Top Ten Arthropod Disguises

If you’ve taken any biology or ecology classes, you may have heard of mimicry. Mimicry is when an animal, plant, or other living organism (the mimic) copies the appearance or behavior of another (the model). More often than not, the mimic copies an organism more dangerous than itself to scare away predators. One of my favorite mimics has got to be the mimic octopus, which can change its appearance to resemble a variety of different animals. However, the phylum Arthropoda has some pretty fantastic mimics of its own. In no particular order, these are my top ten favorite arthropod disguises:

Ant-Mimicking Jumping Spiders

An ant-mimicking spider of the species Myrmarachne formicaria captured by spidereyes2020 on Flickr

I love jumping spiders. They dance, they have pretty adorable faces (for spiders), and now they’re dressing up like one of my favorite insects: the ant. Jumping spiders of the genus Myrmarachne are known for mimicking a specific genus or species of ant depending on their species, and their disguises are good enough to fool humans. Not only do the spiders strongly resemble ants in appearance, but they also walk like ants and move their forelegs about like antennae to really sell the act. Since most jumping spider predators don’t eat ants for fear of getting stung, bit, or swarmed by the whole ant colony, pulling off a good performance can be the difference between life and death for these tiny arachnid actors.

Thistledown Velvet Ant

A close-up-and-personal shot of a thistledown velvet ant uploaded to Flickr by the USGS Bee Inventory and Monitoring Lab

This is the second time a velvet ant has made an ArthroBlogger top ten list, and this little wasp also has a double dose of deception going on. Not only do females of this species lack wings and thus resemble ants (they’re actually wasps), but their fluffy setae make them look like pieces of fluff or creosote seeds being blown around by the wind when they walk. This disguise usually deters predators looking for an insect snack, but as a last resort, thistledown velvet ants, er, wasps, can pack a painful punch with their stingers.

Snake-Mimicking Caterpillar

The closet caterpillar I could find to Hemeroplanes triptolemus on Flickr. Thanks to Alison Day for the elephant hawk moth caterpillar!

I couldn’t find a photo of one on Flickr, but this caterpillar is too cool not to include in this list, so please please please look at the snake-mimicking caterpillar here, you will not be disappointed. Hemeroplanes triptolemus is one of the most amazing arthropod mimics around: while preferring to camouflage itself as a twig or leaf, this particular hawk moth caterpillar can also bear a striking resemblance to a viper when it sucks in air through the spiracles near its head region! The caterpillar is actually harmless, but most predators don’t stick around long enough to find out – especially when it pretends to strike at them with its fake snake head!

Curled Dead Leaf Moth

A beautiful Uropyia meticulodina moth by LiCheng Shih on Flickr

This spot almost went to the dead leaf mantis, but the detail of the curled wings made me choose the dead leaf moth. While far from the only leaf-mimicking animal out there (or even the only leaf-mimicking lepidopteran), Uropyia meticulodina takes the mimicry game to a whole other level – those wings aren’t actually curled! If you don’t believe me, take a look at this picture of the moth from above. That’s what I call a work of art. Mind. Blown.

Bumblebee Robber Fly

A bumblebee robber fly by Andrew Weitzel on Flickr

Once again far from the only bee-mimicking insects, robber flies of the genus Laphria have a certain knack for mimicking bumblebees. Unfortunately, the reason behind their acting game is a bit more sinister than most: while a lot of the arthropods on this list use their mimicry to hide from or scare away predators, Laphria robber flies are wolves in sheep’s clothing. They mostly sit and wait around for pollinators like bees and butterflies to come by, who believe the fly is just another flower-drinking buddy. When its prey gets too close, the fly pounces and devours it. These flies are pretty cute, and they eat pesky insects too, but it’s hard to forgive someone who actively betrays sweet little bumblebees.

Orchid Mantis

An orchid mantis by Pavel Kirillov on Flickr

Another beautiful insect mimic, the juvenile orchid mantis resembles a flower both to ambush pollinator prey and hide from predators. Yes, this is very similar behavior to that of the bumblebee robber fly, but at least the mantis is fooling its prey with the false promise of food rather than fake friendship. While native to Southeast Asia and Indonesia, these mantises are also popular pets but are happiest hiding amongst orchids and similar flowers in the rainforest.

Giant Swallowtail Caterpillar

A Giant Swallowtail caterpillar by Letícia Smania Donanzan on Flickr

Some caterpillars have eyespots to look like snakes, some blend in with leaves and branches, and some can do a remarkable impression of bird poo. I’ve said it before and I’ll say it again – if you’re small and squishy, all that matters is keeping yourself from getting eaten. And I’d say this particular disguise is a pretty good tactic.

Atlas Moth

A gorgeous Atlas moth by Rene Mensen on Flickr

Take a look at the wing tips of the Atlas moth. Do they remind you of anything? Perhaps… the head of a cobra? That’s right, I put two lepidopterans mimicking two different kinds of snakes on this list! Why? Because they’re both awesome-looking and exquisitely crafted insects, that’s why! God probably had a lot of fun making the ant and bee mimics, but with these guys, I think He was just showing off.

Ladybug Mimic Fungus Beetle

A fuzzy fungus beetle by giovzaid85 on Flickr

First of all, these guys belong to the family Endomychidae, which makes them “handsome fungus beetles” and I think that name is adorable. Second of all, just look at this cutey! He’s so fluffy, and the ladybug spots make him even cuter! This beetle mimics the coloration of a ladybug to warn predators of its terrible taste.

Stick Insects

A stick insect captured by Sid Mosdell on Flickr

Who better to end this list with than one of the most well-known and beloved mimics out there: the stick insect? These fantastic fellows come in a variety of colors and sizes and are found in forests around the globe, although they prefer to stay near the tropics. Stick insects are pretty great at blending in with the branches of bushes and trees, but if they are spotted by a predator, they can fall to the ground and blend in with the foliage below. If that doesn’t work either, they can drop the act all together and startle foes by showing off their flashy, colorful wings. Although there are definitely some very tiny species, the stick insect Phobaeticus chani holds the record of being the world’s longest insect.

The Beetle that Only Eats Asparagus

A common asparagus beetle by stanze on Flickr

I can’t believe these actually exist. There must be a beetle for every word in the English language.

“Asparagus Beetle” is actually a very logical name for these guys, because they only eat asparagus. I don’t know why that’s so funny to me, but it is. I just… why asparagus? It’s so absurdly specific. Like, imagine an asparagus beetle at an insect dinner party:

Ant: Hey, Earl, have you tasted the honeydew Helga brought? It’s sooo good!

Asparagus Beetle: Nope. Could someone pass the asparagus?

Bee: Dude, that’s all you ever eat! Try this pollen my sister found this morning.

Asparagus Beetle: You know, I’d really rather just eat asparagus. Like, all the asparagus. You guys are good if I take the whole plate, right?

Termite: Come on, there are plenty of other great foods besides asparagus. If you keep an open mind, the world is your dinner plate! (Begins gnawing on the table)

Asparagus Beetle: …Okay, then. Seriously guys, I only eat asparagus. That’s all I need. Just asparagus.

Bee: Haven’t you heard of a balanced diet? How can you only eat one food all the time and nothing else?

Monarch caterpillar: (looks up from its milkweed salad) Eh, I get it.

There are actually two asparagus beetle species: the common asparagus beetle and the spotted asparagus beetle, the latter of whom bears a resemblance to ladybugs. Because asparagus beetles (unsurprisingly) are pests of asparagus crops, anyone hoping to rid them from their garden has to pay close attention to make sure they aren’t accidentally getting rid of ladybugs, which actually eat a lot of pests (including asparagus beetle larvae). Asparagus beetles can become particularly annoying because, unlike most crops, asparagus grows better if it is planted in the same place for a long time rather than rotated out with other plants. This gives the beetles ample time to become a major infestation if you aren’t diligently monitoring your plants, especially because asparagus beetles can go through two to five generations in a single year.

A spotted asparagus beetle by gbohne on Flickr

Adult asparagus beetles lay their eggs on asparagus plants. After about a week, the eggs hatch and the larvae begin feeding on asparagus berries or leaves depending on their species. The larvae develop quickly, eating for a couple weeks before pupating in the soil and emerging as adults only one week later. Then, as you already know, the asparagus beetles return to munching on asparagus. Spotted asparagus beetles, however, are considered the less detrimental pest because they are less common (that explains the “common” asparagus beetle’s name) and have less of an impact on the whole asparagus plant with their larvae only eating the berries. However, spotted asparagus beetles have been known to branch out and eat other foods on occasion, particularly gourds and melons.

Huh. I guess you can get tired of eating the same food all the time after all.

Monarch butterfly: (looks up from sipping flower nectar) Eh, I get it.

Magnificent Mole Crickets

A mole cricket by oliver.dodd on Flickr. Awwwww, just look at his lil’ face!

I have only known about the existence of mole crickets since last spring, when my roommate convinced me and one of our friends to join her on a Plastic Ocean Project cleanup near the Cape Fear Memorial Bridge. After picking up some garbage near where we’d received our gear, I was speed walking to catch my friends when I noticed an elongated cricket wriggling around in the dirt. Apparently caring more about a cute insect than getting left behind and lost in the city (I was actually fine, they were like ten yards away in broad daylight), I knelt down and used the Seek app on my phone to identify the little creature. Low and behold, I had stumbled upon my first mole cricket.

Although common on almost every continent, mole crickets are hardly ever seen due to their nocturnal, underground lifestyle. Unfortunately, the burrows and eating habits of invasive mole crickets especially are a pain to agricultural fields and front lawns alike: mole cricket burrows can disrupt the roots of grasses, and the crickets themselves may eat the roots of grasses and other small plants, sometimes dragging the whole plant underground and consuming it. Although obviously considered a pest, mole crickets are relatively docile and are not likely to bite unless you try to grab them.

The forelimbs of a mole cricket bear a striking resemblance to the front paws of, well, moles. These clawed shovels make the mole cricket an excellent digger and also contain the insect’s tympana, or ear drums. Mole crickets can also use their shovel-hands like paddles to swim to shore if they somehow find themselves in a body of water, and the thick layer of setae (arthropod hair) covering their body traps in air and helps to keep them afloat. Some species can even jump from the water using fancy paddle-feet and the water’s surface tension! As if conquering soil and water wasn’t enough, mole crickets can also take to the skies on admittedly clumsy but functional wings for short flights. Is there anything mole crickets can’t do?

Well, besides avoid fluorescent lights at fast-food restaurants and gas stations, I mean. Despite living in the dirt and being nocturnal, mole crickets are for some reason attracted to bright lights. Which means we can add bug zappers to the list of mole cricket predators, I suppose.

Hold on a second – why do those even exist? Apparently people use bug zappers in hopes of killing mosquitoes, but those little pests are attracted to blood and carbon dioxide and, well, humans, not shiny things they can’t bite. To the few of you still using these things, please stop hurting the poor little moths and mole crickets and turn off your electric death boxes.

Thank you. Now, back to mole crickets:

Mole cricket burrows are called galleries when they’re shallow (often making a noticeable bulge in the ground and annoying the mess out of golfers) and tunnels when they extend deeper underground. Female mole crickets also add nurseries called egg chambers to their burrows. When mating season arrives, male mole crickets will widen the entrances to their galleries to act like a speaker before professing their love through song to attract females. Mole crickets make their music by strumming the stridulatory file of one wing across the scraper of the other, much like how one would strum a guitar with a pick.

If it weren’t for the agricultural damage, I’d say mole crickets are just short of perfect. Between their cute little faces and impressive adaptability, I’m kind of surprised that they aren’t more popular. Who cares if they aren’t colorful, mole crickets deserve to be just as well known and beloved as butterflies and ladybugs! Maybe they’re just shy, and that’s why they hide in the dirt all the time where no one can get to know them for the magnificent creatures they are.

Just you wait, folks. As soon as the world gets a little more familiar with mole crickets, they’re gonna knock those snobby butterflies right off their pedestal and become everyone’s new favorite insect.

Icky, Sticky Velvet Worms

The first time I ever saw, let alone heard of velvet worms was in my invertebrate zoology lab last semester. To explain how perplexing that encounter was, you need to understand how this class worked: when I attended lab every Tuesday around noon, I usually had to complete between ten and twelve workstations regarding that week’s invertebrate animal phylum. Each station either consisted of one or several microscopes, about three to twenty shells or jars of preserved organisms, sometimes newspaper articles, live animal(s) and/or dissected animal(s), plus a worksheet with the assignment printed on it.

Due to the bulk of notes I had to take and animals/animal parts I had to draw and label, each station could take anywhere between 10 and 20 minutes or more. This meant that by the time I reached my final station each week, I was hungry, cramping in the hand, cold because that lab was always freakishly chilly, probably calculating how much time I had left before my bus arrived, and definitely not operating at 100% brain capacity.

On November 2, 2021, this was the state in which I knelt on the chair at my last station of the day, peered into the microscope, and immediately wondered if I was hallucinating. Staring back at me from the slide was the caterpillar from the black lagoon. This dude, to be precise:

The velvet worm from my invertebrate zoology lab, as seen through a microscope. Most of the time these guys are red and blue, so I don’t know why this one is green. He was not a living specimen, so that may have had something to do with it.

Velvet worms, as you may have guessed from the antennae and limbs, are not actually worms. Nor are they caterpillars. Nor are they, in fact, arthropods. But, seeing as their phylum Onychophora is part of the Panarthropoda clade with Tardigrada and Arthropoda, I’m going to say that they’re close enough to get featured on this blog. Plus, they’re really wacky and I really want to talk about them, so here goes nothing:

First of all, velvet worms have retractable claws. Seriously! Velvet worms have anywhere between 14 and 43 stubby little legs, and each leg hides a little claw that can be retracted when walking around. These claws are the reason behind the velvet worms’ phylum name, Onychophora, which means “claw-bearers.”

If you’re like me and you’ve never seen one of these funky fellas before, you might live in the Northern Hemisphere. Velvet worms live in South America, Australia, and parts of Africa and Southern Hemisphere islands, but even in their native range they can be tricky to find. Like a lot of arthropods, velvet worms breathe through holes in their cuticle (outer body covering) called spiracles. Unlike most arthropods, however, velvet worms have no way of closing their spiracles, so they must live in warm, damp areas like leaf litter to avoid drying out. If you’re out looking for velvet worms yourself, you’ve got decent odds at finding them under rocks, logs or leaves in the woods.

Notice that white bulge under the velvet worm’s antennae? That’s one of its oral papillae, which the velvet worm uses to spit a glue-like substance at its insect prey. Once the insect is thoroughly covered in spit and rendered immobile, the velvet worm feeds like a spider: it bites open the insect’s exoskeleton and spits digestive fluids inside, then slurps up the resulting bug-soup. Yum. Gross.

A living velvet worm captured by Marshal Hedin on Flickr

Another interesting factoid about velvet worms is that most are ovoviviparous, meaning their eggs hatch inside their bodies, while others lay eggs or birth fully developed young like mammals. One species even reproduces by parthenogenesis, in which females basically give birth to clones of themselves. In terms of their similarities to the Arthropoda phylum, velvet worms must shed their cuticle to grow and can communicate with one another using pheromones, chemical secretions released from the velvet worm’s crural gland.

Although they may spit glue at you and possibly nip you if you bother them, velvet worms aren’t poisonous and pose no threat to humans. Nothing much seems to be threatening them at the moment, either; although negatively impacted by habitat loss and being captured as pets, velvet worms are not endangered and actually have stable population numbers around the globe.

Like a lot of other Americans I know, I am kind of afraid of Australia on account of the wide array of dangerous creatures lurking there. Now, however, the velvet worms have provided me with an incentive to visit. Then again, I can also find them in Chile, New Zealand, and plenty of other hopefully-less-dangerous places… Kudos to you, Australia, but I don’t think I’m ready to join you in surviving killer snakes, spiders, and buff kangaroos just yet. If any of y’all come across a velvet worm, though, send me a pic!

Cleaner Shrimp: Dentists of the Coral Reef

A Pacific Cleaner Shrimp photographed by prilfish on Flickr. Aww, look at his little eyes! Too cute.

If you’ve ever seen a saltwater fish aquarium, chances are there was a bright red shrimp with long, white antennae scurrying around in there, too. That would be a Pacific Cleaner Shrimp, also known as a Scarlet Skunk Cleaner Shrimp for the white stripe running down its back. As their more generic name implies, Pacific Cleaner Shrimp are valuable fish tank occupants for their cleaning prowess, happily eating whatever parasites and dead skin they find on their fish roommates. They’ll even clean inside the fishes’ mouths with their chelipeds (claws) like little arthropod dentists!

In the wild, Pacific Cleaner Shrimp are a common sight in coral reefs. The coral and rocks provide a place to hide from predators, as well as a convenient spot to perch and wait for clients who need their scales and teeth cleaned. This relationship between shrimp and fish is an excellent example of mutualism between species: the shrimp gets to eat, and the fish are cleansed of decay and parasites! Shrimp will even clean fishes’ wounds, which can reduce inflammation and the likelihood of infection. Interestingly, rather than hiding from fish who prey on shrimp, Pacific Cleaner Shrimp will show preference to their predators and clean them more frequently as a way of keeping the peace and saying “please don’t eat me, I’m worth more as your dentist than your lunch!”

Although common in reefs, Pacific Cleaner Shrimp can also be found in small troupes (colonies) by underwater cave entrances about 20 meters deep. Individual shrimp in a troupe tend to keep their distance, but they still get along well with one another and other shrimp species living in the same area.

Pacific Cleaner Shrimp are simultaneous hermaphrodites, which means individual shrimp are both male and female at the same time. Therefore, all Pacific Cleaner Shrimp can carry their own brood of eggs. After hatching, the shrimp larvae (called zoeae) live in the plankton and will molt fourteen times before reaching adulthood.

Unsurprisingly, Pacific Cleaner Shrimp are extremely popular in saltwater reef aquariums. However, only experience aquarium owners should purchase a dentist shrimp for themselves: they require very specific ranges in pH, temperature and salinity in order to thrive in their environment. You’ll also want to make sure that none of the fish species already in your tank view Pacific Cleaner Shrimp as food. If properly cared for, your shrimp could live for more than three years.

To finish out this post, I think we can all agree “Pacific Cleaner Shrimp” is boring and “Scarlet Skunk Cleaner Shrimp” is just rude, so let’s call them Barbershop Shrimp. For one, the Pacific Cleaner Shrimp’s stripes and long antennae are a signal alerting fish to the shrimp’s grooming services, similarly to how a barbershop pole advertises a barbershop. Secondly, barbershop poles are colored red and white to symbolize the outdated medical practice of bloodletting, which parallels to the medical side of the Pacific Cleaner Shrimp’s cleaning behavior. Lastly (and most importantly), Pacific Cleaner Shrimp antennae look like fabulous mustaches, and where do you get a mustache professionally trimmed? At a barbershop. Boom.

Of course, this means we can now refer to troupes of Barbershop Shrimp as quartets. It just gets better and better! Someone call a lawyer, a taxonomist, and National Geographic – we have an arthropod to rename.

Giant Weta: The Cricket the Size of a Hamster

A Giant Weta photographed by Sid Mosdell on Flickr

The first time I saw a Giant Weta was in the pages of a children’s science magazine in elementary school. In the photo, someone was holding what I at first believed was a massive cricket in one hand while feeding it a regular-sized carrot with the other. Of course, I immediately wanted one as a pet.

While Giant Weta do love carrots (as well as fruits and smaller insects), my dreams of owning a Giant Weta will never come to pass: these colossal critters only live in New Zealand. The Giant Weta is also endangered as a result of invasive predators (especially rats and cats) and habitat destruction, so it wouldn’t be a good idea to take one even if I could.

Along with grasshoppers and crickets, the Giant Weta is a member of the order Orthoptera. While not actually the world’s largest insect (that title belong to the giant walking stick), it is the heaviest, weighing in at up to 2.5 ounces. Its weight renders the Giant Weta flightless and unable to jump, which used to not be a problem before predatory mammals were brought to the islands where it lives. Nowadays, that is definitely an issue.

While rats and Weta fill similar ecological roles, birds and reptiles like kiwi and tuatara depend on Weta as an important food source. Fortunately, groups like the New Zealand Department of Conservation are working hard to restore the populations of many Weta species. One ongoing project involves relocating Tusked Weta to islands devoid of invasive predators. Weta are also being bred in captivity, where they can be studied for conservation purposes and later released to boost population numbers in their native habitats.

Although their genus name (Deinacrida) means “fierce grasshopper,” Giant Weta are rather mellow compared to other Weta species. It is very rare to be bitten by a Giant Weta: although their mandibles are strong enough to crunch carrots, they are much more likely to run away than draw blood if threatened. In fact, handfeeding carrots to Giant Weta is pretty common in New Zealand.

Maybe I’ll have to make my way around to New Zealand after all. Even if I can’t bring one home with me, handfeeding a cricket the size of a hamster sounds like an extraordinary experience.

Don’t Touch the Disembodied Mustache

A Southern Flannel Moth caterpillar captured by Judy Gallagher on Flickr

If you’ve ever seen a mustache crawling up a tree, chances are you actually found yourself face-to-face with a Southern Flannel Moth caterpillar. These incredibly fluffy larvae grow up to be equally fluffy moths and live everywhere from Texas to Florida and up to New Jersey in the United States. Now that I’ve finally seen a luna moth, this fuzzy fellow is next on my bucket list of moths I must see in person.

You can look for them in local trees and bushes, but don’t touch – these caterpillars (quite tragically) are anything but cuddly. Those luscious locks hide poisonous spines that administer burning stings and swollen rashes. This painful defense mechanism earned them the nickname of “asp caterpillar” in reference to venomous snakes of the same name. If you are stung, applying ice pack to the rash is recommended, as well as using tape or tweezers to remove any spines still stuck in your skin.

Southern Flannel Moth caterpillars actually have a ton of nicknames. You may hear them called “woolly slugs,” “puss caterpillars,” “possum bugs,” and my personal favorite because it’s what I call my dog a lot: “perritos,” the Spanish word for puppies. With each molt, perritos (of course that’s what I’m calling them now) typically fade from yellow or brown to white and get progressively hairier until it’s time to pupate, and they typically feed on the leaves of common deciduous trees as they grow.

Perritos tend to build their cocoons on their host trees (the trees they eat from), other nearby plants, or on the sides of buildings. As they pupate, they shed their fluff and pack it into a bump in the cocoon called the hair pocket. I mean, I guess that’s easier than pausing metamorphosis to unzip the cocoon and dump all that hair out, right? Interestingly, Southern Flannel Moths do not emerge bald but are fluffy once more by the end of their pupation.

The perrito’s tough cocoon will protect it throughout the winter or summer, releasing the adult moth in early summer or fall for two generations of moths each year (or three in the Deep South, where the climate is warmer year-round). After the moth flies away, the empty cocoon persists for a long time and can be used as a shelter for other insects or spiders.

A Southern Flannel Moth adult from the Flickr page of the Smithsonian Environmental Research Center. Don’t you just want to hug it? It’s so fluffy! I need a stuffed animal version of this asap.

As adults, Southern Flannel Moths no longer possess poison spines, but they still don’t have much time for being cuddled: female moths will lay hundreds of eggs just days after completing their metamorphosis. The eggs take about a week to hatch, and then American parks are filled with crawling, poison-tipped mustaches again.

You may be wondering, “why are these moths so fluffy, anyway?” Well, apart from just making them look cute, moth fur (really setae, or fancy, hair-like scales) keeps the insect warm but also pulls off easily so the moth can escape if it gets stuck in a spider web.

That’s right, moth fluff is both fashionable and practical. Is God the master tailor, or is God the master tailor? That, or He thought it’d be funny to use the fur He’d set aside for the naked mole rats on moths instead. Either way, just one look at these fluffy insects will tell you He has a knack for subtle beauty – and of course, a sense of humor.

Dance of the Balloon Flies

A female balloon fly captured by Katja Schulz on Flickr

It’s February, and you know what that means – it’s time to talk about arthropods in love.

Dance flies, dipterans of the family Empididae and this week’s featured arthropod, are probably best known for their unique and romantic mating rituals. When dance fly mating season rolls around, male (or in some species female) dance flies swarm together and begin to dance in hopes of wooing the opposite sex. Then the female or male dance flies take to the sky to join the fun, and when two dancing dipterans catch each other’s eye, they join together and drop out of the swarm – literally. They just hug each other and fall out of the sky like cartoon characters who’ve just realized they’re running on air.

Okay, so there is a little more to it than that: dance flies don’t pick their dance partner (plummet partner?) willy-nilly. Males are looking for females with large abdominal sacs, which may signify the number of eggs the female has. Females, on the other hand, are looking for the male carrying the best present. See, apart from memorizing all that dance choreography, male dance flies have to carry a gift of food for the female. These gifts are wrapped in silk balloons, earning these dipterans the nickname “balloon flies.”

Dance flies do not mate for life and actually mate with several different partners during the mating season. To score as many free meals as possible, female dance flies often inflate their abdominal sacs in hopes of wooing more males. While it’s true that dance flies may be a bit more concerned about food than true love, I still think it’s cute that they dance and picnic together.

Interestingly, dance flies of the species Empis snoddyi present empty balloons to their mates. Males of this species with medium-sized balloons tend to be chosen by the most females, as their present isn’t too small to go unnoticed but isn’t large enough to burden them when their mate chases them out of the dance hall.

Oh, yes – Empis snoddyi females chase after males before deciding to mate with them. Maybe they’re testing their flying ability. Maybe they’re trying to play tag. We’ll never know – actually no, we probably will know at some point. Scientists really enjoy studying flies.

Apart from performing amusing dances in the sky, dance flies make pretty great neighbors because they prey on mosquitoes and other pesky insects. On the other hand, some species drink nectar and are invaluable pollinators, especially at high altitudes and in areas devoid of bees. This Valentine’s Day, let your love extend to these important insects, and maybe take their advice and treat your significant other to their favorite meal… just maybe don’t wrap it in fly silk.

Indestructible Tardigrades

At less than 0.05 inches long, most tardigrades are too small to be seen (or at least differentiated from the common dust speck) without a microscope. However, no matter where you live, these tiny animals are probably close by if you’re willing to look for them.

A tardigrade is a teensy aquatic animal belonging to the phylum Tardigrada. Tardigrada is part of the larger clade Panarthropoda along with phyla Onychophora and Arthropoda – that said, I’m kind of cheating talking about tardigrades on an arthropod blog since they aren’t arthropods themselves. Nevertheless, I think tardigrades are pretty stinkin’ cool, and it’s kind of unclear where they actually belong in terms of animal phylogeny anyway. So, I’m going to say they’re close enough to being arthropods, and we’re gonna talk about ’em.

Tardigrades are often referred to as “water bears,” which I guess makes sense as long as you ignore the fact that they have eight legs. And have no ears or fur. And have that weird tubey thing in the middle of what one would assume to be their face.

A tardigrade illustration uploaded to Flickr by Rebekah Smith

Honestly, they look a lot more like legged micro-croissants than any animal I’ve seen. But “water bear” is a cute name, so I guess we’ll stick with that for now.

Water bears like to live in moist environments, preferably in moss (earning them the additional nickname “moss piglet”). Commonly herbivorous (but occasionally cannibalistic), tardigrades use that funky tube or stylet to puncture plant cell walls and drink up the cytoplasm inside. They also hunt down and suck up the innards of harmful bacteria.

One of the reasons I find water bears so fascinating is that they are virtually indestructible – and keep in mind, this is an animal whose skin is thin enough to see through under a microscope. While these itty-bitty animals prefer the comfy microclimate of a moss bed, they are found everywhere: on the highest mountain peaks, in the deepest depths of the ocean, on every continent and in every biome. However, not all environments are equally suitable for a tardigrade to live in, especially habitats devoid of water. When water runs low, the tardigrade undergoes a process called cryptobiosis in which it basically reversibly dies. It’s like if you ran out of food and fell into a coma but woke up again the instant someone walked in with the groceries.

The specific form of cryptobiosis most tardigrades undergo is called anhydrobiosis, in which the tardigrade expels all the water from its body and folds up like an accordion into a special state called a tun. Water bears could teach us all a lesson in patience: a tardigrade tun will spring back to life as soon as it comes in contact with water again, but it can wait in this state for decades. In fact, tardigrades were once revived from a moss sample in a museum that was 100 years old!

A tardigrade photographed by Phillipe Garcelon on Flickr. The two tiny dots on its head are its eyes.

Even in harsh environments, tuns are incredibly resistant: they have been known to survive extremely hot and cold temperatures, obscene levels of radiation, and even outer space. Let me rephrase that last bit: someone thought “hey, let’s launch some tardigrades into the cold emptiness of space and see if they survive.” And they did! Dehydrated water bears can float around completely exposed in the vacuum of space and live to tell the tale. And not just for a few hours, either: those tardigrade tuns were left in orbit for ten days, and most went on to live happy, healthy lives after being rehydrated.

Alas, even the mighty water bear has its limits: tardigrades are unable to survive the human digestive system, or being fired from a gun. No, not being fired at with a gun – being fired out of a gun.

Scientist 1: Wow, tardigrades can survive in the vacuum of space, amazing! There really is no limit to their resiliency.

Scientist 2: Or is there?

Scientist 1: How could there be? We’ve frozen them, cooked them, bombarded them with radiation… what else could we possibly subject them to?

Scientists 2: Have you ever seen a human cannonball act?

So, to sum up today’s post: there are probably some tiny, nigh-indestructible animals called water bears in your vicinity, and scientists have way too much time on their hands.

If Alexander Hamilton Was a Spider…

I have been obsessed with Hamilton ever since it came out on Disney+, so you’d better believe I wasn’t going to pass up “My Shot” when I realized one of these biweekly posts would fall on Alexander Hamilton’s birthday. And I have the perfect arthropod for such an occasion: ladies and gentlemen, allow me to introduce you to the yellow garden spider, also known as the writing spider.

A gorgeous writing spider captured by Melissa McMasters on Flickr

Outside of the popular musical, Alexander Hamilton is especially well known for his writing, including but certainly not limited to the bulk of the Federalist Papers and articles for his newspaper, then called the New York Evening Post. Likewise, many writing spiders are accomplished essayists and journalists, some of whom have written articles advocating for the ethical treatment of pigs.

Just kidding. They’re actually famous for writing nonsense zig-zags that look much more like a zipper to me than anything actually legible. Perhaps writing spiders aren’t the best analogy for Hamilton after all.

The purpose of that “zipper,” or stabilimentum (fancy word for web decoration), is a bit of a mystery. It’s theorized that stabilimenta help stabilize the web (I see where the word probably comes from now), keep birds from flying into the web, or play a role in attracting insects.

Each web takes hours to weave, and the spiders spin a brand-new web every day, often in the same place. Once the web is constructed, the writing spider will sit in the middle and “Wait For It”: when prey get snagged in the web, vibrations alert the spider, who quickly descends upon its meal. Writing spiders may also engage in web-flexing, a common orb weaver behavior in which the spider shakes its web defensively or to further entangle its prey.

It could be that bugs get snagged trying to read that intricate zipper, but it’s more likely that they can’t see the web at all and fly right into it. Like most spiders, writing spiders construct their webs out of silk that reflects UV light, making their sticky traps virtually invisible to unsuspecting insects. Even though you can see them with your fancy human eyes, you still ought to let these big arachnids “Stay Alive” in your yard or garden: writing spiders prey on all sorts of annoying pests like mosquitoes, flies, and aphids. Plus, I think they’re really pretty, and their venom poses little to no threat to humans. And that’s a really good thing, because my family and I were attacked by hordes of writing spiders at Carolina Beach State Park.

Okay, that’s a bit of an exaggeration, but don’t hike the Flytrap Trail if you’re arachnophobic. We took the trail back in the fall of 2019 hoping to see some Venus flytraps, but instead my brother, parents and I saw writing spider after writing spider after writing spider. We had to walk directly under a number of spiders, and their blanket-sized webs on either side of the trail soundly deterred us from taking any shortcuts – we were feeling quite unnerved and “Helpless” to say the least. It was still a nice hike, and we ended up seeing some pitcher plants, but some of my less arachnid-loving family members were pretty relieved when we made it back to the parking lot.

Venus flytraps are carnivorous plants endemic to the longleaf pine forests of Southeastern North Carolina and parts of South Carolina. I still haven’t seen one in the wild, but they do grow naturally at Carolina Beach State Park. Thanks to NC Wetland’s Flickr page for the photo!

If you’re a spider lover but you don’t live in the Wilmington area, don’t worry – as long as you live in North or Central America, you still have a pretty good chance at running into a writing spider. I mean, hopefully not literally, as neither one of you would find that very pleasant, but they’re pretty cool to admire from a few feet back. Plus, there’s a myth that if you damage the spider’s web, it’ll write your name in its stabilimentum the next day, which is… bad, for some reason? That actually sounds pretty cool. But don’t try it, “We Know” these spiders are illiterate, so you’d just be wrecking their food nets for no reason.

Happy Birthday, Alexander Hamilton. I hope you would’ve been “Satisfied” with this post about writing spiders and all the “Non-Stop” Hamilton references.

And remember everyone: “The World [Is] Wide Enough” for both writing spiders and us. If you could just leave them alone for those of us who don’t like mosquitoes and garden pests, “That Would Be Enough.”

“Your Obedient Servant,”

– A. Blogger