How ants could help stop the tree-killing lanternfly

Virginia faces a stubborn enemy: the spotted lanternfly (SLF). These invasive insects damage trees, crops, and gardens by feeding on plant sap and leaving behind sticky honeydew. A research team led by Assistant Professor Scotty Yang at Virginia Tech has discovered an unexpected helper in the battle against this pest: ants.

Yang and his team found that ants, drawn to honeydew, can carry traces of lanternfly DNA in their bodies. By analyzing the ants, scientists can now detect whether the pest has reached an area, even without spotting the insect directly.

Ants collect lanternfly DNA through waste

The research is based on environmental DNA, or eDNA. This approach collects genetic material that organisms leave behind in their surroundings.

Spotted lanternflies leave DNA in their sugary waste, which ants readily consume. Scientists then apply a lab technique called polymerase chain reaction, or PCR, to identify SLF DNA inside the ants.

“Ants are nature’s sugar seekers,” Yang said. “If there’s even a tiny drop of honeydew left behind by a spotted lanternfly, ants are likely to find it.”

Yang’s team named the method “antDNA.” Even a single meal of honeydew lets ants retain the lanternfly’s DNA for up to five days. Because ants roam widely, this method can detect SLF activity from as far as 100 meters from the infestation.

Field tests across Virginia

Researchers tested the method at three Virginia sites: Salem, Lynchburg Site 1, and Lynchburg Site 2. These locations represented low, medium, and high lanternfly densities.

At each site, they placed honey-baited lure stations along transects, attracting ants with cotton balls soaked in honey.

The Salem site showed a 46.7 percent positive rate for SLF DNA. Lynchburg Site 1 and Site 2 showed 62.1 percent and 62.5 percent, respectively. Most stations attracted ants within 30 minutes, proving the method’s ease of use.

The study also tested ants from nine species. SLF DNA was found even in ants that had not directly fed on honeydew, likely due to food sharing within colonies. This behavior, known as trophallaxis, helps spread the DNA signal among nestmates.

Ants outperform other lanternfly detectors

The antDNA technique works across landscapes and does not depend on the pest being visible. Unlike other methods, it does not require water, filtration, or special storage. Ants can be preserved in ethanol without refrigeration, reducing the burden on field teams.

Ants are present in nearly every habitat, from forests to cities. The collection setup is simple and inexpensive. The ants’ ability to hold liquid in their crop allows the DNA to stay detectable longer than in typical surface samples.

The study confirmed that DNA from honeydew lasts longer than DNA from insect tissue, making honeydew a more stable source.

Importance of early detection

Spotted lanternflies harm many plants, including grapevines, hardwoods, and hops. As they feed, they weaken plants and coat them in honeydew. This sticky substance promotes sooty mold, which further harms plant health.

Early detection is critical because removing the pest becomes harder once it spreads. Current surveillance efforts rely on human sightings of the insect or its egg masses. These sightings often occur only when the population has already grown.

The ant surveillance method allows early detection of lanternfly species even in low-density zones and inaccessible areas.

Scaling up and looking forward

Yang and his team are now working on a portable test kit for use in the field. This will allow real-time molecular testing without needing a full lab. Faster results mean quicker action against the pest.

“One of the biggest advantages of using ants is that they live almost everywhere, such as forests, farms, cities – you name it,” Yang said. “Their constant search for food makes them ideal frontline samplers for spotted lanternfly DNA.”

This approach offers a new way to watch for invasive species like lanternflies using ants, without depending on visual surveys. It opens up possibilities for surveillance that is fast, flexible, and low-cost.

Ants may detect other pests like lanternflies

The method could be expanded to track other pests. Many insects excrete honeydew, and ants can pick up their DNA too. This opens the door for broader pest detection strategies using the same principle.

Ants, in their natural role as sugar hunters, may become an essential part of protecting crops, forests, and native ecosystems. With antDNA, researchers are tapping into nature’s own behaviors to find smarter ways of monitoring invasive threats.

The study is published in the journal NeoBiota.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–