Potato Bug

Potato Bug

If you’ve seen strange bugs in your crops or garden, and somebody said that they are potato bugs, what you immediately want to know is how to get rid of them once and for all.

You also want to know how these pests look like for quick identification in a future encounter with them, and also the types these creatures have.

Are they harmful to people? This is also an important question to tackle. 

Potato Bug

Potato bugs are harmful to your potato plants. I saw them first in my own garden last year, and when I saw them and the destruction they were making, I immediately searched for information about them on the internet.

What I learned is that they come in two types. So, we have the Jerusalem type and the Colorado type. Those names do not imply places of origin.

The type that I hate so much is the Colorado type, which is the one that decimated my prized potato plants. We were left with a meager potato harvest after the infestation. Their larvae are gross-looking and touching them is really disgusting.

I learned also about the way that the insects were used during the Cold War against East Germany. Apparently, American planes hover over the fields of that country and dropped potato beetles on them.

Potatoes were the main thing people had to eat in East Germany during this time, so people were shocked to learn that their food supply was under threat. This event supposedly took place in the 1950s.

One larva of these pests can consume 40 sq. cm. of potato leaf per day. One female bug can lay 800 eggs in its lifetime.

These beetles spread to Asia and Europe via importation from the US in the latter part of the 19th century and the early part of the 20th century.

Facts About Potato Bugs

For quick identification and how potato bugs affect potato gardens and other crops, here are details to know specifically for these insects.


I have mentioned above the gross appearance of the insect’s larvae, but I can also say that the adult bug insect is equally hair-raising in its appearance.

In particular, with the Jerusalem cricket, the features that really stand out are the big jaw, along with the head that looks like a human head with a size that is disproportionate to the body. The head is way too big in comparison to the size of the body.

Overall, these insects can grow up to a length of two and a half inches, which is quite enormous compared to Colorado’s largest growth of up to only 0.375 inches long.

The Jerusalem insect has legs, thorax, and head typically with an amber-yellow color. On the abdominal part of the insect, you will see brown and black bands. Their legs are spiny, allowing them to easily dig soil using their spiky extremities.

Colorado is small in size and has an oval-shaped body with ten vertical stripes at the back. They have wings with a yellow-orange hue.

Taxonomy and Classification

The Colorado potato beetle (Leptinotarsa decemlineata) was discovered by Thomas Nuttall in 1811. Full description of the insect was given by Thomas Say, an American entomologist, in 1824. One of the founders of the Academy of Natural Sciences in Philadelphia, Thomas Say was also a herpetologist and a conchologist.

The Colorado beetles were collected at the Rocky Mountains where they were found feeding themselves with buffalo bur. The genus Leptinotarsa assigned to the Colorado beetle is shared by the other five species, namely, Doryphora, Calligrapha, Zygogramma, Labidomera, and Proseicela.

The Jerusalem cricket (Stenopelmatus fuscus), on the other hand, is one of the 20 species described under the genus Stenopelmatus. There are at least 30 more species that are not yet described under the genus.

The family to which the genus belongs is called Stenopelmatidae. It contains several genera, but only the subfamily of Stenopelmatinae is referred to as Jerusalem crickets.

The inclusion of the word Jerusalem is attributed to some folk legends. One of them has something to do with the Navajo belief system and indoctrination of the natives into Christianity by Catholic priests. Jesus, the Savior of humanity according to Christianity, was somehow compared to the bug’s humanlike face and head.

The second folk explanation is that the word Jerusalem was used as a swear word in the 19th century. The word when uttered during that time shows that someone is surprised or alarmed.

When people back then saw the bug for the first time, they would say “Jerusalem”, so, that word eventually became synonymous to the insect. 

Life Cycle

Potato Bug Life Cycle

For the Colorado beetle, the eggs hatch within five days, and the larva when it comes out will feed on the host plant. There are four larval stages for this insect that will last for 21 days, after which the larva falls to the ground for a pupation stage that will take 10 to 15 more days. In total, that is about 40 days of bodily changes until the insect reaches adulthood.

That kind of life cycle the Colorado beetle has is hugely different from what the Jerusalem cricket experiences, which primarily involves molting or what we call the ecdysis process that snakes exhibit.

The species take one year and nine months to fully develop from egg hatch to maturity. In some climates, it can take up to three years for it to fully mature. Basically, there are three life stages involved – egg, nymph, and adult.

As they feed and mature, Jerusalem crickets outgrow their skin, then grow a new layer of skin and shed the old skin, which is what we have already referred to as the molting process.

This process is repeated for about a dozen times within the insect’s lifetime. After the skin is shed, the nymphs eat the cast skin to recycle its mineral content.

Female Jerusalem crickets oviposit their eggs into the soil a few inches deep, and young nymphs are usually seen in the fall. You may also see nymphs during spring, but not as many as the ones that you see during the fall season.

In looking for a mate, the female strikes their abdomen on the ground, a behavior called drumming. This produces soil vibrations that can reach a possible mate nearby.

After consummation of sexual union, the female cricket kills her partner.


Potato bugs generally eat organic materials. Contrary to what the name is suggesting, these insects don’t really prefer eating just potato plant parts. Other tubers, roots, and crops are also eaten by these insects. Tomatoes, pepper, and eggplants are some of the food items they eat.

Bite and Toxicity

Both the Colorado and the Jerusalem types are not carriers of any diseases and when they bite, they don’t release venomous substances, although the bite can really be painful, especially if inflicted by a Jerusalem cricket.

When bitten by this cricket, you may have flu-like symptoms, skin rash, and sores on the affected area. 


Before 1820, the Colorado potato beetle was already exposed to potatoes, but it was only in 1859 that a major infestation involving the insect occurred. Serious damage was observed in potato fields west of Nebraska.

In Colorado, the first severe damage was reported in 1874. However, a considerable population of the beetles in Colorado was already observed ten years earlier. This eventually resulted in the inclusion of the word “Colorado” in the generally accepted common name.

These beetles are now considered to be the worst insect potato defoliator. Both larvae and adults devour whole leaves without exhibiting a preference for specific leaf parts. During the adult stage, a single beetle can consume 10 square centimeters of potato foliage per day.

Once the foliage is completely consumed, the insects will turn to the remaining exposed tubers and stems for food.

Large infestations involving Jerusalem crickets are quite rare. They do not infest or reproduce indoors, so the rate of reproduction is limited.

Jerusalem cricket infestations have high moisture requirements. As such, they are most active in the wet seasons of fall and spring. During summer, they burrow deep down into the soil and only occasionally climb up to the surface at night. 

Types of Potato Bugs

Here we add some more information and the differences characteristic of these bugs.

Jerusalem Cricket

Potato Bug

The Jerusalem potato bug is a wingless insect that can give a painful sting when handled roughly. Wikipedia reports that the insect is neither a true cricket nor a true bug.

Here in America, the parts where they are usually found are the western sections of the country. The bug is also found in Mexico.

In the daytime, one usually does not see these insects, but at night, they come out from the ground where they live in search of mates or food. If you want to see them in the daytime, go to damp places such as woodpiles or tree barks lying on the ground. 

Colorado Potato Beetle

Colorado Potato Beetle

The Colorado potato bug is an insect pest of the Solanaceae family of flowering plants. According to Wikipedia, the Colorado bug is also called a ten-striped spearman and ten-lined potato beetle for the ten stripes that it has on its back.

This insect does not eat potato, but once they found their way to a potato garden, they will wreak havoc by consuming the plant’s roots and leaves.

The Colorado potato bug is found not only in Colorado but also in many areas across the US and also in Mexico. These are the worst pests in potato gardens, according to plant growers, and since they already have built immunity against many of the insecticides available, farmers have a difficult time annihilating them.

Rolly Polly

Rolly Polly

There is another type which people also refer to as potato bugs. It is called the rolly polly pill bug, a name that suits perfectly for this insect for its ability to straighten its body out and also close it up to create a ball-like form.

Rolly polly does not bite, is also not poisonous, and also does not carry diseases. However, because they feed on the plant’s roots, they can do damage to your garden, and that is why they are also considered as pest.

The rolly polly insect is actually more related to the family of crabs and lobster, so in that sense, they are considered as crustaceans. Places where they are usually found are decaying garbage piles and mulch.

How to Recognize Potato Bug Damage

Once these bugs found their way to your potato garden, signs of infestations start at the tastiest and the most tender parts of the plant. Some of the most relishing items for them are those that belong to the solanaceous family of plants and also those belonging to the nightshade family.

For potato plants, you check first the flower buds, because these are the tastiest parts of the plant for them. After the bud has been consumed, the next target is the leaves. For the Colorado beetles, eggs are orange in color and can be found on the undersides of leaves. 

Potato Bug Damage

How to Prevent and Control Potato Bugs

Crop diversity is one way to avoid these bugs from staying and continuously causing damage in your gardens. Thus, avoid monocropping. If you only have tomatoes there, you are creating an irresistible situation for these bugs where they can happily live and multiply. The same is likely to happen if you only have potatoes there.

Study the seasonal patterns and rotate your crops accordingly. Potato bugs overwinter in the soil and appear at the same time that potato vegetation also appears. Rotating your crops allows starvation of potato bugs in certain months of the year, thus preventing quick infestation and easy management of pest control.

Along with crop rotation, you can also use beneficial fauna in your garden. You can have ground beetles, ladybugs, and wasps to a form a natural competition against potato bug eggs and larvae and adult potato beetles and crickets. 

Jerusalem Cricket

In particular for the Jerusalem cricket:

  • Remove rocks and piles that serve as their hiding spots.
  • Moisture is essential for these insects to live. Keep spaces dry. If it is possible to do, create pathways of concrete as these insects hate walking across dry areas.
  • Don’t overwater your plants.
  • Place sticky traps on the walls or areas where you have spotted them. 

Colorado Potato Beetle

And for the Colorado beetle:

  • Use natural predators. Aside from other types of beetles and wasps, toads and birds are good predators of the Colorado potato beetle. Better yet if you have chickens and geese. Success in control and prevention using chickens and geese has long been documented.
  • In the early morning, shake parts of the plants and capture the larvae with a piece of cloth. Dump them all into soapy water.
  • The movement of overwintering adults can also be impeded. Use mulch as deep as 3 inches for this purpose.
  • Organic pesticides can help for control and management, but when you use this approach, it will affect the environmental conditions of your garden and even kill the natural enemies of the pest you want to control.

Strict monitoring may be needed and treatment may be recommended in certain conditions.

Here are the thresholds for considering a treatment:

  • You observed at least 10% defoliation. 
  • For adults: You have counted 25 or more adults per 50 plants.
  • Small larvae: At least 4 larvae per plant
  • Large larvae: At 1.5 per plant (computation is based on 50 plants)

It has been shown that for rotated fields, damage by adult potato bugs is minimal or insignificant, so you can really consider crop rotation as a means to ensure high yield. Potatoes can tolerate up to 20% defoliation without significantly affecting yield. 

How to Get Rid of Potato Bugs in Your Garden

Potato Bug Control

Basically, you do 4 steps – identification, inspection, treatment, and prevention. They are already there intending to decimate your garden the way they decimated my potato crops.


You start with identification if the bugs are really potato bugs and not something else. So, get hold of one of the insects you see and check if there are black stripes at their back. You should be able to count ten stripes running from the top of the back to the base.

The mature ones can be identified with the color of their head, which is different when they were still larvae. For mature beetles, the head is pink or salmon color. For younger ones, it is black. Both mature and young beetles have that characteristic ten lines running along the back.

The Jerusalem cricket is far easier to identify. Jerusalem crickets are flightless creatures that grows up to two and a half inches in length. They can’t fly, but they can move around by hopping.

Their body color is yellow to brown, with large heads and black eyes. Looking from the front side of the insect, the head appears to be smaller.

You can also identify them with the unique sound they make, which is different from those of field and house crickets. What you can hear from these insects are sounds comparable to hissing or scratching.


Once you have confirmed potato bug infestation is taking place in your garden, you can now proceed to the inspection phase, which is where you determine the areas where there is much potato bug activity. This is where you start the application of pesticide treatment.

If there are multiple varieties of crops currently being grown, you need to search out for these insects in other varieties. They also feed in other plants such as tomatoes, peppers and eggplants, and many more. 


Apply quick treatment, using a combination of these methods:

  • Apply neem oil, an oil obtained from neem trees. You put this oil on parts of the plants infected with the potato bugs. Commercial neem oil is sold as an insecticide, but this is not the type that harms people’s health or the environment. 
  • Hand-picking those bugs can also help but may take a long time to produce results. If this method is used, prepare a bucket of soapy water where you will throw the bugs to drown them.
  • Vacuum. There are special bug vacuum units specially created for pest control. You may also use the vacuum unit you’re currently using for cleaning your home. 


Prevention is key to pest control management. Some preventative measures to apply include:

  • Clean, clean, clean – that is the mantra. Even just a dry leaf on the ground can serve as a place to live for these insects. The idea is to deprive them of a place conducive for them to grow and multiply.
  • Keep the surrounding dry. Zero moisture means not giving plant pests the chance to gain any foothold.
  • Expert consultation – Get expert advice for prevention, and advice that is specifically situated to your needs and conditions. There are several factors to consider, such as climate, types of soil, kinds of crops that can be used for prevention, etc. An experienced gardener can help you a lot.


Not all bugs are harmful to potato gardens. Even potato bugs bring benefits to the garden system, such as killing other harmful pests and even soil aeration. However, they can’t resist the urge to munch on the parts of your potato plants, so there is really a need to prevent them from infesting your potatoes and even apply drastic measures to completely annihilate them.

In this work, I have presented the things that you can do to identify if it is indeed potato bugs that you see there in your garden, some interesting facts about these creatures, and things to do to make sure you will never, ever see them again. 

Frequently Asked Questions

Are potato bugs poisonous?

The simple answer is no. They do release some chemicals when biting a person, but that is not poisonous. It’s only that the bite can be really painful.

Are potato bugs dangerous to humans?

Again, no. There is no harm to people as they are not carriers of diseases or release toxic substances when biting.

What is the best spray for potato bugs?

When choosing a spray for these bugs, always think about safety and protection to human health and the environment. You can always consult with experts on getting the right spray to use in your potato garden.

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