Best housemate ever: The Bold Jumping Spider

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What a face! The bold jumping spider’s large eyes provide keen vision. Its striking iridescent green fangs are likely for show. Photo by Opoterser, Wikimedia.

Most people don’t welcome spiders in their home, but once they get to know the bold jumping spider, they might change their minds. Don’t grab the nearest shoe to smash it, don’t be put off by its looks. Despite having eight fuzzy legs and large iridescent green fangs, this spider is a helpful, tidy housemate.

Bold jumping spiders are pretty big– their bodies are about a quarter to a half-inch long. And though they may look fierce, they are harmless to humans. According to Penn State entomologists, your chances of being bitten by one are “slim to none.” The rare accounts of jumping spider bites suggest the bite causes a reaction similar to a mosquito bite.

But if you are an insect, these spiders are the stuff of nightmares- a lion stalking you in tall grass, poised to pounce… Unlike many spiders that spin webs, sit back and wait for insects to fly into them, bold jumping spiders are active hunters. In fact, they don’t spin webs at all, which means they won’t leave dusty cobwebs in the corners of your home.

Jumping spiders hunt during the day in open areas, such as walls and windowsills, using their keen eyes to spot their prey. Unlike other types of spiders, they have excellent eyesight and an almost 360-degree field of vision. The bold jumping spider will pounce on any insect smaller than itself, including houseflies, mosquitos, small crickets and other uninvited guests in your home.

Once prey is spotted, jumping spiders sneak up within striking distance– which for a jumping spider is pretty far. They owe their astounding jumping ability to hydraulics, not solely muscle. These spiders are able to rapidly increase the internal fluid pressure in their legs, propelling themselves 10-50 times their body length and pouncing on their insect victims. US Track and Field athlete Mike Powell, who holds the world record in the long jump, can jump less than 5 times his body length– and that’s with a running start.

Though bold jumping spiders don’t construct webs, they do make spider silk. They use a single line of silk as a tether to catch them in case they make a bad jump, kind of like a rock climber’s rope or bungee jumping cord. The female bold jumper also uses her silk to make an egg sac and small “den” where she hides with the sac and then her spiderlings when they hatch.

Jumping spiders are fun to watch– scientists who study their behavior believe they are screen-shot-2017-01-24-at-3-17-06-pmvery “intelligent” given the size of their brains. Most jumping spiders perform courtship “dances.” A couple of years ago a video of a colorful dancing spider went “viral” on the internet. The species shown in the video was the Coastal peacock spider from Australia– a species of jumping spider, just like our very own bold jumper.

Like a good guard dog, the bold jumping spider defends your home from intruders, albeit very small ones. But unlike a dog, that sheds hair and tracks in dirt, jumping spiders don’t leave a mess. So next time a jumping spider has moves into your home, consider letting it stay. While it can’t be counted on to help out with the rent or mortgage, it may still earn its keep.

This article originally appeared in the Grand Junction Daily Sentinel in September 2016.

Best housemate ever: The Bold Jumping Spider

The scorpion’s softer side

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Northern Scorpion. Photo by Meredith Swett Walker

It is hard to think of a creature less likely to inspire warm, fuzzy feelings than the scorpion. They have pincers, an intimidating stinger, and are rumored to hide in shoes. Plus, they are hard to categorize and this makes humans uncomfortable. Is a scorpion an insect? Is it a crustacean like a crab? They look “crunchy”, “pinch-ey” and “stingy” all at once.

It turns out that the unlovable scorpion– which is neither insect nor crustacean– has a softer side. These creepy crawlies turn out to be caring mothers. Their venom may help scientists develop important medications. Though they cause many people to shudder, scorpions deserve a second look.

Scorpions are arachnids like spiders, and like spiders they have eight legs. The two front limbs that bear their pincer claws are technically “pedipalps,” not legs, and are not used in walking. While scorpions may look like an alien visitor from a chilling sci-fi film, they have walked the earth longer than almost any other animal. Scorpions evolved at least 430 million years ago, long before the dinosaurs. In fact, the oldest known fossil of a land dwelling animal is a scorpion found in 2013 in South Africa.  Modern scorpions are found on every continent except Antarctica.

Clearly scorpions have mastered the art of surviving on planet Earth and the secret of their success may be their low-key lifestyle. They are nocturnal and hide from daylight under rocks or in burrows, emerging at night to hunt insects. But scorpions are essentially “couch potatoes.” They have a very inactive lifestyle and a low metabolic rate which means they require very little energy or food. Unlike human couch potatoes, scorpions can go a long time without a meal. Some species have been reported to go up to a year between feedings.

Yet scorpions are not slackers in the parenting department. Female scorpions give birth to live young rather than lay eggs. The newborn scorpions are defenseless– their screen-shot-2017-01-14-at-12-23-12-pmexoskeletons do not harden until they are older so their pincers are soft and useless and their stingers are blunt. To keep them out of danger, mother scorpions carry their babies around on their backs until they are old enough to defend themselves.

Scorpions sometimes use their stingers to subdue prey that they catch with their pincers. They will also sting in self-defense, and if they feel the need to defend themselves from your incoming foot– you may be in for some pain. Most scorpion stings are no more painful than a bee sting and ultimately harmless. Only one scorpion in the U.S. has venom powerful enough to cause life-threatening illness in humans. The Arizona bark scorpion, which is found in the Sonoran Desert, has a neurotoxin in its venom that can cause extreme pain and numbness. But fatalities due to its sting are rare.

Scorpion venom may turn out to provide more benefit than harm to humans. The venom contains a number of different chemicals that have potential as drugs. Scientists are currently investigating components of scorpion venom that may be useful in treating brain tumors and malaria. Who knows what other secrets may hide in the scorpion’s stinger?

Though there are plenty of scorpions in the Grand Valley, they keep a low profile and are seldom seen. If you do encounter a scorpion, before you run away shrieking or stomp it to smithereens, take a breath and consider letting it go its merry way. These secretive creatures are less menacing than may they appear.

This article was originally published in the Grand Junction Daily Sentinel in May 2016

The scorpion’s softer side

Spotted in Fruita- the elusive Spotted bat!

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Friday morning I got a call from my friend Dan Neubaum, “You home? Want to see a Spotted bat?” And I thought, “That is a waste of a question mark Dan,” but I said “Heck yeah!”

A gentleman in my little town had found this bat on his front porch when he headed out in the morning. A bit dumbfounded, as you would be if you found this fantastical creature on your doorstep, he searched the internet and somehow stumbled across this article I wrote on Spotted bats for the local paper about three years ago. In the article I described how biologists were on the lookout for this species and provided Dan’s contact information. Dan is a wildlife biologist with Colorado Parks and Wildlife. Dan loves bats (he did his Master’s research on them), and upon receiving the gentleman’s call he quickly hustled out to Fruita to pick up the bat. It was unable to fly but appeared uninjured. Since the bat was found just a few blocks from my house, he very thoughtfully swung by so I could get a look at it.

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Spotted bats are uncommon and rarely recorded, but this is actually the second spotted bat reported to Dan as a result of my newspaper article. Soon after it was originally published, a local resident contacted Dan to report he had seen one in his yard- and had pictures to prove it! That newspaper assignment paid peanuts, but I consider it one of my best successes in my (very limited) writing career.

Even more exciting, Friday’s Spotted bat was a lactating female. This is exciting because it means that they are breeding in the area (yay!) It’s also exciting if you’ve been wondering what bat boobs look like (but were afraid to admit it). Apparently they look (disturbingly) like human boobs. I guess a boob is a boob- we’re all just mammals.

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Thankfully, Dan said that at this time of year, this mom’s pup was probably flying and feeding independently (though still nursing some) which means that if she recovered they could reunite and mom’s absence wasn’t necessarily a death sentence for her pup. Dan took mama Spotted bat back to his house and let her crawl up in his bat box to rest for the day.

At dusk, mama bat flew out of the box and Dan said she looked pretty strong. Hopefully her weekend turned out better than her Friday. While I enjoyed the experience of “meeting” her, I am sure it wasn’t how she planned to spend her day. Still I am very thankful Dan thought to bring her by so I could check her out. Look at those crazy ears!

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Spotted in Fruita- the elusive Spotted bat!

Don’t fear a book by its cover

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I have a hard time looking at this photo of a Japanese Giant Hornet. (Photo by Hornet Boy 1970/Wikimedia)

I have a confession to make. I have a phobia of wasps and bees. Basically most of the order Hymenoptera, though ants bother me less- probably because they don’t fly (most of the time.) It’s a mild phobia. I don’t have the full-fledged panic attacks and disabling symptoms associated with severe phobias, though I have been known to exhibit ridiculous behavior, such as running, flailing and squealing, in the presence of bees and wasps.

I also have an irrational fear of hyenas. Hymenoptera, hyena. . . do I simply have an aversion to animals whose names start with “HY”? Nope. I think hyraxes are adorable and have neutral feelings towards tiny freshwater hydrozoans in the genus Hydra.

My fear of hyenas most likely stems from an experience I had in Tarangire National Park, Tanzania, when hyenas came into our camp site at night. I had taken my weekly dose of Larium, an anti-malarial drug notorious for sometimes causing bizarre dreams, anxiety, and in extreme cases, hallucinations.

I was awoken from a nightmare involving giant crabs by the noisy hyenas. They were just looking for stray bits of food, like a gang of 120 pound raccoons. But their garrulous snarling, squealing and loud breathing were hair raising even for my fellow campers who were not tripping on Larium that evening. I had also recently read a story in the New Yorker by Joanna Greenfield which detailed her attack by a captive spotted hyena. Great story, but don’t read it before you go camping in Africa. Seriously– don’t.

These irrational fears embarrass me. The hyena fear is less embarrassing because fear of a large, intelligent, predatory mammal that is fully capable of eating you and will give it a try if you look easy, is really not that irrational.

But a fear of wasps, bees and some ants is genuinely embarrassing because I am a biologist, I should know better. I hung out with lots of folks who study wasps and ants in graduate school and they taught me all sorts of cool things about their favorite insects. I learned about the evolution of eusociality, haplodiploidy, and all that fascinating stuff. (Back to hyenas for a moment. Female hyenas have pseudo-penises. Also fascinating, but doesn’t make them any less scary to me.)

I know that the likelihood that I would be killed or seriously injured by a stinging insect is very small. I am not allergic to bee stings. I am much more likely to be killed by a heatwave. I know that the mosquito, Aedes aegypti, is arguably the most dangerous animal in the world.

It’s not like I don’t encounter wasps and bees frequently. I enjoy the outdoors and spend much of my recreation time hiking, camping etc. I should be used to them by now. I have been stung on seven separate occasions. I know what it feels like. Yes, it hurts, but I have endured much worse pain.

I am not scared of many other creatures that people commonly fear. I enjoy catching (non-venomous) snakes with my 6 year-old son- a herpetology enthusiast. There are several black widow spiders living in my yard and I value their contribution to cricket control. I even touched a shark once while snorkeling. (It was a small, docile nurse shark resting in a coral cave, but you get my point.)

Yet hymenoptera– wasps especially– give me the heebie-jeebies. I have tried reasoning with myself. I know their evolution is fascinating, they serve important ecological functions etc., etc. Still they give me the creeps. If a wasp gets into my house and another adult is home, I will ask that person to get it out. If it falls to me to squash it, I will do the deed, but it will make me physically shudder. I will throw the body away but eye the trash can warily for the next couple of hours. If a wasp is trapped in my car, I WILL be pulling over and exiting the vehicle.

I am proud to have made some progress. I am much less fearful of honey bees than I used to be, and I will confidently capture and release them outside if they stray into my house. But there is no way in hell I will ever take up beekeeping or approach a wild honey bee colony. Africanized or “killer bees” are the stuff of my nightmares.

Speaking of nightmares, about 10 years ago I saw a segment in a nature documentary on the Japanese giant hornet that I have still not fully recovered from. I have trouble even looking at pictures of them. If I saw a dead giant hornet pinned and dusty in an insect collection, you’d have to pay me a large sum to touch it. If I ever had the opportunity to travel to Japan, these insects would make me think twice.

We’re admonished not to judge a book by its cover, but we do. (If we didn’t, a lot of graphic artists would be out of work.) So you can imagine how I felt when I received this book in the mail.

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My brain sees this cover and says “Avoid! Avoid! Avoid!” There is a good reason for that. The wasp’s aposematic coloration, which is echoed in the jacket design, is intended as a warning to “stay away.” And the book explains how the hymenopterans’ sting– the danger that this coloration warns us about– allows these insects to exploit diverse environment and resources, and develop complex societies.

The book was sent to me by a publicist at Johns Hopkins University Press, which published it. I had recently written a post for Entomology Today about a study on harvester ants in which I quoted the book’s author Dr. Justin Schmidt. This caught the generous publicist’s eye and she asked if I’d be interested in a copy. I was flattered. No one ever offered me a free book, except when they were trying to religiously convert me.

Of course I’d like a copy! Who can turn down a free book? I realized she probably wanted me to read it and write something about it, but I put that out of my mind. The book arrived and it sat on my nightstand– upside down so I didn’t have to look at the wasp on the cover.

But if I do occasionally (frequently?) procrastinate, in the end I am generally dutiful. So I read “The Sting of the Wild” and I enjoyed it. Schmidt, an entomologist at the Southwestern Biological Institute, is an excellent writer. He can write clear, engaging explanations of sting evolution and venom chemistry, as well as spin a good yarn about his adventures collecting stinging insects. I enjoyed his dry, judiciously applied, wit.

Schmidt is most famous for the “Schmidt Sting Pain Index” which is published in its entirety for the first time in this book. He has painstakingly (emphasis on the pain) documented the stings he has received from various species of hymenoptera. In many cases, he has actively sought stings from certain species in order to add them to his index. The pain delivered by each sting is given a quantitative rating of 1-4, as well as a qualitative, often poetic, description. Some examples:

Western yellowjacket: Hot and smoky, almost irreverent. Imagine W.C. Fields extinguishing a cigar on your tongue. Pain level 2.

Dasymutilla klugii (a huge velvet ant): Explosive and long lasting, you sound insane as you scream. Hot oil from the deep fryer spilling over your entire hand. Pain level 3.

So is Schmidt just a sadomasochist with literary flair and a thing for collecting data? What would compel someone to get stung on purpose in order to make an index of pain? Science would.

If you quantify something, you can compare it to other somethings. Schmidt’s Sting Pain Index allows him to make and test predictions about insect’s stings. Why does a harvester ant’s sting (pain level 3) hurt so much, but the sting of a large, intimidating-looking cicada killer wasp (pain level 1-1.5) hurt less than the common honey bee? The answer has to do with their life history, the predators they face and the food they eat.

Stinging hymenoptera don’t want to sting you. In fact, they generally give you fair warning to stay away. Aposematic coloring and patterns of high contrast yellow, white, red and black are just one of the signals these insects use to say “leave me alone.” Schmidt also describes auditory warning signals, including loud buzzing and stridulations, as well as olfactory messages.

(This information actually made me feel better about my fear. I’m not irrational, I’m just a good listener. I am simply respecting stinging insects’ requests that I stay away.)

So take it from someone who didn’t initially want to read “The Sting of the Wild” but found it captivating (and a bit spine-tingling)– this book is worth your time. Justin Schmidt is a science hero in my eyes (I would love to know what gives him the creeps.) Creating a “Sting Pain Index,” would be for me a task akin to navigating Dante’s nine circles of hell.

This is a man who has methodically documented the sting of a tarantula wasp (pain level 4). His advice if you are unfortunate enough to be stung by this giant iridescent insect is to “lie down and scream”:

The pain is so debilitating and excruciating that the victim is at risk of further injury by tripping in a hole or over an object in the path and then falling onto a cactus or into a barbed-wire fence. Such is the sting pain that almost nobody can maintain normal coordination or cognitive control to prevent accidental injury. Screaming is satisfying and helps reduce attention to the pain of the sting.

Schmidt endured that sting and many, many others. And he did it for science.

Don’t fear a book by its cover

Biological Weapons

About a year ago I started writing occasional articles for the Entomological Society of America’s website “Entomology Today.” These assignments prompted me to delve into some biology I might not have otherwise and it has been so much fun. I’d like to share my entomology articles with my blog readers by posting links to them here. If you are interested, check out what I am doing over there. I hope you enjoy it.

Here’s a look at the diabolical biological weaponry predators and parasites use against one another. Click on the killer photo by entomologist and photographer extraordinaire, Alex Wild, to read the article.

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Biological Weapons

Colorado Ivory

 

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Elk ivories, which are technically vestigial tusks, are small– just over an inch long including the root. Photo by Meredith Swett Walker

 

Elk hunting is a big deal in Colorado, and while many hunters are primarily interested in harvesting an elk for its meat, some hunters are after a trophy bull. Trophy elk are scored based on how large their antlers are and how many “points” or tines they have on each. But if humans had been hunting for trophy elk 25 million years ago or so, they would have been after the animal with the largest tusks, not antlers.

 

Elk are members of the deer family, and while modern male deer are noted for their antlers, prehistoric deer lacked antlers, but had tusks instead. Tusks are technically teeth (usually canine teeth), but are distinctive in that they grow continuously and protrude from the mouth. Today’s elk still bear remnants of their toothy past. Partially hidden in the upper jaw of both male and female elk are vestigial tusks, more commonly known as “ivories.”

 

An elk’s ivories are actually canine teeth. They are not large­– less than an inch of the tooth is exposed in an adult elk– and they aren’t used in chewing. There is no corresponding tooth on the lower jaw for them to make contact with, but they do wear down some over time. While some elk ivories are pearly white, others are stained deep brown by tannins in the plants the elk eats and digestive juices. (Elk aren’t known to use Crest Whitestrips®.)

 

The term “ivory” technically refers to animal tusk material used in art or craft. Humans have used elk ivories to make jewelry and decorate other goods for centuries. Among many Native American tribes, ivories were used to adorn women’s dresses and were a symbol of prosperity.

 

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A Kiowa couple, Eonah-pah and his wife Alma, photographed in the late 1870s by William S. Soule. Alma is wearing a dress decorated with elk ivories.

 

In the late 1800s and early 1900s elk ivory became very fashionable and the teeth were used to decorate watch fobs, the short chains attached to pocket watches. At that time these watch fobs were an unofficial symbol of the Benevolent and Protective Order of Elks (B.P.O.E.), a fraternal order and social club still active today and commonly known at “the Elks.” But elk ivory’s popularity led to a spike in prices for the teeth, which in turn created an elk poaching problem. In 1907, in an effort to stop the poaching, the B.P.O.E spoke out against the use of elk ivories for jewelry and helped establish the National Elk Refuge in Wyoming.

 

While humans use elk ivories for adornment, elk use them in a manner that recalls a time when these teeth were much more impressive– they use them to threaten their rivals. An angry elk will sometimes curl its upper lip in a “sneer display” that reveals its vestigial tusks.

 

It is thought that as ancient deer evolved antlers, they lost their tusks. Only a handful of modern species of deer and deer-relatives still bear prominent tusks. Chinese water deer, muntjacs, and tufted deer, are all relatively small species that live in Asia and still have tusks. These species generally lack antlers. With their diminutive size, big brown eyes and large fang-like tusks, these deer almost look made-up, like Bambi masquerading as a vampire for Halloween.

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Siberian musk deer live in Northeast Asia. This is a small deer, weighing less than 40 pounds, but it sports impressive tusks. Photo by Николай Усик.

 

Scientists are not entirely sure if any of the prehistoric deer that moved into North America from Asia many millions of years ago had tusks. Most of the fossil remains that paleontologists have found so far are incomplete. According to Dr. Darrin Pagnac, a paleontologist at the South Dakota School of Mines who studies ancient grasslands and the herbivores that grazed on them, “The earliest ‘deer’ in North America is Eocoileus, from the late Miocene (7-5 million years ago).  All we have of it is a partial antler and the back of the skull.  No teeth, so we can’t tell if it had canines or not.”

 

Whether or not any tusked deer ever roamed the plains of North America, elk ivories are a reminder of ancient times, when the wildlife on our continent looked very different than it does today. Once upon a time prehistoric cheetahs and camels roamed here. Giant sloths, weighing a ton, browsed on leaves and the giant beaver, who was over six feet long, presumably cut down really big trees. As magnificent as elk and Colorado’s other wildlife is today, the creatures of the past may have been even more impressive.

This article first appeared in the November 21, 2015 issue of the Grand Junction Daily Sentinel.

Colorado Ivory