Understanding and Managing Invasive Species in Pennsylvania

An invasive species is a non-native organism that, when introduced to a new environment, causes harm to the local ecosystem, economy, or human health. These species can outcompete, prey on, or bring diseases to native species, leading to significant ecological disruption. Invasive species often thrive in new environments due to a lack of natural predators or controls, allowing them to spread rapidly and dominate the local flora or fauna. Well-known examples include the zebra mussel in North America and the cane toad in Australia.

While invasive species are those that are harmful to native organisms, the environment, or human health, it is important to make the distinction between non-native and invasive species. There could be a non-native species that is unlikely to become invasive. Likewise, many invasive species are not inherently harmful or intent on causing harm.

Instead, they are simply thriving in an environment that isn't equipped to handle their presence, with their unchecked growth potentially disrupting ecosystems and outcompeting native species for resources. This can have far-reaching consequences on biodiversity and the delicate balance of natural habitats, underlining the need for effective management strategies and conservation efforts to mitigate the impacts of invasive species. Most often, non-native organisms are considered invasive if:

1. They outcompete native species. Non-native organisms will consume resources such as food, water, and habitats, leading to declines or extinctions of native species. This can disrupt local ecosystems and reduce biodiversity.
2. They cause significant economic damage. Invasive species can cause damage to the agriculture, forestry, fisheries, and other industries. For example, they can reduce crop yields, damage infrastructure, and increase pest management and control costs.
3. They spread diseases or cause allergies. Some invasive species can pose direct threats to human health by spreading diseases, causing allergies, or through other harmful interactions. Not all invasive species are dangerous to humans, however.
4. They alter habitats and ecosystems. Certain invasive species can affect soil composition, water availability, and fire regimes. This can lead to long-term environmental changes that are difficult or impossible to reverse.
5. Their presence leads to a decline in the native populations. By preying on native species or competing for the same resources, invasive species can lead to a decline in native populations, sometimes pushing them to the brink of extinction. Native organisms are essential to our local ecosystems because they've adapted to and live in harmony with other native populations.
6. They disrupt important ecological processes. Invasive species can disrupt the natural processes and services that ecosystems provide, such as pollination, water purification, and carbon sequestration, affecting the overall health and functionality of the environment.

Pennsylvania faces challenges from several invasive species that affect its ecosystems, economy, and health. Non-natives are not only animals and insects, but plants, aquatic organisms, and diseases as well. Here we break down each category to discuss what makes it invasive, and what to look out for.

Plants

1. Norway maple
2. Tree of Heaven
3. Mimosa
4. Paulownia
5. Bradford Pear
6. Siberian Elm
7. Butterfly bush
8. Burning bush
9. Privets
10. Shrub honeysuckles
11. English Ivy

For a more comprehensive, state-wide list, check out the PA DCNR's Invasive Plant Fact Sheets.

Birds & Mammals

1. House Sparrow
2. Mute Swan
3. European Starling
4. Wild Boar

To learn more about these creatures, visit the PA Dept. of Agriculture's Invasive Birds & Mammals sheet.

Insects

1. Emerald Ash Borer
2. Spotted Lanternfly
3. Asian Longhorned Beetle
4. Japanese Beetle
5. Hemlock Woolly Adelgid
6. Brown Marmorated Stinkbug
7. Giant Hornet

For a more comprehensive list, visit the PA Dept. of Agriculture's Invasive Insect sheet.

Aquatic Animals

1. Northern Snakehead
2. Common Carp
3. Goldfish
4. Red-Eared Slider
5. Zebra Mussel
6. Asiatic Clam
7. Calico Crayfish
8. Pink Salmon
9. Blue Catfish

Visit the PA Dept. of Agriculture's Invasive Aquatic Animals sheet for more species.

Efforts to manage and mitigate the impacts of these invasive species include monitoring, public awareness campaigns, and various control and eradication programs, which we cover in the next section.

Managing and mitigating the impacts of invasive species is often a multifaceted and resource-intensive endeavor. It involves a combination of scientific research, stringent regulations, public awareness campaigns, and on-the-ground eradication strategies. Addressing the challenges posed by invasive species requires collaboration and coordination not only within individual regions but also across countries and international borders. These efforts are crucial in safeguarding ecosystems, protecting native species, and ensuring the ecological balance of our planet for future generations.

When encountering an invasive species in Pennsylvania, several steps can be taken to help manage and mitigate their impact:

1. Identify the organism and report the encounter.
2. Make sure you correctly identify the species. Use resources such as field guides, apps, or websites from local environmental organizations or government agencies.
3. Report sightings to local authorities or organizations. The Pennsylvania Department of Conservation and Natural Resources (DCNR), the Pennsylvania Fish and Boat Commission, and the Pennsylvania Department of Agriculture all have programs for reporting invasive species.
4. Prevent the spread by using mitigation techniques.
5. Always clean your hiking, fishing, and camping gear to prevent the spread of seeds and larvae.
6. Choose native plants for your garden, use fertilizer sparingly, and minimize ground disturbance to reduce the risk of harboring invasive plant species.
7. Never release pets or plants into the wild, as they can become invasive.
8. Use approved control methods.
9. Mechanically remove the invasive plant by digging or pulling it out, making sure to remove the roots to prevent regrowth.
10. Use herbicides or pesticides as recommended by local guidelines and only when necessary. Follow all safety instructions.
11. Support and advocate for research and implementation of biological control methods, where natural predators are introduced to control invasive species.
12. Get involved with your community.
13. Keep up to date with local news and resources on invasive species.
14. Participate in local eradication efforts and community science projects.
15. Educate friends, family, and community members about the impacts of invasive species.
16. Get involved with the system.
17. Support laws and policies that aim to prevent the introduction and spread of invasive species.
18. Advocate for funding towards research and management programs focused on invasive species.
19. Contact a professional.
20. For large infestations or when dealing with potentially dangerous species, it’s best to hire professionals who are trained in handling invasive species.

Reporting Contacts in Pennsylvania

• PA iMapInvasives: An online tool for reporting a variety of invasive species.
• PA Fish and Boat Commission: For aquatic invasive species.
• PA Department of Agriculture: For pests affecting agriculture and forestry.

Additional Resources

PA DCNR Invasive Plant Fact Sheets

PA DA Invasive Plant Pathogens Sheet

PA DA Invasive Birds & Mammals Sheet

PA DA Invasive Insects Sheet

PA DA Invasive Aquatic Animals Sheet

PA DA Invasive Aquatic Animal Pathogens Sheet

PA DA Invasive Mollusks and Other Land Invertebrates Sheet