Brown recluse spider

Summary:1) Scientific classification

2) Characteristics

3) Life-cycle

4) Behavior

5) Habitat

6) Location

7) Bite

8) Effects of its bite

9) Sources

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Kingdom: Animalia

Phylum: Arthropoda

Class: Arachnida

Order: Araneae

Family: Sicariidae

Genus: Loxosceles

Species: Loxosceles reclusa

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It’s between 6–20 mm

Typically light to medium brown, range color: from cream to dark brown

Usually have a violin pattern on its back of the cephalothorax, with the neck of the violin pointing to the rear of the spider, resulting in the nicknames fiddle back spider, brown fiddler, or violin spider.

While most spiders have eight eyes, recluse spiders have six eyes arranged in pairs (dyads) with one median pair and two lateral pairs.


Adult brown recluse spiders often lives about one to two years.

Each female produces several egg sacs over a period of two to three months, from May to July, with approximately fifty eggs in each sack.

The spiderlings take about one year to grow to adulthood. The brown recluse spider is resilient and can tolerate up to six months of extreme drought and scarcity or absence of food.


When is threatened it usually flees, seemingly to avoid a conflict. The spider doesn’t usually jump unless be touched brusquely, and even then its avoidance movement is more of a horizontal lunge.

A brown recluse's stance on a flat surface is usually with all legs radially extended. When alarmed it may lower its body, withdraw the two front legs backwards in a defensive position, withdraw the rearmost pair of legs into a position for lunging forward.


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The range lies roughly south of a line from southeastern Nebraska through southern Iowa, Illinois, and Indiana to southwestern Ohio.

In the southern states, it is native from central Texas to western Georgia and north to Kentucky.


Kentucky

GeorgiaTexas

Nebraska

Iowa

Illinois

Ohio

The brown recluse venom is extremely poisonous. Its powerful necrotizing venom (destroys living tissue) contains the dermonecrotic agent sphingomyelinase D.

It’s even more potent than a rattlesnake. The recluse venom causes less disease than a rattlesnake bite because of the small quantities injected into its victims. It’s toxic to cells and tissues.

The brown recluse spider is rarely aggressive, and bites from the species are uncommon. The spider usually bites only when pressed against the skin, such as when tangled within clothes, towels, bedding and inside work gloves.

This species of spider normally attacks its prey by injecting venom along with its bite. The venom is powerful and it is used to kill other insects.

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The bite frequently is not felt initially and may not be immediately painful, but it can be serious.

The bites produced a range of symptoms common to many members of the Loxosceles genus known as loxoscelism, which may be severe dermonecrotic lesions (i.e. necrosis); an even smaller number produce severe cutaneous (skin) or viscerocutaneous (systemic) symptoms.

The systemic symptoms most commonly experienced include nausea, vomiting, fever, rashes, and muscle and joint pain. Rarely, such bites can result in hemolysis (the bursting of red blood cells.), thrombocytopenia, disseminated intravascular coagulation, organ damage, and even death.


Most fatalities are in children under the age of seven or those with a weak immune system.

The bite forms a necrotizing ulcer that destroys soft tissue and may take months to heal, leaving deep scars. These bites usually become painful and itchy within 2 to 8 hours. Pain and other local effects worsen 12 to 36 hours after the bite, and the necrosis develops over the next few days.

Over time, the wound may grow to as large as 25 cm. The damaged tissue becomes gangrenous.



Progressed brown recluse spider bite:

Initially the bite site is mildly red

After three days: necrosis (death) of skin and subcutaneous fat.

Ninth day: severe destructive necrotic lesions with deep wide borders result.


Day 38°: After the bite, a wide area of dead tissue was excised, necessitating skin grafting.

View of healed brown recluse wound approximately 10 months after the bite.

http://en.wikipedia.org/wiki/Brown_recluse_spider

http://healthool.com/brown-recluse-spider-bite/

http://www.homeshieldxp.com/recluse-brown/

http://es.orkin.com/otras-plagas/araas/efectos-toxicos-de-la-araa-reclusa-parda-sobre-las-celulas-rojas/

http://www.medicinenet.com/black_widow_brown_recluse_pictures_slideshow/article.htm

http://www.brownreclusespider.org/brown-recluse-spider-information.htm


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Brown recluse spider