Photo: palestrina55 (flickr)
Most creatures run the other way when they detect a forest fire, but not beetles of the genus Melanophila, sometimes referred to as “fire beetles” or the “fire bug”.
When they detect a forest fire, they fly directly toward it. These half-inch long black beetles aren’t exhibiting suicidal tendencies, but just the opposite, survival skills.
Their breeding requires being in the vicinity of coniferous trees freshly destroyed by fire. These wood-boring beetles fly to forest fires in great numbers, and mate while the forest is still burning. Females then deposit their eggs under the bark. The eggs hatch into larvae that feast for up to a year before pupating and tunneling their way out as mature beetles.
The fire beetle has beat trees’ defenses by evolving to breed in deceased trees. If they attempted to breed in living trees, they’d be goners. The tree’s cell growth would squash the beetles or its sticky resin, a natural pesticide, would drown the beetles.
The beetle has also evolved mechanisms to detect fires from great distances. This is necessary because once a forest has burned, it can be protected from future forest fires for decades, sometimes centuries.
The beetles are equipped with super sensitive receptors on their bodies that can detect infrared radiation. Scientists compare the heat-seeking behavior of the beetle to the behavior of a bloodhound, in that if either veers in the wrong direction, they lose the scent, so to speak. They adjust their movements as needed to keep heading in the direction of the signals.
Fire beetles aren’t just interesting to entomologists, but to engineers who may steal some of the beetles’ secrets in designing new infrared radiation detectors for military and other uses.