Researchers in the US have discovered that a tiny jumping worm uses static electricity to increase the chances of attaching to its unsuspecting prey.

The parasitic roundworm Steinernema carpocapsae, which live in soil, are already known to leap some 25 times their body length into the air. They do this by curling into a loop and springing in the air, rotating hundreds of times a second.

If the nematode lands successfully, it releases bacteria that kills the insect within a couple of days upon which the worm feasts and lays its eggs. At the same time, if it fails to attach to a host then it faces death itself.

While static electricity plays a role in how some non-parasitic nematodes detach from large insects, little is known whether static helps their parasitic counterparts to attach to an insect.

To investigate, researchers are Emory University and the University of California, Berkeley, conducted a series of experiments, in which they used highspeed microscopy techniques to film the worms as they leapt onto a fruit fly.

They did this by tethering a fly with a copper wire that was connected to a high-voltage power supply.

They found that a charge of a few hundred volts – similar to that generated in the wild by an insect’s wings rubbing against ions in the air – fosters a negative charge on the worm, creating an attractive force with the positively charged fly.

Carrying out simulations of the worm jumps, they found that without any electrostatics, only 1 in 19 worm trajectories successfully reached their target. The greater the voltage, however, the greater the chance of landing. For 880 V, for example, the probability was 80%.

The team also carried out experiments using a wind tunnel, finding that the presence of wind helped the nematodes drift and this also increased their chances of attaching to the insect.

“Using physics, we learned something new and interesting about an adaptive strategy in an organism,” notes Emory physicist Ranjiangshang Ran. “We’re helping to pioneer the emerging field of electrostatic ecology.”

The post This jumping roundworm uses static electricity to attach to flying insects appeared first on Physics World.

Spending time in space has a big impact on the human body and can cause a range of health issues. Many astronauts develop vision problems because microgravity causes body fluids to redistribute towards the head. This can lead to swelling in the eye and compression of the optic nerve.

While eye conditions can generally be treated with medication, delivering drugs in space is not a straightforward task. Eye drops simply don’t work without gravity, for example. To address this problem, researchers in Hungary are developing a tiny dissolvable eye insert that could deliver medication directly to the eye. The size of a grain of rice, the insert has now been tested by an astronaut on the International Space Station.

This episode of the Physics World Weekly podcast features two of those researchers – Diána Balogh-Weiser of Budapest University of Technology and Economics and Zoltán Nagy of Semmelweis University – who talk about their work with Physics World’s Tami Freeman.

The post Astronauts could soon benefit from dissolvable eye insert appeared first on Physics World.