What Do You Know About Black Widow Spiders? - Science - World

Experts who deal with these spiders learned that an invasion of black widow spiders comes in cycles every 3 to 4 years.

Latrodectus mactans, or black widow spider, is the most poisonous spider in south Eastern Europe, whose venom is 14 times stronger than of rattlesnakes. The venom is neurotoxic and can cause serious symptoms, death even when it comes to especially delicate population.

Experts who deal with these spiders learned that an invasion of black widow spiders comes in cycles every 3 to 4 years, and by the look of it, an inroad is expected this summer.

What does a black widow spider look like?

The body of this spider is velvety black, covered in short and long wiry hair. Red spots are on its back, 13 of them in average, but often that number can be different or specimens can be found without spots. The female is larger and can grow as large as 18 mm when it is fertilised, while the male is significantly smaller, approximately between 3 and 5 mm.

Most habitats on red soil

Black widows usually construct their webs close to the ground, along borders of ditches, in wheat or grass, underneath or near large rocks. It can be found in three holes, burned down olive groves, sometimes on leaves, thick macchia, undergrowth and in areas with red soil.

-.-imageshack.us-.- One also has to keep in mind it has a tendency of staying on construction machines which have been parked for a longer period of time, especially in places where road construction endangers their natural habitat which is why these spiders go down to populated settlements and can also be found in abandoned vehicles, garages, barns, sheds, as well as out-house toilets.

By nature, black widow spiders are not aggressive and they bite only when they feel threatened, i.e. when human skin comes in contact with their hair-covered body. They instinctively defend themselves with biting and injecting neurotoxins.

Bite is lethal for children under 15 kg

In Croatia, most black widow spiders are found in Istria and Dalmatia, especially near Zadar where up to seven bites are recorded every year. Usually, their victims are farmers, while the most endangered group are children, especially those under 15 kilos. A black widow`s bite is lethal for them.

In average, bite death rate is five percent, in cases where the bite is not treated and death is a result of suffocation and convulsion.

Its bite is almost painless, so it often goes by unnoticed. The bite spot becomes reddish and an hour passes before a person feels serious symptoms. This is when painful muscle cramps begin around the bite mark.

The cramps spread to groups of larger muscles, like the back, chest, thighs and the abdomen, which often leads doctors to wrong conclusions.

Five days for recovery after the serum

Nausea and vomiting are other symptoms, as well as headache, perspiration, chest pressure, anxiety, high blood pressure and faster heart rate.

The intensity of the reaction depends on the person, especially on their age, health condition and the place they were bitten.

Small children, the elderly and heart patients have greater risk of developing complications, but usually the bitten person fully recovers within five days if they receive the usual systematic triple therapy which consists of pain killers, miorelaxators for muscle cramps and intravenous application of potassium gluconate.