The fungal communities associated with individual bark and ambrosia beetle specimens were characterised using Illumina Miseq pair end sequencing of ITS2 amplicons. Beetle specimens were collected in UK plantation pine forests over summer 2013.

Bark and ambrosia beetles (Curculionidae: Scolytinae) are known for their symbioses with fungi and play a key role in the dispersal of phytopathogens. The scolytine community of eight pine stands along a latitudinal gradient in the UK was surveyed and beetle-associated fungal communities (mycobiota) were assessed using ITS2 metabarcoding (304 specimens, 12 species). Distribution patterns among 2,257 detected fungal Operational Taxonomic Units (OTUs) revealed that beetle species identity was an important predictor of mycobiotic richness and composition, while the effects of environmental and spatial variables were negligible. Network-based specificity analysis suggested that a relatively small subset of OTUs (75 in total) exhibit an affinity for a subset of beetle species and that these include many Microascales and Saccharomycetes. Notably though, of the OTUs belonging to the family Ophiostomataceae, relatively few display host specificity. Our results add to the complex picture of host-associated fungal communities and suggest that host range limits are unlikely to restrict the spread of economically important phytopathogens.