The brown recluse spider: A secretive menace

The brown recluse spider: A secretive menace

By By Robert A. Hedeen, Naturalist

A few weeks ago I decided to try the impossible and bring some sort of order to my basement which can be described as a disaster area. I was stacking some boxes in a dark corner when I noticed a yellowish-brown spider reposing in its irregular web. “Brown recluse” flashed through my mind as I had seen this dangerous species on a few previous occasions in other localities and was quite familiar with its general appearance. Donning a pair of gloves, I carefully captured the spider and placed her in a small glass container for closer inspection and positive identification. Sure enough, it was a brown recluse or fiddleback spider, as it is sometimes called. How this beast found its way into my basement to setup housekeeping is beyond my imagination, but, needless to say, its presence was disconcerting, to say the least.

Though all spiders have fangs attached to venom glands, the black widows (Latrodectus spp.) and the brown recluse, Loxosceles reclusa, are the only spiders in the United States whose bites are dangerous to man. Though the venom of a black widow is reported (based on a dry weight to dry weight comparison) to be approximately fifty times more potent than the venom of a diamondback rattlesnake, I would prefer to be bitten by a black widow rather than by a brown recluse; if I had a choice in the matter.

Though the brown recluse has certainly been around for a long time, it wasn’t until 1958 that biologists at the University of Missouri recognized its medical importance. It was originally thought to live only in the south-central states, but, in the last few decades, it has been found in a much wider area.

In the southern part of its range this venomous arachnid is more apt to be found outside under rocks and rubble, whereas in more northern climates it is found predominately in and around homes. It is a rather small, yellowish-brown spider; its body, exclusive of the legs, being about 3/8ths of an inch long, with the characteristic, darker bass fiddle-shaped marking on its back. Most other spiders have four pairs of eyes on the top of their fused head and thorax, but the brown recluse has only three pair. It is suggested that one not attempt to count the number of eyes on any living spider in order to identify it.

The brown recluse can live for up to ten years and go without food or water for an extended period of time. It spins an irregular web to capture its prey and lays between 30 and 90 eggs at a time, enclosed in a thin white sac. Fortunately for us, many of the newly hatched spiderlings are cannibalized by their mother.

A few hours after a brown recluse has bitten a person, the skin around the site of the bite becomes red and swollen. The venom has a necrotic affect and most of the cells in the region of the bite die and must be cut away, leaving a deep sore that may take months to heal. In some cases skin grafts are required. The venom also disrupts the human immune system, and, in a few cases, death can occur, usually as a result of secondary infection.

Some years ago, Robert W. Olwine, M.D., of Salisbury, Maryland wrote to me about his personal experience with a brown recluse, and some of his remarks that follow vividly depict what one can expect if bitten:

: “….. I never did see the pesky critter but from the scenario that followed, I knew I had been bitten by a brown recluse. I awakened in the night with a low backache and tender inguinal lymph nodes. The following day, a typical 90 degree August day, I spent under a blanket huddled with shaking chills. The chills recurred to a lesser degree the following day, and later I noticed the typical lesion on my ankle of a 2”ulceration. After about two weeks, the area of ulceration and scab healed, fortunately with no scarring.

At the present time my ankle is well healed and there is no vestige of the original site of invenomation. I consider myself to be very lucky, for, as you know, skin necrosis can sometimes requires grafting and occasional deaths have been reported….”

Dr. Ralph Everson, a family practice physician, informs me he has not treated a brown recluse bite while practicing in Rockford but did see three recluse bites while living in Michigan, two of which required skin grafts to heal the wound.

The old adage that the female of the species is deadlier than the male is applicable to the brown recluse as well as other species. We can take heart in the fact that only the female brown recluse is capable of inflicting a bite on man. The male recluse is an inoffensive little creature who suffers the extreme indignity of being eaten by the female immediately after mating with her.

Dr. Robert Hedeen is a former resident of eastern Maryland, with degrees in zoology and botany. He is a former professor of biological science. He has had 30 scientific papers published, has written numerous magazine articles, and is the author of two books on marine biology of Maryland.

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