Bombardier Beetle’s Chemical Weapon Perplexes University Researchers

An unusual series of pictures, one of them shown above, reveals a bombardier beetle directing a stream of hot, irritating chemicals in response to an attack. The beetle cannot deploy its wings rapidly to fly away from an assault by ants or other predators. So it has developed the hot, stinging spray that is ejected at 212 degrees Fahrenheit and contains toxins such as hydrogen peroxide and irritating quinones. Mixing the chemicals generates the heat.

Researchers at Cornell University report in Tuesday’s Proceedings of the National Academy of Sciences that they used a drop of wax to stick beetles to a fine wire to hold them in place for the pictures. A sensitive microphone triggered a camera to record the sprays. The primary remaining mystery, the team wrote, is why the heat and chemicals don’t harm the beetle.

*

--Compiled by Times medical writer Thomas H. Maugh II