When your tomatoes have holes in them, you start wondering – what causes holes in tomatoes? The answer is pests.
Seriously – pests are the bane of any gardener’s existence. Pests turn a beautiful garden and yield into something made of nightmares.
Nothing is more upsetting than picking a beautiful tomato off the plant to find small holes in your tomatoes. Chances are you have a tomato fruitworm problem – that’s what is eating holes in your tomatoes!
Keep reading to find out how to kill tomato fruitworms organically and all about tomato fruitworm control.
What Is Eating Holes in My Tomatoes?
Tomatoes have three serious pests that cause the most damage – tomato fruitworms, tomato hornworms, and the squash bug. They all cause problems and might cause small holes in tomatoes, but the most likely culprit is the tomato fruitworm.
What are Tomato Fruitworms?
Chances are you’ve never heard of these sneaky pests, but dealing with tomato fruitworms is challenging.
Tomato fruitworms are no fun. Some people refer to them as corn earworms or armyworms. No matter what you call them, tomato fruitworms are caterpillars that eat the leaves and fruits off of a tomato plant.
Once they poke holes into your tomatoes, the fruits start to rot. The larva form of the fruitworm attacks a tomato and tunnels through them. Without you realizing it, they eat through the interior of the tomato. The insides end up fluid and droppings instead of being a delicious tomato.
What a bummer.
After they eat holes in your tomatoes and destroy the fruits, you have to toss them out. The fruits are inedible.
These pesky pests are hard to get rid of, but knowing the signs of tomato fruitworms helps stop more holes in tomatoes from forming and ruining your yield.
How to Identify Tomato Fruitworms
The first question you might have is – what does a tomato fruitworm look like?
Quick identification gives you plenty of time to take care of the problem before they destroy all of your plants.
Fruitworms are small or young caterpillars on tomatoes with unique, distinct markings. They have rows of dark bumps on the backs, and the older tomato fruit worms have a dark grey or yellow to light brown stripe that runs down the length of its body.
Not all armyworms look the same. Some are yellow, green, or reddish-brown in color — most measure between 1.5 and 2 inches long.
If you find black worms on tomatoes, you probably have fruit worms!
The Lifecycle of Tomato Fruitworms
The lifecycle of tomato fruit worms starts with the eggs. Adult moths lay eggs on plants that are off-white, slightly flat, and round. They’re hard, if not impossible, to see because they’re about the size of a pinhead.
When the eggs are close to hatching, they turn a reddish-brown shade or develop a stripe down the eggs. That makes them easier to find on the plants.
The eggs hatch in 3-4 days.
After hatching, the larvae are tiny and light-brown, covered in small hairs. This is the problematic stage; larvae destroy your plants and cause holes in tomatoes. They feed off of the fruit, stems, and leaves.
Older larvae are aggressive and cannibalistic. They don’t share or mess around well.
They stay in the larva form for 14-21 days.
Then, the larvae fall to the ground after this stage and burrow into the soil to pupate. This is the pupal stage, which lasts around 13-14 days in the summer. However, those who end the pupal stage in the fall overwinter in the soil until the spring.
The pupal stage ends and develops into a gray-colored moth with a single, black spot in the center of each wing. The wingspan is about 2 inches.
The adult moths lay eggs on tomato plants, as well as a few other crops, such as:
Female moths are busy creatures. They lay 35 eggs per day for a total of 500-3,000 eggs in their lifespan. It’s easy to see how an infestation can get out of hand fast.
Adult moths are nocturnal, so you won’t see them laying the eggs, but it happens. Then, the life cycle starts over again with the eggs on the leaves and hatching larvae.
The Damage Caused by Tomato Fruitworms
You know that pinholes in tomatoes are part of the damage done by fruit worms, but there is more. Here is the damage that these pests cause to your tomato plants.
Small Holes in Tomatoes
The most obvious problem that these pests cause are small holes in tomatoes. There might be so many holes that the tomato splits open, or if you cut into it, you might find tunneling through the tomatoes. Sometimes, you might find the worms inside of the tomatoes still.
The worms leave a hollow space instead of the fruit. This space fills with water, decay, and rot.
This damage ruins the tomato crop, leaving the fruit inedible. They must be destroyed; don’t stick them into your compost bin.
Believe it or not, these worm-eating tomatoes prefer green fruit over red fruit. The plant still causes the fruit to ripen as the pest destroys it.
Holes in Tomato Leaves
Aside from finding tiny holes in my tomatoes, fruit worms also cause holes in the tomato leaves. This might be harder to spot at first because the holes are little and less obvious.
Usually, tomato fruitworm damage starts first in the leaves until the fruit starts to develop. That’s when they switch to eating the fruits.
Damage to the Stems
In some situations, these pests also cause damage to the stems. They might chew holes into the stems, making small tunnels as they move through them.
This is harder to spot than damage to the leaves or holes in the tomatoes.
Can You Eat Tomatoes with Holes in Them?
It’s tempting to eat the tomatoes with holes in them still; no one wants to waste perfectly good tomatoes!
However, it’s not safe to eat tomatoes with holes.
Tomato Fruitworm Control: How to Get Rid of These Pests in Your Garden
Several methods effectively remove and get rid of tomato fruitworms in your garden. I prefer using only organic methods in my vegetable garden.
Here are a few suggestions for tomato fruitworm control.
1. Use Neem Oil
I’m a huge fan of neem oil, and I always have a bottle or two hanging around. Neem oil is safe for organic gardens, but it must be applied more frequently than other products. Apply neem oil to your garden every week and after each rainfall.
2. Apply B.T.
B.T. stands for Bacillus thuringiensis, and it’s a natural, fast-acting insecticide.
Here’s how it works against pests in your garden.
A tomato fruitworm ingests B.T. after eating the plant you sprayed. Soon, the infected insect stops feeding after ingesting the insecticide. Then, the pest dies from either starvation or rupture of the digestive system.
It doesn’t sound pleasant for the pest, but you have to defend your plants.
I like B.T. because it doesn’t harm most beneficial insects. It’s available in a liquid, powder, or granular form.
The best time to treat your plants with B.T. is in the afternoon or evening; UV rays break it down. Try to apply it as soon as you find the eggs on the plant. That makes it easier to stop an infestation.
3. Hand Pick What You See
If you find any larvae on your plants, make sure to hand-pick them off of your plants. Drop them in a bucket of hot, soapy water.
4. Apply Diatomaceous Earth
I’m a huge fan of D.E. There are many ways to use diatomaceous earth in your garden and homestead.
Spread D.E. around the base of your plants and sprinkle over the leaves. When the larvae ingest this powder, it causes them to die in several days. However, it’s not toxic to humans nor your lovely pets, so fear not!
5. Apply Spinosad
Another organic option is to use Spinosad, which is an approved, effective treatment against fruitworms.
However, be aware that this is toxic to bees, so never apply it to tomato plants that are in bloom or shedding pollen. This means stick to only using this for determinate tomatoes rather than indeterminate tomatoes.
Preventing Tomato Fruitworms
Ideally, you’ll use preventative measures to stop tomato fruit worms from finding your plants to start with, but that doesn’t always happen. Use these preventative measures to protect your plants from the start.
1. Attract Natural Predators
Tomato fruit worms have plenty of natural predators that you could attract to your garden to help control their population. Gardeners can either attract the fruit worms to their garden naturally or purchase them from a garden nursery (typically online) and release them into your garden.
A few natural predators of tomato fruitworms include:
- Damsel Bugs
- Minute Pirate Bugs
- Big-Eyed Bugs
- Parasitic Programmatic Wasps
If you want to attract natural predators to your garden and forego buying them, consider adding these plants near your tomato plants.
- Stinging Nettles
2. Hand Pick Eggs
Eggs are hard to spot until right before they hatch. Check the leaves of your tomato plants every day or every other day. Remove the eggs by hand and put them into hot, soapy dishwater.
3. Cover Your Plants
One of the easiest solutions is to cover your plants with row covers. Covering your plants prevent adult moths from laying eggs on the plants, starting the process.
Make sure you cover the seedlings with the cloth; waiting too long into the season gives the moths plenty of opportunities to lay eggs on the plants.
4. Don’t Plant Near Corn
Avoid planting your tomato plants near corn. Fruitworms love corn almost as much as they love tomatoes, so keep them as separate as possible.
Dealing with holes in tomatoes is no fun. All of your hard work to grow homegrown tomatoes is ruined by tomato fruitworms. Use these tricks to prevent and get rid of tomato fruitworms.
Remember, don’t eat the tomatoes if they have holes in them!