Critters in Our Midst: Spiders

There’s so many critters here in the Florida Keys, I’ve been able to write about a different variety each month. So far I’ve covered those who are feathered, furry, or scaly, from a spectrum of soft bodied insects to mammals, amphibians to birds, with some that slither, run, scurry or crawl and others that sail freely on the wind. 

The male Golden Silk spider is a fraction of the size of the female.

It’s been educational and enjoyable, photographing and researching each subject.  Up till now… my current subject spiders creeps me out.  I am not really afraid of them, but I don’t like looking at them either.  There’s probably some good reason why at Halloween a lot of decorations depict spiders. Arachnophobia!!

A Cellar spider (Pholcidae sp) was attracted to the moisture in my kitchen sink.

When I was five years old, sleepovers at my friend Jennifer’s house were fun, and spiders were part of the excitement.  The rarely used room where we slept had pecky cypress wood covering the walls and ceiling. and brown spiders the size of silver dollars hung from webs in the dark, dusty corners. (I guess the spiders were what the monsters ate when they came out from underneath the beds.)  Researchers believe we are not born with the fear of spiders, but instead are taught this behavior.  Children are curious about spiders, and will capture them and watch how their tiny bodies move via their eight long legs until a parent/teacher intervenes, with the message of “be careful, they bite.“

Southern Black Widow spiders (Latrodectus mactans) are a venomous spider found throughout the Southeastern U.S. Credit: James L. Castner UF

All spiders bite, however only two of them in Florida will provoke a strong reaction in humans:  the Southern Black Widow spider (Latrodectus mactans) and the Brown Recluse spider (Heteropoda venatoria). According to the Florida Poison Information Center at Jackson Memorial Hospital in Miami (1-800-222-1222) if bitten by a Black Widow you will likely experience severe stomach pain, and you should go to the emergency room immediately.  The Black Widow received its name from the belief the female spider would kill and consume the male after mating.

Brown Recluse showing “violin” shaped marking. by Jean Woods

The Brown Recluse spider is typically found in Central and Southern Missouri… not here.  The only documented case in Florida of a Brown Recluse spider bite involved a sailor who was bitten on the hand by a male Brown Recluse in the cargo hold of a naval ship in Jacksonville. The Brown Recluse spider bite causes pain, blistering and frequently necrotic lesions in humans.  They are often blamed for mystery bites, wounds and bacterial infections that require treatment with antibiotics— a misdiagnosis by the public and doctors who are not trained in spider identification, nor have seen the spider inflict the bite.

There are more than 250 species of spiders in Florida.  Around the house, spiders are beneficial insects who consume flying insects, cockroaches and other small domestic pests.  In the wild spiders spend their days hiding in leaf litter, and under debris, and emerge at night to hunt. They also spin elaborate webs in clearings to catch flying insects who cannot see the webs until they are ensnarled.  Once in their web, the spider bites it’s victim and a small amount of venom is used to immobilize the insect, then dissolve it into a “smoothie” for the spider to ingest as they cannot eat solid food.  A spider may bite a human if held or pinched; the bite may hurt for a while but quickly goes away and is much less severe than a bee sting.

The Mabel Orchard Orbweaver (Leucauge argyrobapta) has an orange and green, almost metallic colored body.

I have a general rule when walking in the woods:  always go with someone else, and let them lead the way.  This is because my attention is usually behind the camera lens and I have a bad habit of walking into spider webs.  The two methods people use to avoid walking into spider webs are (1) Carry a long stick to brush away webs in the path, (2) Avoid disturbing the web by walking around it.  The second method respects the spider’s efforts making a web which is light, elastic and stronger than steel, and is how the spider, who may have poor eyesight, senses vibrations from their prey, as the web acts as an extension of their sensory system.

This Ghost spider (Genus Habana) was hiding among the leaves in a fruit tree.

Most spiders have eight eyes and eight legs. and come in a multitude of colors and can be patterned.  Some have tiny hairs on their legs that can sense electric charges around plants or the movement of air emitted from a flying insect’s wings.  Not all spiders spin webs, and those that don’t, rely on their better eyesight to capture prey. 

Pest control is a choice, and my preferred method is preventing a bite by wearing gloves while working where spiders may be found, and shaking out shoes that haven’t been worn recently before putting them on.  You can deter spiders by turning off outside lights at night, so not to attract flying insects, a spider’s preferred food.  Realize that proper identification of the spider is the first step, and if the spider is beneficial, let it be.