Comprehensive Invasive Species List

It is essential to have an invasive species list because these invaders create $120 billion in damages per year across our ecosystems. They upset natural balances and put native animals at risk. In the United States, 42 percent of endangered species are directly threatened by these aggressive newcomers. These are organisms that are not originally from these environments and that harm the environments that they invade.

Throughout my time conducting fieldwork in Louisiana, I have witnessed the destruction of wetlands caused by nutria. Invasive species can often be recognized by their rapid spread and the damage they inflict on native plants. This guide will give you some of the fundamental tools needed to identify these threats. Your knowledge will help you protect at-risk habitats from irreversible damage.

An invasive species can be identified through two rigid parameters: it must be non-native to the ecosystem and must also produce documented damages. An example are the Burmese Pythons in Florida. They came over from Southeast Asia and are currently decimating mammal populations that are native to Florida. The same is true for Zebra Mussels, which clog water infrastructure and are outcompeting local shellfish.

Invasive species are often mistakenly identified as aggressive natives or vice versa. White-tailed deer, for instance, are a native, common species that can lead to some problems if they lose their natural predator. However, the invasive species, Japanese Knotweed, is functionally different from native species. Japanese Knotweed is an invasive organism from a foreign area that lacks a natural predator to keep it in check. The USDA guidelines classify invasive organisms and require information on foreign native, and measurable ecological damage.

I have personally experienced the difference while doing fieldwork in the Everglades. Native species adapt to living in food webs that are not disturbed. Invasive species, such as the Python, can permanently disturb ecosystems. The invasive will have tremendous growth in population, and its presence creates unalterable conditions. Hence, prompt and early detection of invasive species is vital for protecting ecosystems.

To determine if an organism is a true invasive species, it is necessary to verify its origin and its impact. Answer these two questions: Did the organism arrive as a result of human activities? Does it cause harm to biodiversity or human-built systems? If you can answer "Y" in both questions, the organism is another invasive species that requires intervention.

Aquatic invaders exemplified by Zebra Mussels can be incredibly damaging. Zebra Mussels filter a liter of water each day, clogging pipes, resulting in $1 billion in infrastructure repairs. At the same time, Asian Carp can jump as high as 10 feet, dominating rivers across 28 states. Likewise, invasive plants such as Hydrilla grow as much as one inch every day and form dense mats that block out sunlight completely. It is essential to note that Water Hyacinths can double their coverage every two weeks, suffocating fish in the process.

Across land, Burmese pythons have decimated the raccoon population in the Everglades by 99 percent. Feral swine root up from 2 to 8 acres nightly, costing agriculture $2.5 billion a year. Japanese Knotweed grows stems resembling bamboo that can crack foundations, resulting in $2.8 billion in damage. I've seen entire forests smothered in Kudzu vines that can grow a foot per day in summer.

Both of these habitats face threats that are microscopic in size. New Zealand Mud Snails are capable of cloning themselves 430 times a year and reaching 500,000 snails per square meter. The Chytrid fungus has caused the extinction of approximately 90 species of frogs worldwide. Early detection is important. Unusual species can be reported through the USDA process to help protect the local ecosystem from invasive species.

Source: www.flickr.com

Japanese Knotweed

• Growth Pattern: Bamboo-like stems reach 10 ft (3 m) height within a single growing season rapidly
• Structural Damage: Powerful roots crack concrete foundations, costing $2.8B/year in building repairs
• Reproduction: Root fragments regenerate new plants within 6 days, spreading 130 ft (40 m) laterally
• Control Challenges: Requires professional removal since any remaining fragments guarantee regrowth

Source: www.needpix.com

Nutria

• Feeding Impact: Consumes 25% body weight daily, eroding 1 acre (0.4 ha) of marsh per five individuals
• Reproduction Rate: Produces three litters annually with 12 young each, enabling 200% population growth
• Geographic Spread: Colonized 15 states from Gulf Coast to Pacific Northwest in three decades
• Burrowing Effects: Weakens levees and irrigation systems through extensive tunnel network construction

Source: commons.wikimedia.org

Garlic Mustard

• Chemical Warfare: Releases allelopathic toxins killing native tree seedlings within root zones
• Seed Production: Single plant produces 8,000 seeds remaining viable for 10 years in forest soil
• Control Window: Must be hand-pulled before seed set during May-June for effective management
• Ecological Impact: Eliminates native spring wildflowers like trillium and bloodroot within five years

Source: commons.wikimedia.org

Feral Swine

• Economic Impact: Causes $2.5 billion/year losses to agriculture through crop destruction and predation
• Reproduction: Two litters annually yield 6-12 piglets each, doubling populations every 4 months
• Disease Vectors: Carries 30+ pathogens including pseudorabies and brucellosis transmissible to livestock
• Foraging Damage: Roots up 2-8 acres (0.8-3.2 ha) nightly searching for insects and plant material

Source: www.flickr.com

Emerald Ash Borer

• Tree Mortality: Killed over 100 million ash trees across 35 states since 2002 North American introduction
• Spread Mechanism: Travels 20-40 miles (32-64 km) yearly through human firewood transportation
• Identification Signs: Creates distinctive D-shaped exit holes and serpentine larval galleries under bark
• Ecological Cost: Eliminates ash canopy cover critical for urban cooling and wildlife habitat provision

Source: commons.wikimedia.org

Kudzu Vine

• Growth Rate: Expands 1 foot (0.3 m) daily during summer, smothering entire forests and structures
• Economic Cost: Requires $500 million/year for control across 7 million southeastern infested acres
• Spread Method: Root nodes establish new plants wherever stems contact soil, enabling rapid colonization
• Historical Context: Introduced from Asia in 1876 for erosion control before becoming invasive nuisance

Source: commons.wikimedia.org

Burmese Python

• Predatory Impact: Consumes mammals up to deer size, reducing raccoon populations by 99% in Everglades
• Reproduction: Lays 50-100 eggs annually, surviving winter temperatures down to 40°F (4.4°C)
• Control Efforts: Professional hunters remove 5,000+ snakes yearly from Florida's southern wetlands
• Introduction Origin: Released pets established breeding populations after 1992 Hurricane Andrew

Source: commons.wikimedia.org

Spotted Lanternfly

• Crop Damage: Feeds on 70+ plant species including grapes, apples, and hardwood timber trees
• Honeydew Production: Excretes sticky residue promoting sooty mold that kills host plants gradually
• Spread Prevention: Quarantines restrict movement of materials from 17 affected eastern US states
• Lifecycle: Lays 30-50 egg masses annually on any smooth surface including vehicles and outdoor gear

Source: commons.wikimedia.org

Russian Olive

• Water Consumption: Single tree uses 75 gallons (284 liters) daily, drying riparian zones completely
• Seed Dispersal: Birds spread seeds 10+ miles (16+ km) from parent plants along river corridors
• Thorn Hazards: Sharp spines injure livestock and wildlife attempting to browse on foliage or fruit
• Control Methods: Requires combined cutting and herbicide application to prevent stump resprouting

Source: commons.wikimedia.org

Giant Hogweed

• Toxic Sap: Causes severe phytophotodermatitis with third-degree burns and permanent sunlight sensitivity
• Height: Grows 15 ft (4.5 m) tall with 5 ft (1.5 m) wide leaves shading out native vegetation
• Seed Production: Single flower head yields 20,000 seeds remaining viable for 10 years in soil banks
• Public Safety: Requires hazmat-suited removal teams due to dangerous sap exposure risks during work

Federal regulations, such as the Federal Noxious Weed Act, prohibit risk species, including Giant Hogweed and Mediterranean Caper. APHIS-USDA works in partnership with inspectors to enforce these regulations at 350 ports. Fines can reach up to $50,000 for transporting prohibited plants across state lines. This system is designed to prevent the introduction of risk species, whether intentionally or through negligence. I've seen inspectors stop contaminated nursery stock myself.

Methods can differ dramatically in their classification methodologies and enforcement. For example, California's CDFA is working to address the Yellow Starthistle, which is choking out native plants and grasslands. In Florida, FDACS is dealing with Brazilian Pepper trees invading wetlands, while TPWD in Texas is combating Saltcedar trees that are sucking up the water. Indiana's DNR addresses the Garlic Mustard invading forests. Each state has responded to the local threat in a specific manner.

It is important to understand the differences in classification. Prohibited species, for example, the Melaleuca trees in Florida, cannot be possessed. Restricted species, like California's Pampas grass, require containment. Noxious weeds, such as King Ranch Bluestem from Texas, can require an entire control program to manage them. These level classifications define the legal expectations of residents and businesses.

Public reporting of sightings to USDA systems supports these efforts. I have learned through my work as a conservation professional that public alerts to an invasive species generally result in rapid action by my State in addressing that species. Before relocating any plants, animals, or insects from one place to another, ensure you check the proper lists. The more that you pay attention, the less likely a new invasion will occur.

The IUCN Global Invasive Species Database monitors and maintains records on more than 1,200 invasive species with a high risk of threat level and includes extensive detailed profiles. As a researcher, I have utilized the risk assessments in this database to make predictions of the spread of Asian Carp into the Mississippi Basin. The database, which is free and publicly available, publishes distribution maps for each species as well as management case studies. The database is updated quarterly and routinely incorporates data from across 200 countries worldwide, making it an invaluable resource for evidence-based conservation work.

EASIN for Europe & NISbase for Japan are regional databases that specifically address local threats. EASIN tracks approximately 15,000 alien species with near real-time alerts. At the same time, NISbase assesses and models biological range shifts under various climate change scenarios. As these databases address domestic systems with different local vulnerabilities, they also help address regional vulnerabilities, such as the invasion of Miconia in Hawaii. In my work with Okinawa, NISbase was used to identify the arrival of new crab species.

The economic consequences are immense, with the Water Hyacinth responsible for asset losses exceeding $200 million in fisheries across Africa. Ecologically, Cane Toads alone drove 30 of Australia's marsupials to extinction, and Climate change will only exacerbate these risks. I can also confirm that I've already observed and documented pythons expanding their range north as temperatures increase. Databases now incorporate IPCC projections of potential ranges for high-risk species in 2050.

Invasive species enter the country through numerous intentional pathways (e.g., the introduction of ornamental plants) and accidental pathways (e.g., the release of ballast water), according to data from the USDA The horticulture trade accounts for 65% of invasions. I have found contaminated nursery stock with insects during the inspections of imported plants. Another significant pathway is through global shipping, as vessels transport 10,000 species per day in ballast tanks.

Preventing invasive species will require the action of different groups. Homeowners should work to establish native alternatives to plant instead of invasive ornamentals. Boaters should Clean - Drain - Dry any equipment used for the water between water bodies. Pet owners should consider surrender programs to find homes for unwanted pets instead of releasing them. I have seen invasions of Burmese Pythons start from pets that were released in neighborhoods in Florida.

It is essential to report sightings using USDA systems, such as the EDDMapS app and SITC hotline, as this facilitates a rapid response, as seen in the case of Asian Giant Hornet (AGH) sightings in Washington State, for example. In my work in the field of conservation, public reports helped intercept boats contaminated with Zebra Mussels. Early detection can mitigate problems before irreversible damage is inflicted on an ecosystem.

Invasive species invade every ecosystem, from backyard gardens to national parks, with a significant presence in nearly every ecosystem. Their effects are direct and often substantial, with threats to native biodiversity throughout communities. Prevention is cost-effective, estimated to save states and local governments $120 billion a year compared to future eradication efforts. This is not only beneficial for the accessibility and sustainable management of natural resources, but also for local economies.

Your actions have a quantifiable impact, as demonstrated by the numbers supporting numerous conservation success stories. Public reporting through tools such as EDDMapS has affected 30% of all containment victories throughout the country. During my fieldwork, I had the opportunity to document how citizen reporting halted the spread of the Spotted Lanternfly in Pennsylvania. These frontline defense systems empower communities to defend against invasive species.

As a reminder, invasive species management begins with awareness. When you use native alternatives in your gardens or clean your boat between lakes, you are helping to preserve ecosystems. Different case studies on invasive species management in New Zealand and the Great Lakes tell a similar story of how nurturing ecosystems in aggregate can result from individual decisions made in small increments. Your behavior today advocates against the potential ecological disaster of tomorrow.