Here’s the frustrating thing about tomato pests: you almost never catch one in the act. The bug that wrecked your plant works at night, hides under leaves, or camouflages perfectly. You can stare straight at it and see nothing. What you do see is the crime scene, and the good news is that every pest leaves a different one.
So that’s how this guide works. Start with the damage in front of you, match it to a culprit, and then deal with that culprit specifically. The fix for a hornworm has nothing in common with the fix for spider mites. If you want a symptom by symptom walkthrough, our companion piece what’s eating my tomatoes runs the identification from the damage side. And along the way I’ll flag the one moment where doing nothing is the smartest pest control you’ll ever practice.
Read the crime scene first
Run down this list and find your damage. Each one points at a different suspect.
Whole leaves gone overnight, bare stems, dark droppings: a hornworm. One big caterpillar can strip a branch while you sleep.
A seedling lying flat, stem snipped clean at the soil line: a cutworm. It’s the signature move, and it only targets young transplants.
Sticky, shiny leaves with curled tips, maybe a black sooty film: aphids or whiteflies. The stickiness is honeydew, the sugary waste they excrete, and the black film is mold growing on it.
A white cloud that flies up when you brush the plant: whiteflies, confirmed.
Leaves going pale and speckled, like they’ve been sandblasted, with fine webbing in bad cases: spider mites, especially in hot dry spells.
A single neat hole in a fruit, usually near the stem end, rot inside: a tomato fruitworm.
Pale, cloudy, corky patches on otherwise fine fruit, or deformed spots: stink bugs. They pierce the fruit with a needle mouth and never leave a hole you can see.
Ragged holes and slime trails, damage low on the plant: slugs, working the night shift in damp weather.
Got your match? Here’s each culprit up close, with what actually works.
Hornworms: the big one
The tomato hornworm is the most famous tomato pest for a reason. It’s enormous, up to three and a half inches, exactly leaf-green, with white diagonal markings and a harmless-looking horn on its rear. Per Clemson’s pest guide, it defoliates vines fast and gouges big scars into fruit. Despite the size, they’re maddeningly hard to spot. Look along stripped stems at dawn or dusk, or follow the pellet droppings on leaves below.
Control is gloriously low-tech: pick them off and drop them in soapy water. On a home scale, handpicking genuinely beats any spray.
But first, look at its back. If the hornworm is carrying what look like little white grains of rice standing on end, stop. Those are the cocoons of braconid wasps, parasites that have already doomed the caterpillar. Every cocoon is a future wasp that will hunt hornworms for you all season. Clemson’s advice is exactly right: leave that one alone. It’s the best free pest control in the entire garden, and most people squish it out of ignorance.
The full hornworm story, finding them, the moth they become, prevention, lives in our dedicated hornworm guide.
Aphids and whiteflies: the sap suckers
These two run the same racket, piercing the plant and drinking its sap, and they announce themselves the same way, with honeydew stickiness, sooty mold, and curled, stunted new growth. Aphids are pinhead-size, pear-shaped, and cluster in colonies on tender tips and leaf undersides. Whiteflies are the tiny pale insects that erupt in a cloud when you disturb the foliage, and they carry an extra threat. They transmit the viral diseases we cover in the disease identification guide.
The honest control ladder, bottom rung first: a hard blast of water knocks aphid colonies off and most don’t climb back. Insecticidal soap handles stubborn outbreaks of either pest, hitting the undersides where they live. And the long game is protecting their enemies, because ladybugs, lacewings, and hoverfly larvae eat aphids by the hundreds. That’s exactly why reflexively spraying broad insecticides backfires. It kills the predators faster than the pests. A flower-dotted bed that feeds those predators is real pest control. It’s half the case made in our companion planting deep dive. Aphid specifics get their own treatment in the aphids on tomatoes guide.
Cutworms: the seedling assassins
Nothing stings like walking out to find a healthy transplant felled like a tiny tree. Cutworms are soil-dwelling caterpillars that curl around young stems at night and chew straight through at ground level. They only bother seedlings. Once stems thicken, the danger passes.
Which makes prevention absurdly easy: a collar. A ring of cardboard, a toilet paper tube, or a cut-down paper cup around each new transplant, pushed an inch into the soil, physically blocks the cutworm. Cheap, foolproof, and only needed for the first few weeks.
Spider mites: the drought opportunists
Spider mites are nearly invisible, Clemson sizes them at about the period at the end of a sentence, and they thrive precisely when plants are stressed by heat and drought. The tell is stippling. Leaves go pale, flecked, and grayish from thousands of pinprick feeding points, starting low on the plant and climbing, with fine webbing once the infestation matures.
Two moves matter. Water properly, because a well-hydrated plant in a humid canopy is poor mite habitat. Our watering routine is genuinely part of the fix here. Then knock them back with hard water sprays to the leaf undersides or insecticidal soap. One more from Clemson worth stealing: inspect transplants before you buy, since mites often ride home from the nursery.
Fruitworms and stink bugs: the fruit specialists
These two skip the foliage and go straight for the prize.
The tomato fruitworm, which Clemson ranks the most damaging tomato insect in the South, bores into fruit at the stem end and hollows it out. One worm per fruit since, grimly, they eat each other. By the time you see the hole, that fruit is done. Pick and destroy it so the larva doesn’t finish developing and continue the cycle.
Stink bugs are sneakier. They stab fruit with a piercing mouthpart and drink, leaving no hole. Just pale cloudy patches and corky white spongy tissue under the skin, and deformed growth on fruit hit young. Handpick the shield-shaped bugs in the morning when they’re sluggish, and keep the garden’s edges mowed and weed-free since that’s where they stage from. A light strike is cosmetic. The fruit is still fine to eat with the spot cut away.
The boring secret: healthy plants get bothered less
Here’s the IPM foundation Clemson leads with, and it’s the least glamorous, most true thing in pest control: stressed plants attract pests. A tomato that’s underwatered, underfed, or sprawled on the ground reads as easy prey. A vigorous one shrugs off attacks that would flatten a weak neighbor.
Which means your real pest program is the stuff you’re already doing. Steady water, sensible feeding, plants trained up on good supports with airflow through them, mulch, and weeds down. Sprays, even organic ones like insecticidal soap, spinosad, and pyrethrin, are the last rung, used on a confirmed culprit only. Every broad application also kills the wasps, ladybugs, and lacewings quietly working your side of the fight. Before you reach for a bottle, our label by label breakdown of neem oil vs sprays covers what each product actually claims to do.
Two culprits work out of sight entirely. Whole fruits vanishing or showing single bite marks usually means squirrels, birds, or deer, not an insect at all. And a plant that stays stunted no matter what you feed it may have root knot nematodes quietly knotting its roots underground.
If the damage you’re seeing doesn’t match anything here, spots, wilting, yellowing with no bug in sight, you’re likely in disease or stress territory instead. Run it through our plant problem identifier or the master problems guide.
Frequently asked questions
What is eating my tomato plants at night?
The usual night crew: hornworms strip whole leaves and leave dark droppings, and cutworms fell seedlings at the soil line. Slugs chew ragged holes low on the plant and leave slime trails. Match the damage pattern, then check at dusk with a flashlight to confirm the culprit.
How do I get rid of hornworms on tomatoes?
Handpick them into soapy water, checking at dawn or dusk and following the droppings to find them. But if a hornworm carries white rice-like cocoons on its back, leave it. Those are parasitic braconid wasps that have already killed it, and they’ll hatch to hunt other hornworms for you.
What are the tiny white bugs flying around my tomato plants?
Whiteflies. They live and lay eggs on leaf undersides, suck sap, leave sticky honeydew that grows black sooty mold, and can spread viral diseases. Control them with insecticidal soap sprayed under the leaves, and avoid broad insecticides that kill their natural predators.
Why are there holes in my tomatoes?
A clean hole near the stem end means a tomato fruitworm has bored in, and that fruit should be picked and destroyed. Ragged surface gouges point to hornworms or slugs. Pale corky patches with no hole at all are stink bug feeding, and those fruits are still fine to eat trimmed.
Should I spray my tomatoes for bugs?
Not by default. Identify the pest first, and start with the lowest-impact fix (handpicking, water blasts, collars, insecticidal soap). Keep plants healthy, watered, and airy so they attract fewer pests. Broad spraying kills the ladybugs and parasitic wasps doing free pest control, and often makes the problem worse.
Bottom line: read the damage, name the culprit, and use the smallest hammer that works. Fingers for hornworms, water for aphids, a cardboard collar for cutworms, soap for mites and whiteflies, and vigilance for the fruit-stabbers. Protect the beneficials, keep the plants unstressed, and spraying becomes something you almost never do. For everything else going wrong out there, start at our complete problem-solving guide.