Detection of Nosema locustae (Microsporidia:Nosematidae) in frozen grasshoppers (Orthoptera:Acrididae) by using monoclonal antibodies.

We developed several monoclonal antibodies that recognized germinated and nongerminated spores and other developmental stages of Nosema locustae, a pathogen of grasshoppers, by using spore homogenate as antigen. The hybridomas were produced with standard techniques. Indirect fluorescence assay demonstrated recognition by several antibodies to the spore and extruded polar filament. Monoclonal antibody D10-9-11 recognized the spore wall in smears and frozen sections of infected grasshopper fat body tissue, whereas monoclonal antibody D55-12 also labeled the extruded polar filament. Immunoelectron microscopy showed that monoclonal antibody D10-9-11 recognized the spore and several developmental stages. Enzyme-linked immunosorbent assay showed that monoclonal antibody D10-9-11 did not cross-react with immunogen prepared from other grasshopper pathogens, including Vairimorpha sp., Malameba locustae, and entomopox virus from migratory grasshoppers, Melanoplus sanguinipes (F.).