Potato Bugs – Where Are They Found?

The potato bug is a common name for two different insects. They are the Colorado potato beetle and the Jerusalem cricket. Among these two insects, the Colorado potato beetle is the most destructive. Is there a place where they live?

Potato bugs are nocturnal and live underground most of the time. You may find them crawling over the ground or hidden under rocks. They prefer moist areas and manure heaps. Mexico and the western United States are home to potato bugs.

Where Are Potato Bugs Most Common? Are They In The Us?

Thomas Say discovered the Colorado potato beetle in the Rocky Mountains in 1824. It is native to the area between Colorado and northern Mexico. Except for Alaska, California, Hawaii, and Nevada, they occur now in every state. Colorado potato beetles are now a threat to most of Europe and Asia.

The Jerusalem cricket is nocturnal and spends the day beneath the soil surface or under rocks. Despite their scary appearance, they’re harmless and slow-moving. The Jerusalem cricket uses its powerful mandibles to consume dead organic matter. 

The chances of seeing Jerusalem crickets are high at night or in the twilight. Farmers see them often when they turn the soil or after heavy rainfall. The bald, round, humanoid head and the orange abdomen with black rings make them easy to identify.

The potato bug is not poisonous. If Jerusalem cricket bites you, its strong jaws can sink into your skin and cause you to shriek in pain. Potato bugs’ saliva contains toxins that can damage plants.

How Can I Identify The Colorado Potato Beetle (CPB)?

An adult Colorado Potato Beetle (CPB) measures 6-11 mm (about 3/8 inch) long and 3 mm wide. They weigh between 50 and 170 milligrams. 

Mature CPBs are oval-shaped and have a yellow-orange prothorax. There are ten characteristic black stripes on their elytra. 

The CPB females lay yellow to orange eggs in clusters of about 30 on the underside of leaves. A female can lay over 500 eggs within four to five weeks. Eggs hatch into larvae within 4-15 days. 

Larvae are reddish-brown with blackheads. They have two rows of dark brown spots on either side of their humped back. 

The larvae feed on the leaves of their host plants. It develops through four distinct phases called instars. The fourth (last) instars measure about 8 mm (0.31 inch) in length and last 4-7 days. It is during this fourth instar that larvae cause the most damage. This stage accounts for up to 75% of defoliation. 

The fourth instar spends several days as a nonfeeding prepupa. During this period, it is inactive and has a lighter coloration. The prepupae drop into the soil and burrow several inches deep to pupate. The adult beetle emerges within 5 to 10 days. The Colorado potato beetle matures in 21 days. 

In the soil, Colorado potato beetles overwinter as adults. They come out of hibernation in the spring. It may result in three or more generations per growing season. They begin feeding on weeds and potatoes or enter the soil to attack emerging foliage. 

What Is The Difference Between False Potato Beetles And CPB?

It’s possible to confuse the Colorado potato beetle with the false potato beetle. Their appearances are somewhat similar. The false potato beetle (Leptinotarsa juncta) is not an agricultural pest. It has alternating black and white stripes on its back. 

The difference is that each wing cover lacks one of the white strips in the center. Instead, a light brown strip replaces it. False potato beetle larvae are paler (almost white) and have only one row of black spots on either side.

What Attracts Potato Bugs?

Potatoes, roots, and tubers are the main things that attract potato bugs to your garden. It is common to see them around potato or sweet potato plants. Dampness, food sources, shelter, and a favorable breeding ground can attract potato bugs.

How Do Colorado Potato Beetles Damage Plants?

There is a strong association between CPBs and plants in the family Solanaceae. It is particular to the genus Solanum which includes potato, tomato, and eggplant. CPBs also attack pepper, buffalo bur, and tobacco.

Adult beetles and larvae feed on the potato foliage. As a result, they can reduce yields and even cause plants to die. Colorado potato beetles are capable of developing rapid resistance to insecticides. 

The development of resistance is evident when you repeat the same insecticide. They became resistant to DDT in 1952 and dieldrin in 1958. CPBs have developed resistance to all major classes of insecticides as a whole.

Is There A Way To Keep Potato Bugs Away?

Biological or mechanical control is effective since CPBs are resistant to many chemicals. By identifying their lifecycle, you can destroy them at the very beginning. Controlling them at an early stage is more convenient than at maturity.

Look for yellow-orange egg clusters, reddish-brown larvae, and ten-striped adults daily. Pick adult beetles off plants and drop them into a bucket of soapy water. Scrape or crush the eggs off the underside of the leaves. You can put larvae and eggs in the same bucket to destroy them.

Apply sprays containing spinosad or azadirachtin to control beetles in their larval stage. Fermentation of natural soil organisms produces azadirachtin. Apply Spinosad every 10 to 14 days during the larval stage. 

Is Biological Control A Viable Way To Get Rid Of Potato Bugs?

Controlling CPBs by encouraging their natural enemies is an effective strategy. Potato bugs have several natural predators that attack their eggs or larvae. 

Twelve-spotted lady beetle and the ground beetle Lebia grandis prey on the eggs and larvae of CPB. The spined soldier bug and the parasitic tachinid fly Myiopharus doryphorae attack larvae. 

Bacterium Bacillus thuringiensis (BT) produces toxins to kill larvae. Using this bacterial insecticide early in the larval stage will be effective.

Beauveria bassiana is a pathogenic fungus that can infect Colorado potato beetles. The combination with Bacillus thuringiensis (BT) makes it more effective. Beneficial nematodes can attack potato beetles at their immature stages in the soil.

Tansy steam distillate is rich in camphor and umbellules. These chemicals repel the Colorado potato beetle. Apply neem oil as a natural pesticide to deter the potato beetle. This oil can reduce insect feeding and interfere with beetle hormone function.

What Cultural Controls Can We Use To Keep Potato Bugs Away?

Rotating crops can reduce the accumulation of early-season beetle populations. Change potato plants with non-host plants to disrupt the life cycle of potato bugs. 

Mulch the potato crop early in the growing season with straw. As a result, the beetle is less likely to be able to locate potato fields. Mulch creates favorable habitats for predators.

You can plant marigolds, nasturtium, coriander, or tansy alongside potatoes as companion plants. These plants can repel Colorado potato beetles. Controlling potato beetles with traps and flamethrowers is a practical method. Plant early-season potatoes like Caribe, Norland, or Yukon gold. As the season progresses, potato beetle damage gets worse. Consider potatoes resistant to Colorado potato beetles, such as Russet Burbank.