Huyck Preserve imports silverflies to try to save hemlocks

By Melissa Hale-Spencer
RENSSELAERVILLE — Can a Pacific Northwest silverfly save eastern hemlocks in New York State? The Huyck Preserve in Rensselaerville is leading the way in finding out.

It’s called biological control, and it means putting a natural predator near its prey as a way of managing a pest — in the way that lady bugs killing aphids, or deer mice eat gypsy moths.

The Edmund Niles Huyck Preserve, an accredited land trust with over 2,000 acres and a biological research station, is working with the New York Hemlock Initiative at Cornell University to implement biological control of the hemlock woolly adelgid, a destructive pest of eastern hemlock trees from Asia that was introduced in Virginia in the early 1900s. Since that time, adelgid has killed millions of hemlocks from northern Georgia to Nova Scotia.

The Huyck Preserve is a partner in the Capital Region Partnership for Regional Invasive Species Management, a not-for-profit quasi-governmental agency hosted by the Cornell Cooperative Extension of Saratoga County and funded through the state’s Department of Environmental Conservation via the Environmental Protection Fund.

In 2018, the Huyck Preserve began work on its first invasive-species management and monitoring plan, according to a release from the preserve, and Capital Region PRISM (Partnership for Regional Invasive Species Management) became a significant resource for protecting the lands and waters of the preserve from the harmful effects of invasive species, including forest pests like hemlock woolly adelgid.

The Huyck Preserve undertook its first chemical treatment of woolly adelgid in 2020. But the pest has continued to spread across the nearly 350 acres of hemlocks at the Huyck Preserve. This spring, the New York State Hemlock Initiative released two species of silverflies, Leucopis argenticollis and Leucopis piniperda. These tiny flies are native to the Pacific Northwest of the United States and are specialist predators of the woolly adelgid.

In other words, they feed only on the adelgid and are at very low risk of causing ecological problems. The silverflies feed on adelgid eggs as larvae and are some of their most numerous predators on the western hemlocks of the Pacific Northwest.

This year’s release is part of a long-term study coordinated by the three organizations, and future monitoring will determine the success of establishment of silverfly and control of the adelgid. Only time will tell if the release of a small number of silverflies (compared to the vast infestation of the hemlock wooly adelgid at the preserve) is successful.

Source: Huyck Preserve imports silverflies to try to save hemlocks – The Altamont Enterprise, 2021-05-11

Parasitic wasps released in Water Gap park to stop invasive beetles from killing trees

By Bruce Scruton
MIDDLE SMITHFIELD, Pa. — Three species of a small wasp that can attack the eggs of the emerald ash borer were released by National Park Service biologists within the Delaware Water Gap National Recreation Area this past weekend.

The borer, an invasive beetle from Asia, is capable of killing a full-grown ash tree within a couple of years and has been found in several locations in Sussex County in the past two years.

The release was in the Mosier’s Knob area, just below the Walpack Bend of the Delaware River and across the river from Worthington State Forest where the New Jersey Department of Agriculture recently released its own biological agents to stem the invasion of the pest.

Kara Deutsch, chief of resource management for the park, said the emerald ash borer has been found on both sides of the river. The choice of Mosier’s Knob for the release came at the recommendation of regional NPS experts.

The wasps, known in scientific circles as “parasitoids,” were supplied by the United States Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) and came from the Plant Protection and Quarantine (PPQ) EAB Parasitoid Rearing Facility in Brighton, Mich.

There were three species of wasps released — one release was of adults and the others were pupae of separate species.

The three are themselves invasives, native to the Asian areas where the emerald ash borer are native. The borer was imported to this area first identified in the area around Detroit and believed to have arrived in 2002 inside of wooden packing material.

In less than two decades since, the borer, a type of beetle, has been found in the U.S. from the Atlantic Coast (except Forida) as far west as Colorado and has spread throughout the eastern two-thirds of Canada.

The wasp parasites — the adults are about the size of a mosquito and don’t sting — get the borer in both egg and larval states.

The adult Oobius agrili female will lay her own egg inside the egg of an ash borer and there are two life cycles of the wasp for one life cycle of the borer. In experiments and observation, more than half an emerald ash borer’s eggs became victims of the wasp.

The other two wasps attack the larval stage of the borer and it is that stage that causes the damage to ash trees.

Source: Parasitic wasps released in Water Gap park to stop invasive beetles from killing trees – New Jersey Herald, 2019-08-26

Beetles making difference in woolly adelgid fight

By David Singleton
A beetle is winning the battle against the hemlock woolly adelgid at Nay Aug Gorge.

Almost 20 years after the woolly adelgid arrived at Nay Aug Park and started threatening the hemlocks in and around the gorge, officials believe they’ve finally gained the upper hand against the invasive, tree-killing pest, thanks in large part to a predatory beetle called S. tsugae.

“I think we caught it in time, and we have turned the corner. There is no doubt about it,” city forester Tony Santoli said. “I have seen great improvement.”

Since it started working with Santoli in 2011, Tree-Savers, a private company with offices in Waymart that specializes in saving endangered hemlocks, has released about 10,000 S. tsugae beetles at Nay Aug as part of an effort to eradicate the woolly adelgid and restore the park’s weakened hemlocks to health.

Like the woolly adelgid, the beetle — its full scientific name is Sasajiscymnus tsugae — is native to Japan. It is the woolly adelgid’s natural enemy, feeding on the tiny insect’s eggs.

A beetle is winning the battle against the hemlock woolly adelgid at Nay Aug Gorge.

Source: Beetles making difference in woolly adelgid fight at Nay Aug Park – The Times-Tribune, 2017-04-15