A source for information on spiders
Brown Recluse Spider Loxosceles
Although all spiders are capable of biting, most spider bites cause little
harm to humans. However, bites from spiders’ such as the brown recluse can result in necrosis and severe
illness. Long-legged and yellow-tan in color, brown recluse spiders of both genders are best distinguished by
a fiddle-shaped pattern close to the eyes. Adults measure approximately ½-inch in length.
Brown recluse spiders dwell in dark, sheltered places and can be found in homes,
barns and basements, as well as outdoor habitats. Webs tend to appear disorganized and are built most commonly near
ground level. The spider is a hunter, so the web is not intended to catch prey. The brown recluse is throughout the
American Midwest and South.
Brown recluse spiders are shy and rarely bite unless provoked. They are incapable
of biting through clothing and bites sometimes go unnoticed until effects become obvious a few hours later. A pale
blister ringed in red appears first. Fever, convulsions, nausea and weakness set in within one day. If untreated,
the early blister may become a lesion, resulting in necrosis and severe nerve damage.
Brown widows vary in color from light tan to dark
brown or black, with black, white, yellow, orange, or brown markings on their abdomens. The underside contains the
hourglass marking, which is orange to yellow-orange, and the legs have dark bands.
Mature females are 1 to 1 ½-inches in length (with legs extended).
The brown widow spider can produce 10-20 egg sacs, each containing up to 250 eggs. Unlike the other widow
species’ smooth egg sacs, the brown widow spider’s egg sac is tan and covered with many pointed projections, and
can have a fluffy appearance. Aside from its dark brown color, this characteristic is the one that most clearly
differentiates the brown widow from the western and southern black widow. They can be easily spotted within the
web, most often in the tunnel section where the female lives. Their webs are usually about a foot and a half in
The egg sac is attached to the web, and after two weeks will hatch. The spiderlings remain in the nest area for
several weeks where they undergo 6-9 molts before reaching maturity and drifting off on silken threads propelled by
air currents. Female brown widows can live up to a year when food, which consists mainly of insects, is
The brown widow spider is the most abundant and is commonly found in urban areas. They favor outdoor hiding places
such as the crawl space beneath homes and among piles of stored lumber, hollow tile blocks, stored items on
shelves, and in abandoned vehicles, storage sheds and utility ducts.
Within the home, the brown widow may be found beneath tables and desks, behind shutters, in the angles of doors and
windows, in the folds of clothing, in shoes, and under objects in dark, secluded areas. Brown widow spiders are shy
and will tend to avoid contact with humans. Females are not aggressive and usually make no effort to attack,
preferring instead to retreat and lie perfectly still. When confronted or provoked, however, they will bite and can
inject a neurotoxic venom.
Bite Signs and Symptoms:
The bite from the brown widow spider causes a set of symptoms in the bite victim known collectively as
latrodectism, which is caused by the neurotoxins in its venom. The initial bite has been likened to a pinprick - it
is often painless and goes unnoticed. The toxin then travels through the nervous system.
The first significant symptom is a dull, numbing ache in the region of the actual bite. This ache may progress to
painful muscle cramps in the large muscle masses of the body, particularly the abdomen. Additional symptoms may
include sweating, nausea, a rise in blood pressure, leg cramps, muscle tremors, loss of muscle tone, irregular
heartbeat, and vomiting.
Symptoms and pain begin between 15 and 60 minutes after the bite and generally peak within one to three hours.
Symptoms usually disappear within 12 to 24 hours. Fatal bites are extremely rare. Very young children and elderly
adults are the most susceptible to the brown widow’s venom and are therefore the most likely to experience severe
When working outdoors, wear gloves and long-sleeved shirts and pants when handling firewood or other items that
have been stored outdoors or in tool sheds. Inspect and shake out shoes and clothing that have been stored in the
garage or attic before bringing them inside or putting them on.
Check firewood and other items stored outdoors for cobwebs and spiders before bringing them inside the home.
Eliminate harborages: Keep indoor closets, attics, and basements dry by either increasing ventilation or using a
dehumidifier. Remove clutter and move boxes or other objects off the floor and away from the wall to eliminate
possible spider nesting sites. Seal any openings around pipes and seal cracks around doors and windows to keep them
from entering the home.
If a building has experienced brown recluse spiders, the occupants can reduce the chances of bites by following
the recommendations below:
- Clothing can be stored in sealed plastic bags inside drawers or inside plastic storage compartments hanging
- Shoes should be stored inside plastic shoeboxes.
- Clothes that have been left on the floor, in a clothing basket, or are otherwise exposed should always be
shaken well and inspected before being put on.
- Avoid keeping clothing on floors.
- Beds should be moved out so they do not touch walls or curtains.
- Bed skirts around the box springs should be removed from beds, and bedspreads that come near or touch the
floor should not be used. These items allow spiders easy access to climb onto the bed.
- Persons living in infested homes should get into the habit of inspecting bedding prior to climbing in.