The 10 invasive land-living species of greatest concern for New York State

NEW YORK - From tree-killing beetles to plants that cause burns, New York’s Department of Environmental Conservation (DEC) is warning about invasive species that are altering the state’s landscapes and ecosystems.

What we know:

The DEC tracks terrestrial invasive species that pose the highest risks to New York’s environment. Some, like the emerald ash borer and spongy moth, are already widespread. Others, like oak wilt and laurel wilt, are diseases that threaten entire tree families. Officials say preventing new infestations and slowing the spread of existing ones are top priorities.

These invasives can devastate forests, weaken agriculture, and harm public health. For example, giant hogweed’s toxic sap can cause severe skin burns, while spotted lanternflies target vineyards, orchards and hardwoods.

Invasive terrestrial species of greatest concern in New York

• Asian longhorned beetle — A wood-boring insect that feeds on hardwoods including maple, birch, elm, ash, poplar, horsechestnut and willow. It threatens the health of New York’s hardwood forests and impacts agriculture and tourism.
• Beech leaf disease — A newly discovered disease associated with a microscopic nematode. It kills native and ornamental beech trees, though much about its spread and biology is still unknown.
• Emerald ash borer — An invasive beetle from Asia that feeds on all native ash trees. Since its arrival, it has killed millions of trees and caused billions of dollars in damage across the U.S.

• Giant hogweed — A massive, invasive plant whose sap can cause severe burns and permanent scarring when combined with sunlight.
• Hemlock woolly adelgid — A tiny, aphid-like insect from Asia that infests hemlocks. It is easy to spot by the white, cottony masses it leaves on the underside of branches. Left untreated, infestations can kill hemlock stands.
• Laurel wilt — A fungal disease spread by the invasive redbay ambrosia beetle. It kills trees and shrubs in the laurel family, including sassafras and spicebush, often within weeks.
• Oak wilt — A fungal disease that affects all oak species. Red oaks die especially quickly, sometimes within a single growing season, while white oaks decline more slowly.
• Southern pine beetle — A bark beetle, only the size of a grain of rice, that attacks pines. Warmer winters have allowed it to spread north into New York, threatening pine forests.
• Spongy moth (formerly gypsy moth) — A naturalized invasive insect whose caterpillars feed on hundreds of tree species, causing large-scale defoliation and weakening forests.
• Spotted lanternfly — A planthopper pest from Asia. Known for clustering on trees, it damages vineyards, orchards and hardwoods, while posing risks to New York’s agriculture and tourism industries.

Why you should care:

Left unchecked, invasive species cost New York millions in tree loss, reduced crop yields and ecological disruption. They also make forests more vulnerable to storms, drought, and climate change.

DEC urges New Yorkers to help by reporting sightings, avoiding the movement of firewood and being careful not to spread invasive plants and insects.

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