Cucumber With Holes: What Causes Holes In Cucumbers

Nothing’s more disappointing than cucumbers with holes. What causes holes in cucumber fruit and how can they be prevented? Read on to find out.

What Causes Holes in Cucumbers?

Some cucumbers are almost hollow inside, which is usually due to improper irrigation or a lack of water. However, a cucumber with holes riddling it is most probably due to an insect of some kind.


In my neck of the woods, the Pacific Northwest, the most likely culprit for cucumber holes may be slugs. These guys will eat almost anything and will drill holes through both green and ripe fruit. Sprinkling some slug bait around the plants, however, will likely keep them away from your cucumber plants.

Cucumber Beetles

As the name suggests, cucumber beetles can be very damaging to not only cucumber but other cucurbits such as melons, pumpkins and squash. Cucumber beetles have no preference and will ravage all parts of the plant from foliage to flowers to fruit. They are found throughout the growing season (June-September), but are more likely to cause scarring rather than outright cucumber holes.

Additionally, cucumber beetles transmit bacterial wilt in cucumbers. Bacterial wilt overwinters in the intestines of the pests and is then transmitted from plant to plant as the beetle feeds. Some new varieties of cucurbits have resistance to this disease.

There are several types of cucumber beetle. The spotted cucumber beetle is yellowish green with 11 black dots on its back and a black head with black antennae. The yellow striped cucumber beetle is 1/5-inch (5 mm.) long with three black stripes on the tope wings. Lastly, the banded cucumber beetle has yellowish-green stripes that run across the wings.

Handpicking any of these pests is time consuming but effective. Otherwise, the use of fabric row covers is an effective barrier between the pests and plants. Keep the garden free of weeds so the beetles have fewer places to hide. There are also some predatory insects that may be able to aid in the eradication of the beetles. An application of Neem oil or Pyrethrin can eradicate the pests, as well as a number of chemical pesticides.


Lastly, pickleworms may be the cause of cucumbers with holes. Pickleworms attack most cucurbits — cucumbers, cantaloupes, summer squash and pumpkins may all be severely damaged by the pickleworms’ voracious appetite. Pickleworms aren’t picky and will tunnel through not only fruit, but flowers, buds and stems. Damaged fruit is not edible.

In warmer regions, pickleworms overwinter while in colder areas, the pests freeze during the winter. They go through a complete cycle of egg, larva, pupa and adult. Eggs are irregular in shape and look something like grains of sand. They are laid on leaves in small batches and hatch in three to four days.

The resulting larvae feed on buds, blossoms and tender foliage before they begin on fruit. These brown headed caterpillars molt four times. At the last molt, the caterpillar loses its reddish-brown spots and becomes entirely green or copper in color. It then stops feeding and spins a cocoon to pupate. Pupae are usually found in a curled or rolled leaf and emerge as adults in seven to 10 days as brownish-yellow moths with a hint of purple.

Choose early maturing varieties and plant as soon as possible before the pickleworm population explodes. To control the populations, also destroy any damaged fruit and squash any rolled sections of leaves that contain pupae. Some less toxic or natural controls include Bacillus thuringiensis, Pyrethrin, Neem oil extract and Spinosad as well as other chemical pesticides.

8 Common Cucumber Pests To Watch Out For

Bethany Hayes

Bethany is a suburban homesteader who grows over 30 types of vegetables in her garden every year to provide the vegetables needed to feed her family of six for the entire year. She practices organic gardening without the use of any pesticide and chemical.

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Cucumbers are one of the best summer veggie crops because they’re easy to grow, versatile, and delicious. Cucumber plants produce heavy yields, but even the most seasoned gardener may encounter pests, impacting the harvest.

Cucumber pests can cause serious damage to your plants, not only reducing the yield, but potentially killing the plants. That’s why it’s important to know the pests that you might face and how to deal with them.

Here are the most common to keep an eye out for.

Bacterial Wilt

The main symptom of this disease is severe wilting of the vines, followed by rapid death of the plant. The disease is caused by the bacterium Erwinia tracheiphila, and at first may only affect a few vines on a plant. However, as the disease progresses, more leaves wilt, and eventually the entire vine is affected. Bacterial wilt is most severe on cucumber and cantaloupe and less severe on squash, pumpkin and watermelon.

Prevention & Treatment: There is no chemical control for bacterial wilt once plants become infected. The bacteria are carried from plant to plant by striped or spotted cucumber beetles. The beetles spread the wilt bacterium by feeding on infected vines and then feeding on healthy plants.

Bacterial wilt can be reduced in your garden if the beetles are kept under control at the first sign of activity. Insecticides that control striped and spotted cucumber beetles in the home vegetable garden include carbaryl, bifenthrin, cyhalothrin or cyfluthrin. Bees pollinate many of these vegetables, so spray all insecticides in the late afternoon. Apply all chemicals according to directions on the label.

Identifying Cucumber Beetle’s Damage

Plants Affected

Cucumber beetles usually feed on the flowers, pollen, and foliage of its host plant. They are common in plants from the Cucurbit family, which include cucumber, squash, melon, gourds, zucchini, and pumpkin, among others. They also feast on corn, asparagus, and beans.


The following are some of the signs that cucumber beetles are present in the garden or in the host plant:

  • The leaves will show the biggest evidence of the damage from cucumber beetles. You will see holes on the surface. This causes a deficiency in the nutrients that the plant requires for survival. Therefore, it leads to the discoloration of leaves. From green, they will turn to yellow.
  • Plant stunting is also a common symptom. In case you are unfamiliar, this is a condition wherein the plant does not grow fully. It appears smaller than the usual. The leaves will also appear sickly, which is evident in color and vigor.
  • There are also some parts that will look like they have been chewed. This is especially common in the roots of the host plant. Young shoots are also vulnerable to this damage.
  • Cucumber plant beetles also affect the fruit of the plant. In most cases, if the infestation is severe, the crop will look unattractive and no longer fit for consumption.

Results of Infestation

Like in the case of other pests, the damages from cucumber beetles can be devastating. When they feed on young plants, the latter will no longer reach maturity. If they are standing in an upright position, after infestation, they will wilt and fall.

The most obvious from the results of the infestation caused by the pest is bacterial wilt. They will chew on the leaves of the plant and this is the start of spreading damage to the rest of the plant. The bacteria will also quickly multiply, and hence, amplifying the damage that it brings. It damages the vascular system and can also attract other pests that can worsen the problem.

The Cucumber Beetle Spreads Bacterial Wilt from Infected to Healthy Plants

What are the plants to grow with cucumber?

In many cases, the major crop will need other crops to serve as weed controllers, but in this case, the cucumber plant itself is a weed control plant.

The advantages of planting other crops with cucumber are numerous.

But then, there are crops that are necessary for cucumber to blossom.

These crops are mentioned below:

1. Radish:

One of the major characteristics of the radish plant is that it is a natural repellent.

When planted with cucumber, it repels the cucumber beetles, thereby keeping your plant free from bacteria wilt.

2. Marigold:

This is a powerful flower that is known for its ability to repel beetles with its fragrance.

Aside from beetles, it is also a good plant that fights nematodes in the soil.

3. Nasturtium:

This flower can confidently repel aphids, cucumber beetles and some other pests that attack your cucumber.

It also does not compete with cucumber for necessities.

The growth of cucumber is boosted when planted with nasturtium.

Also, it helps to make the cucumber taste better.

4. Dill:

One crop that is also important on your farm is Dill.

Dill is a beneficial attractant.

This feature is unique because it is able to attract beneficial pests that help fight off harmful pests.

Aside from this, Dill can also improve the taste of cucumber.

5. Corn:

The vines of cucumber can use the corn stalks as trellises.

It is one great companion for cucumber because it is also a plant that does not need to be in a really cold environment.

In addition, the root of the corn has the ability to increase the level of nitrogen in the soil.

6. Sunflower:

It might be surprising for you to know that sunflowers can also serve as trellises for your cucumber.

Aside from that, its beautiful coloured petals attract pollinating insects to your cucumber.

Of course, you know that your cucumber needs those insects for reproduction.

7. Beans:

Aa a leguminous crop, the root system of beans will provide and increase the nitrogen in the soil.

Remember that pole beans will also need trellises.

Getting on trellises for both beans and cucumber can be very beneficial to both plants.

8. Peas:

Another legume that is needed to be planted with cucumber is peas.

Just like beans, it can help provide, fix and increase nitrogen needed in the soil for healthy growth.

9. Lettuce:

This vegetable plant is one that can be easily grown.

Growing alongside cucumber is not an exception.

Both plants can comfortably grow side-by-side.

10. Tansy:

This plant helps cucumbers to fight against ants, cucumber beetles and whiteflies.

11. Oregano:

This is a herb that is a very good repellent against pests of cucumber.

Common pests and diseases: Cucumbers

When growing vegetables, it is always exciting to care for the plant throughout its growing phase and then harvest it for delicious recipes later on, but one thing to watch out for is pests and diseases. Different plants are susceptible to different types of pests and diseases, and it is important to make yourself aware so you can keep a watchful eye and also take any preventative methods to keep your plants safe throughout their lifespan.

Cucumbers can fall victim to several different pests and diseases.


Insects affecting cucumber plants include aphids, cabbage loopers and cucumber beetles.

Aphids are soft-bodied insects that bring problems to lots of plants. They create discoloration of any leaves, necrotic spots and stunted growth. Use tolerant varieties and only apply insecticides if there’s a high infestation.

Cabbage loopers are pale green and will extensively damage the leaves by creating large holes. Handpick the larvae off plants, or encourage beneficial insects and birds in your garden. Apply Bacillus thuringiensis to kill the younger larvae.

Cucumber beetles are spotted yellow beetles that cause stunted seedlings and damaged leaves, as well as plants exhibiting signs of bacterial wilt, and scars the cucumbers. These beetles will overwinter in the soil. To prevent them, use floating row covers, apply kaolin clay and if necessary, use an insecticide.


Diseases that can affect cucumbers include Alternaria leaf blight, anthracnose, belly rot, cucumber wilt and cucumber mosaic.

Alternaria leaf blight creates yellow-brown spots with a halo which appears on older leaves first. Leaves will curl and die. This disease often occurs in hot areas with frequent rainfall. To prevent it, rotate your cucumbers and other curcubit plants every two years and remove crop debris as soon as possible.

Anthracnose creates lesions on leaves, stems and the fruit. This disease prefers warm temperatures. To prevent it, plant resistant varieties and apply fungicides, as well as utilize crop rotation.

Belly rot creates discoloration on the fruit and brown mold on the rotting areas. It will cause cucumber seedlings to collapse. It prefers warm and humid conditions. To prevent this disease, till the soil prior to planting and use a plastic mulch around the plants. Use a site with good drainage and apply fungicides when plants start to vine.

Cucumber wilt will rot the seedling stems at the soil, and it will create lesions and discoloration. It favors warm and moist soil. To prevent this, plant seeds treated with a fungicide and rotate crops frequently.

Cucumber mosaic will stunt the plants severely, and the foliage will become covered in a yellow mosaic. The leaves curl down, and the leaves will be small. Fruits will be distorted and small and discolored. To prevent this, deter aphids feeding and treat aphids if they appear.

Cucumber Beetles

Have you ever walked through your garden in the morning in complete happiness only to discover that there are a few tiny holes in one of your cucumber leaves? You tell your yourself "Hey, its just a few holes, no big deal" and keep walking. Then, the evening comes and somehow those few tiny holes have become hundreds of tiny holes and they are on 3 or 4 leaves now? This article will tell you all about the nasty garden pest causing those holes and will give you some helpful suggestions on how to deal with them.

What are Cucumber Beetles?

Cucumber beetles (Acalymma Vittata) are about 1/4" long with a yellow body and 3 black stripes. The adults will chew the leaves, blossoms and seedlings of cucurbits. The Larvae will feed on the roots of plants underground and any fruit laying on the soil. In my part of Ontario they are able to survive the winter.

Life Cycle

The adult cucumber beetle can overwinter in garden debris and weedy areas. They will emerge in the spring to make and lay their eggs in soil or on plants. The larvae burrow into the soil and feed off of the plants roots for a few weeks. During this time, the adults will feast away at the leaves of cucurbits. Curcurbits is the family name for gourds and includes cucumbers, melons, pumpkins and squash. There is only 1 new generation of beetles per year, but they dont all emerge and reproduce at the same time so it may seem like there are more.

Why are Cucumber Beetles a Pest?

Here in Zone 5B/6 the best time to get your cucumber seeds into the ground just happens to be the time the adult beetles "wake up." Young seedlings are especially suseptible to the damage from the beetles because they are not strong or big enough yet to survive the leaf damage.

But hold on! Dont get too excited yet. I know what you are thinking. You are thinking that you dont have to worry because you bought some cucumber plants or you grew some indoors from seed earlier. You are thinking that your 1 month old plants will survive and you have nothing to worry about. Well my friend, YOU ARE WRONG!

Cucumber Beetles can also transmit bacterial wilt and cucumber mosiac virus. They pick these up from weeds and other plants that they feed on and then pass it on to your beautiful healthy plants. Once your plants have been infected all you can do is pull the whole plant to prevent the spread.

How To Control Cucumber Beetles

If you have read any of my other articles you will know that I choose not to use any pesticides or chemicals in my gardens. I will also never use any method of control that will harm any other beneficial insect. I will start off by telling you about some insect friendly methods.

#1 Till Your Garden In The Late Fall

This exposes the hidden beetles to the colder winter conditions. This will help reduce the population of adults that will reproduce next year. Also remove any garden debris after harvest is finished. These garden debris are important for other over wintering insects, you can carefully move them to a part of your yard that is away from your planting area.

#2 Add Plants That Repel Cucumber Beetles

This is essentially companion planting. Many flowers and herbs do a wonderful job at controlling pests and improving the flavors and taste of vegetable plants. Plants that are useful against cucumber beetles include tansy, catnip, marigolds, nasturtium, calendula. I always have marigolds and nasturtiums between any plants suseptible to pest damage.

#3 Practice Crop Roation

Simply put, this just means never planting similar plants in the same place next year. Some people even wait 2 years to replant. This prevents pests and diseases from building up. It also helps to keep the soil nutrients balanced.

#4 Grow Resistant Varieties

When you are picking out plants or seeds look for varieties that are resistant to bacterial wilt and cucumber mosiac virus. Research through the winter and ask long time gardeners for their opinions on the best kinds to grow. This will not guarantee that you will never get a cucumber beetle, but you will have less chance of your plant dying from a disease caused by them.

#5 Hold Off For A Few Weeks

If you know that a certain area plagued you last year just try planting later. By holding off for a few more weeks the cucumber beetles will have to look elsewhere for a food source.

#6 Use Floating Row Covers

I have never tried this personally but it seems simple enough. Check under the covers often and pull off any beetles. Also check under the leaves for eggs. Make sure to remove the covers when the plant flowers so the pollinators can do their jobs.

#7 PIck Them Off By Hand

You can use a rigged up dust buster to suck them up or just pick them off by hand and throw them in a bucket of soapy water. I have even heard of people wearing yellow gloves slathered in vaseline to pick them off.

#8 Plant A Trap Crop

Try planting blue hubbard squash at the edge of the garden, this will draw the cucumber beetles to feed off of it, hopefully leaving your other plants alone. For every 5 or 6 trap crop plants you could potentially save 75 other plants.

Are You Looking For More Ways To Control Cucumber Beetles?

*** Please note that these could potentially harm beneficial insects as well***

#1- Yellow Bowls of Soapy Water.

These are highly effective but will also trap insects that could be preying on the beetles (soldier beetles and braconid wasps). Nestle bowls of soapy water into the soil with the rim about 1/4'' above the soil level.

#2- Organic Neem Oil

Neem oil is a common natural insecticide. You can buy this as a spray to use on the leaves and the soil around the plant. This will kill the beetles as well as their eggs on contact.

#3- DE (diatomaceous earth)

Diatomaceous earth can be sprinkled over the plant and soil, this will need to be re-applied after rain.

*** A quick note about yellow sticky traps: Although the yellow sticky traps are smaller than white rodent glue traps please re-consider the use of glue traps. Chipmunks, mice, birds, etc can find their way onto these and become hopelessly stuck, dehydrated, starved to death or they die from injuries from trying to free themselves. As you can see above, there are many other friendly ways to rid yourself of pests.

Final Thoughts

While I find it very upsetting to lose plants that I worked so hard to take care of, I understand that we share these spaces with other animals and insects. If you want to spray and powder your whole garden to prevent 1 pest, you will lose so many other wonderful insects. By adding in the companion herbs and flowers you not only get a beautiful looking garden, you get free pest control. You will start to see more butterflies and bees visiting your plants, you will add diversity to your gardens and you will learn to appreciate nature more. Each year gardeners face obstacles, there will never be a year when everything is perfect.

So far this year in Southern Ontario we have had a milder winter, a cooler spring, and now a hotter and drier summer. The pests are out of control and the squirrels and chipmunks are a menace. This has led many new gardeners to become discouraged, but just think of all the new things you are learning all at once instead of over many seasons. All of these problems will slowly melt away once you start eating those juicy cucumbers and summer squash, and you will tell yourself it was all worth it in the end.

Watch the video: How to Identify u0026 Control Common Garden Pests by Leaf Signatures

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