Conidioogenous cell differences among mutant and wild-type pathotypes of Hirsutella thompsonii var. thompsonii

Two mutants with different conidiogenesis were isolated from wild phatotypes of Hirsutella thompsonii var. thompsonii collected from the citrus rust mite in Florida. One mutant (WSI) produces more typical single-neck phialides and conidia than the wild type. The other mutant (SS) was developmentally altered in producing condiogenous cells earlier than the wild type as well as phialides with multiple neck capable of conidiogenesis. The mutant (SS) appeared more virulent than mutant (WSI) and the wild type when bioassayed using the citrus rust mite as a host.