Black Worms on Tomato Plants

Black worms on tomato plants are pests that will really stress the hell out of you. One day, you are just strolling around your tomato garden. You are admiring the hard work you have done to maintain it each and every day. At the same time, the tomatoes are seeming healthy. It looks like everything is working just fine. It’s until you take one step closer and see something odd in the leaves of your tomato plants. You look around and some tomato fruits have weird things on them too. All of those are too subtle that you can’t really notice them through a quick, first glance.

Later on, you realize that the culprit are black worms. These black worms on tomato plants need to be gone fast for they can cause massive destruction. In addition to this, the destruction that they can do is like the domino effect. Once it’s done, it’s going to spread. Before it’s too late, take the necessary actions.

The first step to fight pests like these is to be informed about them in the first place. Today, this blog will teach you about the most common black worms on tomato plants that you must look out for. Also, you will know the preventive as well as controlling measures to combat these pests. So make sure to stick around!


There are a variety of pests that tomato plants are combating each and every day. One of them are the black worms that are also consisting of numerous kinds or types. Some of them are straight black. On the other hand, others of them are a combination of colors, but black is still the dominant color that you will see.

Enumerated here are the black worms on tomato plants that are the most common of their kind. These are the pests that gardeners and/or farmers are most likely to encounter in their tomato garden. Beware of these pests because they can definitely cause havoc to your plants or crops. Practice certain measures to prevent them in the first place. However, if they are already infecting your tomatoes, eliminate them as soon as possible.


These pests with the scientific name Helicoverpa zea are also called as corn earworms and cotton bollworms. They have black spots or pale stripes, and they are hairy as well. At the same time, their color ranges from cream, yellow, green, reddish, or brown. Moreover, they can grow from about 1 ½ to 2 inches long.

When they are still eggs and about the size of a pinhead, they are white or cream-colored. Additionally, they are also slightly flat, spherical in shape, and will further develop brown or reddish stripes before hatching. Moreover, as they enter the larva stage, they resemble the likeness of a caterpillar. They are indeed light-colored with either brown or dark-colored head as well as dark hairs. They also feed on leaves and fruits. After this stage comes the pupa phase where they are brown in colored. They also overwinter in the soil, around in the top 2 to 3 inches.

Tomato fruitworm earworm insect caterpillar larvae stage | Flickr
Photo credits: C Watts/ Flickr

Then finally comes the adult stage. In this final phase, they become tan or brown-colored moths with a single dark spot in the center of each of their wing. Their wings also reach from around 1 to 1 ¼ inches. Furthermore, they appear during springtime and will absolutely lay eggs on tomato leaves. From there, the cycle repeats itself.

Take note that tomato fruitworms in their larva stage like green tomatoes a lot! What they will do is enter a tomato through the stem end. In addition to this, their entry hole will be up to the size of a pea. As they work their way through the fruit, they will drive away other fruitworms. They like the fruit where they are in to be their own. Clearly, sharing isn’t in their vocabulary. No one can definitely stop them even if that means that they will eat each other out. Furthermore, they will finish growing inside the tomato unless it’s too small that they need to transfer from one to another. On the other hand, when these pests are already adults, they will lay eggs around the nighttime.

How do you know if your tomato plant is pest-ridden with tomato fruitworms? You can already suspect if the tomatoes are ripening faster than their normal pace.

Now, how can you control these pests in the first place? There are various ways to drive them away early on since combating them when they are already inside the tomato is just a pointless endeavor.  

This one is a microbial biological control against fruitworms. Additionally, you can choose from its varieties such as the liquid, powder, or granules kind. Put them during the afternoon or evening since it will break down at daytime due to the UV light.

Remember to apply them as soon as you suspect that there are fruitworms in your tomato plant. When they ingest the chemical, they will definitely be paralyzed until they die.


These oils such as the neem oil and insecticidal soaps can be applied once a week as well as after raining.


Look for other insecticides that may help with your fruitworms problems. There are certainly powerful and effective ones out there in the market today.


These pests with the scientific name Keiferia lycopersicella were first attributed as the eggplant leafminer. Then they were later redescribed as new species. Moreover, they are usually found in warm places.

When they are still eggs, these pinworms are tiny and elliptical in shape. Additionally, their color ranges from light yellow to orange. They are also deposited in small groups of around 3 to 7 on both the upper and lower surfaces of leaves. As they enter their larva stage, they are still small but are already yellowish-gray and with a brown head.  Moreover, as they grow, they reach to about 1/3 inches in length. At the same time, their color changes to mottled orange-brown and then into purplish black. Next is the pupa phase where they reach to about 1/5 inches in length and turn from green to brown. Then finally comes the adult stage where they transform into small grayish moths with wings of about ½ inches in length.

Take note that larvae tunnel into leaves by making blotch-type mines. Then they will feed on the leaves. The larvae may also enter the tomato fruit through the calyx then create dry burrows. Moreover, mature larvae will drop to the soil on a silk thread, spin a loosely woven cell, and pupate. Bear in mind that four to five generations of these pinworms are possible to be produced in just a year.

How do you know if your tomato plant is pest-ridden with tomato pinworms? First, know that these pests are certainly very hard to detect until they are feeding long enough. And when they do so, there will be a shallow web covering produced by young larvae. Additionally, they will create narrow straight or serpentine mines as they make their way onto the leaves. At the same time, there will also be frass or insect poop at the entrance of those mines. Moreover, there will be visible blotch mines next to leaf folds. Also, there will be frass at the edge of the tomato fruit’s calyx.

Now, how can you control these pests in the first place? There are various ways to drive them away early on since combating them when they are already inside the tomato is just a pointless endeavor.


This one is simply a microbial biological control against pinworms. There are parasites that can definitely help in eliminating pinworms such as the Sympiesis stigmatipennis andthe Parahormius pallidipes,


This entails you to eliminate crop residues by either burning or plowing-under which will definitely remove huge populations of pinworms. Moreover, shred and disc crop residues as soon as harvesting is done. You can also opt for crop rotation as well as removing of weeds. Additionally, check transplants because they are a potential source of infestation as well.


Pheromone mating disruption can be done in isolated fields or in areas where all tomato plants are treated. Here, you will be using mating disruptant products and other chemicals such as abamectin, methoxyfenozide, chlorantraniliprole, emamectin benzoate, indoxacarb, esfenvalerate, or methomyl. Remember to read the instructions carefully, so you know what to do and everything will be safe.


These pests have achieved their name because of their nature to travel in small insect armies. Note that there are different kinds of armyworms. Moreover, each has their own way of destroying tomato plants and many other crops in general.

There are actually three kinds of armyworms: Western Yellowstriped Armyworm, Yellowstriped Armyworm, and Beet Armyworm. The Western Yellowstriped Armyworm has bright yellow stripes down its sides. At the same time, females of this kind of armyworm lay eggs covered by a cottony-type material. On the other hand, the Yellowstriped Armyworm has two large yellow stripes as well as many smaller ones. Lastly, the Beet Armyworm is pale green-colored and has light colored stripes throughout its entire body. At the same time, females of this kind of armyworm lay eggs covered by hair-like scales.

Eggs of these pests are laid on leaves of older tomato plants. Moreover, take note that they have noticeable stripes throughout their whole body when they are in their late larva stage. In addition to this, they become mottled moths and gray-colored as soon as they enter their adult phase. They will also have wings that reaches to about 1 to 1 ½ inch in length. Furthermore, each forewing has a tiny white dot in the center. Also, the hind wings have dark margins.

Take note that larvae of these pests stay on the ground at first until they go up and feed upon tomato leaves and fruits. They certainly make shallow gouges in fruits. Furthermore, they turn leaves into lace. If you are dealing with greenhouses crops, then suspect that there may be armyworms around. This is because these crops are at high-risk to these pests since there are no natural predators around. Some natural predators are parasitic wasps and birds.

Now, how can you control these pests in the first place? There are various ways to drive them away early on since combating them when they are already inside the tomato is just a pointless endeavor.

This one is a microbial biological control against armyworms. Additionally, you can choose from its varieties such as the liquid, powder, or granules kind. Put them during the afternoon or evening since it will break down at daytime due to the UV light.

Remember to apply them using a duster. Put about 1 to 2 ounces of the dust to about 50 square feet of the garden. You can definitely reapply, but bear in mind that it takes days before these pests die after ingesting the chemical. Moreover, use protective gears when using this chemical for your safety.


First, you may certainly opt for using beneficial insects such as lacewing, ladybugs, as well as minute pirate bugs. These insects are actually the first line of natural defense against pests of all kinds. Now, these insects definitely feed on armyworms. There are also the trichogramma wasps that can absolutely parasite newly laid armyworm eggs. Next, you may attract birds which are natural predators of pests like this one. Moreover, there are also the beneficial nematodes which are microscopic soil creatures. They will surely feed on eggs, pupae, and larvae of the armyworms too.


Use pheromone traps against moths of armyworms.


It’s a no-brainer that preventing pests is much favorable than the actual combating when they are already infecting your tomatoes. If you can take certain precautionary measures, you can definitely save yourself from various stresses. Additionally, you can save a lot of resources too. So how do you actually prevent the different kinds of black worms on tomato plants?

  1. Avoid planting tomato plants near corns because the latter are also highly susceptible to pests.
  2. Always be in the lookout for eggs. Observe your plants regularly for signs of them. Definitely look on the tomato leaves. As soon as you saw them, eliminate in that same instance.
  3. You can also opt for netting your tomato fruits.
  4. Use the help of the pests’ predators. There are definitely many of them that can be purchased.
  5. Eliminate affected plants.
  6. Eliminate fruit or crop residues.
  7. Till the soil after harvest to destroy worms’ pupae.
  8. If you are going to purchase, only buy clean transplants.



A: There are the corn, cotton, eggplant, okra, peppers, soybeans, as well as tobacco.


A: Armyworms are especially active in places with warmer climates. Conversely, these pests will overwinter as eggs and pupae beneath the soil in places experiencing mild winters.


A: Some of the sprays that are excellent against black worms are the natural horticultural sprays, neem oil spray, as well as Spinosad. The natural horticultural sprays can be applied on plants showing signs of black worm infestations. On the other hand, the neem oil can be applied on all the various stages of the infestation. Lastly, the Spinosad is an organic one that is also effective against many kinds of pests.


Black worms on tomato plants aren’t just fruitworms, pinworms, and armyworms. Indeed, there are many more black worms out there or harmful worms in general. Moreover, pests aren’t just in the form of worms. You see, growing tomatoes or any other fruit or vegetable is surely hard for the challenges that you can encounter. However, don’t ever succumb because every problem always has a solution.

As a gardener or farmer, whether a newbie or not, you have to be creative and resourceful. Having these two qualities will definitely ensure that you will reach your goals. Obviously, if you are cultivating tomato plants, it means one thing: you want to have tomatoes. Your goal is certainly to harvest. In that case, you have to be ready with challenges such as pests. They are really inevitable.

Black worms on tomato plants are surely a headache, but as what this blog has just taught you, they can be eliminated. You can choose from all the ways that are shared above. Furthermore, you can rest assure that if you do your best as a crop grower, it will come back to you! Regardless of what you are growing, have a fun gardening experience and a good, bountiful harvest too!

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