Bacillus thuringiensis (BT)

Bacillus thuringiensis (BT) is a naturally occurring bacteria that causes diseases in many different insects. The advantage of this bacteria is the various strains of are specific to certain types of insects. For example, when the kurstaki strain of Bt is used to control plant-feeding caterpillars, Ladybird beetles, lace wings and pirate bugs are not affected by the treatment.

    Strains of Bt and the insect pests they control *

  • aizawai - Lepidoptera species such as Geranium Budworm, Peach twig borer, European corn borer, armyworm, grapeleaf skeletonizer
  • israelensis - fly species such as the fungus gnat, a pest of many house plants
  • kurstaki - Lepidoptera species - similar to aizawai
  • Serotype H-14 - labeled for mosquito larva
  • tenebrionis - Coleoptera (beetles) such as Colorado potato beetle, elm leaf beetle and cottonwood leaf beetle

* Extracted from Volume 8, 1995 Insect Control Guide, Meister Publishing Company.

As with any insecticide these materials should be applied when the insect is small and newly-hatched.