BeneficialDiamondback moth
Bt (kurstaki) for diamondback moth
Bacillus thuringiensis kurstaki · microbial insecticide
Against diamondback moth
UF/IFAS calls Bt especially important for diamondback moth because it favours the survival of parasitoids such as Diadegma insulare. But resistance to some Bt products occurs in some areas. UF/IFAS and UMass advise alternating kurstaki with the aizawai strain (e.g. XenTari), which usually works better on resistant populations. Transplants shipped from the South can carry resistant larvae.
RateLabel rate — Thuricide 1–2 tsp per gallon for diamondback moth on cole crops; DiPel DF 0.5–2 lb per acre
TimingOn small larvae from the first windowpane feeding, especially just before heading; rotate with other modes of action
macro · bt (kurstaki) on diamondback moth
The pestDiamondback mothPlutella xylostellaSmall holes and translucent "windowpanes" in brassica leaves; damaged growing pointsFull 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 diamondback moth
- Braconid waspsWild parasitoid · wild, attract it
- Trichogramma spp.Egg parasitoid wasp · 50k–100k /acre weekly (1–2 /ft² in gardens)