B Babesia A genus of Protozoa that is transmitted to animals by ticks.  Babesiosis  Piroplasmosis Babesiosis Several related diseases caused by infection with Babesia protozoans, and transmitted by ticks.  Piroplasmosis Bacillary Paralysis A disease of silkworm larvae caused by ingestion of spores and parasporal crystals of Bacillus thuringiensis. Bacillus larvae (=Paenibacillus larvae; Bacteria) Te bacterium responsible for causing American foulbrood in honey bees; it is now known as Paenibacillus larvae.  American Foulbrood  Paenibacillus Bacillus sphaericus colin berry Cardiff University, Cardiff, Wales, United Kingdom Te bacterium Bacillus sphaericus is best-known to entomologists because of the toxicity of some strains to the larval stages of mosquitoes. Tis tox- icity will be examined below but frst, some con- sideration of the taxonomic group that is known as “Bacillus sphaericus” is necessary. Taxonomy Identifcation of a bacterium as a B. sphaericus iso- late is based on relatively few morphological fea- tures (e.g., the possession of a spherical terminal spore) and a limited number of biochemical tests (e.g., inability to ferment sugars). As a result, the classifcation contains a heterogeneous collection of strains and it has been shown that, at the DNA level, these can be divided into fve major homol- ogy groups (groups I-V), each of which could be considered as a separate species. All of the insecti- cidal strains of B. sphaericus are found within a subdivision of one of these groups – Group IIA; however, not all strains that fall within this group are insecticidal. It is the insecticidal strains of B. sphaericus and their properties that will be con- sidered further below.