Black Flies on Tomato Plants + [How To Get Rid Of Them]

Black Flies on Tomato Plants

Black flies on tomato plants are a significant nuisance. They damage the tomato leaves or bite and suck the plant tissue and juice, killing the plant. Though the flies are tiny, getting rid of them is challenging.

You can squash them with your hand, use an insecticide, or blast them with water. Better still, a few drops of Neem oil in water would work best to spray because it contains no chemicals. Additionally, introducing parasites and predators can kill the black flies without the need for chemicals. 

Most importantly, you must identify the black flies wreaking havoc. Also, prevent pest attacks by caring for your plant’s health.

Keep reading to learn more about the fight against black flies.

ALso Check: Sweet 100 Tomatoes vs. Super Sweet 100

How Do I Get Rid Of Black Flies On Tomato Plants UK?

There are three methods to prevent tomato flies from attacking your tomato plants. You can use a manual, biological or chemical approach to ensure you don’t see these tiny flies again. However, consistency and patience are crucial in some methods.

Tomato is the most vulnerable vegetable to grow because of the frequent attacks by insect pests and diseases from the seedbed to harvesting.

Let’s find out how each method works.


If your tomato garden is not big, you can use your hands or feet to squash the black flies. Preferably, put on gloves if you want to squash the bugs. Usually, they attack the leaves and stems, so check the undersides.

You are likely to find eggs as well. Crash the eggs entirely with your fingers. Make sure you check thoroughly not to leave without squashing everything.

Conversely, you can scrape the black flies from the undersides and drop them inside a jar of soapy water. This way, they won’t escape but will drown.

Blasting the black insects with water is another practical approach. However, don’t use water with a lot of pressure as you might damage the leaves and stems of the growing tomato plants. Be sure to get the undersides also to ensure even the eggs are off the plant.


Believe it or not, some natural pests and diseases can kill black flies. But, you must ensure you use this method before the black flies damage the crop.

Introduce the predators and parasites to your tomato plants against black flies during warm temperatures. It helps if you use this tactic in covered places to ensure they don’t get away from the plants.

Moreover, ensure you introduce the parasites and predators immediately you spot the black flies and the temperatures are over 10°C.

Introducing the Aphidoletes aphidimyza twice is enough. But if the black flies infestation is heavy, more of this parasite would be ideal. This 2mm tiny midge lays around 100 eggs in the two-week lifecycle, and the larvae feed on like 15 black flies. This parasitic midge lays its eggs inside the black flies. Then, the larvae eat the black flies from the inside.  

Ensure the setting is warm and well-lit for best results, and the black flies infestation is not big. Also, only use soap-based insecticides if you opt for a biological control to ensure no toxic residue harms the beneficial insects.


Consider using a chemical solution as the last option because toxins can destroy the plant or soil. But, if the black flies infestation is large, you can search for effective insecticides that are less harmful.

Use a pyrethroid-based insecticide with bifenthrin or permethrin chemicals to spray and kill adult black flies. These sprays kill the pests on contact but are not harsh enough to kill the emerging adults from the soil.

After the black flies consume it, the bacterium produces toxins that interfere with and stops the digestive system from killing the larvae pest before it matures to adulthood.

Strictly follow label instructions when you use pesticides. As an edible plant, ensure tomatoes are on the list of the specific insecticide you choose. Better still, have the store attendant help you choose an effective one for your needs. Follow instructions on the number of applications and intervals of spraying.

How Do I Get Rid Of Black Bugs on Tomato Plants?

There’s no general control for black bugs on tomato plants. You must identify the type of flies attacking your tomatoes to help you find an effective elimination method.

Because they feature many shapes and sizes, identifying them requires knowledge of their habits and traits. Some swarm around the plant while others hide the underside of leaves you can hardly see.

Nonetheless, aphids, gnats, and flea beetles are the common types often seen on tomatoes.

Let’s look at elimination methods for each black bug.

Black Aphids

These tiny bugs suck and feed on the plant’s sap. This insect features a pear-shaped body with two antennae and six legs. Even though they are black, they are so tiny, about 3mm long, that you’ll need a magnifying glass to see them. However, it’s easy to spot clusters of black aphids on the leaf veins, stem, and underside.

The damage caused by black aphids is the best method of identification. After sucking on the sap, they cause yellow leaves, spotted leaves, curled leaves, and stunted growth. Plus, these bugs emit a sweet sticky amber liquid like honeydew.

Because of this honeydew, the black aphids also attract ants. These ants protect the aphids from predators because the honeydew is food for them.

So, how do you get rid of black aphids?

Using Neem oil as the most effective natural method, you can eliminate black aphids. Mix 2 tablespoons of organic Neem oil, 1 liter of water, and 1 tablespoon of liquid Castile soap in a spray bottle.

Spray thoroughly on the plant aiming at the leaves, undersides, and stem once a week. Allow the pesticide to dry, stopping the eggs from hatching and larva from maturing.

Flea Beetles

Unlike others, flea beetles can jump and fly. They have a 2.5mm oval body, typically black but can also be shiny brown or bronze.  

Black flea beetles on tomato plants chew holes on tender young leaves. These tiny black bugs appear during spring from the soil as tiny, cream-colored larvae and can also damage plants. The larvae eat the roots of the tomato plants.

To eradicate the flea beetles, you must sprinkle diatomaceous earth around your tomato plants. DE is a non-toxic white powder that is harsh enough to the beetles’ exoskeletons, causing dehydration until they die. Apply DE on dry ground and replace it immediately after rains.

Neem oil is also effective against flea beetles.  

Fungus Gnats

You can find fungus gnats in any plant-growing soil. These tiny black bugs can also swarm around infected tomato plants. Usually, they result from overwatered houseplants, so they thrive in damp soil.

Furthermore, black gnats lay eggs in wet soil, and the larvae eat the roots. Feeding on roots without prevention causes stunted growth. Once they mature, the adult fungus gnats emerge from the soil, attacking the plant’s stem upwards. When the soil is wet, gnats kill tomatoes and other houseplants.

Fortunately, mature fungus gnats can hardly cause any plant damage. The gnats don’t suck or bite to feed on sap and plant tissue. Still, they are a nuisance when matured when they fly over your face.

Getting rid of fungus gnats requires proper watering of tomato plants. Better still, allow the water to dry before watering again to prevent overwatering. This way, the gnats, and larvae starve of moisture and die. Try watering your plants at the bottom to inhibit a damp environment at the top of the soil for the gnats to lay eggs. Also, sticky traps help reduce fungus gnats’ infestation on your tomatoes.  

How to Get Rid Of Tomato Flies

Tomatoes attract different flies that are bothersome. These flies damage the plants and can also spread diseases to other plants. If you notice flies on your tomatoes, remove them immediately to maintain and ensure a good harvest.

Therefore, blast water on both sides of tomato leaves. Wash off the eggs, larvae, and adult tomato flies from on top and under the leaves. Spray weekly in case the infestation is still there.

If you use insecticidal soap, don’t increase the amount required to avoid plant damage. Discard any heavily infested tomato plants to prevent spreading to other plants. Check if the tomato plant has yellow leaves and mold to verify the severe infestation.

How to Prevent Black Flies on Tomato Plants

Good gardening practices ensure the black flies don’t attack your tomato plants. For instance;

  1. Remove all weeds from your garden. Usually, weeds carry pests to your plants in winter and attack after spring arrives.  
  2. Water and feed your tomato plants properly to ensure they remain healthy and less vulnerable to pests and diseases.
  3. Avoid insecticides so you can attract beneficial insects to uphold a healthy ecosystem. Beneficial insects feed on pests as a natural way of eliminating the infestation.
  4. Crop rotation is another prevention method against black flies. Plant non-host crops when you don’t have tomato plants to ensure the pests have nothing to attack.


Black flies on tomato plants are the main problem a gardener can face when growing tomatoes. It turns out that several insects love the juicy red ripe fruits and the tomato plant as a whole.

Undeniably, it isn’t delightful to see black flies infesting your tomato plants after spending so much time, money, and effort growing your garden.

However, there are different ways of controlling and getting rid of the black flies infestation on your tomato plants, from simple home remedies and chemical to biological methods. The methods differ according to the rate and type of black flies infestation, as shown above.