Invasive Species: Guide to Animal and Pest Species
Invasive species represent one of the most significant threats to New Jersey’s ecological balance, native wildlife populations, and even economic stability. The (NJDEP) New Jersey Department of Environmental Protection works tirelessly to monitor, manage, and mitigate the impact of these non-native organisms that disrupt local ecosystems.
This comprehensive “Combating Invasive Species: Guide to Animals and Pests” explores the distinction between pests and invasive species, highlights prevalent invasive animals and pests in New Jersey, and offers insights into identification and management strategies.
Understanding the Difference: Pests vs. Invasive Species
While the terms “pest” and “invasive species” are often used interchangeably, they represent distinct concepts that warrant clarification:
Pests are organisms that are nuisances and interfere with human activities, damage property, livestock, or crops, or pose health risks. They may be native or non-native to the region and are primarily defined by their impact on human interests rather than ecological considerations. For example, some native insects might be considered pests when they damage garden plants, but they still play essential roles in the local ecosystem.
Invasive species are specifically non-native (or alien) to the local ecosystem. The introduction causes or is likely to cause economic, environmental, or human health harm. What distinguishes invasive species is their ability to spread aggressively and outcompete native species. They often do not have natural predators or diseases in their new environment that would usually control their populations.
It’s important to note that not all non-native species become invasive. Many introduced species remain contained within specific environments without causing significant harm. The NJDEP focuses its resources on those non-native species that demonstrate invasive characteristics and pose substantial threats to New Jersey’s biodiversity and ecosystem functions.
Prevalent Invasive Invertebrates in New Jersey
Emerald Ash Borer (Agrilus planipennis)
This metallic green beetle has devastated ash tree populations across the eastern United States since its discovery in 2002. First detected in New Jersey in 2014, the emerald ash borer attacks all species of ash trees. Its larvae feed under the bark, disrupting the tree’s ability to transport water and nutrients. Signs of infestation include D-shaped exit holes, unusual woodpecker activity, and crown dieback. The NJDEP implements monitoring programs and quarantines to slow its spread while exploring biological control options.
Gypsy Moth Larvae (Lymantria dispar)
Introduced to Massachusetts in the 1860s, the gypsy moth has become a significant defoliator of hardwood trees throughout the Northeast. The larvae (caterpillars) are particularly destructive, with a single caterpillar capable of consuming up to one square foot of leaf surface daily. Recognizable by their distinctive pairs of blue and red dots along their backs, these caterpillars can completely defoliate trees, leading to stress and potential mortality after successive years of infestation. The NJDEP conducts annual aerial surveys and targeted suppression programs in heavily affected areas.
Asian Longhorned Tick (Haemaphysalis longicornis)
First confirmed in New Jersey in 2017, this tick species represents the first invasive tick established in the United States in approximately 80 years. Unlike native ticks, the female Asian longhorned tick can reproduce asexually, allowing populations to grow rapidly. These ticks pose threats to livestock, wildlife, and humans, with the potential to transmit various pathogens. The NJDEP collaborates with public health agencies to monitor distribution and develop management strategies.
Spotted Lanternfly (Lycorma delicatula)
One of the most concerning recent arrivals, the spotted lanternfly, was first detected in New Jersey in 2018. This planthopper undergoes distinct developmental stages:
- Early Instar Nymphs: Black with white spots
- Late Instar Nymphs: Red with white spots and black stripes
- Adults: Gray forewings with black spots and vibrant red hindwings with black patterns
The spotted lanternfly feeds on the sap of more than 70 plant species, including important crops and hardwoods. Its feeding weakens plants, and its excretion of honeydew promotes sooty mold growth, further damaging vegetation. The NJDEP has established quarantine zones and public education campaigns to limit the spread, encouraging residents to report sightings and destroy egg masses.
Invasive Birds Affecting New Jersey Ecosystems
European Starling (Sturnus vulgaris)
Introduced to North America in the 1890s, European starlings have become one of the continent’s most abundant bird species. These glossy black birds with speckled plumage nest in cavities, aggressively outcompeting native cavity-nesting birds like bluebirds and woodpeckers. Forming large flocks that can number in the thousands, they cause agricultural damage by consuming fruits and grains while creating noise and waste issues in urban areas. The NJDEP monitors populations, but control efforts remain challenging due to their widespread establishment.
House Sparrow (Passer domesticus)
These small, brown birds were introduced to Brooklyn in the 1850s and have become ubiquitous across urban and suburban landscapes. Like starlings, house sparrows compete with native birds for nesting sites, often destroying eggs and killing the nestlings of bluebirds, swallows, and other native species. Their adaptability to human environments and aggressive nature have contributed to their success as an invasive species. Management typically focuses on designing birdhouses that deter house sparrows while accommodating native species.
Brown-headed Cowbird (Molothrus ater)
While technically native to North America, brown-headed cowbirds have expanded their range significantly due to human landscape changes, behaving invasively in many eastern regions, including New Jersey. These birds practice “brood parasitism,” laying eggs in the nests of other bird species, leaving the host parents to raise their young. This behavior has contributed to population declines in numerous songbird species, particularly those that have not evolved defenses against such parasitism. The NJDEP monitors impacted native bird populations and implements targeted management in critical habitats.
Invasive Mammals in New Jersey
Feral Cats (Felis catus)
Domestic cats that have returned to a wildlife state represent a significant conservation challenge. Highly efficient predators, such as feral cats, have contributed to the extinction of numerous bird and small mammal species worldwide and continue threatening wildlife in New Jersey. Beyond direct predation, they can transmit diseases to native wildlife. The NJDEP works with animal welfare organizations to promote responsible pet ownership, including spaying/neutering programs and encouraging indoor-only cats.
Norway Rat (Rattus norvegicus)
These rodents, also known as brown rats, arrived in North America on European ships in the 1700s. Highly adaptable, Norway rats thrive in urban environments, causing property damage, contaminating food supplies, and potentially spreading diseases. They displace native small mammals and prey on ground-nesting birds and their eggs. Management typically involves integrated pest management approaches combining sanitation, exclusion, and targeted control methods.
House Mouse (Mus musculus)
One of the most widespread invasive mammals globally, house mice came to North America with European colonists. Though small, their reproductive capacity and adaptability make them formidable invaders. They compete with native mice for resources and can cause substantial economic damage by consuming and contaminating stored foods. On islands and in sensitive habitats, they’ve been known to prey on invertebrates, small reptiles, and bird eggs, disrupting local ecosystems.
Protecting New Jersey’s Biodiversity
The battle against invasive species requires vigilance, education, and coordinated action. The NJDEP relies on public participation to identify new invasions early when management is most effective. Residents can help by learning to identify invasive species, reporting sightings, practicing responsible pet ownership, and avoiding introducing non-native plants and animals into the environment.
By understanding the differences between common pests and truly invasive species, New Jersey residents can make informed decisions about management priorities and contribute to conservation efforts. Preserving the state’s rich ecological heritage depends on our collective commitment to combating these biological invaders.
Contact NJ Pest Control
For professional assistance with invasive species management on your property, contact NJ Pest Control, licensed pest control specialists familiar with New Jersey’s regulations and best practices. Remember that early intervention is crucial to preventing the establishment and spread of potentially damaging species in our communities and natural areas.
