BeneficialFall armyworm
Bt (kurstaki) for fall armyworm
Bacillus thuringiensis kurstaki · microbial insecticide
Against fall armyworm
UF/IFAS says Bt is the only currently feasible biological product against fall armyworm, and that success depends on it being on the foliage when the larvae first appear. In corn that means getting it into the whorl. Neither home label we checked (Thuricide, Monterey B.t.) lists armyworms, but DiPel DF does.
RateLabel rate — DiPel DF lists armyworms (Spodoptera spp., including fall armyworm), 0.5–2 lb per acre on corn and turf; on several crops the label calls for the higher rates against Spodoptera. Check that a home product names armyworms
TimingWhen larvae first appear, while they are small; repeat as the label directs
macro · bt (kurstaki) on fall armyworm
The pestFall armywormSpodoptera frugiperdaLawns browned in a moving front; ragged corn whorls full of frassFull 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 fall armyworm
- Steinernema carpocapsaeNematode · 25 million per 1,000 ft² (about 270,000 /m²) for cutworms and armyworms in turf (UC IPM)
- Braconid waspsWild parasitoid · wild, attract it
- Ground beetlesWild predator · wild, attract it
- Orius insidiosusPredatory bug · 1–2 /m² per release; up to 10 /m² on hot spots