Others have been bitten after accidentally touching the spider when cleaning storage areas. Some people have been bitten in bed after inadvertently rolling over onto the spider. The brown recluse spider is not aggressive, and it normally bites only when crushed, handled or disturbed. They also may be found in outbuildings such as barns, storage sheds, and garages. Outdoors, brown recluse spiders may be found underneath logs, loose stones in rock piles, and stacks of lumber. They may seek shelter in storage boxes, shoes, clothing, folded linens, and behind furniture. Indoors, they may be found in attics, basements, crawl spaces, cellars, closets, and ductwork or registers. They thrive in human-altered environments. In favorable habitats, their populations are usually dense. Brown recluse spiders generally occupy dark, undisturbed sites, and they can occur indoors or outdoors. Recent research indicates that the brown recluse spider is largely a scavenger, preferring dead insects. Mature males also roam in search of females. This spider roams at night searching for insect prey. This web serves as the spider’s daytime retreat, and it often is constructed in an undisturbed corner.

The brown recluse spider spins a loose, irregular web of very sticky, off-white to grayish threads. They can survive long periods of time (about 6 months) without food or water. Adult brown recluse spiders often live about one to two years. It takes an average of one year to reach the adult stage from time of egg deposit. Their development is slow and is influenced by weather conditions and food availability. Spiderlings emerge from the egg sac in about a month or less. Each female may produce several egg sacs over a period of several months. The female lays about 50 eggs that are encased in an off-white silken sac that is about 2/3-inch diameter.

The Desert Recluse Spider (Loxoceles deserta)Įgg laying primarily occurs from May through July.

A few species are harmful to man – including the brown recluse, which occurs in the United States and Chile. They are most common in the western and southern United States. They are light in colour and about 7mm long their six eyes are arranged in two curved rows. It is a reclusive creature that seeks and prefers seclusion. The name refers to its colour and habits. The common name, brown recluse spider, pertains to only one species, Loxosceles reclusa. However, this feature can be very faint depending on the species of recluse spider, particularly those in the southwestern U.S., or how recently the spider has moulted. The Brown Recluse spider (Loxosceles reclusa) is a member of the “brown” spider family, Loxoscelidae. These spiders are also commonly referred to as “fiddleback” spiders or “violin” spiders because of the violin-shaped marking on the top surface of the cephalothorax (fused head and thorax). Generally, the females are not aggressive unless agitated, although they are prone to bite when guarding an egg sac. The females moult 6 to 8 times and occasionally eat the males after mating. Male spiders moult 3 to 6 times before maturing. As the young spiders grow, they construct a loosely woven web and capture progressively larger prey. The young spiders then moult to the second stage and begin feeding. In the US it wasn’t until 1957 that necrotic arachnidism was associated with the bite of the brown recluse spider.Ĭlick here for some closeups of a Brown Recluse from Kevin Wiener. Up to that point the condition was referred to as gangrenous spot. A physician in 1872 associated this symptom with the bite of the Chilean recluse spider. This term refers to the main symptom caused by a bite of these spiders, namely rotting of the flesh. This is the first group of spiders that were discovered to cause the condition known as necrotic arachnidism. The family not only contains the genus Loxoceles, but also the six-eye crab spiders (genus Sicarius) of Central and South America and South Africa. These spiders all have 6 eyes (rather than the normal 8) that are arranged in a horseshoe pattern in 3 clusters of 2 eyes each.

15 January 2021.Spiders in the genus Loxoceles belong to a unique family known as the six-eyed sicariid spiders.