31: Brown Recluse

I write to you from Arapahoe, Ute, and Cheyenne land. I am interested in learning about the different animals that live in the place where I was born. I want to mention that biological classification as taught by western science has its roots in racism, sexism, and transphobia – here’s a good explainer about why.

Today’s animal is an infamous one, the brown recluse spider (Loxosceles reclusa), one of only three spiders in North America with venom strong enough to cause a medical issue. The other two? The black widow, who we already learned about, and one that does not live in Colorado called the Chilean recluse.* The brown recluse’s venom is necrotic, which means that people – including doctors – have been known to mistake things like MRSA and fungal infections for a brown recluse bite.

According to Colorado State University, “The quickest way to positively identify if a spider might be a recluse spider is to examine the arrangement of the eyes. This requires some magnification. Recluse spiders have three pairs of eyes, a very unusual feature among spiders. Overwhelmingly, most spiders found in Colorado have four pairs. The arrangement of the eyes on the recluse spiders is one pair in the front, the other two along the sides, forming a semicircle.” I… am not sure that I will be using a magnifying glass to get close enough to this spider to make the identification.

However, turns out that it will not be a big deal, because these spiders are incredibly rare in Colorado. The only one in the Museum of Nature and Science’s collection that came from Colorado was found in Boulder in 1996. There are also credible reports of them being found in single buildings in Pueblo and in Prowers County in the extreme eastern part of the state, but both of these, and also the Boulder find, would have come from spiders who arrived in something brought from a state with a larger infestation – Texas and parts east.

*perhaps unsurprisingly, this spider is a native of South America, but after being transported by humans has established itself in some parts of the USA and, funnily enough, in the Natural History Museum of Helsinki, where they believe it arrived in a box of fruit