Many kinds of recluse spiders are found in many of the warmer states in the country. They’re also known as violin spiders or fiddle-back spiders because of the violin-shaped mark on their cephalothorax (the part of their body where their eyes and mouthparts are, and where their legs are connected). Note that the neck of the violin would be pointing towards the spider’s abdomen, as many other brown spiders like the Wolf spider also have various similar markings on their body.
These violin-shaped marks are easier to spot in some types of recluse spiders than in others – for example, the desert recluse is a more uniform tan color which makes these markings a bit harder to spot than in a brown recluse where these markings may be more pronounced.
Because of how similar these recluse spiders look, they’re all commonly referred to as just brown recluse spiders. However, only 1 out of 13 species of recluse spiders found in the United States can be properly referred to as such – the brown recluse spider Loxoscelesreclusa(the other recluse spiders mistaken for the brown recluse are just also brown in color).
The good news is that brown recluse spiders are not native to Arizona.
The bad news? Is that two other recluse spiders are – the Arizona recluse and the desert recluse which are common throughout Arizona, and they have venom considered to be just as potent.
Recluse spiders are typically light, medium, or dark brown in color, though sometimes they are a more blackish gray. The cephalothorax and abdomen are not necessarily the same color.
Recluse spiders have a violin shaped mark on their cephalothorax, but because a lot of other markings may be mistaken as such, another way to tell if it’s a recluse spider is by the number of eyes it has.
Most spiders have 8 eyes, but only very few have 6. Recluse spiders have 6 eyes arranged in 3 pairs of 2, called dyads. Each dyad is separated by a small space, and one pair of dyad is at the front and center of its cephalothorax, while the other 2 dyads are on each side a little further back.
Another way to distinguish it from other kinds of spiders would be its more uniformed color throughout the abdomen and legs. It also has what appears to be fine hair while many other types of spider have more stout spines on their legs.
While many other types of spider may have a few of these physical characteristics, a recluse spider must have all of the following:
- 6 eyes in 3 dyads
- Uniformly colored abdomen
- Uniformly colored legs
- Fine hair
- No spines on legs
- No more than 3/8 inches in length
OTHER SPIDERS COMMONLY MISTAKEN FOR RECLUSE SPIDERS:
Hundreds of other spiders, especially those that are brown in color, have been mistaken for recluse spiders. Just some of the most popular spiders being mistaken as recluse spiders are:
- Wolf spider
- Ground spider
- Sac spider
- Grass spider
- Cellar spider
- Southern house spider (which also has somewhat of a violin shaped mark on its cephalothorax)
In the right environment, recluse populations are dense – so if you find one, there likely are many in the area (in fact, the brown recluse spider is a common house spider in the Midwestern US).
Out in nature, they may be found in cracks and crevices in or under rocks, in the loose bark of dead trees, under piles of leaves, or under other detritus or waste debris. Indoors, some of the places they’re found are under trash cans, behind plywood, or in storage boxes.
They build small, irregular web nests they use to hide during the day, and become active hunters at night (though they may also wait for prey near their nests).
They’re nocturnal, and as such typically find other nocturnal prey that is out and about during the night. Ants are a typical menu item, especially carpenter ants.
Recluse spiders also eat larger insects, but usually only those that are already dead.
Recluse spiders have potent venom capable of causing necrotic skin lesions. The brown and desert recluse spiders are thought to have venom equally as potent, while the Chilean recluse (found in the US in CA, MA, FL, and KS) supposedly has more potent venom and the Mediterranean recluse has less potent venom.
Recluse spiders are not known to be aggressive, and like many other spiders, would much rather escape a human “aggressor” whenever possible. Cases where people are bitten are typically because they put on a shoe that a recluse spider had taken refuge in – left with no other recourse, the spider might have bitten in an attempt to dissuade our feet from fully squashing it.
WHAT BITES LOOK LIKE:
Because it’s a long list of things that cause necrotic wounds and because many other spiders are mistaken for recluse spiders, there are many conflicting sources on what recluse spider bites really look like.
The consensus is that a degree of inflammation is involved, with the bite area becoming a reddish bump.
As recluse venom destroys small blood vessels and causes them to constrict, the area may turn white, purple, or blue as fluids are no longer able to flow to the area.
As tissue is destroyed and necrosis sets, the area will sink. This is a more severe symptom, and occurs in about 10% of all recluse bites.
WHAT YOU SHOULD DO
If you think you’ve been bitten by a recluse spider, seek medical attention right away.
If you find recluse spiders in your home, get in touch with a professional pest control company for assistance in getting rid of them.
Check out our other blog entries on spiders in our Spider Archives!