Bioassay of Bacillus thuringiensis Formulation Using Larvae of the Diamondback Moth, Plutella xylostella L.

Abstract

A bioassay of Bacillus thuringiensis subsp. kurstaki formulation to larvae of the diamondback moth, Plutella xylostella L. using an artificial diet was performed. When the reference formulation was bioassayed, the variance of LC₅₀ was nearly the same as that with the silkworm (Bombyx mori L.). The potency of the sample was calculated by the formula below to estimate BMU (Bombyx mori unit) and PXU (Plutella xylostella unit).
Potency of sample=LC₅₀ reference formulation/LC₅₀sample×1, 000 BMU/mg (orPXU/mg)
A sufficiently high correlation coefficient between BMU and PXU (r=0.997) was obtained. BMU calculated from PXU was very close to the experimental results.