Black Widow Identification: Where Do Black Widows Live?
What Do Black Widows Look Like? Where Do Black Widow Spiders Live?
Black widow spiders, scientific name Latrodectus mactans, are among the most venomous of all arachnids. I have been working with insects and spiders for almost 20 years, and I get a lot of questions about black widow spiders. What do black widows look like? Where do black widows live? Is the bite of the black widow spider fatal? These all excellent questions, and with this lens I hope to answer at least some of your questions about these much-feared poisonous spiders.
Black widows are large spiders that spin tangled webs in sheltered places, both in nature and in your house. They are also among the most poisonous insects in North America, and their bite can be fatal in some cases. If you found a spider and you suspect it may be a black widow, this lens will help you identify your specimen. Black widows are relatively rare, and most of us will never see one, but if you do you want to know exactly what you're dealing with! If you ever wondered what it's like to get bitten by a black widow, or the safest way to pick one up (it's not with your fingers), then read on...
What Does a Black Widow Look Like?
Black Widow Identification -- The Red Hourglass
This is the distinctive sign of the black widow -- a bright red hourglass marking on the animal's ventral side (the "bottom" or underneath). It's your surest guide to black widow identification -- no other spider has it. In the natural world, bright red, orange, or yellow markings are universally used to signify protection by venom or caustic chemicals in the insect's haemolymph, or blood. This, in effect, tells everyone: "stay away from me, or you'll be sorry." But the classic hourglass shape is only one morph that spiders in the Black Widow's genus display. There are a couple of other variations that still serve the purpose of warning away predators -- including you.
Close-Up of a Female Black Widow - Note the robust body, long black legs, and red hourglass
If you ever get this close to a black widow, you'll see the true beauty of the species.
Handling a Live Black Widow
Watch as this person lets a huge female black widow crawl all over his hand...
What Does a Black Widow Look Like? - Dorsal and Ventral Markings
Where Do Black Widows Live?
Black widows typically live in your garage or your basement. They prefer dark, sheltered corners where they can spin their tangled webs and wait for the moths and other insects that make up their diet. Black widows do not want you messing with them -- in fact, they view any interaction with you as a threat to their very existence. This is why the spiders will bite you -- it's the only means of self-defense that they have.
Black widows live where you typically don't go, so you'll only encounter them when you're cleaning out a garage, or reaching into a dark corner of a basement. So be careful! Make sure you can see where you're putting your hand, and chances are pretty slim that a black widow will get her fangs into your flesh...
Black Widow Identification -- The Web
The black widow spins a characteristic tangled web in a dark corner. She waits for insects to come along and wander into the web, upon which she grabs her prey, bites it, and sucks the digested insides of the insect out with her hollow fangs. The web is one way to identify back widows, but lots of other spiders spin similar webs, so don't tump to conclusions. Wait to actually see the red hourglass-on-shiny black of an actual black widow spider.
Black Widow Biology -- What Makes a Spider a Spider?
Black Widow identification begins with a question: What defines a spider? Spiders are a kind of Arthropod, a huge group of animals that includes water-dwelling organisms like crabs and shrimp as well as all insects, including butterflies and moths. Spiders form a subset called "arachnids." They are separated from the closely related insects by several feature: spiders have eight legs instead of six, two body sections instead of 3, most spin webs with a special organ called a "spinneret" located at the tip of the abdomen, and ALL spiders are venomous. The venom of most spiders is only effective against the small invertebrates that they feed on, but a few have poison that can hurt vertebrates like humans. The black widow is one of a very few spiders with venom capable of seriously hurting humans.
Parts of the Spider
1 Fang (chelicera)
2 Venom gland
4 Pumping stomach
5 Forward aorta branch
6 Digestive cecum
9 Malphigian tubules
10 Cloacal chamber
11 Rear aorta
13 Silk gland
15 Ovary (female)
16 Book lung
17 Nerve cord
By Philcha (File:Araneae_anatomic_numbers.svg) [Public domain or Public domain], via Wikimedia Commons
Black Widow Identification -- Some Black Widow Spiders Have Different Markings! - (And some are quite beautiful)
Northern Black Widow Variation
Another Beautiful Black Widow Variation
Black Widow Identification: The Male - It's a Tough Job, But...
The male Black Widow, as with many other spiders, is much smaller and less conspicuous than the female. His only real reason to exist is to impregnate the female, and once that's accomplished he becomes just another meal. While this may seem cruel -- and is the source of the Black Widow's common name -- it is actually a perfectly rational survival mechanism developed through millions of years of evolution. After all, when food is survival, and the male is no longer needed, the solution is obvious...
Black Widow Eating
Like most web-spinning spiders, the Black Widow waits for prey to blunder into its sticky web, and then rushes out to bite and subdue its meal. The venom paralyzes, then liquifies, the insect, and the spider wraps the meal in silk to further control and preserve it. This spider has killed a small insect, and is siphoning out the liquified insides with its straw-like fangs.
Spiders, Centipedes, Silverfish...
A Good Guide to the Bugs in Your House
THIS BLOG is an excellent site for information about the creepy-crawlies hanging out in your basement.
Black Widow Egg Sac
In this photo, a female Black Widow tends to its egg sac. Hundreds of minuscule eggs are protected within this tough sphere of silk, and when they hatch the tiny spiderlings will scatter to find dark corners of their own. Some spider species carry the tiny spiderlings on their back as a form of protection.
Black Widow Identification -- The Spiders' Fangs
The fangs of the Black Widow, and all spiders, are believed by some researchers to be a highly evolved pair of legs that long ago became adapted to subduing prey. They are essentially hollow tubes that act like hypodermic needles to inject poison. The poison need to be powerful and fast acting, since the less the prey struggles in the web, the less damage the spider will have to repair. The toxin also often acts as a liquifying agent, turning the prey's insides into a kind of soup that the spider then sucks up through the same fangs that were used to inject the venom.
Black Widow Identification -- Female With Prey
Some spiders are capable of subduing even those insects with poison defenses of their own. This large female has captured not one but two wasps capable of inflicting a powerful sting to any predator, but the spider has avoided the stinger and inflicted its own fatal bite. Soon these wasps will be a meal for the spider.
Spectacular Spiders -- Have You Seen this Book? - Introduce a Child to An Unseen World
This is one of the coolest children's books going. Give your child an up-close view of a natural world you never knew existed -- and watch as they touch a spider web to see how it feels, and see a spider hanging from a string.
The Spectacular Spider book introduces children to the world of spiders!
This unique reference guide offers children a hands-on experience up close and personal with a spider. This book explores the life cycle, habitat, and includes interesting features of spiders. Children can touch the flocking on a spider to see how it feels, or see a spider hang on a string from its web. The Spectacular Spider book also includes a fascinating facts page with interesting information about spiders, a glossary, and an index.
Envenomation by the Black Widow
Black Widow bites are rare, since the animal spends most of its time in its web, unlike the Brown Recluse, which roams at night in search of prey and could wind up under your sheets (a truly unpleasant thought). To be bitten by the Black Widow, you basically need to come to the spider, since it probably won't come to you: this means putting your hand in a dark corner of the basement or garage, or even in a tree stump -- I once found an enormous female who had built a nest in a dead tree, about head level. Once bitten, your prognosis is not good. Fatalities are rare, but you are likely in for several days of the effects of the spider's neurotoxic venom.
Two Little Marks...
That's usually all you can see from a black widow bite. The fangs just puncture the surface, but it's enough to deliver the venom. Hard to believe that a little bite like this can actually kill you, but it can.
Another Dangerous Spider -- The Brown Recluse
"I Was Bitten By a Black Widow Spider"
Excerpt from a First-Person Account of Black Widow Envenomation
I Got Bitten By a Black Widow Spider
...I grabbed a pair of old shoes from the garage, and hastily threw them on over my bare feet, and continued my charge around the house to build momentum to get out the door. About a minute later, I realized that there was some wiggling in the toes of my right shoe, and just as I was about to take my shoe off, I felt a bite on my 2nd toe - not painful, but a bit annoying...
The medical literature suggests that recovery happens within 3 to 5 days. Nights 3 and 4 and 5 were complete disasters for me. For some completely unknown reason, I was sweating profusely at night. As in, literally soaking through my sheets and changing my sheets 3 times on one night and twice the next...
Read the whole story here.
Symptoms of the Black Widow Bite
weakness and tremor
nausea and vomiting
What's In the Black Widow's Venom?
Black Widow venom is complex, and contains a number of compounds that further the evolutionary goal of subduing prey and protecting the animal from predators. The most specific ingredients to the genus Latrodectus are a number of toxins called, appropriately, latrotoxins. Latrotoxins are very large molecules with dozens of different atoms, and the way they work is still not well understood. Black Widow venom contains at least 7 different latrotoxins: most of which specifically effect invertebrates, or insects, which form the bulk of the spider's diet. There is one, however, called alpha-latrotoxin, which targets vertebrates -- including humans. This powerful poison is specific to the genus Latrodectus and is the reason the spider is so toxic to humans.
What Do You Say?
Can We Co-Exist With Black Widow Spiders?
Safe and Effective Handling of the Black Widow and Other Spiders
is the answer to picking up and disposing of poisonous insects and spiders like the black widow. Safely suck up the bug with the attenuated suction, then shake it out far away from your house. Black widows don't travel very far, so you can be relatively sure the animal won't find its way back into your house. This highly effective bug vacuum
Safely Suck Up and Dispose of Black Widow Spiders
Where Do Black Widow Spiders Live in My House?
Controlling Black Widow Spiders in Your House
* Keep beds away from the walls
* Don't store boxes or any items under your bed
* Keep dust ruffles or bed skirts from touching the floor
* Don't store shoes on the floor or any clothes, towels or other linens (always shake out shoes and clothes before using)
* Store sports equipment like rollerskates, gardening clothes, gloves, ski boots in plastic bags that are tightly sealed with no holes.
* Vacuum under furniture, closets, under heaters, around all baseboards and other areas of the house to eliminate habitat.
* Keep screens on windows and fix or replace screens with holes or that don't fit snuggly.
* Seal doors with weather stripping and door sweeps
* Seal cracks, access holes for electrical conduits or plumbing
* Remove spider webs and egg sags when found