Years-long spongy moth epidemic fades

Years-long spongy moth epidemic fades

Spongy moth larvae feed on tree leaves, contributing to stress that could kill an ailing tree.

Provided

MILLBROOK — The spongy moth epidemic of eastern Dutchess and Columbia Counties and northwestern Connecticut appears to be receding after more than three years of infestation, based on forecasting work and early-summer land surveys undertaken at Millbrook’s Cary Institute.

The spongy moth epidemic has marked widespread defoliation, affecting trees particularly in the area of the New York–Connecticut border.

The current epidemic appeared in Dutchess and Columbia Counties and in Connecticut’s northwest corner in 2021 as a result of various regional ecological factors, combined with the spongy moths’ ability for rapid proliferation.

“The white-footed mouse, which preys on spongy moth [egg masses], is usually enough to keep the population under control,” said Clive Jones, a terrestrial ecologist at the Cary Institute. “If the mouse population collapses, as it did, then the spongy moth population can escape.” Populations of parasitic wasps and flies, which bring the population down to normal levels, can take a few years to grow enough to curb the spongy moth. During this time, when the moths have few significant predators, their population grows unchecked and they rapidly defoliate trees.

This year’s wet spring contributed to the counter-epidemic of both a virus and a fungus antagonistic to spongy moth larvae.

The Cary Institute, in its 2025 forecast of the spongy moth’s prevalence, estimated the outbreak would abate during the summer, leading to a negligible population of spongy moths in previously-affected areas. “We see the population collapse due to the fungus and the virus and due to the other natural enemies’ population growing because of the moth’s rise,” Jones said.

Given the passage of an appropriate period of time for natural mechanisms to control the moth population, “we knew at Cary that there was a very low probability of much defoliation by the spongy moth [in previously-affected areas] this year,” Jones said.

Jones and his colleagues at the Cary Institute compiled their forecast of the danger the spongy moth would pose to trees this summer through the collection of data at the Cary Institute’s own 1,924-acre arboretum, the observation of satellite imagery and through samples taken around the Hudson Valley and into Connecticut’s northwest corner.

Defoliation rarely kills trees directly, even if it occurs for years in a row. But defoliation in conjunction with other harmful factors does kill trees. “Many of the trees out there are fine… but quite a lot have succumbed due to the drought in 2022 and then defoliation in ‘23 and ‘24,” Jones said.

“Spongy moth flare-ups are not cyclical in the sense that they are regularly spaced,” Jones said. “You can fit a periodicity to spongy moth outbreaks which shows that they occur about every 10 years, but it’s no more than a very rough guideline and can be completely wrong.” Before the 2021 epidemic, the last spongy moth infestation occurred in Millbrook nearly

30 years prior, limiting the statistical measures which can be taken to forecast a future spongy moth epidemic.

Latest News

Road crews start new sidewalk to Amenia's Beekman Park
Photo by Leila Hawken

AMENIA — Sidewalk construction that will extend the town sidewalk to Beekman Park got underway this week along Route 44.

On Wednesday, August 20, the crew was checking excavation lines.

Keep ReadingShow less
Backgammon series begins at Hotchkiss Library of Sharon
Backgammon lessons kicked off Wednesday, Aug. 13, at The Hotchkiss Library. Instructor Roger Lourie works with Pam Jarvis of Sharon, while his wife, Claude, assists at a second board with Janet Kaufman of Salisbury.
Leila Hawken

In light of rising local interest in the centuries-old game of Backgammon, Wednesday afternoon backgammon instruction and play sessions are being offered at The Hotchkiss Library of Sharon. The first such session was held on Wednesday, Aug. 13, attracting two enthusiastic participants, both of whom resolved to return for the weekly sessions.

Expert player and instructor Roger Lourie of Sharon, along with his equally expert wife, Claude, led the session, jumping right into the action of playing the game. Claude chose to pair with Janet Kaufman of Salisbury, a moderately experienced player looking to improve her skills, while Lourie teamed himself with Pam Jarvis of Sharon, who was new to the game.

Keep ReadingShow less
Dugazon opens in Sharon, blending Southern roots with global style

Pantry essentials at Dugazon

Jennifer Almquist

You are invited to celebrate the opening of Dugazon, a home and lifestyle shop located in a clapboard cottage at 19 West Main Street, the former site of The Edward in Sharon. The opening is Wednesday, Aug. 27 at 11 a.m.

After careers in the world of fashion, Salisbury residents Bobby Graham and his husband, Matt Marden, have curated a collection of beautiful items that reflect their sense of design, love of hospitality, and Graham’s deep Southern roots. Dugazon is his maternal family name.

Keep ReadingShow less