21 Tomato Pests: How to Identify and Prevent Them

Thinking of planting some tomatoes this season, but want to make sure you keep the bugs away when you start planting? Tomatoes have a whole host of different pests that can come after their juicy red fruits, so pest prevention is arguably more important than treatment. In this article, gardening and homestead expert Merideth Cohrs takes a look at the most common tomato pests and how to prevent them.

If you’re thinking about growing tomatoes this year, you’re in great company. Probably one of the most commonly grown vegetables for the home gardener, tomatoes are fairly easy to grow and the fresh, vibrant flavor can’t be beat. 

There are many different types of tomatoes to grow based on how you want to enjoy them.  You can grow beefsteak varieties for slicing and sandwiches, saucing varieties like Romas and San Marzanos, or sweet cherry tomatoes that you pop off the vine right into your mouth!

No matter the variety of tomato plant, the pests you have to look out for are pretty much the same. Let’s take a look at 21 different pests that love tomatoes as much as we do and discover how to keep them away from our plants.

Organic Pest Control Tips

Choosing to garden organically? That’s good news, because there is quite a bit you can do early in the season to help with pest control. From companion planting to encouraging helpful predatory insects, taking steps toward prevention will be far easier and more enjoyable than dealing with an infestation later.

Companion Planting & Biodiversity

I learned about companion planting and the importance of biodiversity from my mom. On the weekends, I helped with her small hobby farm in central Texas and it was an incredible education. My early vision of what a garden should look like – neat, sterile rows of single vegetables – was dashed as I began to see the importance and real benefits that biodiversity brings to a garden.

Every ecosystem works holistically and no element works in isolation from those around it.  The more plants and animals there are in your garden, the more resilient it will be. If you choose to garden organically, this is incredibly important.

Certain plants and flowers encourage stronger growth in your tomatoes, others repel or act as a ‘trap plant’ for particular pests, and still others attract predatory insects that love to eat the pests that may plague you.

Take the time to look into companion planting for tomatoes.  Plants like basil, chives, nasturtiums, and marigolds are a great place to start!

 

Encourage Predatory Species

I’m not a big bug fan and I have a small fear of spiders. With that said, I LOVE LOVE LOVE seeing spiders and other predatory insects in my garden. I just wear gloves when I’m putting my hands in denser foliage!  In all seriousness, the benefits of creating an environment that attracts local wildlife are immense.

Birds, spiders, ladybugs, lacewings, parasitic wasps, and lizards all want to eat the pests that plague your tomatoes, so invite them in!  Grow flowers, herbs, and other vegetables that attract these species, and you’ll be much happier in your gardening experience.

Plant Your Tomatoes in the Right Place

Plants want to grow, and they will do their best even when they’re placed in conditions they aren’t well suited for. The problem is that a stressed plant has fewer defenses against pests and diseases.  When you choose the right plants for your climate, soil type, and sun conditions, they are far more likely to thrive and shrug off serious problems.

Most Common Tomato Pests

The pests your encounter will depend on where you live, but these 21 common tomato pests are the ones you are most likely to come across. If you already have an idea of what’s attacking your tomatoes, you can use this (alphabetical) list to quickly discover how to deal with it. If you’re not sure what pest you’re dealing with, this list should help you identify the likely culprit.

Aphids

Aphids
Aphids produce fungus on the tomato leaves they feed on. This fungus causes the plant to be unable to photosynthesize.

Aphids are the bane of every gardener everywhere. These sap-sucking insects seem to find their way into every garden every year. They can be quite destructive if you don’t address them early.  You will see them commonly on the stems and foliage of your tomato plants, often near the growing tips. They can jump between species as well. So, if you have an infestation on a nearby plant, they can easily migrate to others nearby.

Although you can use Neem oil, insecticidal soaps, and horticultural oils against aphids, I have found the most effective tool to be a hard stream of water from the hose. If you spray aphids off leaves, they have a very hard time finding their way back to the plant. Just make sure to check the undersides of the leaves – aphids love to hide there.

Companion planting can be quite effective at keeping aphids away. They are especially attracted to mustard and nasturtium, which will act as ‘trap plants’ for the pests. If you plant other pollinator friendly flowers and herbs near your tomatoes, they will attract ladybugs and parasitic wasps which love to eat aphids.

Blister Beetles

Blister Beetles
Some types of blisters are dangerous pests, as they can harm vegetables and grain crops, fruit trees, berries, flowers and ornamental plants.

Blister beetles are another pest with a love for tomato plants. While they won’t defoliate your plant overnight like several other pests in this list, they can do quite a bit of damage if left unattended. But for as much damage as they do to tomatoes, these bugs are more well known for the damage they can do to us. 

When crushed or even mildly injured, they release a blistering agent called cantharidin. This isn’t something you want on your bare skin. Make sure you wear gloves if you see these black beetles with bright orange heads roaming your tomatoes.

Blister beetles are seen throughout North America. They are most common in the midwest, midatlantic, and southern portions of the US. If there are large swarms of these in your area, you will be well served to use anchored row covers in your garden. If dealing with only a few, pick them off with gloved hands and place in a jar of soapy water. Birds love to eat these beetles, so attracting them to your garden can help with a large population.

Colorado Potato Beetle

Colorado Potato Beetle
Colorado Potato Beetles prefer to eat potato tops, but they do not bypass tomatoes either.

The Colorado potato beetle is one of the most wide-spread tomato pests in North America and is attracted to other vegetables in the nightshade familypeppers, eggplant, etc – as well. At first glance, they look a little like a strange ladybug, but don’t be fooled. You can easily tell the difference by noting the distinctive shell that sports 10 alternating yellow and black stripes.

Larvae of the Colorado potato beetle are the most damaging. Although the larvae are difficult to see, they eat the leaf in a unique way, leaving only the veins and petioles behind.  If you see leaf damage like this, look around for the adult beetles. 

They can be removed by hand and placed in a jar of soapy water. Your tomato plant will be ok even if it loses 30-50% of its leaves, so you can save it if you catch the problem early.

Note that Colorado potato beetles overwinter in the soil. So if you have an infestation, do not grow tomatoes or other nightshades in that soil the following year. Potatoes can act as trap plants for the beetles, and of course, birds, ladybugs, and lacewings all enjoy eating them.

Cutworms

Cutworms
A young Cutworms caterpillar can immediately bite into the tissue of fruits, such as tomatoes.

Cutworms are moth caterpillars that live in the soil and are usually brown or gray with black or yellow spots. If they find their way to your young tomato plants, they are capable of destroying it overnight

Unlike hornworms that can be found any time, cutworms are stealthy, working at night and hiding below soil or debris during the day. The primary damage comes from attacking the stems of the plant, causing it to collapse and die. 

There are a few things you can do to prevent cutworms. Before planting your tomato seedlings, dig around in the soil and check for them. If you see one, check thoroughly because there will likely be many more hiding. 

Once you plant your tomato, place a collar around the stem – you can use cardboard or aluminum foil – which will create a barrier that the worms cannot climb over. If you’re still having trouble with cutworms, you can sprinkle some cornmeal around the base of the plant, which will kill them when eaten. Bottom line is that the second you see a cutworm, pick it off with your hands and place it in a jar of soapy water.

Flea Beetles

Flea Beetles
Miniature Flea beetles cause serious damage to young tomato plants and other seedlings.

Flea beetles won’t kill your tomatoes, but they can cause your plant to lose vigor and become generally unhealthy.  You can identify these pests easily. Flea beetles are tiny – only 1/10” – jet black, and jump quite far for their size. In my own garden, these pests have been most attracted to young eggplant transplants, so I am sure to always keep my tomatoes away from them.

One way to control an infestation is to dust diatomaceous earth on your plant and the surrounding soil. If you do this, be very careful since it can kill pollinators as well as flea beetles.  A less dangerous option is to use sticky traps to capture jumping adults.  Basil and nasturtiums are wonderful companion plants for tomatoes that may help repel these beetles from settling in the first place.

Hornworm

Hornworm
Hornworm merges against the background of green leaves, destroying not only them, leaving holey traces, but also damaging the fruits of the crop.

Tomato hornworms are incredibly destructive and are very common throughout North America and Australia. The hornworm is the caterpillar of the five-spotted hawkmoth, but don’t confuse this with other butterfly/moth species you want to help propagate. They don’t need the help…

These large caterpillars will eat non stop and can quickly defoliate an entire tomato plant.  They are very well camouflaged against the leaves and stems and can be quite hard to see while still small. 

A telltale sign that you’re dealing with a hornworm is seeing a branch or portion of a branch with no leaves in the morning. As they get larger, hornworms are easier to see, but they will have already done quite a bit of damage. Carefully look along stems, lifting leaves to find the hornworms underneath.

The best way to get rid of hornworms is to pick them off by hand. I think they’re kind of gross so be sure to wear gloves if you’re squeamish at all. They will wiggle like mad and attach themselves strongly to the stem they’re on. If you are lucky enough to have chickens, they love eating hornworms. Otherwise, you can squish them or put them in a jar of soapy water.

Anecdotally, plants like dill, basil and marigolds can help repel hornworms, but be prepared to search for them just in case.

Leafhoppers

Leafhoppers
Whatever species the Leafhoppers belong to, they cause almost the same harm, feeding on the juices of the plants on which they settle.

Leafhoppers tend to be more problematic for other vegetables, but they can do some damage to your tomatoes if left unchecked. Like many insects, leafhoppers enjoy sucking the sap from leaves and stems, causing the foliage to curl. The main problem, however, is that leafhoppers transmit pathogens that can cause devastating disease that quickly spreads plant to plant. 

You can get rid of leafhoppers with a strong stream of water (just like aphids), but if you’re dealing with a large infestation, consider a row cover to protect your plants. As with most pests on this list, populations can be easily controlled by attracting birds and other predatory insects.

Leaf Miners

Leaf Miners
Leaf Miners are polyphagous pests. They feed on almost any plant, but they do the most harm to tomatoes.

Leaf miners are another very common insect that loves tomato plants.  These small flies have a distinctive bright yellow dot on their back and can cause serious damage to your tomato crop.  Adults feed on leaves, but the real damage comes from the larvae. 

Female leaf miners lay their eggs under the surface of the leaf, and when larvae hatch they eat their way through the inside of the leaf. This action interrupts the plant’s ability to conduct photosynthesis, which can kill the plant if allowed to spread. 

The good news is that the larvae leave distinctive white trails on the leaves as they eat their way out, so it’s easy to identify. Once you see a leaf with this trailing pattern, remove it immediately and check for further signs of infestation.

The best way to overcome an infestation of leaf miners is through the introduction of natural predators like parasitic wasps. Also be sure to keep your garden free from weeds and plant debris that can attract leaf miners.

Potato Aphid

Small Potato Aphids on Plant
The Potato Aphid is a very active pest, that is usually found on young plants and can crop quite quickly.

Potato aphids are the largest of the aphid family and specifically attack tomato and potato plants. They are found throughout the United States but are only considered a problematic pest in the mid-atlantic and northeast regions. Potato aphids are distinguished from common aphids due to their size and color.

They are sometimes green, but more often display a pale pink color. Potato aphids attack young leaves – especially the growing tip – which can cause them to curl downwards. They also target blossoms, which can cause the blossom to drop or create fruit deformities.

You can get rid of potato aphids the same way as others – hard sprays of water will dislodge them. But some potato aphids have wings and can find their way back on the plant. The best form of control is predatory insects such as ladybugs, lacewing, and parasitic wasps.

Psyllids

Psyllids
Psyllids are also one of the main carriers of phytoplasma disease. Feeding on the juice of infected plants, insects fly around the area and spread the disease.

Psyllids are a migrating insect that overwinters in warm climates. So unlike many pests, you do not need to worry about new infestations coming from existing soil. Psyllids are a small insect that looks a bit like an aphid-sized cicada.

Their small size makes them difficult to see, but they excrete very distinctive wax-covered pellets known as psyllid sugar. When plants aren’t disturbed by winds, these can collect on leaves and be a useful way to detect the culprit. 

Damage results from the saliva as the psyllid eats causing a range of symptoms described as ‘psyllid yellows’. This leaf yellowing will be the first sign you’re dealing with this pest.

If you are trying to avoid pesticides in your garden, the best defense against psyllids are predatory insects like spiders, damsel bugs and minute pirate bugs. Sticky paper can also help catch adult psyllids but won’t be much help against the nymph already on the plant.

RootKnot Nematodes

RootKnot Nematodes
RootKnot Nematodes – negatively affect almost every crop in the world and can become serious pests in the home garden.

Nematodes are tiny worms that can cause lumpy swelling on roots, yellow foliage, wilting, and poor growth in plants. The damage is done as they attack the root structure of your tomato plants and steal the nutrients that should be delivered to the plant’s leaves, flowers, and fruits.  Nematodes are unfortunately very easy to spread and can find their way into your soil through garden tools, boots, or gloves. 

The key to treating an infestation is total sanitation. Sterilize your tools, wash your gloves and boots, and clean contaminated pots with a bleach solution. You must remove and dispose of any affected soil and plants since there is no recovery from an infestation.  Do NOT compost this material or it will continue to spread. 

If your infestation is in the ground or a large raised bed where you cannot remove all the soil, plant marigolds profusely.  When they are done flowering, dig them under the soil and allow them to decompose. 

There is a chemical that decomposing marigolds release that nematodes hate.  There are also varieties of tomato plants that are naturally resistant to nematodes. Look for a “N” listed under the plant name.

Slugs & Snails

Slugs & Snails
Slugs & Snails are very voracious; one garden snail can eat a whole tomato in a day.

In a healthy ecosystem, slugs and snails are a normal part of the landscape. If populations get out of control, however, they can cause a lot of damage to a garden and your tomato plants in particular. There’s a reason that the animated movie Turbo began with a snail colony living in a tomato garden! 

The key to avoiding excessive damage to your plants is population control.  Birds, frogs, lizards, and some small mammals all enjoy eating slugs and snails so invite them in!  If this isn’t an option for you or you’re dealing with a real infestation, you can pick them off by hand or try a beer trap (although this is really only a temporary solution until you can correct the imbalance in your garden). 

To create a beer trap, fill a dish or shallow tray with beer and place it at soil level around your plants. Slugs and snails will be attracted to it and will drown once they are submerged. 

Spider Mites

Small Spider Mites on Plant
Quite common, spider mites are more commonly seen in greenhouses where it’s more humid.

Spider mites are common in a lot of climates, but typically enjoy hot dry weather.  They infest in very large groups, settling on the undersides of leaves.  You will know this is the pest you’re dealing with if you see delicate webbing around leaves and stems.

Although quite small, spider mites are pretty resistant to most insect sprays. The good news is that they seem to hate cold water and will leave quickly if sprayed directly with ice water.

The easiest thing to do is to keep a spray bottle in the refrigerator and mist the leaves of your plants once or twice a day until the mites are all gone.  You can also aim to prevent spider mites by companion planting aromatic herbs – like garlic, chives, or chamomile – near your tomatoes.

Stalk Borer

Stalk Borer
Stalk Borer is a slender, purple, and white striped caterpillar that is the most common pest of tomatoes, peppers, corn and other plants.

If you’ve ever tried to grow summer squash, you have likely dealt with vine borers. Stalk borers act in a very similar way doing just what their name suggests. They bore into the stem of a plant, causing it to wilt and eventually die. 

The entrance hole can be quite small and difficult to find, but if you see a caterpillar on the surface of your plant, you’ll know what you’re dealing with. The caterpillar itself is easy to identify. It has purple and cream stripes with a solid purple band around its body about ⅓ of the way back from its head.

Sadly, once your tomato has been infested with stalk borers, there’s nothing you can do other than remove the affected plants. Good weed control and mulching can help prevent the stalk borer from finding its way to your tomatoes.

Stink Bugs

Stink Bugs
You’ll see stink bugs most active in the spring, when they actively breeds in spring and eats the shoots of young plants of horticultural crops.

Stink bugs are a rather new invasive species in the US, but they are now commonly seen pretty much everywhere. I always find a few of these feasting on my juicy tomatoes later in the summer. They don’t do much damage to tomato leaves or stems, but they do enjoy feeding on immature fruits.  This can cause them to drop early or even start to shrivel.

The only thing you can really do to fight stink bugs is to hand pick them off your tomatoes. I usually keep a jar of soapy water near my garden specifically for stink bugs and hornworms.  Use gloves if squeamish, but make sure you pick them off rather than flick onto other plants. 

Encourage birds and spiders to make homes in your garden to help keep the population down. Plants like marigolds, garlic, and lavender are all said to be good trap plants for stink bugs, so plant these nearby if you deal with a large number of these pests.

Tarnished Plant Bugs

Tarnished Plant Bugs
Tarnished Plant Bugs attack a wide variety of herbaceous plants, vegetable crops, flowers and buds.

The tarnished plant bug is a small ¼” insect that is brown mottled with yellow, bronze, or reddish marks.  Like many pests on this list, they suck the sap from stems, leaves, flowers, and fruits.  They enjoy tomatoes but will also spread to lettuce, strawberries, peppers, eggplant, and fruit trees. 

Although quite small, tarnished plant bugs leave distinctive damage so you should be able to identify it as your culprit. They will leave black spots on stems and leaves, can cause cloudy spots on mature tomatoes, and most disturbingly, can cause catfacing (a type of physiological damage represented by scarring and cavities near the blossom end) on growing tomatoes.

The good news is that you can take action throughout the growing season to mitigate this pest. Ensure you plant pollinator-friendly flowers to attract predators like damsel and pirate bugs and remove any weeds that tarnished plant bugs enjoy (dandelion, chickweed, wild mustard, etc). 

Row covers can help smaller plants but this can be difficult to use with tall growing tomatoes.  If you know you’re dealing with this pest ahead of time, you can try to spray plants with kaolin clay, which should deter them from laying eggs. Garlic sprays can help deter tarnished plant bugs, but so can planting garlic chives around your tomatoes.

Thrips

Thrips
Feeding on the cell juice of tomatoes, thirps significantly weaken them and reduce resistance to diseases.

Thrips are tiny flying insects that can cause quite a bit of damage before you even know they’re a problem.  That damage can happen in a couple of different ways. First, thrips can affect seedlings before they have become hardy by feeding on young flower buds, growing stems, and new leaves. 

This can cause a young plant to lose its vigor and stall in its growth. The greater damage, however, comes through the spread of tomato spotted wilt virus, which can potentially affect your entire garden. There is unfortunately no treatment for the virus, so your only option is to control the thrips. 

The best thing you can do to fight a thrip infestation is to control weeds and purposefully grow plants that attract ladybugs, pirate bugs, and predatory mites. Yarrow, Queen Ann’s lace, coriander, and dill are all great options.

Tomato Fruit Worms

Tomato Fruit Worms
Most often, Tomato Fruit Worms eat flowers and tomato ovaries, which causes considerable harm to the crop.

Also known as corn earworms, tomato fruit worms are considered one of the most damaging tomato pests. They are known to attack tomatoes, peppers and corn, and they jump species easily. The adult tomato fruit worm is a rather nondescript moth that lays white eggs on the underside of smaller leaves closest to fruit. Once hatched, larvae bore into the fruit itself and then graduate to feeding on leaves. 

Because the larvae are so hard to spot, your best bet is to handpick the eggs or worms off as soon as they appear. A good natural option to rid your plant of this invasive pest is to introduce natural predators. Pirate bugs and certain species of wasps love to eat tomato fruit worms. Make sure to destroy all infested fruit once you have identified it.

Tortoise Beetles

Tortoise Beetles
Tortoise Beetles are small, oval, beetles that resemble miniature turtles that survive chewing holes in the tomato, potato and pepper plants.

I came across tortoise beetles the first year I planted tomatoes in Virginia. They’re quite interesting to look at – if somewhat odd – and the good news is they won’t do much damage to your tomatoes unless there is a very large population. You will typically find tortoise beetles on the underside of your tomato leaves, so if you see one, be sure to check the entire plant. 

Pick the beetles off your tomato plant by hand and relocate them to an area with undesirable weeds. You can consider them a beneficial insect in that environment and let them go to work and feast!

Whitefly

Whitefly
Whitefly, which damages tomato crops, feeds on the liquid contained in tomato leaves.

Whiteflies are tiny insects and very similar to aphids.  The difference is that they mostly affect tomatoes grown indoors or in a greenhouse environment.  Much like aphids, they suck the sap from the leaves and stems of the plant, causing it to become unhealthy and to reduce yield.

The good news is that you can control populations of whiteflies in exactly the same way as aphids. Introduce predatory insects like ladybugs and spray water directly on the undersides of leaves to remove the whiteflies. If you’re dealing with a large infestation, horticultural oil can be used to suffocate whiteflies at any stage of their life.

Wireworms

Wireworms
An annoying pest, wireworms are most commonly seen in newly turned soil.

Wireworms are the larval stage of click beetles and are commonly found across the United States.  They feed on germinating seeds, bulbs, tubers, and young roots, and occasionally burrow up the stem of a plant as well. 

This can cause a young plant to wilt and eventually die. Infestations are most common in newly turned soil that was uncultivated in previous years. The best defense against wireworms is thorough cultivation of the top 6-8” of soil. 

This creates unfavorable conditions for laying eggs, and exposes all stages of the pest to birds and other natural predators. If you are creating a new garden and expect you’re dealing with wireworms, do whatever you can to attract birds to your space. Birdbaths and bird feeders can be helpful.  Once they’re in the area, the birds will do the hard work!

You can also use a potato as a wireworm trap. Cut a potato in half and run a stick through the middle.  Bury the potato in the infested area with the stick protruding. After a few days, pull the potato out of the ground and dispose of any wireworms it attracts. Rinse and repeat!

Final Thoughts

While there are a number of pests that enjoy feasting on tomato plants, there are just as many ways of deterring them. If you read through this entire list, the common theme is to do whatever you can to attract predatory insects to your garden.

Take the time before planting to understand what plants and flowers attract the types of predatory insects most helpful to your area. Then plant them! I promise that creating a biodiverse ecosystem in your garden will lead to a much more enjoyable growing season.

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