The Elusive Recluse

Tim Iverson
Seasonal Naturalist
Cunningham Falls State Park

(1/2015) The Brown Recluse Spider has been put onto a notorious pedestal in American mainstream culture. It has reached some sort of quasi urban legend status through slanderous word of mouth conversations and sensationalist media accounts. But what of its status in the greatest state in the union - that’s Maryland in case you hadn’t heard? Well, despite what you may have heard the Brown Recluse is not found in Maryland. You’re probably saying, "But I know a guy who has fill in the blank (seen, been bitten by, killed) one at his fill in the blank (house, work, woods, romantic picnic date, park, etc.)!" Maybe even you yourself make this claim. I am here to tell you most emphatically and unequivocally that no, you did not.

Time and time again I’ve been drug into this argument in a professional sense as an employee of park and natural resource agencies, with friends, with acquaintances, with strangers, with family, and the list goes on ad infinitum. I don’t make many friends when I rebuke them, but the honest truth is that there is no native population of Brown Recluse Spiders in Maryland. The natural distribution range for this species of spider is roughly the entire Midwest of the United States. They can be found from southern Ohio down to Texas, and from as far west as Nebraska and Iowa to as far east as Kentucky and Georgia. I guess the Appalachian and Rocky Mountains are too much of a hike for them to cross. Outside of this range there is no known established population anywhere else in the United States. If you live outside of this area (which you do if you’re reading this newspaper) you’re golden. This is great news to an arachnophobe like me! This fact flippantly flies in the face of self-reported accounts of citizens, media, and even medical diagnoses.

According to the Maryland Department of Natural Resources, University of Maryland, and the US Department of Agriculture the Brown Recluse spider is not usually found outside of its native range. So despite many rumors and media reports to the contrary it has not established itself elsewhere outside of the Midwest. On rare occasions there have been confirmed cases of the spider outside of its native range. This is almost always attributable to "hitchhiking". The spider may be transported by luggage of people traveling from the Midwest or in packaging material originating from there. There have even been reports of single building infestations in places outside of the range where the spider has successfully made a colony, but a single incident like this does not count as successful colonization of a new area.

If you look, and not even very hard, you’ll find reported medical diagnoses of Brown Recluse bites all over the nation. These are rarely, and I mean almost never ever, authentic Brown Recluse bites. 80% of reported bites nationwide are illegitimate, making only 20% authentic. This verifiable 20% is consolidated within the Midwest, the native range for the Brown Recluse. The necrotic style of wound has become an umbrella catch all for similar wounds, and is usually attributable to other types of illnesses. These can be, but certainly not limited to: Lyme disease, herpes, diabetic ulcers, syphilis, fungal infections, chemical burns, staph infection, vasculitis, and more. Even where the spider does live bites are rare.

In areas where they are found this spider is extremely common. Where you find one you can almost certainly find dozens or more. In 2002, the Journal of Medical Entomology reported one Kansas family living in a home from the 1850’s who collected 2,055 Brown Recluse spiders in a period of six months. Not one member of this family of four had ever been bitten. An anecdotal story of an entomologist in Missouri collected 5 in a child’s bedroom in one night. There’s another anecdotal story of a person who found 6 living under his box spring. If you were to believe sensational media reports and the sheer numbers they’re found in you’d think the entire Midwest ought to be in a constant state of unrest over these villainous violin-backed arachnids. The simple fact is that the name "recluse" is more than accurate. These spiders are very reclusive and are generally not seen. They are primarily nocturnal, and hide in small dark places usually only emerging at night to hunt. They are not aggressive towards humans, and prefer flight to fight. When bites do occur it’s generally a result of being caught between skin and clothing or bedding material.

In the highly unlikely event that you think you’ve found a Brown Recluse in your home or elsewhere there are a few key features that can help you to correctly identify whether or not it is in fact a recluse spider. The spider’s legs are uniformly light brown in color covered only in very fine hairs. If you find a spider with stripes or spines on the legs it is NOT a Brown Recluse. The abdomen will be a light to dark color brown, with a darker brown shape of a violin on the back – the neck of the violin will begin just behind the eyes. The eyes are the most tell tale characteristic of the Brown Recluse. Most spiders have eight eyes arranged in two rows of four. The Brown Recluse has six eyes arranged in three sets of two. The eyes will be positioned with one set directly in front, with the other two positioned on the sides. Finally, the body of the Brown Recluse measures in at 3/8 inch long. If you find a spider that is larger than ½ inch in body length it is NOT a Brown Recluse. If you find a spider that does not meet these specific qualifications it is NOT nor ever will be a Brown Recluse.

Though bites from the Brown Recluse are rare, they ought to be taken seriously. The venom contains a hemotoxin which can cause necrosis of the skin in the affected area. According to the University of Maryland Medical Center symptoms may include: itching, nausea, chills, fever, and a general feeling of discomfort and illness. They recommend washing the affected area with soap and water, applying ice, remaining calm, and most importantly – to seek emergency medical attention. Again, Brown Recluse spiders are not typically aggressive towards humans. These spiders prefer dark sheltered areas. They only bite when threatened. A bite can be easily avoided by just steering clear of the Midwest altogether. If you can’t do that then don’t put hands or feet into areas such as logs, underbrush, clothing that is rarely worn, or any area you can’t visually inspect without checking these areas first. Also, wear protective clothing when traveling through potential habitat.

I’ll readily admit that I am one of the many who suffer self-diagnosed arachnophobia. This is why I’ve taken on the attitude of "know your enemy." Most people squish first and ask questions later, but it’s not necessary. If you see a little brown spider while hiking, camping, or at home you can rest assured it is most emphatically NOT a Brown Recluse. Marylanders can now put those fears to bed, sleep tight.