Gypsy moth caterpillars are ravaging upstate NY trees, raining down feces: 'It's biblical'

David Robinson
New York State Team
View Comments

The historic infestation of gypsy moth caterpillars has now spread across large swaths of the Finger Lakes and North Country regions of New York, munching leaves and leaving behind countless acres of unseasonably barren trees.

The outbreak of millions of fuzzy two-inch invasive insects has wreaked havoc in parts of upstate, raining down feces on hikers and endangering the tourist season as property owners fret over long-term damage to trees.

But there may be reason for hope: The tree damage, in most cases, will be short-lived. The oaks, maples and other broad-leaf species of trees currently on the caterpillars’ menu are expected to regrow leaves over the summer months, experts said, though the maple syrup haul could be diminished.

A virus known as NPV (nucleopolyhedrosis), which is deadly to gypsy moths and often leads to their collapse, has begun to take hold.

Gypsy moth caterpillars on a tree in Monroe County.

And the fattened caterpillars will soon transform into moths. White flightless female moths will cover trees in a bid to lay eggs for next year, as waves of brownish male moths flutter through forests during their fleeting lifespan of a couple weeks.

“It seems like they’re all over the place,” said Liam Somers, a state Department of Environmental Conservation (DEC) entomologist, describing New York’s gypsy moth caterpillar population this spring as the highest in close to three decades.

“It just looks like fall because there’s just nothing on the trees,” he added, referring to the outbreak epicenter in remote parts of northeastern New York.

The infestation is especially high in Clinton, Warren, Saratoga, Monroe, Ontario, Seneca, Yates, and Orleans counties, according to the DEC.

Defoliated trees in Clinton County, New York hit hardest by the gypsy moth caterpillar outbreak.

A ‘biblical’ gypsy moth plague

One of the New Yorkers hit hardest by the voracious caterpillars is Jed Metzger, who owns a seasonal home and hobby farm on a 17-acre plot in the idyllic hills overlooking Canandaigua Lake in the town of Naples, Ontario County.

Swarms of caterpillars ravaged most of Metzger’s trees in recent weeks, including pines and other evergreens that may never recover.

“My wife won’t come to the house because it’s just so disgusting…if you go outside they fall on you and it’s gross,” Metzger said, describing the vast scope of destruction.

Moths: Is the end in sight for gypsy moth invasion? Here's what to know

“It’s not just the devastation of trees. They eat 24 hours a day and they poop everywhere,” he said. “It’s like a biblical thing … It’s like a wildfire, only they eat everything.”

The invasion has Metzger worried about everything from whether a 200-year-old hemlocks on his property will survive to a caterpillar-marred summer tourist season.

“So much of the Finger Lakes region is tourism, and if the trees are all dead then you’ve kind of shot yourself in the foot,” he said.

While experts anticipate most broad-leaf trees will recover leaves in July, some unknowns could leave larger swaths of forest defoliated permanently, such as drought conditions or other diseases that weaken the trees. Many evergreens struck by gypsy moth caterpillars are also likely to die.

Early signs of an uptick in the NPV virus that kills gypsy moth caterpillars also has one expert predicting a potential end to the invasion in the near future.  

A Cessna, one of the aircrafts Chuck Webber will use for aerial spraying to suppress the gypsy moth population, is seen at the Canandaigua Airport.

How to control gypsy moth outbreaks

Susan Martenson’s gypsy moth tale actually began last year when an outbreak struck her family’s property spanning about 200 acres west of Canandaigua Lake.

She recalled personally scraping millions of gypsy moth egg sacks off trees in a futile attempt to curb the infestation.

After suffering through the localized outbreak, Martenson and many neighbors began paying for aerial pesticide spraying of about 10,000 acres in the area.

The spraying cost about $60 per care, or $600,000, and used Bacillus thuringiensis, a biological pesticide that regulators say kills young gypsy moth caterpillars, but is harmless to people, animals and plants, she said.

Pesticides:Aerial pesticide spraying in the Finger Lakes targets gypsy moths 

So far this season, Martenson’s area of the Canandaigua Lakes region has been mostly spared by the caterpillars thanks to the spraying, according to a neighborhood online chat group.

“This is an area that has a lot of natural capital,” Martenson said. “If our trees are dead then that’s not good, and it also could cause erosion.”

“It’s a precious ecosystem here, and we couldn’t have mass devastation of the forest,” she added.

Trees stripped of leaves by gypsy moth caterpillars in Clinton County, New York.

What NY does (and doesn't do) about gypsy moths

Meanwhile, the Department of Environmental Conservation, or DEC, encourages New Yorkers to protect their own trees from gypsy moth outbreaks. The agency typically only takes proactive control measures, such as government-funded spraying, for ecologically or culturally significant forests, according to its website.

“At this time, DEC does not provide funding for controlling gypsy moths on private property,” the website states.

Beyond spraying pesticides, the DEC instructs smaller property owners to kill off caterpillars by “squishing and scraping” them during the early stages of outbreaks.

Sticky bands and traps consisting of burlap sacks are also options, though generally only effective for protecting smaller numbers of trees, the DEC website says.

Investigation:See how much pesticide gets used in New York communities

The lack of government aid, however, leaves some smaller property owners struggling to secure aerial spraying, as some pilots require deals that span large areas.

While it’s too late this year, Metzger said he has been scrambling recently to organize a regional spraying among neighbors to prevent a repeat next year.

Metzger has also contacted local lawmakers to push a change to the DEC’s hands-off approach to gypsy moth outbreaks, contrasting it to dire efforts to control forest fires.

“Why can’t we decide to have some governmental response,” Metzger said of the gypsy moth damage.

DEC Forester Rob Cole addressed the question during a recent public forum on social media. The state had a widespread aerial spraying program in the 1960s and 70s, but it discontinued the effort because the gypsy moths kept spreading, Cole said.

Further, the caterpillars are always being naturally controlled by pathogens and diseases that quell major outbreaks in a matter of several years, Cole added during the Facebook Live broadcast last month.

Today, the DEC will respond to property owner complaints about outbreaks to conduct gypsy moth egg counts and provide consultation about mitigation options, Cole said.

Where gypsy moths came from

Trees stripped of leaves by gypsy moth caterpillars on a Rochester-area property in upstate New York.

Ann Hajek, a Cornell University professor specializing in forest insects, said some other states such as Pennsylvania continue government-backed spraying programs today. But the Keystone state has a lot more oak trees vulnerable to gypsy moths than New York, which fuels more regular outbreaks, she added.

Typically, New York state experiences larger gypsy moth outbreaks every 10 to 15 years, Hajek said. Dry conditions in May and June can limit the spread of a fungal pathogen that kills gypsy moths and ignite a particularly bad season.

Politics: Chemical companies, golf-courses spend millions of dollars on pesticide lobbying

While its still early this season for estimating the outbreak's scope, DEC officials and industry experts are describing it as the largest in more than 20 years.

Meanwhile, the federal government is supporting widespread spraying and trapping efforts in parts of the Midwest, such as Wisconsin, considered to be the frontlines in the battle to contain the gypsy moth spread to new regions, Hajek said.

Initially, gypsy moths were accidentally introduced to the U.S. in 1869, when they were brought here from Europe in the hope they could breed with silkworms to create a hardier variety of silkworm and develop a silk industry in the U.S., according to the DEC website.

Even though they failed as a textile producer, some of the gypsy moths escaped and established their first U.S. population in Massachusetts, the website adds, noting the infestation now spans much of the Mid-Atlantic region and parts of the Mid-West.

Support local journalism



View Comments