Spiders Of North America


Longest Living

Trapdoor Spiders

Imagine building a closet tucked away somewhere safe, and then spending the next 40 years inside. The trapdoor spider does essentially just that, says Marshal Hedin, biology professor at San Diego State University and current president of the American Arachnological Society.

The large, furry females dig a burrow, create a door over the top out of soil, silk and saliva, and never come back out. At night, she props the camouflage door open with the top of her head and waits for vibrations from passing insects. “When something comes by, they grab it with their front legs and go back down into their burrow,” Hedin says. They have been documented in the wild to live up to 35 years old.

Best Throwers

Net-Casting Spider, Deinopis

They go by many evocative names including net-casting, ogre-faced and gladiator spiders. Up close, the Deinopis looks like a walking stick with legs wearing a pair of motorcycle goggles.

“I think they’re adorable, but that’s just me,” says Natalie Stalick, a Wyoming-based spider aficionado.

Their claim to fame, outside of their larger-than-life pair of eyes, is their ability to “catch” their prey. The spider typically hangs upside down in a plant or tree with its back legs and holds a rectangular net of silk with its front two legs. When an insect such as a grasshopper wanders by, the ogre-faced spider throws its web as a fisherman would cast a net, says Paula Cushing, curator of Invertebrate Zoology at the Denver Museum of Nature & Science.

Least Venomous

Feather-legged orb weaver, Uloborus, Family Uloboridae

The dietary habits of most spiders don’t help their creepy reputation. They eat by injecting venom and digestive enzymes into their prey, waiting for the insides to dissolve and sucking it out.

But not this guy. The feather-legged orb weaver is a member of the Uloboridae family, the one North American spider family without any venom at all.

Its webs resemble cotton candy, and entangles prey rather than traps it with a sticky glue, Bradley says. The orb weaver uses the silk and its powerful legs to squeeze dinner to death, then sticks its hollow fangs inside, spits digestive enzymes with its mouth and sucks the emulsified insides back out.

Most Venomous

Black widow Latrodectus sp, Family Theridiidae

Depending on what criteria is used, either the black widow or the brown recluse is the most venomous spider in North America. Both spiders are the only ones with bites venomous enough to require medical attention. Both can kill a human if a bite is left untreated.

But the black widow, argues Bradley, more frequently causes serious reactions including severe cramping, nausea and chest pains. They are widely distributed across most of the southern part of the U.S, and in some areas, such as around Los Angeles, they join brown widows as one of the most common spiders.

Instead of fear, that should instill hope, he argues. “There are probably millions of them in the L.A. Basin, and there are 15 million people there” he said. “The fact that there are millions of spiders and millions of people and very few people get bitten is remarkable.”

Most Maternal

Wolf Spiders, Lycosidae

While the most infamous of spiders might be known for killing its mate shortly after copulation, one family of spiders is known for its loving care.

The wolf spider, a large, nomadic arachnid that hunts its prey rather than snaring it with a web, carries around its eggsac on its spinnerets. “When the babies hatch, the mom chews a hole through the silk, the babies crawl out and hitch a ride on her back until they are old enough to fend for themselves,” according to Cushing.

A female might carry hundreds of babies on her back at any given time, which is why some people believe the spiders shatter when hit because the babies will scatter in every direction.

Most Aggressive

Velveteen tarantula, Calisoga longitarsi

The common name comes from the spider’s iridescent colors, but the niceties end there. If any kind of arachnid would be considered aggressive, it’s the Calisoga, Hedin says.

The large, furry creature lives underground and does not take threats lightly. It will stand on its hind legs and flare its long fangs before chomping down on food or enemy.

“If that spider bit you, it would hurt just from a structural standpoint,” says Hedin. “It’s not medically dangerous, but I could feel it for a week. The pain lingers.” The California spider won’t run you down, but if you mess with it, be prepared.

Most Prehistoric

Lampshade spider, Hypochilus sp

This gray and brown spider is often referred to as a living fossil because it has all of the primitive characteristics of the earliest true spiders, Hedin says. “They occupy an interesting place on the spider tree of life,” he says.

They live isolated in small, rocky outcrops in the Appalachian and Rocky mountains and some ranges in California, and have evolved slower than most of their counterparts. “They have features you might expect to see in an ancestor that has gone extinct,” he says, adding that most of the differences are obscure and specialized.

The Hypochilus is also called a “lampshade spider” because of the beautiful webs they form off of rocks that resemble their namesake.

Biggest

Desert tarantula, Aphonopelma chalcodes

In the genus Aphonopelma, one full of large spiders, the chalcodes stands out. Its body is 2.5 inches long and the leg span is at least twice that, says Bradley. That makes the spider safely at least 5 inches across.

“The average person would look at it and say it is 20 inches long,” he says. But even Bradley admits it is one big spider.

Despite its size, its bite packs little punch. The spider is not terribly venomous to humans, and since the females live in burrows in the desert and are nocturnal, they are rarely seen.

Smartest

Bold Jumper, Phidippus audax

Is a spider capable of solving a puzzle? Jumping spiders are, Bradley says. While the brainiest of all jumping spiders are found in Africa and Australia, North America has a few over-achievers of its own.

The bold jumper, for example, is particularly interesting with its black, white and sometimes orange spots and iridescent green or blue-green fangs. Jumping spiders use their vision to hunt prey instead of sensing vibrations like most other spiders. They can also develop hidden routes to stalk prey, making decisions based on intellect rather than instinct, Hedin says.

Prettiest

American Flag Jumping Spider, Habronattus americanus

Beauty is obviously in the eye of the beholder, and the “prettiest” spider is a subjective category, but Hedin says the American flag spider is certainly the most patriotic.

So patriotic, in fact, it was once featured on a postage stamp. The males sing and dance for the females by flicking their front legs and producing seismic sounds with their abdomens, Hedin says. Their scales are, you can probably guess, colored red, white and blue.

And a bonus Halloween treat, for all the arachnophiles:

Rarest

Cave robber, Trogloraptor, Family Trogloraptoridae

Until 2012, no one knew the Trogloraptor — with its skinny, orange legs — existed. But when a team of scientists found it in old-growth forests in Oregon and California, they realized they had not only found a new genus, but a new family of spiders.

Its finding was so notable, the discovery was featured by publications such as Wired and PBS. It was the first new family of spiders to be added to North America since 1890.

“It’s very unusual for anywhere, in all of life, to walk out in the woods, pick up something, look at it, and say, ‘Bam, this is a new family of life on Earth,’” Jonathan Coddington, associate director for science at the Smithsonian Institution told PBS in 2012. “That isn’t just among spiders. It almost never happens.”

One species lives in caves and the other in redwood forests, a relic of what likely occupied redwood forests that covered much of the western U.S. millennia ago.

“There are legends of big spiders in caves,” California Academy of Science’s Charles Griswold told PBS in 2012. “It’s the stuff of legends, which is why we compare it to Sasquatch. But in this case, the legend has come true.”