Invasive Species

New York State defines “invasive species” as follows: (a) non-native to the ecosystem under consideration; and (b) whose introduction causes or is likely to cause economic or environmental harm or harm to human health. According to NYS DEC, invasive species are a threat to our biodiversity and are judged second only to habitat loss. Invasives hail from around the world, and the rate of invasion is increasing at an alarming rate with the increase in international trade.

Invasive species have been problematic in the past and are certainly a problem now, since they threaten our ecosystems, including all natural systems, managed forests, our food supply, including not only agriculture, but also harvested wildlife, fish and shellfish. Invasives are a threat to our built environments including landscaping, infrastructure, industry, gardens and pets. Invasives can affect recreational areas and human health.

The NYS Invasive Species Council was charged with developing a recommended four-tier system for invasive species management. The regulatory four-tier system required by statute assigns one of three regulatory categories to all species of non-native plants and animals, from the most restrictive category of “Prohibited Species” to “Regulated Species” to “Unregulated Species”. The number of persisting non-native species in New York is 1,405. The number of persisting non-native species assessed as having a High or Very High invasive nature in New York as of January 2010 is 68. Though not an exact figure, Dutchess County probably has at least 75% of all non-native species though only a few are high in density:

Top Ten invasive species with an assessment of “Very High” Invasive Nature based on DEC 4-Tier Assessment.

Number Common Name Scientific Name
1 Eurasian Watermilfoil Myriophyllum spicatum
2 Japanese Knotweed Fallopia japonica
3 Autumn Olive Elaeagnus umbellata
4 Broadleaf Water-Milfoil Myriophyllum heterophyllum
5 Common Reed Grass Phragmites australis
6 Water Thyme Hydrilla verticillata
7 Mile-A-Minute (MaM) Persicaria perfoliata
8 Purple Loosestrife (PL) Lythrum salicaria
9 Japanese Barberry (JB) Berberis thunbergii
10 Black Swallow-wort (BSW) Cynanchum louiseae

There are some additional highly destructive invasive species that are either in Dutchess County or within striking range of Dutchess County that should be mentioned and monitored:

Significant Invasive Species either in, or within close proximity to Dutchess County, NY.

Number Common Name Scientific Name
1 Brown Marmorated Stink Bug (BMSB) Halyomorpha halys
2 Emerald Ash Borer (EAB) Agrilus planipennis
3 Hemlock Woolly Adelgid (HWA) Adelges tsugae
4 Japanese Stilt Grass (JSG) Microstegium vimineum
5 Viburnum Leaf Beetle (VLB) Pyrrhalta viburni

The table below provides a list of other invasive species common to Dutchess County that have increased in population over the past ten years:

Species Common to Dutchess County that have Increased in Population.

Number Common Name Scientific Name
1 Garlic MustardInvasive Alliaria petiolata
2 Porcelain Berry Ampelopsis brevipedunculata
3 Oriental Bittersweet Celastrus orbiculatus
4 Mugwort Artemisia vulgaris
5 Tree of Heaven Ailanthus altissima
6 Chinese Water Chestnut Eleocharis dulcis
7 Zebra Mussels Dreissena polymorpha
8 Japanese Beetle Popillia japonica
9 Multi-Colored Asian Lady Beetle Harmonia axyridis

For More Information on Invasive Species contact the CCEDC Commerical Horticulture Program:

Stephanie Radin:

Last updated March 1, 2024