What are invasive species and why are they a problem?
Invasive species are non-native organisms artificially introduced to an area outside of their native range which negatively affect their new environment. Although their spread can have beneficial aspects, they have become a serious ecological, environmental, and economic threat, and can even damage human health.
This spread of species into a new environment is a natural occurring phenomenon, however, its facilitation by humans has resulted in an increasing rate and spread of invasion with serious repercussions.

Invasive Plant Species
Examples of invasive plant species in our area include: English ivy, Japanese knotweed, purple loosestrife, Japanese barberry, Autumn olive, Bradford pear, Japanese wisteria and honeysuckle, and bamboo.

Invasive Animal Species
Examples of nonnative, invasive animal species include: Burmese pythons (ravaging the everglades), European starlings, pidgeons, sparrows, and earthworms (Lumbricidae).
It is said that humans, especially modern-age humans, are a significant invasive species.
Because they have fewer natural predators, invasives tend to flourish and suppress native species over large areas. They interrupt the functions of the local ecosystem, taking up large amounts of space that would otherwise have been occupied by a diversity of native species. This competition leads to negative impacts on native plants and animals.
Invasive plants can be introduced by human activity in a number of ways: accidentially, by transportation into a region (e.g. mile-a-minute vines, stink bugs, etc.), by landscapers and the nursery trade (purple loosestrife, wisteria, flowering pear, Japanese barberry), and by well-meaning intentional introductions (autumn olive planted for erosion control, kudzu planted as forage and erosion control). However, once in an area they can be spread by birds an animals which eat and then spread the seeds, as well as by wind and water.
Check out our pamphlet Invasive Plants Commercially Available in New Jersey for a list of a dirty dozen of invasive plants with suggestions for substitutes.
Invasive Animals
Pests That Threaten Our Landscape and Forest Trees
- Asian Longhorned Beetle
- Emerald Ash Borer
- Gypsy Moth
- Hemlock Woolly Adelgid
- Spotted Lantern Fly

Emerald Ash Borer

Spotted Lantern Fly
An invasive Asian pest that was accidentally imported into the US in 2002. It was first discovered in Michigan and has since spread to over 25 states. Learn more…
A plant hopper that is native to China, India and Vietnam and has become a major pest in eastern PA and in 8 counties in western NJ. It has been spotted in Ewing landscapes. Learn more…