Ants killed using seaweed-based gel balls in California study

Scientists have developed an eco-friendly bait that could reduce ant populations by nearly 80%.

Researchers from the University of California, Riverside (UC Riverside) hope their seaweed-based hydrogel baits could replace ecologically damaging pesticides.

The hydrogels, which look like small liquid gel balls, can be easily applied to the ground where the ants forage.

They are made of sugar water, which is attractive to the ants, and contain 0.0001% of the insecticide thiamethoxam.

"This is 100-fold less than it is used in a standard ant gel bait and 1,000 times less concentrated than spray insecticides containing thiamethoxam," said Jia-Wei Tay, a post-doctoral scholar at the UC Riverside.

The study found ant populations were initially reduced to between 40% and 68% after four weeks of using the baits.

A second treatment, between weeks four and five of the experiment, saw ant populations reductions maintained between 61% and 79% until the experiment ended after eight weeks.

The hydrogels are designed to be slow-acting, so it takes several days before the ants begin to die, and by that time tens of thousands will have ingested the liquid bait.

The primary focus of the research was for homeowners in an urban environment, although the seaweed-based bait could also be used in agricultural settings, the scientists said.

Future research will address the potential use of the baits on other pest insects as well as how quickly the hydrogels biodegrade.

While insecticide sprays are the most common method for targeting ants, they can harm beneficial insects such as pollinators and cause environmental contamination.

Argentinian ants, which the study focused on, are an invasive species with a worldwide distribution, and a major nuisance in the United States.

In 2007, a survey found that 85% of all urban pest control services in California were targeting the species.