Hey all,

I've killed a couple large house spiders in the past few days.  Mostly outside, but I just killed one of these buggers inside.  Coming from the midwest, I've not run across spiders this large, but my neighbors say they're not dangerous.  They look like a normal house spider, but they're about two inches in diameter.  Are these common northwest critters?  Is this the season for them?

Thanks,
BoB

I was in my back garage yesterday and found dozens of black widows. And I also saw tons of egg sacs, I don't know if they were all black widow sacs. I think they are getting ready to start hatching because I found a bunch of little spiders also. I think the warm weather we've been having is just bringing the spiders out in force.

This wasn't a black widow.  Just a large house spider.  The worst it could be is a hobo, but the abdomen looked a little different.  I extermined with extreme prejudice.  Perhaps next time I'll kill it a little more gently and try to figure out what it is.

BoB

Oh yeah.  We get some big sumbitches!  Not AZ big but OMG WTF was that big.

I've not seen spiders as big here as we'd get back in Michigan, but just in case I ever do....

Kooter,
Black Widow Spiders in WA

There is a black spider that resembles the black widow, but to my knowledge it's not a black widow.  I've never seen a black widow in western Wa.  Always heard they don’t hang up here?

But, for the other large spiders, they can get pretty large.....

Just so you all know  the hobo spiders bite is very similar to a brown recluse. As in  your flesh will die and you will get a big huge gaping abcess on the area of the bite. the hobo spider is relativley hairless is approx 2" in diameter when fully grown. and can be identified by a chevron pattern on the abdomen. Generally they are an outside spider. They like wood piles and dark places. If they are not invading your house I wouldent worry about them. They do more good than harm.
If you want to look up more information the the HOBO spider it is also called the Aggressive house spider. cru.cahe.wsu.edu/CEPublications/eb1548/eb1548.html Here is the Washington State site .

egenaria agrestis, the aggressive house spider, is one of the most common spiders found in houses in the Pacific Northwest. Although this spider was first reported from Seattle in 1930, it did not become common in the Pacific Northwest until the 1960s. In the Pullman-Moscow, Idaho area, it is clearly a prevalent spider in basements and in window wells of houses. It rarely climbs vertical surfaces and is usually found only on the ground or lower floors. We have called it the "aggressive house spider" because it bites with little provocation when cornered or threatened.
     
 Description.
 Tegenaria agrestis is a relatively large, swift running spider. Mature adults range from 4—5 cm diameter (1 to 13/4 inches) including legs (Fig. 7). As with most spiders, males can be identified readily by the expanded, swollen tips of their palps.
     
 

Fig. 7. A sexually mature male Tegenaria agrestis.

     
 Sexually mature males and females are abundant from mid-summer (July) through fall.

During this period males tend to wander relatively long distances in search of females. Eggs are laid into a spherical silken sac spun by the female, usually in September or October in the Pullman area. The sac is then placed within or adjacent to the funnel, usually on the underside of a rock or other object. This sac is usually covered with a thin layer of soil, wood chips, or other debris, including prey. The debris coated sac then is often covered with another layer of silk. Eggs hatch the following spring. Most Tegenaria molt about 10 times over a span of 2 years before reaching sexual maturity. Immatures are commonly found wandering in the spring searching for web sites.

Investigations of aggressive house spider bites show the venom produces skin injuries, or lesions, similar to those produced by the brown recluse. Therefore, ulcerating lesions of this type occurring on humans in Washington, Oregon, and Idaho are probably due to bites by the aggressive house spider. Surprisingly, males are somewhat more venomous than females.

Bites commonly occur as a spider is squeezed against the body when a homeowner picks up a firewood log with a spider on it or when a spider is located in an article of clothing and is squeezed when the clothing is put on.

The initial bite is not painful. It has been described as producing a very slight prickling sensation. However, a small, insensitive, hard area appears within 30 minutes or less, and is surrounded by an expanding reddened area of 5—15 cm in diameter (2—6 inches) (Fig. 8).

     
 

Fig. 8. Typical bite sequence pathology for the aggressive house spider.

     
 Within 15 to 35 hours the area blisters. About 24 hours later the blisters usually break, and the wound oozes serum. A cratered ulcer crusts over to form a scab. Tissues beneath the scab may die and slough away. In some cases the loss of tissue may become so severe that surgical repair is needed. The fully developed lesion can vary from about 1/2 to 1 inch or more in diameter. Lesions may take several months to heal, and frequently leave a permanent scar (Fig. 9).
     
 

Fig. 9. A Tegenaria agrestis bite on finger.

     
 Systemic illness may or may not accompany the bite. However, the most common symptom is a severe headache, sometimes occurring within 30 minutes, usually within 10 hours, that does not respond to aspirin. The headache may persist for 2 to 7 days, and is sometimes accompanied by nausea, weakness, tiredness, temporary loss of memory, and vision impairment. The symptoms are similar to those experienced with migraine headaches. Bites by Tegenaria agrestis have not caused a death. In Europe, their area of origin, there are few records of bites by these spiders causing medical problems. However, a person bitten by one of these spiders should seek immediate medical treatment.

Yeah, this guy had little hairs and a small abdomen, so I'm fairly certain it wasn't a hobo.  Has anyone else seen these before?

Thanks,
BoB

Daddy long legs? They're harmless.

Quoted: Daddy long legs? They're harmless.

No, I've seen those before.  To me, this looked like a house spider at double the size.  Freaked my ass out.

BoB

Did it look like this?

Quoted: Kooter, Black Widow Spiders in WA There is a black spider that resembles the black widow, but to my knowledge it's not a black widow.  I've never seen a black widow in western Wa.  Always heard they don’t hang up here? But, for the other large spiders, they can get pretty large.....

Sure looked like black widows to me. But honestly, I squish them first then they all look alike I will try to catch one so I can torture examine it a little more closely.

Bob:
You will see MORE spiders in the October/November time frame. I don't know what it is about the fall time frame but maybe its the temperature drop that sends them inside seeking warmer shelter?
Maybe its just me, but thats the time of year I tend to notice more of them in the house.

Quoted: Kooter, Black Widow Spiders in WA There is a black spider that resembles the black widow, but to my knowledge it's not a black widow.  I've never seen a black widow in western Wa.  Always heard they don’t hang up here? But, for the other large spiders, they can get pretty large.....

I thought I had found some Black Widows up here in Lynden while I was cleaning out the backyard shed. They look just like a Black Widow, but do not have the red hourglass on their abdoman.
There are Black Widows in BC though.

Quoted: Quoted: Kooter, Black Widow Spiders in WA There is a black spider that resembles the black widow, but to my knowledge it's not a black widow.  I've never seen a black widow in western Wa.  Always heard they don’t hang up here? But, for the other large spiders, they can get pretty large..... Sure looked like black widows to me. But honestly, I squish them first then they all look alike I will try to catch one so I can torture examine it a little more closely.

I know that in SW Washington there are black widows.  While cleaning out my shed before I moved this spring I found several, and yes they had the red hourglass.  One of my friends parents was bitten on the leg by a hobo and that was the nastiest looking bites I have even seen.  When it was all said and done the area of dead skin was about the size of a tennis ball.  Nasty spiders.  Hobo's have migrated all the way to where I live now.  They are more common here then widows or recluse spiders.  Stomp on them!

Quoted: Did it look like this? cru.cahe.wsu.edu/CEPublications/eb1548/fig11.jpg

No, it didn't have that large of an abdomen.  The legs looked a little different as well.  They appeared to come from all around the body as opposed to 4 on a side.  I went and found the carcass of the one I killed in the garage.  It had the spots on the underside (by the legs) that are indicitive of a medium sized house spider (I forget the latin name).

BoB

I think I know what your talking about. Real fast spider that is hairy. Every once in a while I catch one in the corner of my eye running across the carpet. I usually smash them because they are too fast to catch by hand. They are harmless much like most of the insects here in WA. I have seen a blackwidow under my house while I was putting up insulation. I just sprayed it with some bug kill and that was the end of that.

Quoted: I think I know what your talking about. Real fast spider that is hairy. Every once in a while I catch one in the corner of my eye running across the carpet. I usually smash them because they are too fast to catch by hand. They are harmless much like most of the insects here in WA. I have seen a blackwidow under my house while I was putting up insulation. I just sprayed it with some bug kill and that was the end of that.

Yeah, that's the bugger.  Real fast.  They're so fast that I had to spray one (in the garage) with some cleaning solvent as I couldn't get bug spray fast enough (he ran back under some shelves).

BoB