Brown Recluse Spider - Loxosceles reclusa
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Haplogynae » Six-eyed Spiders (Sicariidae) » Brown spiders (Loxosceles) » Brown Recluse (Loxosceles reclusa)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
Brown Recluse - University of Nebraska

The brown recluse spider is a venomous spider, Loxosceles reclusa, of the family Sicariidae (formerly of the family Loxoscelidae). It is usually between ¼ and ¾ inch (6-20mm) but may grow larger. It is brown and usually has markings on the dorsal side of its cephalothorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider, resulting in the nickname "fiddleback spider" or "violin spider". Coloring varies from light tan to brown and the violin marking may not be visible. Since the "violin pattern" is not diagnostic, and other spiders may have similar marking (i.e. cellar spiders (Pholcidae family) and pirate spiders (Mimetidae family)), for purposes of identification it is far more important to examine the eyes. Differing from most spiders, which have 8 eyes, recluse spiders have 6 eyes arranged in pairs (dyads) with one median pair and 2 lateral pairs. Only a few other spiders have 3 pairs of eyes arranged this way (e.g., scytodids), and recluses can be distinguished from these as recluse abdomens have no coloration pattern nor do their legs, which also lack spines.[1] Recluse spiders build irregular webs that frequently include a shelter consisting of disorderly threads. These spiders frequently build their webs in woodpiles and sheds, closets, garages, and other places that are dry and generally undisturbed. Unlike most web weavers, they leave these webs at night to hunt.


Brown Recluse Spider


Fig. 1  Recluse Distribution		 Avoid being bitten by a Brown Recluse Spider

This applies only to those people who live within the areas of the map figure 1.  If you do not live within this area on the map, you do not have recluse spiders. Within this zone, brown recluse spiders are quite common. However, brown recluse spider bites are not common.  Humans of the Midwestern U.S. are living with millions of brown recluses every day and bites are extremely rare. Evidence exists of households that contained dozens of recluses, yet nobody in that household (including infants and toddlers) ever showed any evidence of having been bitten.
This does not mean that you should ignore them.

Here are a few suggestions as to how to reduce your chances of being bitten.


Be aware that it is almost impossible to eliminate recluse spiders from a building once they get established. The best you can hope for is a significant reduction in the numbers of spiders and take steps to reduce the chances of being bitten.

Use sticky traps to trap spiders. Every one you catch is one less recluse that can bite you.

Prevent spiders from occupying your beds: Remove bed skirts from beds, and move the bed away from the wall. Remove everything from under the bed so that the only way the spiders can get up on the bed is to crawl up one of the four legs.

Many bites have occurred when people put on clothes that had been lying around for several weeks or months, and pressed the spider against their skin. Don't throw clothes on the floor and then wear them the next day. If you do, shake them out or squish them into a ball before putting them on. Bang out shoes.

When you store things in the garage, basement or attic, put them in plastic bags that you can close with a plastic zipper lock or twist-tie. This is especially important for things that you stick your hands and feet into like: roller skates, baseball gloves, gardening gloves, boots, raingear. Seal boxes or bags to prevent spider entry. Be careful when you move things out of storage areas, in particular, cardboard boxes. Recluses like to hang out in the space under folded cardboard flaps. Be careful when you carry the boxes as you might place your fingers on a recluse when you pick up the box or press a recluse against your body when you carry it. Remove any spiders inside boxes using a vacuum cleaner and dispose of the bag. Reseal all open edges of cardboard boxes with tape before restoring them.

Clean up clutter and junk that is lying around. Recluses love clutter and prefer to live under and between items, such as plywood, tarps and cardboard on the ground.

Do not stack wood against the house. Recluses like woodpiles and if they take up residence inside wood stacked next to a house, there is more chance that they will wander into the home. Move the woodpile as far from the house as possible, stack it off the ground and cover it with a tarp. These steps make the firewood less attractive to insects and the spiders that feed upon them. Also, when you pick up wood, wear gloves. Of course, check the gloves first for spiders, or stomp on the gloves first to squash a spider (as disgusting as it might seem to put on a glove with a squished spider in the finger, squished spiders don't bite.)

Other things you should know about brown recluses:
Most households with brown recluses never experience a bite
90% of all brown recluse bites heal without severe scarring.
Many brown recluse bites cause just a little red mark that heals without event.
Despite all the hoopla surrounding the brown recluse, there is still not one PROVEN death due to brown recluse bite.

- Adapted from University of California Riverside Dept. of Entomology "Avoiding Brown Recluse Spider Bites"

The most definitive physical feature of recluse spiders is their eyes: most spiders have eight eyes that typically are arranged in two rows of four but recluse spiders have six equal-sized eyes arranged in three pairs, called dyads. There is a dyad at the front of the cephalothorax (the first main body part to which the legs attach) and another dyad on each side further back.

  
              
 
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