“Potato bug” refers to at least three completely different creatures depending on where you live: the Jerusalem cricket, the Colorado potato beetle, and the common pillbug (roly-poly). None of them are actually true bugs. The Jerusalem cricket is the one that most often startles people indoors, while the Colorado potato beetle is the one destroying your garden. Here’s how to tell them apart and what to do about each.
Why “Potato Bug” Means Different Things
The name “potato bug” gets applied loosely to several invertebrates, which causes real confusion. In the western United States, people usually mean the Jerusalem cricket, a large, pale, alien-looking insect that lives underground. In farming communities and across the Midwest and East, “potato bug” almost always refers to the Colorado potato beetle, a striped garden pest. And in parts of the UK and some US regions, it’s slang for pillbugs and sowbugs, those small gray armored creatures that curl into a ball when touched.
Knowing which one you’re dealing with matters because they live in completely different ways, eat different things, and call for different responses.
Jerusalem Crickets: The Big, Bald-Headed Ones
If you found a large, intimidating insect under a rock, a flowerpot, or in your garage, you’re probably looking at a Jerusalem cricket. They grow up to about 2 inches long and are immediately recognizable by their bald, round head that looks oddly human, a fat orange abdomen banded with black stripes, long brown antennae, and spiny hind legs. They have no wings.
Despite their common name, Jerusalem crickets aren’t from Jerusalem and aren’t true crickets. They’re native to the western United States and Mexico and are most often spotted in California at night. They spend most of their lives underground, feeding on decaying plant material, roots, and other insects. You’ll rarely see them unless you disturb their hiding spot or they wander indoors after dark.
Sound Production
Jerusalem crickets don’t chirp like regular crickets. Instead, they “drum” by striking the ground repeatedly with their abdomens. Both males and females do this, calling and responding in a duet until they locate each other to mate. The drumming patterns are unique to each species, varying in rate, rhythm, and the intervals between bursts. If you hear a faint, rhythmic tapping from the soil at night, this could be the source.
Can They Bite?
Jerusalem crickets can bite when handled, and their jaws are powerful enough to cut through fabric and thin plastic. The bite causes moderate, short-lived pain but is not dangerous. They are not venomous or poisonous. The best approach is simply not to pick one up with bare hands. If you find one indoors, scoop it into a container and release it outside. They’re harmless to your garden and actually help break down organic matter in the soil.
Colorado Potato Beetles: The Garden Destroyers
The Colorado potato beetle is the one gardeners dread. It’s a small, rounded beetle about half an inch long with distinctive yellow-and-black striped wing covers and an orange head with black spots. It looks nothing like a Jerusalem cricket.
These beetles target potatoes, eggplant, tomatoes, peppers, and other plants in the nightshade family. Both the adults and their larvae (plump, reddish-pink grubs with black spots along their sides) chew through leaves at an alarming rate. A single adult can eat about 10 square centimeters of foliage per day, roughly the area of one and a half playing cards. The largest larvae are the most destructive life stage, moving actively across plants and stripping them bare. Unmanaged infestations can lead to complete defoliation, which directly reduces your harvest.
What makes Colorado potato beetles especially difficult is their resistance to chemical control. They’ve developed resistance to over 50 different insecticides, often within just a few years of a product’s introduction. This is one of the most pesticide-resistant insects on earth.
How to Protect Your Garden From Potato Beetles
For home gardeners, physical removal is the most reliable first line of defense. Start checking for adult beetles in early May after potato plants have emerged. Look on the plants and the surrounding soil. When you find egg clusters on the undersides of leaves (bright orange-yellow, laid in neat rows), crush them with your fingers. Drop adults and larvae into a bucket of soapy water.
Cultural Controls
Crop rotation is one of the most effective long-term strategies. Don’t plant potatoes, tomatoes, eggplant, or peppers in the same spot year after year. This disrupts the beetle’s life cycle because adults overwinter in the soil near the previous season’s plants and emerge in spring expecting food to be right there. Remove old plants and nightshade-family weeds in and around your plot before, during, and after the growing season to eliminate food sources.
Planting an early-maturing potato variety (one that matures in less than 80 days) lets you harvest before the midsummer wave of newly emerged adults hits. Another clever approach is planting a few extra rows of potatoes near where beetles overwinter to act as a “trap crop.” The beetles concentrate there, and you can remove them in one pass rather than hunting across your whole garden.
For small plantings, exclusion cages or row covers physically block beetles from reaching your plants. These work well but can be expensive and impractical for larger gardens.
Biological and Organic Options
A few natural enemies prey on Colorado potato beetles, including predatory stink bugs and a naturally occurring fungus called Beauveria bassiana that kills both larvae and adults. Encouraging beneficial insects by avoiding broad-spectrum pesticides helps maintain these populations.
For organic sprays, products based on bacteria-derived compounds are the most effective. One type works best on very young larvae and needs to be reapplied every few days as eggs hatch. Another option, derived from a different soil bacterium, works on both larvae and adults and lasts 10 to 14 days per application. Plant-based sprays like neem oil and pyrethrin can also help but break down in less than a day and should target small larvae for best results.
Synthetic insecticides remain an option but carry higher risks and, given the beetle’s extraordinary resistance history, may not even work. If you go this route, rotating between different chemical classes is essential to slow resistance development.
Pillbugs and Sowbugs
The third creature sometimes called a “potato bug” is the pillbug or sowbug, those small, gray, armored crustaceans (not insects) you find under logs and in damp garden beds. Pillbugs roll into a tight ball when disturbed; sowbugs can’t. Both feed primarily on decaying organic matter and are generally beneficial to soil health. They occasionally nibble on seedlings or strawberries touching the ground, but they rarely cause meaningful damage. Reducing moisture and removing debris near vulnerable plants is usually enough to keep them in check.