Southern Black Widow Spiders are Venomous

Southern Black Widow
Southern Black Widow spiders are commonly found hanging upside down, waiting for a meal to wander by.

Les Harrison is the Wakulla County Extension Director.

Out-of-the way corners in abandoned places conjure up a variety of disquieting images. The eerie silence in these neglected locales gives way to the subtle scurrying of unseen lives attempting to avoid contact and confrontation.
While most of the residents of these unkempt sites are harmless, at least from the perspective of venal intent, a sense of defensive cautiousness pervades the interlopers thought. It is possible eyes, lots of eyes, are watching.
Sometimes, the paranoia is justified. In among the cobwebs a slow, deliberate movement is sometimes detected and a distinctive color pattern moves into focus revealing a bright red hourglass shape.
The Southern black widow spider, Latrodectus mactans, is easily identified by its shiny, totally black body and the characteristic bright red shape on its abdomen or backside.

This venomous spider is found throughout the southeastern United States, including Wakulla County, but it is not the wicked aggressor of gothic horror novels. In reality, this reclusive arachnid prefers isolated sites where it can hunt its prey without potential of human contact.
The southern black widow is one of three members of this genus which can be found locally. The less frequently encountered brown widow and red widow have many of the same behavior features, but with different coloring.
There are 32 species in the Latrodectus, or widow spider, genus which are found on every continent except Antarctica. Most of the females of this genus are dark with the distinguishing hourglass mark.
Widow spiders received their common name from the belief they would kill and consume their mate.However, the practice was mainly observed in laboratory settings under crowded conditions.
In natural settings this behavior is more associated with the male’s physical inability to escape rather than the female’s interest in consuming him. Some insects, including the local praying mantis population, engage in similar behavior.
The bite of the southern black widow spider is toxic to mammals with many potentially damaging or deadly results. The females are equipped with the greatest concentrations of a neurotoxin which is used for hunting and defense.
The widow spiders construct a web of irregular, tangled, sticky silken fibers. The spider commonly hangs upside down near the center of its web waiting patiently for insects to blunder in and become entangled.
The spider quickly bites a victim then wraps it in silk before the insect can free itself and flee. It uses its fangs to further administer digestive enzymes, liquefying the prey’s internal organs before beginning to feed.
Southern black widows have poor eyesight and depend on vibrations arriving through their web’s silk strands to find trapped prey or warn them of a possible threats. While not especially aggressive, if cornered they will deliver a painful bite to the closest point of contact.
Most injuries to humans are defensive bites delivered when a spider gets unintentionally squeezed or pinched. No matter the circumstances, immediate medical treatment is advised.
Heavy gloves are recommended when working in areas which may be frequented by southern black widows. These include firewood piles, barns and outbuildings or other spots attractive to insects, and the spiders which prey upon them.
Pay attention if that little voice advises caution in those unkempt places.




Posted: October 5, 2015

Category: Natural Resources, Wildlife
Tags: Agriculture, Black Widow, Bugs, Environment, Extension, Farming, General Information, Insects, Lawn & Garden, Master Gardener, Natural Resources, Natural Wakulla, Pest, Pest Management, Southern Black Widow, Venomous, Wakulla, Wakulla Agriculture, Wakulla CED, Wakulla County, Wakulla Extension

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