Our Species Showcase this time has a creepy creature twist, as we are going to be talking about black widows. Florida has multiple species of widows that call the "Sunshine State" home, including the most commonly found, Southern black widow (Latrodectus mactans), followed by Western black widows (L. hesperus), red widows (L. bishopi), and the brown widows (L. geometricus).
The naming conventions for widow spiders is believed to come from the fact females cannibalize the males after mating, although this is actually partially incorrect. The studies that demonstrated male spiders being consumed after mating were all performed in overcrowded laboratory settings, where any expecting couple would consider cannibalism if it meant a little peace and quiet. In the wild, males usually leave the web alive after mating and are eaten only occasionally, if they physically can't escape.
Black widows are probably one of those spider species that everyone has heard about, if you live in the US, however, many people don't truly know anything about them. Most people's only experience is through stories of bites! You may have met someone who has been bitten or perhaps you've even been bitten by one yourself. However, only females have the potential to envenomate humans. Despite this, and their wide spread range throughout the US, deaths to healthy adults are exceedingly rare, with no deaths despite 2000 bites yearly, with studies within the last several decades being unable to confirm any fatalities from Black Widow bites.
These spiders' venom is a neurotoxin, meaning it attacks the nerves. They mainly use this venom to kill their prey, which includes fire ants, woodlice, millipedes, centipedes, flies, crickets, beetles, moths, and occasionally... other arachnids. They wait for their prey to get trapped within the web and once they feel the vibrations they rush up to the prey item, wrap them up completely, then bite them to let the venom start breaking down the prey. Black widows may seem like a useless, scary spider, but every animal has it's role within the greater ecosystem, and Widows are no exception.
Widows help control invasive fire ant populations and are a regular food source for wasps, scorpions, and centipedes. Overall, these spiders are important and you shouldn't be too worried about them. If you are bitten by one, seek medical attention and you will be fine. Otherwise, let them be and allow these little exterminators to keep our insect populations in balance.
Daphne Kline
Environmental Educator
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