‘Like the coronavirus': Rampaging insect shows up in California, alarming farmers

Napa Valley lanternfly briefing

Napa County Pest District update

Thursday, March 19, 9 a.m.–noon

Napa Valley College Little Theater, 2277 Napa Valley Highway, Building 1200, Napa

Cost: Free

RSVP required:

Register online

Questions: 707-253-4357

SACRAMENTO - It originated in the wilderness of Asia. It spreads quickly. It's already causing millions of dollars in economic losses in the United States. And it may already be spreading through California.

No, it's not the novel coronavirus. It's a surprisingly beautiful 1-inch insect known as the spotted lanternfly that's been rampaging its way through East Coast vineyards and orchards, causing millions of dollars in damage.

California's $50 billion agricultural industry is on high alert after agricultural inspectors found several dead lanternflies recently on cargo planes in Sacramento, Stockton and Ontario, and experts say a live spotted lanternfly may have been seen on the wall of a hotel in Davis this September. No others have been found alive, but the fear is the Davis insect may have hatched in California.

“We definitely don't want them here,” said Warren Bogle, a prominent wine grape grower and vintner in the Sacramento-San Joaquin Delta. “It's like the coronavirus.”

Experts say Bogle's worries are well founded.

The plant-hopping bug arrived in Pennsylvania in 2014 from Asia, and has since spread to New Jersey, Delaware and Virginia. A recent Penn State study estimated the insect costs Pennsylvania alone about $50 million and nearly 500 jobs each year from the damage it causes to vineyards, hardwood timber forests, Christmas tree farms and orchards.

The scary thing, experts say, is that if the bug - native to China, India and Vietnam - is hardy enough to survive frigid Pennsylvania winters, there's no telling what its life cycle would be like in California's Mediterranean climate. It may not be cold enough here to kill adult lanternflies in the winter.

“It's something that should definitely be on people's radar screen out there,” said professor Jayson Harper, one of the Penn State study's authors and the director of the university's Fruit Research and Extension Center.

The bug is dangerous to California - home to the nation's largest agricultural economy - for several other reasons, experts say.

The lanternfly can spread quickly. It can lay its eggs on just about any hard surface, including train boxcars and big-rig trailers - meaning it can spread quickly into new faraway areas and not be detected. Its natural dispersal method also is problematic. Although it has wings, it largely uses them to glide. But large swarms of the bugs will climb to the top of towers or trees and catch wind gusts, enabling swarms to spread miles without human help.

The spotted lanternfly also has a wide diet. It's been observed feeding on the sap of 70 different species of trees and vines, including grapes, nut and fruit trees - posing risks to Central Valley's orchard and wine and table-grape industry.

Almonds alone are a $5.47 billion business here. The wine and table grape industry generates about $6.25 billion annually in California, according to the Department of Food and Agriculture.

The sap-sucking bug is what's known as “a phloem feeder.” It doesn't actually feed on a tree's fruit, but swarms severely weaken plants by draining them of their fluids. It also excretes a sweet goo called “honeydew” that is troublesome for grape vines because gunky mold grows on the dew and causes the plants to rot.

Swarms of the bugs also have been known to hit the same vineyard or orchard over and over, wiping them out in a matter of months or years.

Meanwhile, the lanternfly has no known natural predators in North America. Birds have been seen picking them up with their beaks and spitting them out, Harper said.

Its lovely bright coloring and spots also signal to predators it's likely poisonous, said Dana Rhodes, the state plant regulatory official with the Pennsylvania Department of Agriculture.

“The coloring is kind of nature's ways of saying, ‘You better pause before you eat me. You'll be sorry for it later,'” she said.

The good news is those same distinct lovely colors and its comparatively large size makes it easier for the average person to spot and report it to invasive insect experts at a University of California Cooperative Extension office or a county agricultural commissioner.

Residents also should also be mindful of the trees called the “tree-of-heaven,” also known as Chinese sumac.

In Asia, the tree is the lanternfly's host tree. Tree-of-heavens are considered an invasive plant here in North America, including in California, where they were originally planted as ornamental landscaping. Experts say residents should learn what those trees look like and keep an eye on them for lanternfly infestations.

In Pennsylvania, agricultural officials have been using tree-of-heavens as “trap trees” to monitor and kill the bugs, which experts say can easily be killed with pesticides.

Surendra Dara, an insect expert with the UC Cooperative Extension in San Luis Obispo, said the lanternfly does pose a particular challenge for California, but the hope is that in the next few years, researchers will have the tools to wipe them out. The most likely method would be to use a “biological” method such as breeding one of its natural Asian predators like a wasp to serve as a countermeasure - sort of like the vaccines being developed to counteract the coronavirus.

“With a strong insect, just like the virus everybody is dealing with now, you need to understand the biology,” Dara said. “You have to understand every aspect of it. The more we know the better we can handle the situation.”

Napa Valley lanternfly briefing

Napa County Pest District update

Thursday, March 19, 9 a.m.–noon

Napa Valley College Little Theater, 2277 Napa Valley Highway, Building 1200, Napa

Cost: Free

RSVP required:

Register online

Questions: 707-253-4357

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