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Garden pepper

Most pepper plant problems blamed on bugs start small: a few chewed leaves, a curled shoot tip. The pests that matter are the ones that get into the fruit. European corn borer tunnels in under the cap, fruitworm and hornworm chew into it, and stink bugs pierce it. Once a caterpillar is inside a pepper, no spray will reach it, so timing matters more than product.

Aphids turn up on peppers for most of the season, and are usually the least serious of the lot. University of Kentucky entomologists note that lady beetles, lacewings, damsel bugs and hoverfly larvae usually control them adequately, as long as pyrethroid sprays have not killed those predators first.

crop context · bell peppers setting fruit, midsummer

Common pepper plant pests, in the order you meet them

AT TRANSPLANTING

Cutworms

Chew stems at the soil line and leave the severed top uneaten.

ReleaseGround beetlesNothing to release — give them cover
MAY–JUNE

Flea beetles

Shot holes in the leaves of young transplants, worst in spring; the pale-striped flea beetle is one that feeds on pepper.

ReleaseBraconid waspsNothing to release — the native parasitoid is not sold (UMN)
SPRING & AUTUMN

Aphids

Colonies under the newest leaves; leaves curl and turn sticky. Predators usually catch up.

ReleaseHoverfliesWild — attract adults with open flowers
JUNE & AUGUST

European corn borer

Tunnels into the fruit under the cap. The midsummer generation is the one that matters.

ReleaseTrichogramma90,000–120,000 /acre weekly for 4 weeks (UMass); 1–2 /ft² in gardens
JULY ONWARD

Tomato hornworm

Strips leaves and chews holes in the fruit. Easy to hand-pick once you find its droppings.

ReleaseBraconid waspsNothing to release — leave the caterpillar where it is
SUMMER–EARLY AUTUMN

Brown marmorated stink bug

Pierces the fruit, leaving pale, corky areas beneath the skin.

ReleaseSamurai waspWild — conserve; not for release (not sold; interstate movement restricted)
LATE SUMMER

Tomato fruitworm

The corn earworm under another name. Larvae bore into fruit and move from one to the next.

ReleaseDamsel bugsWild — not sold; conserve the ones already present

Season calendar

TEMPERATE US · OUTDOOR PEPPERS · QUALITATIVE
JFMAMJJASOND
CutwormsJan: QuietFeb: QuietMar: QuietApr: BuildingMay: Pest pressure highJun: BuildingJul: QuietAug: QuietSep: QuietOct: QuietNov: QuietDec: Quiet
Flea beetlesJan: QuietFeb: QuietMar: QuietApr: BuildingMay: Pest pressure highJun: Pest pressure highJul: BuildingAug: BuildingSep: QuietOct: QuietNov: QuietDec: Quiet
AphidsJan: QuietFeb: QuietMar: BuildingApr: Pest pressure highMay: Pest pressure highJun: BuildingJul: BuildingAug: BuildingSep: Pest pressure highOct: Pest pressure highNov: BuildingDec: Quiet
Corn borerJan: QuietFeb: QuietMar: QuietApr: QuietMay: BuildingJun: BuildingJul: BuildingAug: Pest pressure highSep: BuildingOct: QuietNov: QuietDec: Quiet
HornwormsJan: QuietFeb: QuietMar: QuietApr: QuietMay: QuietJun: BuildingJul: Pest pressure highAug: Pest pressure highSep: BuildingOct: QuietNov: QuietDec: Quiet
Stink bugsJan: QuietFeb: QuietMar: QuietApr: QuietMay: BuildingJun: BuildingJul: BuildingAug: Pest pressure highSep: Pest pressure highOct: QuietNov: QuietDec: Quiet
FruitwormJan: QuietFeb: QuietMar: QuietApr: QuietMay: QuietJun: QuietJul: BuildingAug: Pest pressure highSep: Pest pressure highOct: BuildingNov: QuietDec: Quiet
Trichogramma (corn borer)Jan: QuietFeb: QuietMar: QuietApr: QuietMay: QuietJun: QuietJul: QuietAug: Release windowSep: QuietOct: QuietNov: QuietDec: Quiet

Starter program

Most of this is things to leave alone. Trichogramma is the one purchase, and it only pays where corn borer has damaged peppers before. Time it to the moth flight, not the calendar.

  1. AT TRANSPLANTINGGround beetlesNothing to release. Put a collar round each stem and leave mulch or a grassy edge where the beetles shelter.
  2. SPRINGHoverfliesNothing to release. Leave aphid colonies that already have larvae in them, and skip pyrethroid sprays.
  3. MIDSUMMER CORN BORER FLIGHTTrichogramma1–2 /ft² per release in gardens, weekly for about 4 weeks from the start of the midsummer moth flight, the generation that reaches peppers. Farms use 90,000–120,000 per acre (UMass).
  4. MIDSUMMERBraconid waspsHand-pick hornworms, but leave any carrying white cocoons.
  5. SMALL CATERPILLARSBt kurstakiLabel rate. Bt kills caterpillars only while they feed on the outside of the plant, so spray small larvae before they enter the fruit. Check that peppers are on the label.

Setting up the garden

The pepper decisions that matter are made before the fruit sets.

Collar every transplant

A cardboard or foil collar, pushed a few inches into the soil, keeps cutworms off the stem.

Leave pyrethroids on the shelf

They kill the lady beetles, lacewings, damsel bugs and hoverfly larvae that usually keep pepper aphids down.

Act before the larvae go in

Corn borer and fruitworm are out of reach once inside the fruit. Any treatment has to land while the eggs are hatching.

Hand-pick stink bugs

Knock adults and nymphs into soapy water and crush egg masses on the leaves. Sprays do little against adults.