Metarhizium cylindrosporae CHEN et GUO (Deuteromycotina : Hyphomycetes), the Causative Agent of an Epizootic on Graptopsaltria nigrofuscata MOTCHULSKI (Homoptera : Cicadiae)

Abstract

An epizootic of a Metarhizium specis occurred in a population of the large brown cicada, Graptopsaltria nigrofuscata, in forests of Japanese alder, Alnus japanica, in Ibaraki, Japan. The average density of the cadavers of G. nigrofuscata per trunk base (defined as the bottom 6 m of trunk) was 9.3 in the center of the epizootic. Living adults were seldom observed. The isolates produced 2 types of conidia, macro- and microconidia, on a common phialide. Macroconidia were cylindrical to banana-shaped, 16.9×3.8 μm, and microconidia were ellipsoid, 5.4×2.7 μm. The conidial chain was united in a column. Cultures derived from either micro- or macroconidia produced 2 types of conidia. This fungus was identified as Metarhizium cylindrosporae, although only macroconidia had been described in its original description.