitats. (photo © Sam McNally)
European Harvestman columbia county oregon
European Harvestman – Known as “Daddy Longlegs”, Harvestmen are not spiders. They have no venom, no silk, and a head that appears indistinct from the body. (photo © insectology)
Black Harvestman oregon columbia county
Black Harvestman – This native valley species uses its legs and especially robust mouthparts to subdue its prey. It is also called the “Crab-clawed Harvestman”. (photo © Tobyhays)

Northwest Cave Harvestman (Nelima paessleri) – This resident of our forested mountain ranges overwinters in caves in large aggregations. (photo © Andy Harmsen)

Pacific Tree Harvestman (Leptobunus parvulus) – This local forest species is arboreal, found from low brush to over 90 feet high in Douglas Fir. (photo © Matt Goff)
Western Black-legged Tick – A small tick just 1/10th of an inch long, but carries Lyme Disease and several other diseases. Sometimes called “deer ticks”. (photo © Thomas Barbin)
American Dog Tick – This is a female, the males have a similar white marble across the entire body. These ticks are much larger and don’t carry as many diseases. (photo © Mike Burrell)
Trombidium mite oregon columbia county
Red Velvet Mites – These little red mites are active predators in the soil as adults. In India they are collected for traditional medicine. (photo © David Anderson)
Pseudoscorption oregon columbia county
Pseudoscorpions– Tiny arachnids with pinchers like scorpions but are much smaller and have no stinger. Usually found under cover in dead wood or soil. (photo © Matt Hunter)

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