How To Identify Pinworm And Control / Prevent Them On Tomato Plants?

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This is a detailed guide to help you identify and control pinworms on tomato plants.

Let us get started!

What Is Pinworm And How Does It Harms Tomato Plants?

Tomato pinworms (Keiferia lycopersicella) are small nocturnal worms about ¼ inch long. They vary in color and have spots depending on the age of the larva.

Pinworms may attack foliage, stems, and immature and ripe tomato fruits.

Check this video for more information:

How To Confirm That Pinworm Is Troubling Your Tomato Plants?

Inspect the tomato plants for any signs every week. You may notice pinworms mine on the leaves, leaving blotchy spots.

The identifying characteristic of the presence of pinworms is tiny boreholes in the fruit or stem surrounded by a brown zone. It also causes discoloration of the fruit.

Natural Ways To Control Pinworm On Tomato Plants

Monitor your tomato crops to check for tomato pinworm infestation. The different natural ways to control pinworms are the application of neem oil and Bt sprays. You may also try releasing parasitic wasps to reduce pinworm populations.

Let us examine different natural ways in detail.

1. Neem oil

Neem oil is an effective biopesticide and repellent. It helps in controlling pinworms on tomato plants. It is a natural product and 100% biodegradable.

  • Test a small patch– Spray neem oil on a tiny section of plants and observe for 24 hours to check if the leaf has been damaged.
  • Apply on infested plants– Spray the whole infested area. Take care to use neem oil only in indirect light or in the evening. Do not apply to water-stressed tomato plants.

Check out this video on how to use neem oil to control pinworms:

2. Bt Spray

Bacillus thuringiensis is a gram-positive, rod-shaped bacterium that is effective against pinworms. It does not harm other beneficial insects.

  • Prepare Bt spray– Purchase organic Bt and dilute it in water according to the manufacturer’s instructions.
  • Spray the infested plants– You may spray it on the infested plants to kill the pinworm. Apply as soon as the young larvae are detected to effectively control pinworms. Alternatively, you may also dust Bt on the foliage to deter pinworms.

Check out this video on mixing and applying Bt:

3. Biological Control

Several wasps, including Trichogramma wasps and fly parasites, act as a natural control for pinworms in tomato plants.

  • Purchase beneficial wasps– Beneficial wasps and parasites are commercially available in insectaries for augmentative release. Purchase them according to your area.
  • Release beneficial insects– Release these beneficial insects into the tomato garden. They may help in controlling the pinworm population.

Physical Ways To Control Pinworm On Tomato Plants

Hand-removal of the worms and infested leaves may reduce the build-up of population. You may also use light traps to reduce adult populations. Pheromone traps can be set to disrupt mating if you have a larger garden area.

Next, let us discuss the different physical ways to control pinworms in detail.

1. Handpicking

Handpicking is the most non-toxic way of removing pinworms.

  • Inspect for infestations– Observe the tomato foliage for any pinworms.
  • Remove pinworms– Pick any visible worms by hand and crush them. You may also remove brown and curled leaves that may harbor certain pathogens.

2. Light Traps

Tomato pinworm adults may be attracted to lights. So, light traps help in reducing the adulating populations.

  • Choose light traps– Many light traps are commercially available. Choose the one suitable for your tomato garden.
  • Place the light traps– Keep the light trap in the suspected area, and pinworm adults get attracted to these light traps.

Chemical Ways To Control Pinworm On Tomato Plants

The organic pesticides may be helpful if you can spot the pinworms before they enter the tomato fruits. But, they are extremely difficult to control with pesticides once inside the fruit.

The different chemical ways to control pinworms are discussed below.

1. Abamectin

Narrow-spectrum insecticide abamectin can be used to control pinworms in the home garden. One advantage is that it does not accumulate in the environment.

  • Prepare the abamectin– Prepare the abamectin according to the manufacturer’s instructions. Transfer to a spray bottle.
  • Spray the infested plants– Apply on the infected foliage. Reapply as required.

2. Spinosad

Spinosad works on the pinworm’s nervous system and causes death. But, it should be applied in the late evening on tomato plants that are not blooming and pollen-shedding. It is available as powder, granules, and liquid.

  • Prepare spinosad spray– Read the manufacturer’s instructions and dilute the spinosad concentrate.
  • Spray the plants– Shake the spinosad spray well and apply it to the infested area. Apply as soon as you spot the pinworms before they tunnel into the tomato fruits.

Here is a useful video on using spinosad to control pinworms:

How To Prevent Pinworm In Tomato Plants?

End-of-season garden clean-up helps in preventing future pinworm attacks on tomato plants. You may also try anti-insect nets, row covers, and pinworm predators to protect the tomato plants from pinworms.

Method 1- End Of Season Cleanup

The first step in controlling tomato pinworm is practicing end-of-season clean-up.  I prefer to turn the soil deeply to remove any overwintering pupae. Also, clear the garden debris and burn them.

You may also plow under to help reduce the overwintering populations of pinworms.

Method 2- Anti-insect nets

You may place anti-insect nets about 1/5 inch mesh to deter pinworms from attacking tomato plants. Take care to position hoops so that it does not touch any parts of the tomato plants. The nets can be removed once the risk of pinworms is reduced.

Method 3- Encourage Pinworm Predators

Encourage beneficial insects, including Nesibus and Mirical in the tomato garden. They are effective against pinworm eggs and young larvae.

You may also plant carrots, dill, parsley, coriander, and celery with your tomatoes to attract predatory insects.

What Causes Pinworm Attacks In Tomato Plants?

Tomato pinworms are usually found in regions of warmer climates, including Florida, California, and Texas. They can not survive a cold winter. They may also be found in greenhouses.

If the weather is very cold, these worms hide on the dirt floor and come out in summer to attack the plants.

Frequently Asked Questions

Can we use pheromone traps to control pinworm?

The pheromone traps have been used successfully to control pinworms in larger field plantings.  A single trap will work for 10 acres of land to trap moths. But it may be impractical for your backyard gardens.

Is tomato pinworm the same as tomato leaf miners?

No, tomato pinworm is different from tomato leaf miners. Both form blotch-type mines in tomato leaves but the mines of leaf miners are small. They cause similar damage to fruits and is difficult to distinguish the damage. Tomato leaf miners are called South American tomato leaf miners.


Hopefully, this guide has provided valuable information to protect tomato plants from pinworm attacks.

I am interested to hear if you have tried any other method to control pinworms.

Do share the guide with your friends to help them out too!

Know more about various other tomato issues and how to tackle them here>