Map shows the regions most heavily 
infested by the brown recluse spider. 
This pest is principally found in the 
Southern and Central States. 
CONTROLLING THE 
BROWN RECLUSE SPIDER 
The brown recluse spider, Loxosce/es rec/usa, is wide- 
ly distributed in the United States and is commonly 
found around homes and farm buildings. Its bite is 
serious enough to require medical attention. 
The brown recluse spider is not aggressive. It pre- 
fers to hide in dark quiet places. But it will some- 
times bite if handled, or when it is trapped in 
clothing. 
The bite of this pest is especially dangerous to 
children, to the elderly, and to those in poor physical 
condition. However, fatalities from the bite of the 
brown recluse are very rare. Normal reactions usually 
include intense local pain, a blister, inflammation 
of the affected area, and an ulcerating sore. 
Where It Is Found 
The brown recluse spider infests a large geo- 
graphic area (see map) but its major distribution is 
in the Southern and Central States. The present 
known range includes 15 States. Single specimens 
have been found in Washington, D.C., Arizona, Cali- 
fornia, Florida, New Jersey, North Carolina, Pennsyl- 
vania, and Wyoming. 
This pest is believed to have been in North 
America for centuries, but until 1957 it was not 
known to have a poisonous bite. Since then, studies 
of its biology and geographic distribution have been 
made, and identical symptoms formerly attributed 
to “insect bite” are now suspected to have been 
caused by the bite of the brown recluse spider. 
The natural home of the brown recluse spider is 
in sheltered places outdoors—under rocks and loose 
bark. But buildings that are dry, littered, and contain 
many insects are the indoor areas most likely to 
attract the spider. 
Many brown recluse spiders have been found in 
undisturbed places in basements, attics, water 
heater closets, storage places, and barns. 
A favorite hiding place for the spider is a jacket . 
or other garment left hanging in a barn, outbuilding, 
or similar structure. For protection, shake these gar- 
ments before wearing them. 
