Red Widow (Latrodectus bishopi)
Venomous Spiders in Florida
In Florida, only two main types of venomous spiders occur: widow spiders and recluse spiders. Both types are rare. 7 individual species of venomous spiders are known to occur in Florida today; 4 widows, and 3 recluses.
There are at least 50 other species of spiders in Florida that while not poisonous, may cause a severe allergic reaction in humans who are sensitive to their bites.
Three species of widow spiders are native to Florida, and a fourth species has been introduced. No species of recluse spiders are native to Florida, but three species have been intercepted and occasionally have established populations in single buildings at scattered locations.
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Both types of spiders tend to be found in similar places, which is in or under objects where their presence is not necessarily obvious. In the interest of safety, it is recommended that people engaged in activities in which they cannot see where their hands are being placed (such as lifting boards or firewood, or reaching into storage boxes) should wear gloves to prevent being bitten by a hidden spider. Also, clothing — especially if unused for a considerable time — should be checked before wearing, as a spider may have taken up residence within it.
7 species of venomous spiders occur in Florida: the southern black widow, northern black widow, red widow, brown widow, brown recluse, Mediterranean recluse, and Chilean recluse. The last two species (Mediterranean and Chilean recluses are extremely rare).
Southern Black Widow (Latrodectus mactans)
There Are Four Species of Widow Spiders in Florida:
Latrodectus mactans, the southern black widow
Latrodectus variolus, the northern black widow
Latrodectus bishopi, the red widow
Latrodectus geometricus, the brown widow
Latrodectus mactans, the southern black widow
Latrodectus variolus, the northern black widow
Latrodectus bishopi, the red widow
Latrodectus geometricus, the brown widow
While encountering Latrodectus mactans, the southern black widow (above), could be nightmare inducing, it is also very rare unless you're spending an awful lot of time in the Florida woods.
Widow Spiders
The widow spiders, genus Latrodectus (family Theridiidae), are worldwide in distribution. Females range from 8-15 mm in body length; males are smaller, sometimes very small (2 mm). Most have globose, shiny abdomens that are predominantly black with red markings (although some may be pale and/or have lateral stripes), with moderately long, slender legs.
These spiders are nocturnal and build a three-dimensional tangled web, often with a conical tent of dense silk in a corner where the spider hides during the day. In nature, most species are found under rocks and logs, but they readily adapt to human-altered environments, where they are most commonly found in outbuildings (sheds, barns, privies), water meter holes, nursery cans, and under any item or structure (e.g., barbeque grill, slide, sand box) that has been undisturbed for a lengthy period.
Above and Below: Brown Widow (Latrodectus geometricus)
Latrodectus (black widow) bites occur most frequently when the spider is trapped against human skin, either when someone reaches under an object where the spider is hiding or when someone puts on clothing, gloves or shoes containing the spider. Widow spiders are generally very timid and only bite in self-defense when they accidentally contact humans.
Bite symptoms are systemic, spreading through the lymphatic system, and usually start about one to three hours after the bite. The most common symptoms are intense pain, rigid abdominal muscles, muscle cramping, malaise, local sweating, nausea, vomiting and hypertension. If left untreated, Latrodectus bite symptoms usually last three to five days. Calcium gluconate and/or antivenin may be administered to relieve or counteract symptoms.
Northern Black Widow (Latrodectus variolus)
The four species of widow spiders are very similar in body shape. All are about 1/2" long with legs extended. Their life cycle is also similar. The female lays about 250 eggs in a pear-shaped egg sac that is about 1/2" to 5/8" in diameter. The eggs hatch in about 20 days. As the young spiders mature, they construct a loosely woven web and capture progressively larger prey. In Florida, all the widows except the northern black widow breed year-round.
Anyone bitten by a spider should preserve it in rubbing alcohol for positive identification. Most spider bites are not considered dangerous, but if you suspect one of the widow or brown recluse spiders, get medical attention immediately.
There Are Three Species of Recluse Spiders in Florida:
brown recluse spider (Loxosceles reclusa)
Mediterranean recluse (Loxosceles rufescens)
Chilean recluse (Loxosceles laeta)
Recluse Spiders
The Mediterranean recluse (Loxosceles rufescens) has been found in Dade, Escambia, Orange and Osceola counties. It is very similar in appearance to the brown recluse, but the violin mark tends to be lighter in color and has parallel sides.
The Chilean recluse (Loxosceles laeta) has only recently been found in Florida, in Polk County. It is the largest and most dangerous of the recluse species. The violin mark of this species is dark and wider in front (above) than behind (below). 
The Recluse and The Violin
The recluse carapace is pale yellow to reddish brown, with a dusky brown patch just in front of the median groove (which is encompassed by a narrow, dark line); this patch is united to the front of the carapace by dusky brown stripes. In total, these markings appear in the form of a violin. In addition, three dusky patches may occur along the margin on each side.
View a Florida Pest Alert on the Chilean recluse. On July 7, 2002, an infestation of the Chilean recluse, Loxosceles laeta, was discovered
in a residence in Winter Haven, Polk County, Florida. Recluse spiders are rare in Florida: the native brown recluse,
Loxosceles reclusa, is known from a few scattered localities in five northern Florida counties; and
the Mediterranean recluse, Loxosceles rufescens, has been recorded from four counties in central and southern
Florida. The 2002 infestation of the Chilean recluse was treated.
But the fact remains that this spider, a world traveler, has made it here and will turn up again.
More information about recluse spiders in Florida can be found in this citation: Entomology Circular 406.
There are many websites devoted to spiders. A few are listed below.
Spiders and Other Arachnids
Spiders on the Web
Recluse Spiders
Myths of Brown Recluse
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We've Read:
Tom Daley Wonderland.
He shared a selection of underwater photographs taken for the shoot on Instagram @tomdaley
The photographer, Bartek Szmigulski, also shared images on his own Instagram (@smiggi), including a small video clip.
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