Trichogramma wasps for tomato hornworm
Hornworm moths lay pale green eggs on the leaves, and Trichogramma attack them. UC IPM notes that wasps released against tomato fruitworm also parasitise hornworm eggs. Rincon-Vitova releases T. pretiosum or T. minutum weekly against hornworm in large garden plantings. The wasps do nothing to a caterpillar that has already hatched. So check the leaves for eggs before you order, and look for blackened eggs a few days after each release. In a small garden, hand-picking is still the standard control.
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.
How many do I need?
Area and infestation level in; quantity, cost and a weekly schedule out. Open the calculator →
Other controls for tomato hornworm
- Bacillus thuringiensis kurstakiMicrobial insecticide · Label rate — Thuricide 1–3 tsp per gallon for tomato hornworm; Monterey B.t. 4 tsp per gallon
- Braconid waspsWild parasitoid · Nothing to release — leave the caterpillar where it is