The most economical and safest way to manage invasive species is by prevention. Early detection and rapid response (EDRR) of invasive species is much more effective than trying to control a widespread infestation. If eradication is not possible, the invasive species may be subject to control and management efforts.
There are various methods used for the control and management of invasive species:
- Biological control is the intentional manipulation of natural enemies by humans for the purpose of controlling pests or plants reducing the population using prey targeting the invasive species. Natural enemies used in classical biological control of weeds include different organisms, such as insects, mites, nematodes, and pathogens. In North America, most weed biological control agents are plant-feeding insects, of which beetles, flies, and moths are among the most commonly used. Biological control agents also includes imported fish, and other organisms that eat or infect targeted species. This option involves much research and testing to make sure the prey targets only the invasive species intended.
- Chemical control includes the use of pesticides, herbicides, fungicides, and insecticides. Although chemical use can be very effective, they can be dangerous to other species or to the ecosystem in general. Chemical control may be difficult, expensive, and create concerns about environmental health.
- Cultural control includes manipulation of habits to increase mortality of invasives or reduce it's its rate of damage (selection of pest-resistant crops, winter cover crops, changing planting dates). Cultural measures are aimed at changing human behavior to address the issue of spreading invasives -- using opportunities to educate people about practices to increase awareness to prevent the spread of invasives (signage, public awareness campaigns). Cultural practices include mulching, soil solarization with plastic film, thermal weed control (e.g., flaming, hot water, and steam), prescribed burning, water manipulation, and prescribed grazing with domesticated herbivores (e.g., cattle, sheep, goats, and horses).
- Mechanical control techniques include mowing, hoeing, tilling, girdling, chopping, and constructing barriers using tools or machines to "harvest" invasive plants by removing and collecting them, and transporting elsewhere and allowing them them to decompose in place. Mechanical treatments complement herbicide (chemical) control and sometimes increase efficiency.
- Physical or manual control involves physical activities (i.e. harvesting) such as hand-pulling, digging, flooding, drawdowns (de-watering), dredging, mulching, manual destruction or removal of nests, egg masses, or other life stages, or shading to control invasive plants. Methods generally includes the destruction of invasive species by hand. Manual control can be labor-intensive, costly, and provide only temporary control.
You can also use a combination of control methods for an integrated approach using Integrated Pest Management (IPM). The IPM approach does not refer to a specific management technique, but uses a multi-strategic approach with compatible techniques and methods to maintain pest populations below levels that will cause significant economic and environmental damage.
The section below contains highly relevant resources for this subject, organized by source.