BugBytes: Thoughts on cool beetles and squeamish adults


Marian Lyman Kirst

These mating oil beetles—probably Meloe impressus—are a common sight around Norm’s Island in early to mid spring. The translucent, yellow membrane beneath the beetles’ thorax is thought to mimic the insects’ cantharidin-infused blood, thus serving as a possible visual deterrent to potential predators.

Finally, springtime is in full swing and summer is just around the corner. This invigorating seasonal shift signals the revival of two key insect-related events:

1) The transformation of our house’s western exposure into a Bacchanalian bone zone for randy swarms of box elder bugs recently sun-flushed from their winter hideaways and onto our front stoop. The result is like something out of a John Waters film: excrement-stained walls and windows, a mailbox filled with copulating foursomes doing it in the dark, and let’s not forget the dribbled gobs of abandoned egg clusters that, when crushed, dissolve into a smear of blood-hued vitals.

Spring at our place. It’s a scene, man.


2) The return of BugBytes: Billings’ go-to-guide for info and stories about local mini-beasts and the area’s many-legged majority.

BugBytes’ return is due largely to you, our readers, and the fantastic folks who attended our winter fundraiser. Your support and generosity for this, admittedly strange, little column is just phenomenal and has infected the whole BugBytes team with a serious case of warm fuzzies, not to mention a renewed sense of hope for the future of insect-human relations (and, thus, for humanity in general).

For me, the fundraiser was particularly notable for the stories many shared regarding your new or revitalized efforts to avoid unnecessary invertebrate carnage: sweeping insect interlopers outside or—baby steps—making eye contact with any sink-trapped spider before flushing it to the depths of your plumbing.

These stories suggest that reasonable adults, when armed with correct information, can actually alter ingrained, reactionary behaviors (at least when it comes to invertebrates). Our readers’ determined attempts to harness their inner Attenborough are especially reassuring given the depressing display of overcautious, dirt-averse “adultness” I witnessed during a nature walk/trash pick-up activity my husband and I led this past Earth Day.

First, a father refused to let his son rescue a piece of plastic from the edge of a pond for fear the boy would get his shoes muddy. Later, I attempted to show some Girl Scouts how to sip nectar from the tips of plucked honeysuckle blossoms. Their troop leader responded by swiftly swatting the flowers from one Scout’s hands as if I’d just passed the girl a crack pipe. The troop leader suggested the freshly opened flowers—all petal and perfume—were “dirty” and reminded the Scouts that “we don’t eat flowers.”

Similarly, when an inquisitive youngster resolved to hold a small stone centipede we’d discovered, it wasn’t the pink-sweatered 7-year-old who flinched but, rather, her mother, who made the girl set the tiny creature down and insisted the whole business was “gross.”

Yeah, that’s right, lady, I’m super gross. And in lots of hilarious ways, too; but least of all for picking up harmless arthropods. Sheesh.

Indeed, I used to believe that engagement in and curiosity about the natural world is a concept smarty-pants “adults” must impart, with lots of hrrrumphing and earnest lecturing, to tech-distracted kids. I now wonder if I’ve had this backward.

Neil deGrasse Tyson said in an interview on a recent Nerdette podcast, “All children have curious minds. So, in that sense, all children are scientists. They’re born that way.”

Agreed. But adults can be again. So, with bug-hunting season upon us, let me introduce you to a cool pair of local coleopterans that can help reacquaint you with that inner curious kid.


Marian Lyman Kirst

Tiger beetles are fleet-footed predators easily recognized by their long legs, bulging eyes and fierce, front-facing jaws. This big sand tiger beetle (Cicindela formosa) is an eye-catching, if common, species in Montana.

Tiger beetles

Tiger beetles (family Carabidae) abound in Montana and, thanks to the insects’ often vivid iridescent body-work, are relatively easy to spot as they missile down sun-lit paths and sweep along lakeshores and stream sides hunting prey.

Fair warning, though: these beetles are not the easiest creatures to catch. A hands-and-knees, sneak-and-lunge method occasionally works but more often results in humiliation, with the insect magically reappearing just out of reach where it turns to face you, as if to say, “You, madam, are terrible at this.”

But such misses are understandable given these beetles’ incredible stealth. Researchers at Cornell University clocked a top running speed of .53 meters per second for the bronzed tiger beetle (Cicindela repanda), a common streamside species. Scaled to account for the beetle’s size, this rate equates to a running speed of nearly 54 body lengths per second—approximately 10 times faster than our swiftest human sprinters!

What’s more, the beetles appear to experience periods of temporary blindness, during which the insects’ large eyes fail to collect enough reflected photons to form images of their prey. This forces the beetles to make multiple millisecond stops, mid-chase, to reorient, resulting in a distinctive stop-start style of hunting. To compensate for these sightless seconds of speedy pursuit, the beetles rely on their robust antennae, which—held rigidly forward as they hunt—help the beetles locate and navigate obstacles.

Tiger beetle larvae are no less fierce or fascinating. These bizarre, grub-like creatures reside in narrow, vertically walled soil burrows, some as deep as 18 inches. The larvae anchor themselves in these retreats using a pair of stout abdominal hooks and align their armored, plate-like heads flush with soil’s surface. When suitable prey approaches, the larva lunges, snatches the victim and pulls it into the lair for consumption.

As yet, I haven’t had the good fortune to witness this weirdness in the wild, but this video of a guy “fishing” for tiger beetle young using ant prey on a string is pretty illustrative and compels comparisons of tiger beetle larvae to the asteroid-dwelling, space-ship swallowing Exogorths of “Stars Wars” fame. “This is no cave!” indeed, Mr. Solo.


Elley Swan

Artist Elley Swan’s illustration “Cantharidin Orbs” depicts the oil beetles’ defensive habit of oozing oily yellow-orange drops of skin-blistering “blood” when threatened or roughly handled.

Oil beetles

Oil beetles are a particularly distinctive genus (Meloe) of blister beetle both in mien and manner. For one thing, it’s easy to tell the guys from the gals: in addition to being smaller and slimmer than the females, male oil beetles boast goofy, C-shaped kinks in their antennae that are used to grasp female antennae during courtship displays.

Our local oil beetles are waxy black with an occasional bluish, purplish sheen and feature super short forewings, resulting in a strong resemblance to charred hop umbels with legs or bloated, side-bustled coffee beans.

These corpulent cuties are found on the ground or feeding on foliage in the spring and fall. Like other blister beetles, oil beetles can “bleed” defensively, releasing gorgeous nectarine-orange globes of cantharidin-infused hemolymph from their leg joints. Cantharidin is a colorless skin-blistering chemical occasionally used to remove warts and historically used as a questionable aphrodisiac called “Spanish Fly.”

Don’t let this characteristic stop you from observing or even holding these gentle giants. (I’ve never been able to raise blisters on myself from voluntary applications—to my wrists—of the beetles’ secretions.) But do use caution and care when handling these beetles (especially if you have allergic sensitivities) and definitely wash your hands before touching your face or food.

And if you think the adult beetles’ chemical weaponry is neat, just wait. Oil beetle larvae, called triungulins, are flat-out fiendish.

Parasites of ground nesting bees, triungulins use an ingenious three-step scheme to gain entry into bee nests, where they feast on pollen, nectar and eggs.

First, the tiny worm-like beasts cooperatively gather at the tip of a stem in the shape of a female bee! There, the larvae release pheromones that fool nearby male bees into mounting the “attractive” aggregation. The larvae then attach to the male’s underside, essentially hitching a ride (a biological symbiosis called phoresy) to an actual female who, eventually, and unknowingly, transports the larvae to her well-provisioned nest.

There’s got to be a ride sharing-based horror movie plot in all this, yeah?

Drop us a line

Have a bug-related question or cool invertebrate photo? Want an ID for that crawling creepy in your bathtub? The get in touch! The BugBytes’ team would love to hear from you. Just send your queries to BugBytesMT@gmail.com.


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