Dc. Steinkraus et Sy. Young, Bacillus thuringiensis for use against armyworm, Pseudaletia unipuncta (Lepidoptera : Noctuidae), on wheat, FLA ENTOMOL, 82(2), 1999, pp. 209-218
Spray table tests with Bacillus thuringiensis (Javelin WG) on wheat leaves
against armyworm, Pseudaletia unipuncta (Haworth), showed that Ist and 3rd
instars had LC(50)s of 0.09 and 0.55 kg per ha, respectively, 7 d after tre
atment. Wheat sprayed in the field in 1995 with Javelin WG at rates of 0, 0
.28, 0.56, 1.12, and 2.24 kg per ha resulted in 82% and 62% Ist instar mort
ality 7 d after feeding on treated flag and middle leaves, respectively, at
the highest rate. In 1996, the test was repeated and mortality was higher,
with 98, 97, and 92.9% Ist instar mortality 7 d after feeding on treated f
lag, middle, and bottom leaves, respectively, at the highest rate. Third in
stars were less susceptible, with 89, 81, and 76% mortality 7 d after treat
ment at the highest rate on flag, middle, and bottom leaves, respectively.
Leaf position had little effect on spray droplet numbers or mortality of la
rvae fed treated leaves, indicating that spray distribution was relatively
even throughout the wheat canopy.