This poster created by a pest control company claims to show dangerous American spiders. It is full of bad information. Half of the species on this chart don’t even occur in the USA. Please, don’t share it anymore!
Please don’t rely on this chart for meaningful information about American spiders. This chart is the result of a clever company re-purposing something they put together for Australia. Seriously; the Australian spider chart is exactly the same! And, frankly, the info isn’t all that accurate for Australians, either.
This post will address the parts of this poster that are wrong (pretty much all of it), and then suggest some resources for accurate information about American spiders.
Info that is completely wrong on the poster:
- Mouse spider: does not occur in the US. Mouse spiders are not aggressive, and often “dry bite” when disturbed. In other words, most of the time they don’t even inject venom!
- Black House Spider: does not occur in the US. Also, known to be timid and not dangerous.
- St. Andrew’s Cross Spider: Does not occur in the US. Harmless.
Info that is mostly wrong on the poster:
- Hobo spider: the species pictured does not occur in the US. We have some spiders called hobo spiders, but they are not the same species as the Australian one with a scary bite. Introduced hobo spiders in the US don’t seem to have venom as toxic as the rumors. In fact, a recent study of the introduced hobo species found they were fairly harmless.
- Brown Recluse: This is actually a complex of up to 6 different species of spider, and they do not occur in all areas of the US. There is a complex mythology about the bite of the brown recluse. Research suggests that the bite, while not pleasant, is not a pathway to nasty necrosis. A lot of other things cause necrosis of the skin, which is often blamed on a hapless spider.
- Wolf spiders: Lots of wolf spiders occur in the US, but they are of minimal medical importance. No serious medical consequences of a wolf spider bite has been reported, and their bite is not painful or toxic.
Information that is slightly right on the poster:
- Garden orb-weaving spiders do occur in the US, and are beneficial and harmless.
- Huntsman spiders: the species in the photo does not occur in the US. We have some huntsman spiders, but they are much more modestly sized than the Australian and tropical versions. Harmless unless provoked, and even then pretty harmless.
- Trap Door spiders do occur in the US, although not the species pictured. They are harmless and fascinating!
- Black Widow Spiders do have a toxic bite, and do occur in the US, but that’s about as far as the correctness goes. There are 5 different Widow species in the US, and Black Widow bites are not lethal to humans. In fact, as of 2011, there are no known reported deaths from black widow bites in the US. Black widow spider bites can cause muscle cramping and abdominal pain in some people; pregnant women and children are most at risk.
To sum up: This poster is unhelpful and mostly filled with bullshit with regards to US spiders. Don’t rely on it, and don’t share it.
How can you know what information online about spiders is good information?
Easy! Go to your local Extension website. In the United States, every single state has an Extension service (or did until state budget cuts a few years ago, anyway).
“Each U.S. state and territory has a state office at its land-grant university and a network of local or regional offices. These offices are staffed by one or more experts who provide useful, practical, and research-based information to agricultural producers, small business owners, youth, consumers, and others in communities of all sizes.”
The Extension Service is charged by the USDA and each state government with producing factual, well-researched information for consumer use. You can tell you are on an Extension website because it will be affiliated with a land-grant university, and have a .edu web address. So, for example, searching for “Nebraska fact sheet spiders” gives me this information specific to that state (and also some tips about keeping a wolf spider as a pet!).
There are amazing, free resources available to you. Use them! And look for that .edu web address. Don’t listen to stories of a friend who knows a friend who lost their Aunt Gertie to a giant toxic banana spider that was in a pack of underpants. Seek out reliable information.
Some actual helpful, authoritative resources about American spiders:
- Spiders do not bite. Some common sense about spiders from an expert. A Must Read!
- Real, peer-reviewed info about American Spiders
- Common spiders of the East Coast
- Seriously, you weren’t bitten by a brown recluse
- How to identify a Hobo spider (PDF)
- Sac spiders don’t really make webs in your scrotum.
A personal note:
I just finished a move across country. As part of this move, I had to clean out the space behind my washing machine. I was hunkered over shelves, trying to wipe things off, and when I stood up I’m fairly sure that my entire head was covered in cobwebs. I…may have let out a sound of a frequency last produced by Little Richard hitting one of his high notes.
I mention this to let you know that even bug people get the heebie jeebies around spiders sometimes. It’s ok to not like spiders as long as you remember the vast majority of spiders are your friends. You don’t have to kill them! They are valuable (and free!) pest control for your yard and garden. Unless there is something seriously wrong with your personal hygiene, spiders have no interest in living on you or in you. Try to live and let live.