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Mostly Harmless, Very Creepy
The video above is one I took several years ago. The one on the left is a large specimen of an orb weaver sent to me by a customer this morning. She told me she had recently bragged about how she wasn't scared of spiders. While the orb weaver isn't particularly dangerous to humans, the sizes they reach between now and Halloween will make even the bravest among us jump back, and maybe even shriek. Just a little.
Orb weavers build elaborate, pretty webs where they expect insects to fly, which is often somewhere on the outside of your house you'd rather not have them--face-level on the porch, right in front of the garage door, basically, many of the places where you'll totally freak out when you run into the web.
Poisonous vs. Venomous vs. Dangerous
Someone asked us recently how poisonous they are, which means a little 'splainin is in order. Poisonous refers to a toxin that is absorbed, ingested, or inhaled, while venomous refers to toxins injected into you by an animal. For example, poison ivy isn't venomous, and eating a rattlesnake isn't poisonous.
There is still much research to be done on whether individuals can react to spider venom the way individuals react to bee or wasp stings. While not everyone reacts the same way when stung by a honeybee, it may be that some humans are more allergic to toxins within spider venom that others don't react to at all.
In this part of the world (Eastern WA, Northern ID, Northeastern OR), the only verifiably spider dangerous to humans is the black widow. It was once thought the hobo spider was dangerous, but it was shown long ago that there's nothing in the venom of Tegenaria agrestis to make it any more dangerous than any other spider in its genus, which fits the typical pattern.
What About the Hobo Spider?
If it somehow were especially dangerous, and none of its cousins were, it would make it unique in the "dangerous arthropods" world--all of the Widow spiders (Lactrodectus) are highly venomous to humans, as are all the Recluse spiders (Loxosceles). The other spiders in the genus Tegenaria, however, show the same toxin profile as the hobo--which is to say, not worrisome to humans.
So while 99.9% of all spiders are venomous, their venom doesn't usually affect humans much or even at all. What caused tissue damage in early reports of the Hobo spider panic hayday was actually a bacteria rubbed into the puncture wound left by the spider, not the venom itself.
Bite Wounds in General
Which brings up a very good point--whether or not the spider's venom is particularly dangerous to humans, try not to let ANYTHING bite you. We are qualified and licensed to kill arthropods that may bite you, but as for that vicious chihuahua across the street, or that pesky 3-year-old who's "going through a phase," you're on your own.