While maintained under all combinations of three temperatures and two RH, fifth instar larvae of the Mediterranean flour moth, Ephestia kuehniella were fed wheat treated with spores and crystals of Bacillus thuringiensis var. kurstaki. Larvae that had fed on wheat with the bacterial preparation contained higher concentrations of nodules in their haemocoel than did larvae fed on wheat without ba...

Batch and fed-batch cultivation of Bacillus thurillgiellsis var. kurstaki was carried out to achieve high cell and spore density with maximum insecticidal activity. Cell cultivation was done in fully equipped fermentors under controlled conditions at different feed rates. Increased cell mass, high spore counts and improved insecticidal activity were achieved with fed-batch cultivation system. W...

Ever since the discovery of the first Bacillus thuringiensis strain capable of killing mosquito larvae, namely, B. thuringiensis var israelensis, there are several reports from different parts of the world about the occurrence of mosquitocidal strains belonging to different subspecies/serotypes numbering thirty-six. The main sources of these wild type strains are soils/sediments, plants, animal...

Resistance to the microbial insecticide Bacillus thuringiensis Berliner has evolved in field populations of diamondback moth, Plutella xylostella (L.), in Hawaii. Three field populations that had been treated repeatedly with commercial formulations of the sporecrystal protein complex of B. thuringiensis subsp. kurstaki developed significant resistance to it. The LC50 of the most resistant popul...

Bacillus thuringiensis is the most widely used bacterial bio-insecticide, and most insecticidal crystal protein-coding genes are located on plasmids. Most strains of B. thuringiensis harbor numerous diverse plasmids, although the plasmid copy numbers (PCNs) of all native plasmids in this host and the corresponding total plasmid DNA amount remains unknown. In this study, we determined the PCNs o...