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Similar to how invasive plants can take over your garden (yes, we’re looking at you, kudzu), there are also invasive insects that you need to be cautious of. Why? Because halting their spread is beneficial for not only your immediate landscape but also the broader environment. According to the U.S. Department of Agriculture (USDA), the destruction caused by invasive pests and diseases results in an estimated annual loss of $40 billion in plants, trees, and agricultural crops in the United States. Here’s what you should understand about invasive insects and how to manage them.
Meet Our Expert
Kathryn Bronsky serves as a national policy manager at the USDA’s Animal and Plant Health Inspection Service.
What Are Invasive Insects?
Insects often unknowingly travel on products, people, and plant materials, as explained by Kathryn Bronsky, the national policy manager at the USDA’s Animal and Plant Health Inspection Service. They can hitch a ride on plants and seeds brought in by travelers or hide in product shipments. Once introduced into a new area, they can be spread through plants, produce, soil, logs, firewood, and mulch.
An organism that is not native, whether it be an insect, plant, or microbe, is classified as invasive once it exhibits certain harmful traits. Bronsky states, “Invasive species are non-native organisms, including plants, insects, or diseases, that negatively impact our economy, food security, and the environment.” These species usually originate from other countries, and when they enter a new region, lacking natural predators, they can rapidly proliferate, disrupting the natural ecosystem, displacing native species, and reducing biodiversity.
Unchecked, invasive insects “can cause damage to our gardens and overall plant health in the U.S. and globally,” Bronsky mentions. On a global scale, she states, “The United Nations estimates that invasive pests annually destroy up to 40 percent of food crops, resulting in $220 billion in trade losses worldwide. Therefore, it is crucial for everyone to do their part in slowing the spread by adhering to import and domestic regulations.”
Related: 10 Native Plant Alternatives to Popular but Invasive Garden Species
Which Pests to be Cautious of
From giant snails to fire ants, there are numerous invasive species to watch out for in your yard. Below are the primary threats identified by the USDA, along with steps to take if you come across them.
Related: How to Identify 6 Common Houseplant Pests and Naturally Eliminate Them
1. Spotted Lanternfly
The spotted lanternfly (Lycorma delicatula) is a moth-like “planthopper” that poses a threat to various food crops like grapes, stone fruit, hops, and hardwood trees, with its favored host being the fast-spreading tree-of-heaven (Ailanthus altissima). The egg masses can be attached to almost any outdoor
The ash tree is known for its adaptability to different climates and its ability to easily spread through infested firewood, logs, or nursery stock. Signs of infestation include D-shaped exit holes in the bark, dead branches at the tree’s top, or increased woodpecker activity hunting down the larvae. To prevent the spread of the Emerald Ash Borer (EAB), it is recommended to purchase local firewood or certified heat-treated firewood.
The Gypsy Moth is a widespread pest that feeds on over 300 tree and shrub species, posing a threat to forests. Its eggs can be transported on items like firewood, outdoor furniture, or toys. Before moving homes or traveling out of an affected area, it is advised to check for egg masses, as some states require this by law.
Invasive fruit flies, such as the Mediterranean fruit fly, are listed by the USDA as one of the most threatening pests, infesting various fruits and causing significant damage. To prevent the spread of these fruit flies, it is crucial not to ship or move fruit to another state without clearance from the State Agriculture Department.
To prevent the spread of invasive pests, it is important to stay informed and take necessary precautions. Consider declaring items at customs when traveling internationally, responsibly sourcing plants online, avoiding moving untreated firewood, and being aware of state or federal quarantines for plants and insects. If you suspect a new pest infestation, report it to local authorities promptly.
