The brown recluse spider is most common in the south-central United States.  These spiders are also generally referred to as “fiddleback” because of the marking on the cephalothorax (fused head and thorax).   They are regularly found in dark, stuffy areas, which are rarely disturbed by humans and animals.  Many pest control companies receive numerous “brown” spider calls that homeowners erroneously think are brown recluse spiders.

Brown Recluse Description

The adult brown recluse spider, including other species of recluse spiders, the violin marking is found on the fused head and thorax area. The abdomen is consistently colored, although the coloration can range from tan to dark brown. The brown recluse has long, thin, brown legs which are covered with fine hairs - no spines. Adult brown recluse spiders have a leg span about the size of a quarter. Both sexes are venomous. The immature stages closely resemble the adults except for size and a slightly lighter color. Unlike most spiders, the brown recluse has pairs of six eyes.

Note:  The “violin” marking can be very faint depending on the species of recluse spider, mainly those in the southwestern U.S., or brown recluses that have recently

HABITAT

Brown recluse spiders prefer isolated corners and sheltered areas with low moisture levels.  These spiders are called “Recluse” for a reason – they prefer areas unoccupied and not disturbed by humans.  In a study accomplished by Jamél Sandidge, Entomologist, the top 10 areas where brown recluse spiders are found in homes:

1. Windowsills
2. Behind entertainment center
3. Bedrooms
4. Near furnace and water heater
5. Second floor bedrooms – unoccupied
6. Any room without air conditioning or ventilation
7. Bathroom – behind toilet or tub
8. Near plants
9. Basement – under stairs
10. Basement – in piles of wood, boxes, carpet or clothing

LIFE CYCLE

BITE SYMPTOMS

The reaction to a brown recluse spider bite depends on the amount of venom injected and and individual’s sensitivity to it. Some people are unaffected by a bite, whereas others experience immediate or delayed effects as the venom kills the tissues (necrosis) at the site of the bite. Symptoms are reactions signs sometime include:

• The bite may feel like a pinprick and/or stinging sensation followed by intense pain
• The initial bite area may have a little red mark.
• The lesion from a brown recluse spider bite may grow 1½ inches by 2¾ inches or smaller.  The lesion may exhibit blue-gray or blue-white colors and surrounded by redness—hence the “red, white, and blue sign.”
• A small white blister usually initially rises at the bite site surrounded by a swollen area. The affected area enlarges and becomes red, and the tissue is hard to the touch for some time.
• After a few days, the bite site can erupt into a “volcano lesion,” basically a hole in the flesh due to damaged, gangrenous tissue.
• Sometimes a person may not be aware of the bite for 2 to 8 hours.
• Some victims experience general systemic reactions that may include restlessness, generalized itching, fever, chills, nausea, vomiting, or shock.   

FIRST AID

If bitten brown recluse spider, remain calm, and immediately seek medical attention by contacting your physician, hospital and/or poison control center.  Actions to take:

1. Apply an ice pack directly to the bite area to relieve swelling and pain.
2. Collect the spider (even a mangled specimen has diagnostic value), if possible, for positive identification by a spider expert.
3. A plastic bag or small jar is useful and with no preservative. However, rubbing alcohol helps to preserve the spider.

CONTROL

Control of brown recluse indoor infestations can take a long time - 6 months or more. These infestations tend to be widely dispersed within a building, and they seek out-of-the-way sites. Controlling brown recluse spiders, is best attained by following an integrated pest management (IPM) strategy. IPM involves multiple approaches such as preventive measures, exclusion, sanitation, trapping, and chemical treatments.