By name, it may seem localized to the midwestern United States, but nothing could be further from the truth. The Colorado potato beetle is one of the most invasive insects in the entire world, causing the most significant crop damage across European potato fields more so than in North America.
Colorado potato beetles are among the colorfully diverse leaf beetle family Chrysomelidae and can be easily recognized by the distinct 10 black stripes that run the length of their pale yellow bodies, often being called the ten-lined or ten-striped potato beetle.
The Colorado potato beetle is far more notorious than other pests because they are known to feed on host plants indiscriminately as both developing larvae and matured adults. Even removing the Colorado potato beetle from your garden has proven to be problematic since they quickly develop a tolerance to just about any commercial pesticide available.
How to Get Rid of Colorado Potato Beetle
- Colorado Potato Beetle Distribution: 1 of about 1,500 species of leaf beetles across North America. Widely invasive to Europe.
- Colorado Potato Beetle Host Plants: Potato, tomato, eggplant, pepper, petunia, nicotiana, tobacco
- Colorado Potato Beetle Life Cycle: 1-2 years
- Colorado Potato Beetle Eggs Per Lifetime: ~350-500
- Colorado Potato Beetle Control: Removal of eggs and pests by hand, predatory insects, neem oil spray, BT spray (Bacillus Thuringiensis)
- Colorado Potato Beetle Predators: Ladybugs, lacewings, spiders, grasshoppers
- Most Common in North America: Common Colorado Potato Beetle (Leptinotarsa decemlineata)
What Do Colorado Potato Beetles Look Like?
While leaf beetles are one of the most colorfully diverse insects in the world, each of these species of beetle generally have such a unique patterning that they can easily be identified by their appearance.
The Colorado potato beetle is no exception. Sometimes referred to as the ten-lined potato beetle or the ten-striped spearman, Colorado potato beetle earns its name because of the ten distinct black stripes that run down the length of its pale yellow body.
It’s head, appendages, and underbelly are noticeably orange with some black splotching, but the Colorado potato beetle is widely characterized as being a yellow beetle with black stripes, even those invasive to Europe. Still just as problematic as adult beetles, the larvae of the Colorado potato beetle are distinctly reddish and pink with light black spotting.
Colorado Potato Beetle Damage
In both adult and larvae form, the Colorado potato beetle is known to chew extensively on foliage, which is unique since it is often the developing larvae that are most harmful to plants while the adults are known to become beneficial.
The adult potato beetle doesn’t adjust its diet and turn to feed on troublesome pests, but will continue to feed from the same host plant as when it was a larva, which is generally rare in the insect population.
Because adult Colorado potato beetles are more developed than the young larvae, the chewing marks from adults appear to be more defined and notched while damage left behind from larvae may seem more haphazard and ragged. Regardless of which is infesting your host plant, neither are ideal.
What Do Colorado Potato Beetles Eat?
The Colorado potato beetle is part of an extensive family of leaf-eating beetles known to feed on just about any fruiting, vegetable, or ornamental crop in North America. However, the Colorado potato beetle is generally found to prefer the toxic vegetation and early development from crops in the Solanaceae family such as potato, tomato, eggplant, pepper, tobacco, and petunia.
While the Colorado potato beetle is still widely distributed throughout the United States, it hardly compares to the damage and loss of potato crops across Europe. As an invasive species to Europe, the Colorado potato beetle almost exclusively feeds on potatoes whereas North America experiences more diverse crop loss at the hands of these leaf-eaters.
Colorado Potato Beetle Eggs
Adult Colorado potato beetles are hard-shell arthropods with the ability to survive through winter, generally found safe beneath ground foliage near a host plant from the previous year.
As the new plant seedlings finally begin to mature in late spring, adult Colorado potato beetles will lay their eggs on the underside of developed leaves belonging to crops in the Solanaceae family.
Eggs of the Colorado potato beetle can be easily mistaken for those of ladybugs, both producing chicken egg-shaped orangish-yellow eggs neatly laid in clusters on the underside of a mature leaf.
While adult females are known to produce about 350-500 eggs per lifetime, they will only lay 12-36 at any given time, laying eggs on several host plants within a given area.
How to Get Rid of Colorado Potato Beetle
One of the most effective ways to rid the garden of Colorado potato beetles is to spot them early as eggs or underdeveloped soft-bodied larvae. Like many garden pests, potato beetle eggs are large enough to be spotted and destroyed by hand without any need for sprays or beneficial insects.
Ladybugs are a natural predator to the Colorado potato beetle and can usually be purchased at most nurseries.
Try plant companion plants such as marigold, nasturtium, catnip, and cilantro to attract beneficial predators such as spiders, lacewings, and ladybugs to your garden.
Colorado Potato Beetle Pesticide
The Colorado potato beetle is notorious in the garden for being able to quickly adapt and grow tolerances to many pesticides, both organic and conventional. Diluted neem oil spray and BT spray (Bacillus Thuringiensis) are two organic options that won’t necessarily kill the adults, but will make your host plants less appetizing.
- Bacillus thuringiensis (Bt) - Store bought spray consisiting of natural soil-borne bacteria
- Spinosad Spray - Natural soil bacteria effective in treating several garden pests
- Organic Neem Oil Spray - 1 tsp neem oil and 1/4 tsp dish soap to 1 quart water
- Castile Soap - 1 tbsp to 1 quart water
- Beauveria bassiana Spray - Natural fungi proven effective in treating many small garden pests
- High Pressure Hose - Many insecticides are sold to be attached to the end of any common gardening hose for immediate control