Mycobiota of Ips sexdentatus (Börner, 1776) (Coleoptera, Curculionidae: Scolytinae) in Belarus

Abstract

The fungal component of the microbiome associated with the six-toothed bark beetle Ips sexdentatus (Börner, 1776) in the territory of Belarus was studied in order to clarify the role of this xylophage as a vector of dangerous phytopathogenic fungi. More than 360 pure fungal cultures isolated from the surface and hemocoel of I. sexdentatus were analyzed by morphological and molecular genetic methods, and 35 species from 25 genera, 17 families, and 3 divisions of fungi were identified. All these species were conventionally classified into three groups based on their impact on wood: (1) fungi that cause wood discoloration (mold, blue stain, etc.), (2) fungi that cause rot in living trees and cut wood, and (3) fungi whose effect on harvested timber remains unclear. Five species of Ophiostomataceae fungi associated with blue rot were identified: Leptographium Lagerb. & Melin sp., Ophiostoma ips (Rumbold) Nannf., O. minus (Hedgc.) Syd. & P. Syd., O. canum (Münch) Syd. & P. Syd., and O. piceae (Münch) Syd. & P. Syd. The root rot agent Heterobasidion annosum (Fr.) Bref. was detected in 7.8% of the studied fungal samples. The fairly high occurrence of I. sexdentatus confirms its participation in the development of complex pine dieback foci in Belarus. A considerable level of infection with four species of entomopathogenic fungi (11.4%) was recorded in the I. sexdentatus population by molecular genetic methods.