Morphology and growth in culture of Microhilum oncoperae, the cause of a mycosis of Oncopera spp. larvae

Abstract

Microscopic and colony morphology of thirteen isolates of the entomopathogenic fungus Microhilum oncoperae were studied under a range of cultural conditions. Contrary to the original description, several conidia can be produced from a single denticle. All thirteen isolates of M. oncoperae were able to germinate, produce hyphae and sporulate on several different mycological media at temperatures between 5 and 25 °C. None of the isolates could grow above 30°, and at 5° isolates differed in the rate of conidial germination. M. oncoperae conidia germinated more rapidly at 5° than those of two Metarhizium anisopliae and five Beauveria bassiana isolates. Selective agars used for isolating other entomopathogenic fungi from soil were inhibitory to the growth of M. oncoperae .