Diagnosis of the major entomopathogenic fungus Metarhizium anisopliae using ultra-fast PCR

Abstract

Because of the use of Protaetia brevitarsis seulensis (Coleoptera: Cetoniidae) larvae (for foods) and imago (for educational pets), the number of farmers breeding this insect has been increasing. Breeding requires a fast and accurate diagnostic method for early detection of insect diseases, to avoid losses. Metarhizium spp. frequently infect P. b. seulensis larvae; Metarhizium anisopliae (Ma) is the pathogenic species in more than 80% of cases. However, conventional PCR takes several days to identify the fungus. We utilized a portable ultra-fast PCR machine to identify entomopathogenic fungi from infected sawdust or tissues. We used a one-stop method that does not require genomic DNA to be isolated at the breeding farm. Pathogen samples were extracted at the farm, and detection of entomopathogenic fungi was possible within approximately 12 minutes. Relative quantification was also possible, which will enable estimation of disease progression.