A team of researchers are fighting an invasive and destructive pest threatening North American forests with an unusual strategy. Male emerald ash borers trying to mate with "female" decoys are in for a fatally shocking surprise. And more surprisingly still, the strategy seems to be working.
That's at least according to a study recently published in the journal Proceeding of the National Academy of Sciences (PNAS), which details how engineers and entomologists from Penn State University worked together to create decoys that mimicked female emerald ash borers as effectively as possible.
These deadly decoys were pinned to leaves across a field study site in a Hungarian forest. Some were even hooked up to an electrocution trap boasting a fatal 4,000-volt charge - more than enough to smite even the most wary of males as long as he makes temporary contact.
According to the PNAS study, the researchers used three different decoys in all, including 3-D printed decoys and even the painted bodies of dead female emerald ash beetles. (Scroll to read on...)
"We learned that not only do color and shape of a resting female beetle play a role in attracting males to a mate, but also the fine-scale texture of the visible surface is important," entomologist Michael Domingue explained in a recent release. "Small bumps and spines on the outer surface of their wings and heads that aren't visible to the human eye scatter light in a distinctive pattern. Beetles appear to be able to recognize this feature of the decoys and are strongly attracted to it."
He adds that while only temporary electrocution contact is needed to kill off a male, making the decoys more attractive than even live females can easily help control populations where they are becoming a major problem, such as in North America.
By focusing on the features that make it easier for males to spot the green females, even while they rest on green leaves, the team can ensure they will attract and kill as many males as possible.
"We have made progress in our research so far in Hungary these past few summers, and it looks like our decoys can be refined to attract and detect these other, new and potentially invasive pest species effectively," Domingue said.