Four novel Bacillus thuringiensis strains, which are deposited at the
BCCM-LMG under accession nos. LMG P-12592, LMG P-12593, LMG P-12594, and
LMG P-13493, produce new crystal proteins during sporulation that are
toxic to Lepidoptera, more particularly against Noctuidae such as
Spodoptera spp. and Agrotis ipsilon, against Pyralidae such as Ostrinta
nubilalis, and against Yponomeutidae such as Plutella xylostella, and that
are encoded by a novel gene. The crystal proteins contain protoxins, which
can yield a toxin as trypsin-digestion product. A plant, the genome of
which is transformed with a DNA sequence that comes from either one of the
strains and that encodes its respective toxin, is resistant to
Lepidoptera. Each strain, itself, or its crystals, crystal proteins,
protoxin or toxin can be used as the active ingredient in an insecticidal
composition for combatting Lepidoptera.
