Tag Archives: insects

Featured Creature Friday: Hawaii’s Carnivorous Caterpillars

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Your childhood readings of The Very Hungry Caterpillar will do little to prepare you for today’s featured creature, because these particular caterpillars are not the cute, fuzzy, slow, living-bootbrush kind of creatures that you’re thinking of. These ones are quite rare specimens among caterpillars, even though their genus Eupithecia are found around the world, and they’re a terrific example of the stunning specificity of survival adaptions that occur on isolated islands. Because unlike their seed- and plant-eating cousins, these caterpillars eat meat.

Just imagine this slow-motion scene accompanied by the theme music from Jaws and you’re on the right track. OMG FLY THE SERIAL KILLER IS ABOUT TO GET YOU I TOLD YOU NOT TO GO INTO THE BASEMENT. (All photos on this post are stills from the BBC’s South Pacific, which is linked to below. Please buy it and support Benedict Cumberbatch’s documentary-narration career.)

The grappling inchworm chilling out in its FREAKING HANDCRAFTED SNIPER NEST.

These hunting Eupithecia — which have been given the excellent common name of “grappling inchworms” — have a pair of hair-like appendages on the abdomen which, when touched by prey like the common fruit fly, cause the inchworm to arch itself backwards, deploying its frankly bad-ass-looking grappling arms to grab the insect before it can escape. Then it eats it, because delicious, right? They also employ some pretty ingenious techniques — like the “looking like a stick” technique and the “just the edge of a leaf, nothing to see here” technique — to disguise themselves, so hapless prey won’t know what hit them until, well… it hits them. And even then they might not know, because they’re flies and if we’re honest, flies just don’t seem like the most well-read species to me.

Because Hawaii lacks many of the other forms of predatory insects that are found elsewhere, these inchworms apparently found a vacant ecological niche — and a very plentiful food source — and adapted to fill it. By being awesome. Less than 1% of the planet’s known 160,000-odd species of butterflies and moths eat other insects, and no other Eupithecia do outside of Hawaii.

The following absolutely gorgeous video from the absolutely fantastic BBC documentary series South Pacific is kind enough to offer you excellent video footage of this caterpillar in action, with the added bonus of narration by Benedict Cumberbatch:


(If the embedded video isn’t working for you, just click here.)

(On a side note, I can’t recommend this documentary series highly enough; it’s beautifully filmed, beautifully produced, beautifully narrated, and endlessly fascinating. You can purchase a copy from the BBC America shop, the BBC UK shop, or I would imagine from any major DVD retailer. You can also rent the discs on Netflix, though tragically as of this writing it isn’t available to stream.)

For more on these inchworms from someone who actually knows what they’re talking about, I’d like to highly recommend this blog post from the fantastic Bioblog.

Featured Creature Friday: The Wonderful Woolly Bear Caterpillar

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I’m not really an entomology sort of person. It’s partly because insects are often creepy and partly because I’m just not good enough at spotting them to foster an interest. It’s the same reason I’ll never take up birdwatching: when your eyesight is bad enough that it takes you five minutes to spot a full-grown eagle, it might be time to consider an interest in elephants, instead.

I am generally a fan of caterpillars, though. For one thing, they’re often incredibly cute in a bizarre and alien sort of way, and like the butterflies and moths they become, caterpillars come in a truly staggering array of colors and configurations. Some of them look like tiny cacti and some have horns and some are poisonous and some will burn you with acid and I’m sure that deep down, some of them just want to be loved.

But we’re here to talk about a particularly magnificent specimen in the form of the Woolly Bear Caterpillar, which is particularly extraordinary because it has considerably lengthened its lifespan through cunning use of cryogenic technology.

I've named this one "Fry." It was only trying to deliver a pizza...
photo by IronChris, by way of Wikimedia Commons and used here under Creative Commons license.

Compared to some other caterpillars, the Woolly Bear might not be much to look at — it’s sort of like a multicolored scrub brush — but it’s anything but mediocre. Where most species of caterpillar live only a few weeks, the Woolly Bear has adapted to cold climates by simply freezing solid when the temperature drops, which has extended this little Lepidoptera’s lifespan considerably. In warmer climates they’ll live a few years; in the arctic, their badassery extends to fourteen years or more. Every winter they freeze, every summer they thaw, eat, and grow bigger, until they finally become moths, live just long enough to reproduce, and then die. It’s a bit of an anti-climax, but who knows, maybe being a moth sucks.

As you all know, I’m a sucker for scientists getting all excited about nerdy things — they’re like teenage girls at a Bieber concert — so here’s a fantastic video from the new series Frozen Planet with a lovely gentleman and his lovely accent telling you all about the Woolly Bear and how completely awesome it is.

But wait, there’s more! Woolly Bear Caterpillars were also the first insects shown to self-medicate to stop parasitic infestation. Woolly Bears are plagued by a type of parasitic fly which is kind enough to leave a gift of larvae inside the poor caterpillar; when the little bastards hatch, they eat the caterpillar from the inside and then bust right out of there like they think they’re extras in Alien. But infected Woolly Bears can fight back by eating alkaloid-laden plants.

Bernays and her colleagues showed that infected woolly bears eat more toxic alkaloids than their non-infected peers. Healthy woolly bears also ingest alkaloids, but only in small amounts, apparently to make themselves unsavory to predators.

In addition, the team showed that parasite-free woolly bears that binge on alkaloids are more likely to die compared with woolly bears that take the drug in moderation. – source National Geographic

So not only have they figured out how to treat their own medical problems in a totally groovy holistic fashion, but they’re also better at moderation with their alkaloids than I am with chocolate. Thanks a lot, Woolly Bear caterpillars. Now I feel like crap about myself. Which is probably how you’re going to feel when you finally turn from a bad-ass caterpillar into a completely boring moth. CHECKMATE.

Featured Creature Friday: Crafty Crows, Agricultural Ants, and Pyro Bonobos

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When I was a kid, I remember reading dated books about natural human history that showed early human ancestors (typically clad in Flintstones-style approximations of what I can only assume were sabertoothed tiger skins), and they explained the process of our evolution, and what forces had contributed to our eventual rise to true civilization (which at the time meant listening to Phil Collins and wearing stirrup pants and jellies.)

Our large brains separated us from the animals, we were told. We learned to create and use tools. To farm and keep livestock. To harness fire. We were convinced that all of this made us better than the beasts.

Of course, in the time since then, we’ve learned that there are animals that do all of those things too. They just haven’t taken it that one step further by building monster trucks, synthesizing bovine growth hormone, or inventing nuclear weapons, all of which truly makes us superior to the dumb beasts of the world.

Still, you have to give the animals credit for being just ridiculously clever, so let’s take a look at a few of them and boggle together at how much smarter they appear to be than we are. They’re at least out there making their way in the world, pulling themselves up by their proverbial bootstraps, instead of sitting around at home and watching Jersey Shore.

Art by John Gerrard Keulemans, in the public domain

The Toolsmiths: New Caledonian Crows

We all know that many birds are kind of ridiculously intelligent. They’ve been observed doing things like dropping turtles from great heights to break their shells, or using the tires of passing cars to crack open nutshells. Birds have been shown to show some ability for counting, problem-solving, deception, pre-planning, operating  and incredible skills of dancing. And although many birds have a demonstrated ability to use tools, the current master toolsmith of the bird world is the New Caledonian Crow of New Zealand. These birds have been shown to not only use tools but also to create them, and to use one tool to acquire another tool to acquire another tool to get to a food source. Here’s a TED talk from a fellow who built a crow vending machine, where they could exchange coins for peanuts. (I can only assume that this gentleman is now both very rich and also a regular at his bank’s coin-counting machine.)

The Farmers: The Herding Ants

There are actually a surprising number of animals that actively engage in farming. Termite mounds are essentially giant terrariums designed to create optimum conditions for the fungus they like to eat. You might think Leaf-Cutter Ants cut leaves so they can eat them, but actually they’re creating compost for growing their own fungus farms. Ambrosia Beetles grow their fungus farms in trees, while Marsh Snails use their tongues to slice into cordgrass, creating a perfect environment for the fungi they prefer to feast on. Even the oceanic creatures get in on the action: spotted jellyfish are their own living greenhouses, and make use of photosynthesis and their own transparent skins to help them create a rich fungal crop inside their own bodies. (I’m beginning to sense that animals love fungi.) Damselfish, meanwhile, grow algae and are as aggressively protective as a farmer with a shotgun… plus, the algae they prefer are a bit wimpy, and probably wouldn’t really survive without cultivation. If you’ve ever read Michael Pollan’s The Botany of Desire, that may sound like a familiar story.

But I was going to talk about ants. Ants are particularly interesting because they don’t raise mere crops like the rest of their fungus-loving friends. They actually farm livestock. Several species of ants keep herds of aphids, which they “milk” for their excrement, “honeydew,” which is extremely sugary. (Before you start judging the ants, remember that humans make a common practice of not only eating all sorts of animal meat but also their mammary secretions and in the case of birds, the byproducts of their menstrual cycle.) The relationship between ants and aphids directly mirrors that between humans and our own livestock animals. The ants get to enjoy good nutrition and delicious treats, plus an extremely reliable food source. They relocate their herds to better grazing when necessary, defend them from predators, clean up their waste (which would otherwise attract unwanted visitors), keep them out of the weather, and even help them reproduce by sheltering, protecting and nurturing their larvae.

New research also suggests that humans aren’t the only ones to use pharmaceuticals on our livestock, or to physically modify them the same way we might castrate calves or dock a lamb’s tail. The ants sometimes nip off the adult aphids’ wings so they can’t fly about on their own. A new study suggests that chemicals the ants track around on their feet may serve as some sort of signal or actual tranquilizer for the aphids.

The Firestarters: Bonobo Apes

Okay, this one’s a little bit of a cheat, but you’re going to love it anyway. This TED talk shows video of bonobos starting a fire, driving a golf cart, playing musical instruments, inventing new uses for tools, and playing Pac-Man. Yeah, you heard me. They weren’t taught these things as tricks, but basically the behaviors were modeled for them, and they picked them right up and started experimenting for themselves.

So I guess we’re just not as special as we thought we were, nor are animals quite the dumb beasts that they’ve been made out to be… and we’d better be careful, because we’ve taught them how to start fires. I’m just saying.