Mountain pine beetles (Dendroctonus ponderosae Hopk.) have their own microbiome, and it is poorly understood. A microbiome is the community of organisms that share space with the mountain pine beetle - they could be symbiotic, pathogenic or commensal. Better understanding of this varied community occurring at different beetle population levels may elucidate factors affecting fluctuations in beetle populations. The biogeography of the Colorado Rocky Mountains allowed scientists to examine various components of this microbiome in different tree hosts for the beetle.
Scientists studied the fungal and mite aspects of the mountain pine beetle microbiome as the beetles attacked host trees ranging in elevations of 1800 to 3000 meters in the Roosevelt Forest in Colorado. Until now, the mite and fungal associations were not known.
This research found that mites were found to carry both beneficial and potentially detrimental fungal species to the beetle.
The frequency of several organisms varied significantly between some years but not within hosts or elevation.
Populations of omnivorous mites combined with reductions of blue-stain associates correlated with population decline of the bark beetle.
Changes in microbiome populations correlated with beetle population changes and provide new evidence contributing to understanding beetle fluctuations.
Previously undocumented species of mite and fungal associates from southern Rockies were found during the study.
Our findings strengthen our knowledge of the distribution of important microbiome components of the beetle in Colorado.