Did you know the poisonous spiders in Florida are among the dangerous arachnids of America? Keep reading to beware of spiders in Florida that can cause serious harm.

Which are the poisonous spiders in Florida?

Generally, poisonous spiders in Florida have venom that can be used for the prey. Still, ones that cause harmful conditions leading to death are categorized as venomous, and Florida has two categories of these:

1) Widow Spiders (native to Florida)

Among the poisonous spiders in Florida, Widow spiders belonging to the family Theridiidae (Genus Latrodectus) are found in many places. They have shiny abdomens, primarily black with red marks, and long legs.

The female species are maximum of 15 mm in length, and males are quite small with a minimum of 2 mm.

The features of these spiders include:

1) They are nocturnal

2) They build a 3d tangled web with a conical corner where they hide during the day.

3) They are primarily found in buildings outside, understructures, and water holes.

Symptoms after bites of these spiders include heavy pain, muscle cramps, sweating, vomiting, nausea, and hypertension. They can last up to five days if left untreated, and counter medication can be taken to cure.

The poisonous widow spiders in Florida include four species:

1.1) Southern black widow (Latrodectus mactans)

Location:

Considered the most commonly found native spider among the poisonous spiders in Florida, this widow spider occurs in all the spider habitats. They are mostly found in a protected outdoor place like under the rocks and inside old buildings.

Color and marks:

Southern black widow spider is has a jet black body, from top to bottom. They only have an hourglass mark of bright red color under the abdomen and a red spot above and behind the spinnerets.

1.2) Northern black widow (Latrodectus variolus)

Location:

The poisonous spiders in Florida also include the northern black widow spider, found in the Florida panhandle (west to Tallahassee), with a large tangled mass at a low tree branch as its web (usually 20 feet above ground).

Color and marks:

The northern black widow spider is quite similar to the southern poisonous spiders in Florida, except for the hourglass mark, which is found in 2 markings that are triangle shaped and red spots on the upper abdomen.

Bites of venomous spiders in the widow species

Bites of both the black widow spiders feel like a prick, with only swelling and red marks left behind after the initial pain.

The usual symptoms of a widow spider bite include Muscle cramps, high blood pressure, nausea, and sweating. These last for almost 3 hours; death can be avoided if treated soon.

1.3) Red widow (Latrodectus Bishopi)

Location:

Among the poisonous spiders in Florida category, the red widow spider is found from Marion to Martin County. It creates a tangled web inside a small palmetto, which continues as a silk sheet till the open leaves.

Color and mark:

Predominantly black, the underside of the red widow has a flattened red triangle, and the back has red dots with an outline of a yellow circle.

The red widow has a reddish-orange head (with legs and thorax of similar color), the red marks on its underside make it have an incomplete hourglass figure.

1.4) Brown widow (Latrodectus Geometricus)

Location:

The poisonous spiders in Florida list includes the brown widow spider, which is quite timid and does not bite generally, and it is found near man-made structures frequently.

Brown spiders have a constant reproduction process which makes them tough to control, they are found mostly along the coast of Daytona Beach. The brown widows are introduced from elsewhere, yet most adapted to Florida, among its species.

Color and mark:

Brown widow spiders have variable colors ranging from white, light brown to darker hues, with an hourglass on the underside of the abdomen of orange color.

On their backs, brown widows have white spots and stripes. Egg sac (tan and spherical) is the best identity marker, especially to tell apart from black widows.

2) Recluse Spiders (non-native to Florida)

Recluse spiders are found throughout the world (commonly in tropical climates), usually medium-sized with abdomen colors varying from tan to dark brown.

Their peculiar feature is the set of six eyes arranged in three dyads, with an anterior and lateral one.

The recluse spiders are known to be hunters, so they often leave their silken web to search for prey. Their similarity to widow spiders is in biting only when near the victim’s skin.

A recluse spider bite may have the following effects: Blisters, heavy pain, and Swelling. If the bite turns purple, it may be necrotic.

2.1) Brown recluse Spider (Loxosceles Reclusa)

Location:

The brown recluse spider spans across Florida in places like Alachua, Jefferson, Duval, and Leon counties.

Brown recluse spiders are found in secluded places like garages and sheds, with dark corners that also house many insects who are a target. They are labeled, as ‘recluses’ due to their want to be secluded.

Color and marks:

Brown recluse spiders have a unique identity – a dark violin-shaped marking on their head and thorax. The lack of hair in a brown recluse spider might also be a distinguishing feature, especially among brown spiders.

The colors of a brown recluse spider vary from a light tan to a deep red and brown shade, and it is medium-sized.

Bite of the brown recluse:

For human beings, having the brown recluse bite, the pain may not be there for many hours. Side effects of this venomous spider might include a blister that might swell. Healing the bite of a brown recluse might take up to 8 weeks.

Apart from the poisonous spiders listed above, Florida also houses many nonpoisonous ones whose bites may not require medical treatment like False black widow spiders, funnel weaver spiders, and Wolf spiders.

To look at some of the most common spiders of Florida, click here.

3) How to treat an infestation of spiders?

Whether a spider’s venomous bite or not, likely places to be its base can be avoided in the following ways:

1) Get rid of the spider’s food source – get pest control done once discovered. Multiple spider bites may occur while trying to get rid of them, be careful. 

2) Check where the spiders are commonly located – which might be identifiable with their webs and shed skin. If possible, try getting rid of flies and mosquitoes, a regular food source for the spiders.

However, we can’t reduce Florida to just these dangerous species – click here to read an interesting piece on the fascinating locations of Florida.