Efficiency of using ephemeropteran exuviae for harpellalean research

Abstract

Infection by harpellalean fungi was judged by observing the hindgut lining of exuviae left on stones protruding through the surface of a small stream after the emergence of the ephemeropteran species Isonychia japonica. Both 70% ethanol-preserved and dried specimens that had been preserved for more than 9 years were used. Trichospores (deciduous monosporous sporangia) , hyphae, and holdfasts of a species belonging to Legeriomycetaceae (Harpellales) were detected on specimens irrespective of the method of preservation. Ethanol-preserved specimens were more suited for light microscopic observation. The exuviae of aquatic insects appear to be suitable for harpellalean fungus research.