Just imagine a soldier carrying a cannon on his back, ready to respond to any threat at a rate of fifty shells a second. This artilleryman exists in nature, in the form of a tiny beetle with a sophisticated firing mechanism
We all know tigers and bears are scary animals by all accounts. Even the insect world doesn’t have a shortage of frightening representatives: for example wasps, dragonflies and even cockroaches. But a beetle? Why would anyone fear such an innocent creature?
Well, now it is time to meet the bombardier beetle. Although first appearances show nothing special, it possesses a unique deterrent in its arsenal. This small beetle, less than a centimeter in size, has an explosive device - when an enemy attacks, it activates a controlled detonation. At the back of its body is a pair of vestibules, which in times of danger release a burst from two jets of foul-smelling boiling liquid that hits the enemy and immobilizes it. This defense mechanism is accompanied with a popping sound, which gave the beetle its name.
Bombardier Beetle | Photograph: Peter Halasz, Wikipedia
How does this mechanism work?
The beetle's body has glands that produce two different materials - one of which contains 10 percent hydroquinone and the other that contains 23 percent hydrogen peroxide. These substances are mixed in two reservoirs and pumped by the glands into the "explosion chamber", which is a little muscle that has a high resistance to pressure and temperature.
The combination of these two materials releases a great amount of energy. When the beetle detects danger it secretes an enzyme (protein) that creates the strong reaction between the ingredients, and a powerful jet of hot liquid is sprayed out accompanied by a loud popping sound. The liquid released is called benzoquinone and is also used by other insects in protection. The bombardier beetle is unique, however, compared to other insects for the fact it heats the liquid and sprays it in a series of tiny pulses at a rate that can reach fifty pulses per second.
Watch the beetle’s amazing defense strategy:
Bombs and does not explode
For years, researchers have wondered how this beetle causes these explosions but does not get hurt from the blast and magnitude of the explosion? A new study has suggested a solution to the mystery.
Researchers used an X-ray and documented the process of the explosion with a speed camera that captures 2,000 frames per second. It was discovered the bombardier beetle synthesizes the chemicals only at the moment when they are required and it is done within a protected explosion chamber. The chamber is a hard structure that protects the beetle when temperatures rise and at the time of the explosion. The isolated chamber, where the chemically exothermic (emitting heat) reaction takes place, is controlled by a unique valve muscle.
Other components within the system, such as transportation pipes, are more flexible and allow the beetle to control the pulse of the liquid jet spray. Another mechanism that allows the beetle to bomb its enemies without getting hurt is its use of pulses - a means of allowing the chamber to cool a bit between the liquid jet sprays.
This mechanism allows for a comfortable life for the beetle with very few predators, besides those very special enemies that have successfully developed safeguards against the toxic hot spray.