With Spring Comes the Brown Recluse Spider

The phylum Arthropoda includes all joint legged invertebrates.  Class Insecta are insects in the phylum with six jointed legs, three body segments, and two antennae.  All spiders and insects are arthropods, but spiders are not insects and insects are not spiders.

Time to rake up all that pine needle litter that accumulated over the winter

Time to rake up all that pine needle litter that accumulated over the winter

The Brown Recluse spider (Loxosceles reclusa) earned its name for it’s reclusive ways.  It can be found outdoors in corners and in other secluded areas, like under leaves and in woodpiles.  Springtime and heading back outdoors can spark unwanted encounters after a long winter as it is time to tidy up our yards.

It can also be found in houses and outbuildings.  Inside, it may be on the floor or behind furniture, but it seems to especially like dark closets, preferring to take shelter in clothing and linens.  This is not a good thing for people because it bites when it is disturbed and the venom of this spider is particularly poisonous.

People can become ill when bitten and the wound that develops can be nasty to put it mildly.  However, the reactions vary individually from none to severe depending on the amount of venom and the persons’ sensitivity.  Symptoms can include rash, fever, chills, nausea, vomiting, joint pain, renal failure, seizures, and coma.

Sometimes, the bite is not felt until six to eight hours later when pain and swelling develop.  The surrounding tissue may redden or darken in an irregular shape developing a raised edge and a sunken area (giving a halo appearance).  In severe cases, the irritated skin forms a crust that later falls off leaving a crater that may require skin grafts and may not heal for months.  Death is rare, but bites are most dangerous to young children, elderly, and people in poor physical condition.

It is difficult for a doctor to diagnose a “brown recluse bite” based on wound characteristics alone and is a good idea to have the spider for identification.  Even a mangled, dead specimen in a plastic bag can be useful.  An effective commercial antivenin is not available and treatment varies, but seeking medical attention immediately is necessary.

While this spider used to be home from Kansas to Texas, its range has expanded rapidly due to accidental human transport.  The Brown Recluse can now be found from Illinois east to West Virginia and south to Georgia.

Actually, it is believed that the spider could possibly be encountered in any state in the continental U.S., but it is not believed to reproduce in northern and western regions.

The male is a bit smaller then the female that is about three-eighths an inch long.  The spider is segmented like all Arthropods.  Its head and thorax are fused into a cephalothorax, which is where the legs are attached.  This area has a well-defined dark violin pattern on it, with the neck of the violin pointing toward the bulb-like abdomen.  This pattern gives rise to its other common name, the Fiddle-back spider.

The abdomen is uniformly colored gray to dark brown.  The legs are uniformly colored gray to dark brown with no stripes, bands, or spines – only fine hairs.  The final defining characteristic is the Brown Recluse has six eyes arranged in pairs with one pair in front and a pair on either side.  (Most spiders have eight eyes in two rows of four.)  A magnifying glass is needed to distinguish the eye feature.

Their webs are loose, small, and irregularly shaped.  The spider often spends the day in the web and roams at night searching for insects being most active from spring to fall.  Males also roam in search of females.  Research indicates this spider is largely a scavenger, preferring dead insects.

The eggs hang in an off-white silken sack from the sticky web.  Egg laying is usually from May through July with the female producing several egg sacks of about 50 eggs each over several months.  Development is influenced by weather conditions and food availability (i.e. eggs can overwinter).  Adult spiders live one to two years and can survive for up to six months without food or water.

Prevention is always the best route.  For example, shake out clothing, shoes, bedding, and towels before use, wear gloves (that have been inspected for spiders before putting them on) when handling firewood, remove storage boxes from under beds, and be aware that recluse spiders are often found under folded cardboard box flaps.

The use of sealed plastic bags to store loose items in the attic or garage is suggested, as well as, eliminating clutter in closets and garages and anywhere the spider may hide.  Always clean up dead insects that the spider can feed on and the use sticky tape to capture spiders is also recommended.

Spring-cleaning just took on a whole new dimension.


Previously published in The Brunswick Beacon. Reprinted with permission.

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