Aspergillus parasiticus Speare and Beauveria bassiana (Bals.) Vuillemin were isolated from melanopline grasshoppers in Saskatchewan in 1986 and 1987. The pathogenicity of these isolates for Melanoplus sanguinipes (Fabricius) nymphs was assessed by topical, oral, and injected applications of 1.0 × 103, 104, or 105 conidia per individual. The A. parasiticus isolate was pathogenic to M. sanguinipes by injection and topical application but not orally. The B. bassiana isolate was pathogenic when injected or topically applied resulting in high mortality (82–100%), at all doses tested, between days 3 and 5 post-inoculation. Beauveria bassiana was infectious, at the highest dose tested, when orally applied with the majority of mortality occurring between 7 and 14 days post-inoculation.