Scientist tracking mosquitoes with cell phone.

Mosquitoes can be deadly, transmitting malaria, dengue, and Zika. But tracking them is tough. Now, researchers—led by bioengineer Manu Prakash of Stanford University in Palo Alto, California—have developed a new, cheap way to monitor these insects with mobile phones and a Shazam-like app that tells them apart based on their “songs.” Most mosquito species can be identified by the frequency of their wingbeats, so the web app—aptly named Abuzz—lets users upload recordings of mosquito sounds, identify the species, and map its location. But getting a good recording can be tricky: The insect cannot be more than 10 centimeters away from the microphone, and background noise cannot be louder than light traffic.