First Record of Raffaelea promiscua Associated with Ambrosia Beetles in Korea

In the present study, we isolated a fungus from an ambrosia beetle collected from a trapin an apple orchard in Gunwi-gun, Daegu, South Korea. The isolate was designated asARI-25-A11. To classify the strain at a species level, both morphological and molecularanalyses were conducted, and its phylogenetic position was determined. For culturalcharacterization, ARI-25-A11 was cultured on 2% malt extract agar at 25°C for 10 days, resulting in a colony diameter of 30.4-32.9 mm. White mycelium was observed at the center, and as the incubation period progressed, the center gradually darkened from olive to brown.Morphologically, the conidiophores were mononematous, septate, and hyaline, whereasthe conidia were aseptate, predominantly oval, with an enlarged upper part and a taperedbase, measuring an average of 5.9 × 3.5 ?m. For molecular identification, the large subunitribosomal RNA (LSU), small subunit ribosomal RNA (SSU), and ?-tubulin (?-tub) genes wereamplified and sequenced. The LSU and SSU sequences showed 100% identity with those ofRaffaelea promiscua PL1001, and the ?-tub gene sequence completely matched that of bothR. promiscua PL1001 and CMW55899T. Phylogenetic analysis identified ARI-25-A11 withinthe same clade as R. promiscua. Based on morphological and molecular data, ARI-25-A11was identified as R. promiscua, representing the first report of this species among ambrosiabeetles in Korea.