Biological control: Shazam for mosquitoes

Smartphones can tell one type of mosquito from another by its hum, which may be useful in fighting mosquito-borne diseases, according to new research from Stanford University in the US.

Calling their project "Shazam for Mosquitoes", after the phone app that identifies music, students from the university's Bio-X institute showed that common phones could record mosquito wing beats accurately enough to distinguish, for example, Culex mosquitoes, which spread West Nile virus, from Aedes mosquitoes, which spread Zika.

Even older flip phones, which are still used in parts of Africa, are sensitive enough to do the job.

The students envision a crowdsourcing initiative in which phone users around the world send in sound samples of mosquitoes landing on them, which could be sorted by the embedded GPS and time co-ordinates to build a worldwide mosquito distribution map.

It would be far less cumbersome than the current technique: trapping insects for hand sorting.

Mosquitoes use their wing-beat hums to find one another for mating. The sounds are distinct, and even big and small members of one species make similar hums.

Less than half a second of flight is needed to capture a mosquito's acoustic signature, and the technique works even against background noise like sirens or conversation, said Haripriya Mukundarajan, a mechanical engineering student who presented the research at the recent annual conference of the American Society of Tropical Medicine and Hygiene.

Preliminary testing in California and Madagascar proved the concept, she said, although more work remained.

Brian D. Foy, a specialist in mosquito-borne diseases at Colorado State University, said he thought the idea sounded "cool" and would promote citizen science, but he remained sceptical that it would replace trapping.

Sound wouldn't tell, for example, whether the mosquitoes carried diseases.

Joseph M. Conlon, a technical adviser to the American Mosquito Control Association, said wing-beat identification was "more of a novelty than a viable tool", but the technology should be explored.