The first-ever in-Russia discoveries of the entomopathogenic fungus Akanthomyces uredinophilus from the Republic of Adygea

The first finding of cryptic entomopathogenic fungus Akanthomyces uredinophilus (Ascomycota, Hypocreales, Cordycipitaceae) in Russia is reported. Specimens were found in 2019 and 2022 in the North Caucasus at two 60 km distant points in the Republic of Adygea (1st – southern outskirts of Maykop, wooded damp ravine, N44°34ʹ24ʺ E40°08ʹ54ʺ, 240 m a. s. l.; 2nd – vicinity of Nickel settlement, Syuk River gorge, N44°10ʹ46ʺ E40°09ʹ29ʺ, 570 m a. s. l.) on dead insects: alien North American species of сitrus flatid planthopper Metcalfa pruinosa (Hemiptera, Auchenorrhyncha, Flatidae), whitefly Aleyrodes lonicerae (Hemiptera, Aleyrodidae), psyllid (Hemiptera, Psylloidea), and cranefly (Diptera, Tipuloidea). We have demonstrated high morphological and genetic (five gene loci EF1A, RPB1, RPB2, LSU and SSU) similarity of Adygean isolates with the type strain KACC44082 (Republic of Korea) from uredinia of the rust fungus Pucciniastrum agrimoniae and other isolates of Akanthomyces uredinophilus previously found in China and Argentina on dead insects. Under laboratory conditions all four Adygean isolates showed high virulence against larvae of population of green peach aphid Myzus persicae (Hemiptera, Aphididae) feeding on Vicia faba under experimental conditions including 25 ± 1°C temperature and spraying suspension with a spores (conidia) concentration 107 per 1 ml aphid mortality ranged from 30% [isolate MPi-Ad(Mp)19→Ak6] to 89% (isolate HPs – Ad22→B10) after three days. After seven days the mortality reached 100% in all variants, while it was only 15% in the control sample. This indicates the expediency of further study of these isolates as potential producers of commercial mycoinsecticides against harmful phytophagous insects.