A large-scale operational field trial was conducted from June 1993 to October 1994 to evaluate the efficacy of Bacillus sphaericus (strain B-101, serotype H5a,5b) for control of the vectors of filariasis (Culex quinquefasciatus) and Japanese encephalitis (Cx. tritaeniorhynchus and Cx. vishnui) in Rourkela city. Application of B. sphaericus, when sprayed at 1 g/m2 in storm drains, wastewater poo...

Field resistance to Bacillus sphaericus was observed in a population of Culex quinquefasciatus in Kochi, India, exposed to 35 rounds of spraying with a formulation of B. sphaericus 1593 M over a 2-year period. Larvae from the sprayed area gave LC50 and LC90 values that were 146 and 180 times greater than corresponding values for a susceptible strain from an unsprayed locality. When the resistan...

Biological fitness components of a field-collected colony of Culex quinquefasciatus Say that was highly resistant to Bacillus sphaericus strain 2362 (resistance ratio greater than 163,000) after 46 generations of selection were compared to those of a susceptible colony (CqSF) that had originated from the same parental cohort but that had not been exposed to B. sphaericus. The effect of B. sphae...

Gram positive aerobic or facultatively anaerobic spore forming gram positive bacilli were first identified by Christian Gottfried Ehrenberg in 1885 and were later classified by Ferdinand Cohn in to a separate genus Bacillus [1]. Aerobic spore forming gram positive bacteria are commonly referred to as ASB’s and includes members of Bacillus spp which are basically saprophytes living as thermophil...

In the course of sporulation, some strains of Bacillus sphaericus synthesize a parasporal inclusion or "crystal" (Fig. 1), which contains proteins toxic for larvae of a variety of mosquito species (64, 74). Upon completion of sporulation, the crystal remains associated with the endospore, both being enclosed within the exosporium (74). The major components of the crystal are two proteins of 51 ...

We have shown that urea-extracted cell wall of entomopathogenic Bacillus sphaericus 2297 and some other strains is a potent larvicide against Culex pipiens mosquitoes, with 50% lethal concentrations comparable to that of the well-known B. sphaericus binary toxin, with which it acts synergistically. The wall toxicity develops in B. sphaericus 2297 cultures during the late logarithmic stage, earl...

Tetragonal layer protein (T-layer) isolated from Bacillus sphaericus NTCC 9602 (wild type) or 9602 Lmw (variant) bonded specifically to the sacculi (peptidoglycan) of either cell type. Only uncleaved T-layer subunits were capable of specific recognition of the B. sphaericus sacculi; other Bacillus strains and gram-positive bacterial sacculi would not adsorb B. sphaericus strain 9602 T-layer. Th...

Insecticide resistance to the microbial insecticides Bacillus thuringiensis subsp. israelensis (Bti) and Bacillus sphaericus (Bs) represents a serious threat to their success. Available evidence indicates that the risk for resistance to Bti is low due to the makeup of its parasporal crystal, which contains Cyt1A, Cry4A, Cry4B, and Cry11A toxic proteins. Disrupting the toxin complex in Bti enabl...