Parasitic nematodes have developed a unique way to find and attach to their insect hosts in midair, according to new research from the University of California, Berkeley and Emory University. The study reveals that these tiny worms use static electricity generated by flying insects as a guide during their jumps.
Victor Ortega-Jiménez, assistant professor of integrative biology at UC Berkeley, led experiments examining whether electrical attraction helps nematodes locate and land on their prey. His earlier work showed that spider webs can capture insects through electrostatic forces, and recent findings suggest ticks are similarly attracted to animals due to static charges.
“We live in an electrical world, electricity is all around us, but the electrostatics of small organisms remains mostly an enigma,” Ortega-Jiménez said. “We are developing the tools to investigate many more valuable questions surrounding this mystery.”
The research team used high-speed cameras operating at 10,000 frames per second to record attempts by Steinernema carpocapsae nematodes jumping toward electrically charged fruit flies tethered in place. A battery supplied the charge necessary for the experiment. These roundworms—less than a millimeter long—are capable of leaping up to 25 times their body length.
“I believe these nematodes are some of the smallest, best jumpers in the world,” Ortega-Jiménez said.
Justin Burton from Emory University contributed a mathematical model that postdoctoral fellow Ranjiangshang Ran applied to analyze how electric charges affect worm jumps. Their analysis found that even moderate static charges produced by an insect’s wingbeats could significantly improve a worm’s chance of making contact with its target. At 100 volts, there was less than a 10% probability of success; at 800 volts, this increased to 80%. Mild wind conditions also improved success rates.
“Our findings suggest that, without electrostatics, it would make no sense for this jumping predatory behavior to have evolved in these worms,” Ran said.
If successful in landing on an insect host, the worm enters through natural openings and releases bacteria fatal to insects within two days. The nematode then feeds on both multiplying bacteria and insect tissue before laying eggs inside the cadaver. Multiple generations can develop within one host before juvenile worms emerge into the environment seeking new prey.
“Using physics, we learned something new and interesting about an adaptive strategy in an organism,” Ran added. “We’re helping to pioneer the emerging field of electrostatic ecology.”
The full study appears in Proceedings of the National Academy of Sciences (https://www.pnas.org/doi/10.1073/pnas.2401743121). Additional coverage is available from Emory University (https://news.emory.edu/stories/2024/06/escience_burton_nematode_electrostatics_17-06-2024/story.html).
