Bark beetles found in piñons in New Mexico form symbiotic relationships with Ophiostomatoid fungi. Recent findings indicate that bark beetles and their fungal symbionts are also associated with bacteria that may act as neutralizing agents against antagonistic fungi and thereby facilitate bark-beetle-fungal pathogenesis. Our goal was to identify some of the common bacteria associated with Ophiostomatoid fungi and bark beetles. Ophiostoma cultures were isolated from bark beetles, tree cores, and fruiting bodies from infected piñons on experimental drought plots at the Sevilleta Long Term Ecological Research site in New Mexico.  Bacteria were isolated from Ophiostomatoid isolates and DNA was extracted, amplified, and sequenced using 16S rDNA primers.  

Results/Conclusions

Ophiostomatoid fungi were highly colonized by a large number of bacteria. Among common bacterial isolates were close relatives of Erwinia, a plant pathogen within the family Enterobacteriaceae and other gut-associated bacteria associated with Ips pini (pine engraver) and Dendroctonus frontalis (southern pine beetle). Other isolates were closely related to Serratia, a bacterium found in ants and other insects. Possible roles of these bacteria on massive  P. edulis die-offs in New Mexico will be discussed.