To a farmer, good insects pollinate. And bad insects decimate. And they’ve often had a tough time knowing which flying creatures were invading their crops. Now eavesdropping researchers might offer help.

For 60 years, scientists have tried to identify insects by their wing sounds. The challenge increases with distance, wind and other noises. So researchers created a monitor using lasers. When an insect crosses the laser, the shadow of the wing beats gets recorded and translated into an mp3. Here’s a female aedes aegypti mosquito. Here’s a female culex quinque fasciatus.

The researchers spent three years gathering data from dozens of sensors. They have tens of millions of data points—more than had been previously collected all together—for their algorithms. Using wing beats plus location and time of day, they’ve achieved up to 99 percent accuracy identifying six insect species thus far.

The research will be published in the Journal of Insect Behavior. [Yanping Chen, Eamonn Keogh et al, Flying Insect Classification With Inexpensive Sensors]

The prototype was made of LEGOs, a 99-cent laser pointer and part of a TV remote. So researchers say a setup could be manufactured for less than $10. It could identify both farm pests and disease carriers. Which could help people picnic in peace.

—Cynthia Graber

[The above text is a transcript of this podcast.]