Creation/Evolution Journal

The Bombardier Beetle Shoots Back

Christopher Weber claims he has exploded the Bombardier beetle myth, because he has found factual errors and logical deficiencies in the argument for creation developed around this clever little creature (1981). Well, they say that confession is good for the soul, so I had better confess. I am the source of the original little pamphlet about the Bombardier beetle which was published way back in the early sixties. My first information was from an article in the science page of Time magazine (1961) and then a follow-up of Hermann Schildknecht's first research article which was published in Angewandte Chemie in 1961. My translation of this article was cursory, rather sloppy, and the idea of spontaneous explosion of the beetle's hydrogen peroxide-hydroquinone mix came from the Time article. So please don't lay so much blame on Dr. Gish. I must accept responsibility for the misinformation.

Having said this, however, it does appear to me that Chris Weber has not proved his case very well and, therefore, our case still stands. In fact, he ignored or overlooked some basic facts that his readers really ought to know if he claims to have demolished our case.

It is true that a mixture of the two reactants dissolved in water does not spontaneously explode, but Dr. Schildknecht noted that the mixture is quite unstable in vitro and begins to react immediately. He also reported some experimentation with the mixture stored in the reservoir. It seems that the mixture of hydroquinones and hydrogen peroxide remains stored indefinitely in the reservoir without reacting, preserved in a clear water-white condition. He says:

It is thus astonishing that the content of the pygidial gland remains completely colorless in the interior of the bag. This may be investigated if one keeps an isolated pair of pygidial glands together with a moist cotton pad in a small weighing bottle. The contents of the bag remain water-clear for a long time. When after up to two days the bag begins itself by subsequent decomposition to become colored black, there is still to be noted no decomposition of its contents, which, after four days, always still is in reaction-ready condition, as the violent effervescence with formation of quinone and oxygen caused by touching the bag, by this time strongly decomposed, demonstrates... .

In comparison it may be shown by experiment that the phygidial bladder

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contents are stable only in the interior of the bladder and spontaneously decompose in a brief time, if one withdraws it from the bladder, perhaps by puncturing the inactivated bladder with a fine capillary.

According to these investigations, there is a principle active in the biological system that a solution of hydroquinone and hydrogen peroxide is stabilized. This principle is either chemical or physical chemical in nature, but it appears to be connected with the morphology of the collection bladder of the pygidial gland system. Stabilization by a homogeneous chemical stabilizer distributed in the solution appears improbable.

Now let us analyze this defense system from the evolutionary viewpoint. Mr. Weber makes it sound all too easy. Within the framework of his preliminary speculations, we have to imagine a beetle which merely was a stinker, dripping hydroquinones from his anus to be as unappetizing as possible, which would certainly have an adaptive value. But then, somehow, some hydrogen peroxide began to get mixed with the hydroquinone. This was supposedly advantageous, so that gradually natural selection led to increased peroxide content. At first the two compounds reacted until the peroxide was used up. Now this might be advantageous, since the resulting quinone would be an irritant to enemy predators. So now the beetle both stank and burnt the mouths of predators. But then, by chance, a still unknown mechanism developed-either all at once or slowly which prevented the reaction. This would supposedly provide some unknown advantage greater than the previously described advantage of having the reaction take place. Then, gradually, the gland or glands producing the two reactants evolved the power to produce greater and greater concentrations of a stable mixture of hydroquinones and peroxide, eventually reaching 10 percent and 23-25 percent, respectively. This process supposedly had some progressively advantageous value to the beetle.

Schildknecht points out that it is reasonable to imagine that in the biochemical production of each two moles of hydroquinone from quinone, a natural by product would be one mole of oxygen (molecular), and that this could be converted to one mole of hydrogen peroxide. This would yield a weight ratio for hydroquinone to peroxide of 6.5 to 1. But in the stored liquid produced by the beetle's pygidial glands, the ratio for hydroquinone to hydrogen peroxide is 1 to 2.4, an almost fifteen-fold excess of peroxide. This is apparently needed to get both oxidation explosively of the hydroquinone and a large amount of oxygen gas to provide extra propulsion force for the defensive charge. It seems that evolution is always thinking ahead?

Returning now to our developmental train of thought, in the meantime, or at some subsequent time, the vestibule developed with attached glands producing the two enzymes necessary to produce an explosion when mixed with the hydroquinone-peroxide solution. But presumably in the early evolutionary stages the amounts of the enzymes would be small and the concentrations of the reactants

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also small, so no explosions would occur. Perhaps the beetle just walked around with its stinking behind getting gradually hotter and hotter. Maybe it got too hot back there, so it became advantageous for the beetle to evolve the muscle and valve to shut off the reservoir from the vestibule containing the enzymes. Then the beetle would find it advantageous to squirt out short spurts of the mixture which would explode in the vestibule, once the concentrations all got properly balanced. Of course, until controlled explosions became possible to the beetle, there would be no need for the aimable orifices or guns that are now attached to the vestibules of the beetle. So we might speculate that the earlier forms of beetles of the genus Brachinus used shotguns which were not very efficient. Greater efficiency was gained by evolving the shotgun barrels into rifle barrels. Then the beetle could shoot his enemies by aiming his rear end at them and pulling a trigger mechanism which he had just happened to evolve in the nick of time. It would be pretty bad when the robber walked in if the hero found his gun did not have a trigger or if he had not learned how to aim it. Later it became advantageous for the twin rifles to be installed in moveable turrets so that they could cover an arc of 270 degrees. And this all by spontaneous materialistic process!

It does seem to me that to believe such a scenario is credible requires strong faith in the capabilities of atoms and science, but those who believe in evolution have such a faith. Those who believe in creation likewise have strong faith. The difference is that they place their faith in a Being of infinite intelligence and power whose intelligent, purposeful designs are evident everywhere in nature.


Schildknecht, H., and Holoubek, K., January 7, 1961. "Die Bombardierkafer and ihre Explosionschemie." Angewandte Chemie. 73:1:1-7.

Time. November 24, 1961.

Weber, Christopher Gregory. Winter 1981. "The Bombardier Beetle Myth Exploded."
Creation/Evolution. III:1-5.


Translations from the German are due to the author, with trepidation.

By Robert E. Kofahl
This version might differ slightly from the print publication.