BROWN RECLUSE
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Identification
The brown recluse belongs to the group of violin spiders because of a fiddle-shaped pattern it shows on the head region of the dorsal side of the cephalothorax. Its brown body is fairly small and its legs are long and slender, the dorsal pattern is normally shiny and darker. It's a relatively hairless spider seemingly smooth. It's possible to mistake it with other common house spider but its characteristic eye number and arrangement stands it out: it has only 6 eyes arranged in three pairs.
Behaviour
The brown recluse, living up to its name, is naturally non aggressive toward humans and prefers to live in undisturbed attics, woodpiles, and storage sheds. Its web is quite irregular and usually located in dark areas, it feeds on insects like crickets but its nutritional practice is rather singular owing to its incredible capability to survive up to five months with no food or water. Female deposits its eggs n white silken cases than can reach 10 mm in diameter, after about 30 days spiderlings emerge and in base of weather condition and food availability they slowly reach maturity in 12 month on average.
Venom
Brown recluse venom is considered cytotoxic and haemolytic; between its components we find various enzymes such as hyaluronidase, deoxyribonuclease, ribonuclease, alkaline phosphatase and lipase, but the one thought to be the principle responsible of toxicity is sphingomyelinase D. The bite initially cause a stinging sensation that evolves in severe pain and itching in 6-8 hours, local reaction includes redness of the skin, tenderness and possible blistering; after 12- 24 hours fever, nausea, chills and joint pain occur. Edema develops in the bite area, the tissue becomes ischemic owing to the acting of necrotic and haemolytic enzymes; then disseminated intravascular coagulation and renal failure arise. The intense inflammatory response that involves prostaglandins and chemotactic infiltration of neutrophils leads to the activation of mediator C-reactive protein and complement that progressively contribute to the necrotic degeneration.