If you live anywhere from central Virginia to southern New England, you’ve probably seen them up close: the polka-dot pests swarming in droves on vines, branches, and buildings. In the spring, they emerge as black-and-white larvae that rain down from tree canopies. They then go through several months of development, molting each time until they get bigger and better at flying long distances. Then, by late summer, they morph into adults with flashy red, white, black, and beige wings that cover tree trunks and splash onto sidewalks.
Red-bellied butterfly (Ricoluma delicatura The exact distribution of origin is debated.However, scientific records agree that the species originated in China. The insect was first discovered in southeastern Pennsylvania, USA, in 2014. Now, a decade later, the insect has grown into a widespread, talked-about, invasive and costly agricultural pest, especially for grape growers and vineyards. The lantern fly, with its piercing and sucking mouthparts, Eat a variety of plantsand can stress and even kill certain species because they swarm on their preferred host plants. Confirmed in 17 states It spreads along the East Coast into the Midwest and Southeast.
They don’t sting or bite, and they don’t spread disease to humans. But even if you’re not a grape grower, the sudden appearance of local infestations in numbers can be a worrying nuisance. And if you live in an area where the population is growing, you might be wondering what the future holds. Will every surface eventually be covered in them? Is there hope? And what are we doing to stop it?
Thankfully, experts who have studied the lantern fly closely are providing insight, and some silver linings are emerging. Scientists aren’t giving up on the search for ways to better control the lantern fly. So far, they’ve found that the pesky insects are Ecological They are a threat, and in Pennsylvania counties where they first appeared a decade ago, lanternfly numbers are declining.
But first, the bad news: Eradicating the spotted bee from the United States will be nearly impossible. “We’re past that point,” says Brian Walsh, a horticulture educator and spotted bee researcher with the Pennsylvania State University Extension Program. With an invasive species this well-established, “eradication is generally not the goal,” Walsh agrees. Hannah BroadleyEntomologist and biologist with the United States Department of Agriculture’s Plant Quarantine Inspection Service.
Instead, active management is State Quarantine Monitoring programs are also underway, and researchers are working to find better ways to control the insects’ populations in places where they already exist, with the goal being to “get to a threshold where they’re no longer a pest,” Broadley said.
Biological control underway
Currently, insecticides and physical traps are the only proven ways to control the pests locally. But traps and poisons both have drawbacks: Sticky traps can trap native wildlife, and insecticides can harm the environment. What’s more, lanternflies will likely eventually develop resistance to current methods, setting off a costly chemical arms race, says Kelly Huber, a professor of entomology at Pennsylvania State University.
Instead, the ideal way to minimize planthopper populations in the long term would be biological control, or using natural predators or enemies to kill the planthoppers, Huber says. Through research, a suitable biological control is getting closer and closer; Broadley is currently investigating parasitic wasps as a potential solution. Dryonus sinicus teeth This tiny insect, also native to China, kills lantern fly larvae by injecting their eggs into them as part of their reproductive cycle.
For several months now, Broadley and his colleagues at the Department of Agriculture have Drynosis “We will continue to focus on the lantern fly if there are other hosts available. It’s important to make sure the biological control doesn’t backfire and harm native species, just as happened before with the infamous failed release,” he said. “It’s still very early days, but so far we’ve seen good results.” [Dryinus sinicus] “Looks good,” she says.
And it’s not just one parasitic wasp that targets the lanternfly’s flesh: Other studies have found that several North American fungi attack and kill the pests, and native animal species are starting to take a liking to the invaders, too. So far, none of this has been enough to reduce lanternfly populations, but with a little human intervention, that could soon change.
Huber studies the natural predation of lanternflies. Recent ResearchIn 2018, she presented her community science observations. A variety of animals eat stink bugs (scientifically, they are “true bugs”). Stink bugs sequester toxins from Robinia pseudoacacia, one of their preferred hosts and another species that is widely invasive in the U.S., and can become poisonous themselves. But birds, some mammals, and even occasional amphibians and fish appear to eat stink bugs. But the most frequent predators of stink bugs are far more creepy bugs. More than half of the predation cases documented in Huber’s study were arthropod-on-arthropod incidents. Moreover, Huber says that predatory insects and spiders are “totally unaffected” by the chemicals stored by stink bugs, according to a soon-to-be-published study from her lab.
Specifically, insects such as praying mantises and stink bugs have been found to reduce mantis populations in enclosures fairly quickly. Now, Huber is investigating whether mantises prefer them over other prey. If so, predatory stink bugs could be another biological control in the toolkit. So far, “I think these are pretty promising,” she says. Even better news is that praying mantises are already used for biological control of other pests, and they’re widely bred and available. Perhaps grape growers and state agencies could start targeted releases to boost native insect populations in areas where mantis damage is most severe, Huber suggests.
There is historical precedent for both natural enemies and introduced biological controls being effective. Broadley gives the example of winter moths, an invasive species brought from Europe that devastates forests. The introduction of parasitic flies has proven effective in reducing pest populations in New England. Walsh points out that the Japanese beetle has also been suppressed in part by the introduction of multiple predators and parasitic flies.
Another invasive species that first appeared in Pennsylvania, the German-winged stink bug, was once a similar scourge along the Mid-Atlantic coast, where it became a household and agricultural pest in large numbers around 2010. Native predators and Parasitic wasps accidentally introduced“This technology has reduced the population in the area to manageable levels,” Huber said.
Cautious optimism
Even if any of the hoped-for biological control of bats doesn’t work anytime soon, there’s good news: A decade of research hasn’t yet shown that the longhorn beetle poses a serious threat to native species, Walsh says. Not only do bats voraciously eat a small number of hosts, but their feeding on plant sap causes planthoppers to produce copious amounts of sugary honeydew that coats leaves, breeds unsightly sooty mildew fungi, and limits photosynthesis locally. But even this seems relatively harmless on a larger scale.
“Ten years is a short time in the ecosystem,” he adds. “So we have to be very cautious.” After all, there could be problems in the long run, or if the insects spread to new vulnerable places. But for now, the question of whether lanternflies are destabilizing the habitats they invade can only be answered with a tentative “no.” “We just haven’t experienced that yet,” he says. Huber agrees. She thinks the reason they don’t have a reverberating effect on the ecosystem is because of their affinity for black locust. As with grapes, swarms of lanternflies could kill invasive plants, but black locusts are a pest in their own right, and native species don’t depend on them for anything.
And here’s some data from the Pennsylvania counties that first battled the lanternfly: [population] “The areas where it first started and the cities where it first got bad, like Philadelphia, are seeing a decline in cases,” Walsh said. “We’re seeing a significant decline in cases. Typically, you see a three, four, five year period where you see an increase and then a decrease.”
The reasons aren’t clear, but he says there are several hypotheses: Perhaps their preferred food resources have been depleted over time. Perhaps native predators are filling in more than individual studies suggest. Perhaps the insects have simply dispersed and moved around. Or perhaps other population dynamics factors are at play. “It’s all speculation at this point. We’re not sure, but it’s probably a mix of all of these.”
Huber points out that they can come back, and sometimes appear to come back as their host plants recover, but keep in mind that their populations can’t grow indefinitely — like everything in nature, there are limits.
The history of other invasive insects shows that many species go through boom-and-bust cycles. Sponge moths, for example, may be all but gone for years before bursting into numbers and devouring forest foliage. “If I had a crystal ball, I’d probably start seeing something similar with lanternflies after the peak,” Walsh says. “We might see some bounce back each year, but we’ll probably never see anything like the worst of it.” probably.”
Achieving balance
Still, where an invasion has already begun, Walsh says, active management is important to prevent further spread and mitigate damage. Major wine-producing states, including California, Oregon and Washington, have begun proactively preparing for a possible invasion, Huber notes. Researchers on the West Coast are testing potential biological controls on native species and investigating other management tactics.
Seven states have quarantine programs that restrict the transport of lanternfly eggs or live insects across borders. If you live in a quarantined area, you may have a legal obligation not to transport lanternflies elsewhere. Check the rules and regulations in your area.
Finally, the key to striking a balance is accepting and understanding that the “solution” can be worse than the problem if applied carelessly. Walsh urges residents struggling with lanternflies in their yards or backyards to deal with the invaders with care. Swatting is always recommended, but “keep in mind that there are other downsides to using insecticides,” he says. In some cases, targeted insecticide sprays or traps may be appropriate. In other cases, they probably aren’t necessary. In either scenario, education is key. Penn State University Extension recommends: Comprehensive Administration Guide It helps people decide when, how and what to spray or place in their homes.
“Make good choices,” Walsh says, and remember that patience is also an option: “Even in places with biblical plagues, things are likely to calm down. You don’t have to kill them all yourself.”
