Bombardier Beetle

How does a bombardier beetle survive for up to two hours in the stomach of a toad, bathed in harsh tummy acid? No one really knows. How do scientists know that this beetle can survive for so long in a toad's tummy? They watched, as toads, with a lightning-fast flick of their tongue, instantly swallowed a beetle. Then, within a few minutes or even up to a couple of hours later, the toad barfed up the beetle—coated in stomach slime—which slowly crawled away. The dazed-looking toads showed no interest in trying to gulp the beetle a second time.

How does the bombardier beetle accomplish such a Jonah-in-the-whale's-stomach feat? It doesn't need God to order the toad to barf up the little beetle, as he did the whale to liberate Jonah. The bug mixes two chemicals in its butt—hydrogen peroxide and hydroquinone (a derivative of benzene). When these chemicals come in contact, they create an explosion of hot gas that blows out the beetle's butt. The nasty projectile either fends off predators or stuns prey. It's even able to swivel a nozzle on its tail end, to spray the hot fuel in different directions.

Hydrogen peroxide, besides being a sterilizer, can also be used as rocket fuel. It powered the German V1 rocket in WWII. There is no evidence to suggest that the Germans learned this trick from the bombardier beetle. It seems to have been their own brand of rocket science.

Beetles are likely the most prolific type of critter on Earth. They are found everywhere and eat most everything. They are a vital part of the ecosystem. As evidence of beetles' profusion, some 25% of all animal life forms are beetles, and they constitute about 40% of all insects. Entomologists don't even know how many species exist—maybe half a million, maybe several million. 

Beetles are a true insect, which means they have two pairs of wings, but their front pair is hardened into stiff wing cases. In order to fly, a beetle lifts those hard wings and then activates its delicate flying wings hidden underneath. It can't take off instantly, as a fly can, so it's rather vulnerable for a moment or two. That moment is plenty of time for the swift tongue of the toad to swoop out and scoop in the bug.

To set up their experiment, Japanese scientists at Kobe University went into the field and captured several species of toads and beetles. A toad and a beetle were then placed in a glass enclosure. Like Romans watching gladiators, the researchers observed, as the toad scarfed up the beetle and then settled down to digest its catch. Some time later, the bombardier beetle went into action—blending its toxic chemicals into miniature rocket fuel. The scientists could sometimes actually hear the explosion coming from inside the toad's belly, followed by a couple of heaves of the toad's tummy, followed by the ejection of the live beetle, which then slowly crawled away. Just another amazing discovery in the annals of science.

Firefly Antics

This is the season to watch the antics of fireflies. Late June and early July are such fun times—gazing at the flashing, flying, glowing creatures. Fireflies are another of those insects with “fly” in their name, that are not flies at all. Another common moniker they have is lightening bug, but they’re also not a bug.

Fire“flies” are beetles, and they ought to be proud of that, since beetles are the most abundant and diverse critters on Earth. One in every four animals is a beetle! One in five of all species (including plants) is a beetle. Yikes, they’re everywhere! Just in North America we sport 24,000 different species of beetles.

Have you ever watched a beetle fly? They look quite ungainly, compared to their distant cousins, the “true” flies (who have only two wings). Beetles have four wings; but the forward pair are for protection—and are unable to flap and help in the flying game. They are hard plates that are lifted up and held ungainly out to the sides, as the aft pair gets the beetle precariously airborne.

There’s quite a variation between the different species of fireflies. Most females can fly, but some are wingless. Some females deceive another species’ males and eat them. Some species don’t flash at all—the so-called day-active non-luminescent fireflies. (Huh? Isn’t that an oxymoron?)

But I digress. I wanted to write about a recent firefly antic that I was treated to. Ordinarily, I watch the lanterns of these luminescent beetles flash on and off when it’s dark. It’s very rare that I can follow an individual firefly after he blinks off. If I see another flash, I have no idea if it’s him or another nearby suitor. I even have no idea of how many flashers I’m watching. It may be just a couple of them dashing and flashing here and there, or a bunch of them hovering lazily in one location and occasionally flashing.

On this recent occasion it was early dusk, so I could see him, even when his beacon was extinguished. It was mesmerizing. He’d helicopter slowly along, a couple of feet above the ground, then quickly dip downward and flash. Bobbing back up, he’d dawdle along for a bit, then swiftly dip and flash again. He looked to be in hunting mode. After each flash he’d pause, as if waiting for a potential mate to respond, and then move on, when he got no answer.

He kept searching, drawing me into his undertaking. At one point an answering flash came from below, with the same timing. There she was! But he missed the signal! He moved dreamily on, dipping and flashing. I wanted to call out to him, telling him he’d just missed a golden opportunity. I hoped he’d U-turn and come back to find her, but he plodded fruitlessly along. Could he even have heeded my call? Does a firefly have ears for human coaches?