Spotted lanternfly

One potentially invasive species is being used to fight another that could soon hurt the wine and beer industry.

In Pennsylvania, people were were calling 911 over spotted lanternfly sightings. In Delaware, you're told to take a photograph, email it to the state agriculture department, and squish the bug with your foot.

"The general public can kill as many as they want, but it's probably not going to make much of a dent in their population," advised U.S. Agriculture Department scientist Dr. Kim Hoelmer.

The spotted lanternfly hitched a ride to the area from Asia. It was first spotted in Delaware in November of 2017.

Since then, its population has exploded. Delaware recently expanded its quarantine of the invasive pest to include all areas of New Castle County, north of the canal. Neighboring states are also seeing high numbers of the exotic bug, a serious concern for crop growers.

"It's an important pest of grapes for example, we know now that it also feeds on hops," said Hoelmer. "It can impact a number of forest trees like walnut, and we don't know for sure what kind of impact it could have on other crops, such as tree fruit crops."

The wine and beer industries could be heavily impacted because of how much sap the large insect extracts.

"It's been known to feed on grapevines in such large numbers that it can actually kill the grapevines, and there are signs that it's capable of causing...full-grown trees to decline and eventually die as well."

The lanternfly feeds on trees in uncontrolled habitats like heavily wooded areas, making insecticide a poor form of treatment to eradicate the pest.

But Hoelmer is exploring alternatives. The USDA's Beneficial Insects Introduction Research Unit at the University of Delaware in Newark--the only of its kind in the state--is ground zero for research and testing on how to get rid of the invasive pest.

"One of the major reasons they do become a pest in a newly invaded area is because they come here without their natural enemies."

So, Dr. Hoelmer went to China, to bring some of the lanternfly's natural enemies back. Tiny Chinese wasps are being held in a highly-controlled, quarantine lab in Newark. The insects are kept in a growth chamber under red lights because insects can't see the spectrum of light. Hoelmer believes these wasps keep the lanternfly's population in check in Asia.

"When we bring an exotic insect, even if it's a beneficial insect...we conduct all of our research inside the quarantine facility until such time as we decide it may be safe enough to introduce into the environment," said Hoelmer.

Exactly how the wasps prey on the spotted lanternfly is like out of a science fiction movie. 

"It kind of builds a cocoon...the spotted lantern fly doesn't die immediately, so it will be hopping around thinking everything is fine, while this bulge is slowly growing out of them, what's inside that bulge is the larvae of the wasp kind of eating it from the inside out," explained a scientist in the lab.

But more research is needed to determine whether the strategy would be successful as Hoelmer investigating the impact and collateral damage to other plants and species releasing the wasps in North America could have.

Hoelmer said, if the bug is released, the circle of life would do its thing.  

"We don't need to continually release large numbers because it will establish and spread on its own; this is what it does, it occurs naturally in China, and if it is an effective, natural enemy, it will establish, and it will eventually spread by itself."