Lack of toxicity to adults of the Mexican fruit fly (Diptera: Tephritidae) of beta-exotoxin in Bacillus thuringiensis endotoxin preparations.
beta-Exotoxin (thuringiensin) was found in high titers in centrifugation supernatants and acetone/lactose powders produced from centrifugation pellets of strains Guat 1 and HD 2 of Bacillus thuringiensis (Berliner). Diets containing powders of either strain were toxic, diets containing Guat 1 supernatant were not toxic, diets containing HD 2 supernatant were slightly toxic, and diets containing powders or supernatants from uninoculated culturing medium spiked with beta-exotoxin were not toxic. Most mortality occurred within 3 d when flies fed on powders but not until 6-7 d when flies fed on HD 2 supernatant. These results indicated that the primary toxic principals of the powders were endotoxins/spores and that beta-exotoxin alone was not toxic to adult flies at the concentrations found in the supernatants or powders.
Robacker
D C
DC
Crop Quality and Fruit Insects Research, USDA-ARS, Weslaco, TX 78596, USA.
Garcia
J A
JA
Martinez
A J
AJ
D000241:Adenosine / Q000031:analogs & derivatives*; D000818:Animals; D001413:Bacillus thuringiensis; D001427:Bacterial Toxins; D004175:Diptera; D004731:Endotoxins / Q000302:isolation & purification; D010572:Pest Control, Biological / Q000379:methods*; D013400:Sugar Acids
D001427:Bacterial Toxins; D004731:Endotoxins; D013400:Sugar Acids; C068295:thuringiensin; D000241:Adenosine