Larval susceptibility of the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae), to Bacillus thuringiensis H serovars isolated in Japan.
A total of 1700 Japanese strains of Bacillus thuringiensis, belonging to at least 47 H serogroups, were examined for insecticidal activity against larvae of the diamondback moth, Plutella xylostella. The high-level toxicity was associated with 612 isolates (36.0%). Of these, 608 isolates (99.3%) fell into 13 H serogroups belonging to the low-numbered H serotypes, H1-H10. Conversely, most isolates belonging to the high-numbered serotypes (>H10) had little or no larvicidal activity; only one isolate of the serovar japonensis H23 was active. P xylostella larvae were susceptible to 89.8% of the serovar morrisoni H8a:8b strains and 85.7% of galleriae H5a:5b strains. High values of 60-80% were also obtained in six serovars (thuringiensis H1, alesti H3a:3c, kurstaki H3a:3b:3c, kenyae H4a:4c, aizawai H7, and tolworhi H9), while relatively low values of <60% in two other common serovars, sotto H4a:4b and darmstadiensis H10a:10b. Five selected isolates, belonging to H serovars other than kurstaki and aizawai, were 10-60 times less toxic than the reference strain HD-1 (serovar kurstaki). Parasporal inclusion proteins of these strains were immunologically unrelated to those of the strain HD-1 and the aizawai type strain.
Higuchi
K
K
Biotechnology & Food Research Institute, Fukuoka Industrial Technology Center, Kurume, Japan.
Saitoh
H
H
Mizuki
E
E
Ichimatsu
T
T
Ohba
M
M
D000818:Animals; D001413:Bacillus thuringiensis / Q000145:classification / Q000378:metabolism / Q000502:physiology*; D001426:Bacterial Proteins / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D005779:Immunodiffusion; D002479:Inclusion Bodies / Q000378:metabolism; D007564:Japan; D007814:Larva / Q000254:growth & development; D009036:Moths / Q000254:growth & development*; D010572:Pest Control, Biological; D012703:Serotyping; D013171:Spores, Bacterial / Q000254:growth & development
D001426:Bacterial Proteins