Why Are There Holes Chewed in My Peppers?

You pick what looks like a perfect pepper, turn it over, and find a hole bored into it — and often a hollowed, frass-filled, rotting interior. Something has tunnelled into the fruit. A few caterpillars and maggots specialise in boring into peppers, and because they feed inside, they are hard to spot until the damage is done. Let me help you identify the culprit and protect your crop.

Caterpillars boring into the fruit

The most common cause is a caterpillar. Several species — including corn earworm/fruitworm and the European corn borer in some regions — will chew an entrance hole, usually near the stem cap, and tunnel inside to feed on the seeds and inner walls. You will often see a small hole near the top of the pepper, dark droppings (frass) around it or inside, and a hollowed or rotting interior when you cut the fruit open. The caterpillar may still be inside, or may have moved on to another fruit. The internal damage usually triggers rot, spoiling the pepper.

Pepper maggots and other borers

In some regions the pepper maggot is a specific pest: the adult fly lays eggs in the fruit, and the maggot tunnels inside, causing premature ripening, internal rot, and a small dimple or sting mark where the egg was laid. Other beetles and weevils can also damage pepper fruit. The common thread is an entry point and internal tunnelling, with the outside sometimes looking nearly normal while the inside is ruined — which is why a pepper can look fine until you cut it.

How to protect your peppers

Because the pests feed inside the fruit, prevention is key. Scout regularly and remove any fruit showing entry holes or frass, binning it (not composting) to break the pest's life cycle and stop the next generation. Hand-pick caterpillars you find on the plants. Bt, a natural caterpillar control, applied to the plants can kill young caterpillars before they bore in, but timing matters — it works on caterpillars feeding on the surface, not those already inside. Floating row cover can exclude egg-laying adults, though it must be removed for pollination. Keeping the wider garden clear of related host plants and weeds reduces pressure.

Garden hygiene and timing

Reduce borers over the season and into the next. Clear away crop debris and fallen fruit where pests overwinter or pupate, and rotate crops. Some borers have predictable flight and egg-laying periods, so in regions where a specific pest like the pepper maggot is known, timing protection or harvest to dodge the peak helps. Promptly harvesting ripe fruit, rather than leaving it on the plant, gives borers less opportunity. With regular scouting, prompt removal of affected fruit, and barriers against egg-laying, you can keep fruit borers from ruining your harvest.