Electric charge connects jumping worm to prey

A tiny worm that leaps high into the air — up to 25 times its body length — to attach to flying insects uses static electricity to perform this astounding feat, scientists have found. The journal PNAS published the work on the nematode Steinernema carpocapsae, a parasitic roundworm, led by researchers at Emory University and the University of California, Berkeley. 

“We’ve identified the electrostatic mechanism this worm uses to hit its target, and we’ve shown the importance of this mechanism for the worm’s survival,” says co-author Justin Burton, an Emory professor of physics whose lab led the mathematical analyses of laboratory experiments. “Higher voltage, combined with a tiny breath of wind, greatly boosts the odds of a jumping worm connecting to a flying insect.” 

“You might expect to find big discoveries in big animals, but the tiny ones also hold a lot of interesting secrets,” adds Victor Ortega-Jiménez, co-lead author and assistant professor of biomechanics at the University of California, Berkeley. He conducted the experiments, including the use of highspeed microscopy techniques to film the parasitic worm — whose length is about the diameter of a needle point — as it leaped onto electrically charged fruit flies. 

The researchers showed how a charge of a few hundred volts, similar to that generated by an insect’s wings beating the air, initiates an opposite charge in the worm, creating an attractive force. They identified electrostatic induction as the charging mechanism driving this process.

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