Toxicity of Bacillus thuringiensis to laboratory populations of the olive fruit fly (Dacus oleae)
A survey of Bacillus thuringiensis recovered from the environments of olive groves in Greece was carried out. Of 80 soil samples, 24 were found to contain B. thuringiensis with parasporal crystal inclusions; these were tested for toxicity against the olive fruit fly (Dacus oleae). Mortality levels of larvae caused by the different isolates varied from 7 to 87%. Higher levels of mortality were observed if a mixture of relatively pure crystals and spores was used compared with the mortality resulting from either fraction alone. We were able to show that the toxicity of the most active isolate is likely to be specific for D. oleae.
New flagellar (H) antigenic subfactors in Bacillus thuringiensis H serotype 3 with description of two new subspecies, Bacillus thuringiensis subsp. sumiyoshiensis (H serotype 3a:3d) and Bacillus thuringiensis subsp. fukuokaensis (H serotype 3a:3d:3e)
Abstract Flagellar (H) antigenic structures of the following four strains of Bacillus thuringiensis H serotype 3 were investigated: the type strains of B. thuringiensis subsp. alesti and B. thuringiensis subsp. kurstaki and two soil isolates, 84-F-26-3 and 84-F-51-46. Cross-saturation of H antisera with heterologous H antigens revealed the presence of five H antigenic subfactors (3a, 3b, 3c, 3d, and 3e) in this serotype. H antigenic structures of the type strains of subsp. alesti and subsp. kurstaki (formerly H serotypes 3a and 3a:3b, respectively) were 3a:3c and 3a:3b:3c, respectively. Soil isolates, 84-F-51-46 and 84-F-26-3, had H antigenic structures of 3a:3d and 3a:3d:3e, respectively. These two isolates, which produced similar spherical parasporal inclusions, were toxic to larvae of the three lepidopterous species (Bombyx mori, Hyphantria cunea, and Clostera anastomosis) but nontoxic to larvae of the two mosquito species (Aedes aegypti and Culex tritaeniorhynchus) and the house fly, Musca domestica. Two new subspecies names, Bacillus thuringiensis subsp. sumiyoshiensis (H serotype 3a:3d) and Bacillus thuringiensis subsp. fukuokaensis (H serotype 3a:3d:3e), are proposed for the type strains, 84-F-51-46 and 84-F-26-3, respectively.
Insecticidal activity of HD-1, a new isolate of Bacillus thuringiensis var. alesti.
Abstract Preparations from fermentation beers of HD-1, a new isolate of Bacillus thuringiensis var. alesti , were 200 times more active in laboratory tests against the pink bollworm, Pectinophora gossypiella , the tobacco budworm, Heliothis virescens , and the cabbage looper, Trichoplusia ni , than a typical commercial formulation, and were 20 times more active than an improved commercial product now undergoing tests. The activity of two preparations of HD-1 and the commercial products in the three test species was also compared against the proposed international standard, E-61, produced by the Institut Pasteur, Paris, France. One lot of HD-1, coded HD-1-PL-1, was adopted as a secondary standard; it had a potency of 16,000 IU/mg. The homology of the international standard to the four test materials was considered.