Fatal attraction: Electrostatic forces pull jumping nematodes directly to their charged prey

Entomopathogenic nematodes are recognized as some of the smallest, most diverse, and highly specialized jumpers in the animal kingdom. It has been suggested that these microscopic parasites launch themselves violently into the air to reach their insect host. Most research on their locomotion abilities has been focused on their explosive jumping mechanism, which seems driven by elastic and capillary forces. However, how physical and environmental phenomena (such as electrical forces or the wind) impact their mid-air approach to prey is unknown. In particular, the influence of electrostatics is intriguing because it is well-known that flying insects can be easily charged during flapping or even when walking over plant litter. Here we present experimental results of how flow currents and exposure to electrically charged insects affect jumping Steinernema carpocapsae nematodes. Worms jumping against an airflow passively drifted downstream, significantly increasing their horizontal range. We discovered that electrically charged insects or even water droplets attract jumping nematodes. Thus, our results indicate that wind can be a fundamental driver for nematode dispersal and that electrostatic forces can significantly increase the likelihood of physical contact and attachment of a parasite to its prey.