Tag Archives: Eratigena duellica

San Juan County, WA Spider Information – Resource Sheet 

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Scared of Spiders?  Here’s a go-to info-sheet (that I plan to update as time allows) with links to verifiable, research-backed Spider Information/Literature.  Let’s end all the misinformation and our arachnophobia.  Too often people buy into false reports.  Don’t listen to someone’s tall tale of horror.  These stories are sensationalized and inaccurate.  Know the facts.  Dispel the rumors.  Spiders are not out to kill you.  It’s just not true. 

YOU have to do the reading!  These are scientifically based, accurate studies with information related to spider bites.  

Hobo Spiders (Tegenaria agrestis) ****Medically insignificant 

*Bennett RG, Vetter RS. An approach to spider bites. Erroneous attribution of dermonecrotic lesions to brown recluse or hobo spider bites in Canada. Can Fam Physician. 2004 Aug;50:1098-101. PMID: 15455808; PMCID: PMC2214648 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2214648/pdf/15455808.pdf.

*Melissa M. Gaver-Wainwright, Richard S. Zack, Matthew J. Foradori, Laura Corley Lavine, Misdiagnosis of Spider Bites: Bacterial Associates, Mechanical Pathogen Transfer, and Hemolytic Potential of Venom From the Hobo Spider, Tegenaria agrestis (Araneae: Agelenidae), Journal of Medical Entomology, Volume 48, Issue 2, 1 March 2011, Pages 382–388, https://doi.org/10.1603/ME09224

How to identify and misidentify a Hobo Spider –https://s3.wp.wsu.edu/uploads/sites/2210/2015/05/PLS116_1.pdf

Brown Recluse Spiders (Loxoceles sp) – NO! I repeat “NO, none, nada!” established populations in our area.  

In the attached links below, you will find links to information about the Brown Recluse Spider.  Information that comes from a verified, reputable source – from an actual expert.  Brown Recluse spiders do not live in the San Juan Islands.  Caveat: this is not to say that if you move here from an area where there ARE established populations, one might be found hitching on your moving boxes.  It’s possible, BUT – they have not been able to survive and breed here.  If you see a large brown spider in your house – especially on the ceiling, it is most likely (99.99%) going to be a Giant House Spider (Eratigena duellica).  They are very common and harmless.  If you don’t like them, just catch in a cup and take it to a sheltered area outside – preferably another structure where it might have a chance to survive.  They won’t hurt you. 

Map showing distribution of Brown Recluse spiders (Please note that San Juan County is NOT found on this map)  – https://spiders.ucr.edu/spiders-map

Map of Brown Recluse Spider distribution – UC Riverside

Where else can I find reliable information on Spiders?

There are a few sources I’ll list here.  The first two are the ones you should look at first.  They are valuable resources with information from highly credentialed experts in all things arachnid-related.  If you read something written by either Rod Crawford (Seattle Burke Museum curator of the arachnid collection) or by Rick Vetter (UC Riverside Department of Entomology), you can be assured it is correct. 

As a local resource, you can also check out the Facebook Bug Group (Bugs of the San Juan Islands).  There are several group “experts” with experience identifying spiders.  These folks generously volunteer their time and knowledge, so keep that in mind and please refrain if you feel inclined to INSIST they are wrong and there are INDEED Brown Recluse Spiders living in your house in San Juan County.  If you have a spider you’d like identified, it helps to have a couple of clear photos to submit.  Try and get a shot of the dorsal (top) of the spider, and if you’re able, one of its face – showing eye pattern.   You may contact me, Cynthia Brast-Bormann at cynthiabrast@icloud.com to submit live or deceased specimens for identification.  I will help you coordinate a drop off point for collection.  Please don’t indiscriminately KILL a spider though and ask me to ID it.  It will likely make reliable identification more difficult.  Just get a cup and a lid with some air holes punched in the top.  I appreciate your showing kindness to the helpless creature you’ve caught.  I will ID and humanely release.  

Here’s a link to Rod Crawford’s site – http://staff.washington.edu/tiso/

If you’re interested, here’s a link to his blogpost of our 2022 outing on San Juan at Reuben Tarte Park collecting spiders – https://crawford.tardigrade.net/journal/album8630.html

More great links featuring Rod Crawford: 

  1. Spiders aren’t out to get you – https://www.seattletimes.com/seattle-news/science/seattles-real-spider-man-sets-us-straight-theyre-not-out-to-get-you/

Rick Vetter UCR  

Myth of the Brown Recluse: Fact, Fear, and Loathing

https://spiders.ucr.edu/myth-brown-recluse-fact-fear-and-loathing

Local help: 

Bugs of the San Juan Islands Facebook Group – There are at least 4 spider group experts and folks with entomology degrees or experienced backgrounds in the group who are more than qualified to help you.  https://m.facebook.com/groups/bugsofthesanjuanislands/about/

Bugging You from San Juan Island (Cynthia Brast-Bormann’s entomology blog for the San Juan Islands)  https://buggingyoufromsanjuanisland.com

Great YouTube information and fun links to watch from one of Bugs of the San Juan Island’s group experts, Arlo Pelegrin (entomologist and arachnologist) 

  1. Spiders of the West and their Medical Significance – Arlo Pelegrin at Dept of Health

Sleuthing Spiders in the San Juans- Day TWO (It’s all about the NAME!)

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Sleuthing Spiders Day TWO! It’s all about the NAME.

Did you know I name the spiders in my house? I also can recognize some of the cuties that are repeat offenders. Repeat offenders? Oh yes! These are the ones who I find in my kitchen or bathroom sink on a regular basis.

I even have some that end up in the shower or bathtub. The toilet you ask? Well, we keep our toilet lids down so they don’t accidentally fall in and drown. Also, keeping that toilet lid down (especially when you flush) prevents weird germy bacteria and viruses from spewing out into the air where you might breathe it back in! That’s another topic entirely though. Tomorrow, I’ll cover why spiders end up in bathrooms in the first place, so stay tuned!

Are any of these spiders in my house going to bite me? Doubtful. And, even if they did, most likely all that would happen is NOTHING! At most, I might feel a small pinch like I did when the one hanging out in my bath towel bit me.

I knew it was a spider because I was patting myself dry, felt it bite my leg, then watched it drop to the floor. Sadly, I was the one inflicting pain and had mortally wounded the poor creature. All I suffered was a tiny raised red mark on my skin that went away in less than 20 minutes.

Was I worried about the bite? First off, I’m no spider expert because entomologists study INSECTS and spiders are ARACHNIDS. It’s all about legs (and math). Entomologists can’t count beyond 6 and Arachnologists can count to 8. Bad joke, right? I wasn’t worried because most spiders (and I’m referring to the ones that are found in the San Juan Islands) are harmless (or you can use the scientific description of “medically insignificant” to impress your friends)!

Learning to correctly identify some of these spiders will put your fears to rest. We’ll go through some of the ones commonly found in homes, especially at this time of year. We will learn to identify a black widow and where they might be found. Also, we’ll be learning about widow look-a-likes that you might not want to squish in your home because they chase the real widows away!

But today! Today, we are going to NAME that spider in our house. I found a list of very cool spider names online (check out either of these links if you need ideas – https://animalhype.com/arachnids/spider-names/ and https://petpress.net/pet-spider-names/ My favorites were Zorro, Otto, Blossom, Skreech, Jinx, Twitch, Tinkerbelle, and get this…SPINDRA!

I named my spider Tinkerbelle! I think Tinkerbelle is a SHE spider. Tinkerbelle is giant house spider hanging out in my bathroom this week. Her scientific name is Eratigena duellica.

Giant House Spider (Eratigena duellica)
Giant House Spider (Eratigena duellica)
Shelf-like spider webs in bathroom

I looked around the ceiling of the bathroom and can see little shelf-like webs where some of those super irritating fruit flies are landing. I’ve resisted my OCD urges to clean the webs away and actually appreciating the natural pest control that is free of toxic chemicals.

If you want to become FEAR-Less of Giant House Spiders, and we’ll be seeing LOTS of them through the upcoming fall months, someone I know put together an awesome YouTube video about them. You can check out Arlo’s video here –

AND, don’t forget! Post your spider photos at Bugs of the San Juan Islands https://www.facebook.com/groups/bugsofthesanjuanislands!

Brownie points for whoever has the most creative name!