Subscribe to the OSS Weekly Newsletter!

Do Not Mess with a Bombardier Beetle!

Why not? Because you risk being sprayed with a hot solution containing irritant chemicals known as benzoquinones. In all likelihood it would be a memorable, but unhappy experience. Based on their ability to discharge “chemical bombs” when threatened, bombardier beetles are aptly named.

Why not? Because you risk being sprayed with a hot solution containing irritant chemicals known as benzoquinones.  In all likelihood it would be a memorable, but unhappy experience.  Based on their ability to discharge “chemical bombs” when threatened, bombardier beetles are aptly named.  

Beetles are different from other insects in that while they can fly, they cannot do so instantly.  Their wings are stored under wing covers and have to be released before they can take to the air.  Sort of like Clark Kent having to shed his everyday clothes before becoming Superman.  Since beetles cannot instantly fly away when attacked, they have evolved emergency defenses to use while they plot their getaway.  The African bombardier beetle, Stenaptinus insignis, has been extensively studied to understand its remarkable defense system.  When attacked by predators, mostly ants, the beetle unleashes bursts of its hot chemical spray accompanied by audible detonations.  

The spray originates from a turret-like appendage under its abdomen which the beetle manoevres to achieve remarkable accuracy.  But it is the chemistry of the spray that is truly amazing.  The irritant chenmical is formed just prior to launch by mixing the contents of two separate glands.  One contains hydrogen peroxide and hydroquinone, while the other harbours a mixture of enzymes known as catalases and peroxidases that can react with hydrogen peroxide to form oxygen gas and water.  When the contents of the two glands are mixed, oxygen forms and in turn reacts with hydroquinone to convert it to benzoquinone.  This reaction is so highly exothermic that the chemical mixture can reach a temperature of 100 degrees C.  Pressure due to the buildup of oxygen then causes the hot mixture of water and benzoquinone to be expelled with a “pop,” much to the woe of any attacking ants.  

Bombardier beetles can launch their chemical “bombs” up to twenty times before running out of ammunition.  But by that time they will have succeeded in unfurling their wings and are ready to leave their attackers behind wallowing in their hot, toxic wake.  While bombardier beetles have been able to free themselves of ants, they have not been as successful with creationists who argue that the existence of these arthropods is proof of the theory of creation.  Why would separate glands have evolved, they ask, when it is clear that there is no evolutionary advantage until their contents are mixed?  The beetle must therefore have been created as is, ready to fight off predators.  Evolutionists don’t buy the argument.  They say that the beetle is actually an excellent example of survival of the fittest.  Random mutations over many years resulted in the protective mechanism that increased the chances for survival-the essence of evolution.  Whatever be the case, nobody can contest the fact that the bombardier beetle is in possession of an impressive chemical weapon.  So if you encounter one, leave him be.


@JoeSchwarcz

Want to engage with this content? Comment on this article on Facebook!