Nav: Home

Using seaweed to kill invasive ants

May 18, 2017

RIVERSIDE, Calif. -- Scientists at the University of California, Riverside have developed an inexpensive, biodegradable, seaweed-based ant bait that can help homeowners and farmers control invasive Argentine ant populations.

The researchers found the "hydrogel" baits, which look like liquid gel pills but have a jello-like consistency, reduced ant populations 40 to 68 percent after four weeks. After a second treatment, between weeks four and five, ant population reductions were maintained at 61 to 79 percent until the experiment ended after eight weeks.

"A 70 percent reduction is really successful, especially considering we are not spraying an insecticide but instead using a very targeted method that is better for the environment," said Dong-Hwan Choe, an assistant professor of entomology at UC Riverside and an assistant cooperative extension specialist. "With 70 percent control, homeowners really don't see any ants."

Jia-Wei Tay, a post-doctoral scholar in Choe's lab, is the lead author of the paper. Co-authors are Choe; Mark Hoddle, an entomologist at UC Riverside; and Ashok Mulchandani, a distinguished professor of chemical and environmental engineering.

In addition to the applications for homeowners in an urban environment, which was the focus of this paper, the hydrogels have applications in agriculture, including in citrus groves and grape vineyards.

For example, the Asian citrus psyllid has decimated citrus trees in Asia, South America, Florida and now threatens California's citrus industry. To combat the bug in California, Hoddle coordinated the release of wasps that are native to Pakistan and a natural enemy of the Asian citrus psyllid. Unexpectedly, Hoddle found Argentine ants were killing the wasps.

This summer, the team will coordinate research in citrus groves in southern California. The team wants to measure the effectiveness of hydrogels in controlling Argentine ant populations. If the hydrogel baits can control the ants, the wasps can do their job protecting citrus trees from Asian citrus psyllid, which transmit Huanglongbing, a bacterial disease that kills citrus trees.

The Argentine ant is an invasive species with a worldwide distribution. It is a major nuisance in southern states including Georgia, South Carolina, Alabama, Mississippi, Louisiana, Florida, Tennessee, and North Carolina, and also in California. In fact, a 2007 survey found that 85 percent of all urban pest control services in California were focused on the Argentine ant.

A common method for managing the Argentine ant has been insecticide sprays. However, the downside of this tactic is that the insecticides can harm non-target organisms that do beneficial things. The misuse of the pesticide sprays can also cause environmental contamination.

As a result of these downsides, research has focused on liquid baits that use a combination of sugar water (to attract the ants) and a small amount of toxicant to kill the ants. The problem with the liquid baits is that they need to be dispensed in bait stations, which are costly to maintain.

"Hydrogels eliminate the need for the bait stations. The hydrogels are applied on the ground where the ants forage. Once an ant finds the hydrogel, it drinks from the surface of it. It then goes back to its nest and shares the toxic liquid with nest mates. The ants also create a trail to the hydrogels that their nest mates will follow," Tay said. The hydrogels are designed to be slow-acting, so it takes several days before the ants die. By that time tens of thousands will have ingested the liquid bait.

The hydrogels created by the team are highly absorbent - the material used is similar to what is used in diapers. They retain water so that they will remain attractive to ants for an extended amount of time.

The researchers used sugar water containing 0.0001 percent of the insecticide thiamethoxam in the hydrogels. "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," Tay said.

Future research will address the potential use of the hydrogels on other pest insects as well as how quickly the hydrogels biodegrade.
-end-
The article, published in Pest Management Science, is called "Development of an alginate hydrogel to deliver aqueous bait for pest ant management." The research was funded by the California Department of Pesticide Regulation and the Early Career Chair in Urban Entomology Fund.

The UCR Office of Technology Commercialization has filed a patent application for the inventions above.

A short video that media can use and share in on YouTube: https://www.youtube.com/watch?v=CwDB8uyCCmg

University of California - Riverside

Related Hydrogel Articles:

Micron-sized hydrogel cubes show highly efficient delivery of a potent anti-cancer drug
Researchers at the University of Alabama at Birmingham and Texas Tech University Health Sciences Center have developed micro-cubes that can sponge up a hydrophobic anti-cancer drug and deliver it to cancer cells.
3-D-printable implants may ease damaged knees
A cartilage-mimicking material created by researchers at Duke University may allow surgeons to 3-D print knee menisci or other replacement parts that are custom-shaped to each patient's anatomy.
Rabbits' detached retina 'glued' with new hydrogel
A newly developed elastic gel administered in liquid form and shown to turn jellylike within minutes after injection into rabbits' eyes to replace the clear gelatinous fluid inside their eyeballs, may help pave the way for new eye surgery techniques, says an international team of researchers led by Japanese scientists.
Transparent gel-based robots can catch and release live fish
Engineers at MIT have fabricated transparent, gel-based robots that move when water is pumped in and out of them.
Skin cells 'crawl' together to heal wounds treated with unique hydrogel layer
A team led by Professor Milica Radisic in U of T Engineering has demonstrated for the first time that their peptide-hydrogel biomaterial prompts skin cells to 'crawl' toward one another, closing chronic, non-healing wounds often associated with diabetes, such as bed sores and foot ulcers.
New hydrogel can take organoids from dish to clinic
EPFL scientists have developed a gel for growing miniaturized body organs that can be used in clinical diagnostics and drug development.
Controlling bleeding disorders with fitted hydrogel casts
A team of researchers at Harvard's Wyss Institute for Biologically Inspired Engineering, Brigham and Women's Hospital, the Mayo Clinic and MIT provides proof-of-concept and first preclinical evidence in animal models that a shear-controlled hydrogel-based embolic agent can be delivered by catheters and injected into blood vessels to form robust and safe blockages.
Collagen hydrogel scaffold and fibroblast growth factor-2 accelerate periodontal healing of class II
A new regenerative scaffold made of biosafe collagen hydrogel and collagensponge could possess the ability of retaining fibroblastic growth factor-2 (FGF2) and stimulate the periodontal tissue regeneration, according to new research published in The Open Dentistry Journal.
Researchers create stretchy, biocompatible optical fibers
Researchers from MIT and Harvard Medical School have developed a biocompatible and highly stretchable optical fiber made from hydrogel -- an elastic, rubbery material composed mostly of water.
Researchers reduce expensive noble metals for fuel cell reactions
Washington State University researchers have developed a novel nanomaterial that could improve the performance and lower the costs of fuel cells by using fewer precious metals like platinum or palladium.

Related Hydrogel Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Changing The World
What does it take to change the world for the better? This hour, TED speakers explore ideas on activism—what motivates it, why it matters, and how each of us can make a difference. Guests include civil rights activist Ruby Sales, labor leader and civil rights activist Dolores Huerta, author Jeremy Heimans, "craftivist" Sarah Corbett, and designer and futurist Angela Oguntala.
Now Playing: Science for the People

#521 The Curious Life of Krill
Krill may be one of the most abundant forms of life on our planet... but it turns out we don't know that much about them. For a create that underpins a massive ocean ecosystem and lives in our oceans in massive numbers, they're surprisingly difficult to study. We sit down and shine some light on these underappreciated crustaceans with Stephen Nicol, Adjunct Professor at the University of Tasmania, Scientific Advisor to the Association of Responsible Krill Harvesting Companies, and author of the book "The Curious Life of Krill: A Conservation Story from the Bottom of the World".