BeneficialCorn earworm
Trichogramma wasps for corn earworm
Trichogramma spp. · egg parasitoid wasp
Against corn earworm
Corn earworm, called tomato fruitworm on tomato, lays its eggs singly on leaf hairs and corn silk, the stage Trichogramma attack. UC IPM recommends releasing T. pretiosum at 100,000 per acre during egg-laying in tomatoes and checking the eggs for parasitism within a few days. Once a larva has entered the ear or the fruit, the wasps can do nothing to it.
RateAbout 100,000 T. pretiosum per acre during egg-laying (UC IPM, tomato); 1–2 /ft² in gardens (Sound Horticulture)
TimingThrough the egg-laying period, from the first eggs on leaves or fresh silk; check eggs for blackening a few days after each release
Temperature18–29 °C best; weaker at 15 °C
macro · trichogramma wasps on corn earworm
The pestCorn earwormHelicoverpa zeaEar tips eaten and full of frass; holes in tomato fruitFull pest profile →Before you order
Released weekly from cards while moths are flying and laying; the wasps kill the eggs before a caterpillar hatches. How it works, how to tell it has established and the supplier list are on the full Trichogramma spp. profile.
Release calculator
How many do I need?
Area and infestation level in; quantity, cost and a weekly schedule out. Open the calculator →
Other controls for corn earworm
- Bacillus thuringiensis kurstakiMicrobial insecticide · Label rate — DiPel DF lists corn earworm/tomato fruitworm; Thuricide 2–4 tsp per gallon on tomato claims suppression only
- Orius insidiosusPredatory bug · 1–2 /m² per release; up to 10 /m² on hot spots
- Braconid waspsWild parasitoid · wild, attract it
- Damsel bugsWild predator · Wild — not sold; conserve the ones already present