BeneficialTobacco hornworm
Bt (kurstaki) for tobacco hornworm
Bacillus thuringiensis kurstaki · microbial insecticide
Against tobacco hornworm
Tobacco hornworm is managed exactly like the tomato hornworm. Bt works only if the caterpillar eats it, so cover the leaves it is feeding on, and it works best on young larvae. A full-grown hornworm is easier to pick off by hand. Leave any hornworm carrying white cocoons alone, because the Cotesia wasps inside it are already killing it.
RateLabel rate — DiPel DF lists tobacco hornworm (0.5–1.0 lb per acre on tobacco); the Thuricide home label names only tomato hornworm, at 1–3 tsp per gallon on tomato, pepper and eggplant
TimingAt the first droppings or feeding, while caterpillars are small; repeat while they are active
macro · bt (kurstaki) on tobacco hornworm
The pestTobacco hornwormManduca sextaWhole leaves eaten, green fruit gougedFull pest profile →Before you order
A bacterium sprayed on leaves. Caterpillars that eat it stop feeding and die within a few days. It works only on the larvae of moths and butterflies, and has little or no effect on bees, lady beetles, lacewings or parasitic wasps. How it works, how to tell it has established and the supplier list are on the full Bacillus thuringiensis kurstaki profile.
Other controls for tobacco hornworm
- Braconid waspsWild parasitoid · Nothing to release — leave the caterpillar where it is
- Tachinid fliesWild parasitoid · Wild — keep nectar plants near the crop, no broad-spectrum sprays
- Trichogramma spp.Egg parasitoid wasp · 50k–100k /acre weekly (1–2 /ft² in gardens)
- Paper waspsWild predator (stings) · Wild — tolerate nests away from doors and paths