Phylogenetic Comparison of Ascomycete Mycangial Fungi and Dendroctonus Bark Beetles (Coleoptera: Scolytidae)

The existence of a long-shared evolutionary history among Dendroctonus bark beetles and their symbiotic mycangial fungi (Ascomycotina: Ophiostomataceae) was investigated by comparing independently derived phylogenies of the 2 groups of organisms. Two phylogenetic comparisons were made. In the 1st comparison, all mycangium-associated fungi were included in the fungal phylogeny (some beetles possessed 2 mycangial associates). In the 2nd comparison, only the most common mycangial associate of each beetle was included. Statistical tests did not support the existence of widespread cospeciation among the beetles and fungi in the 1st comparison. In the 2nd comparison, a maximum of 4 cospeciation events was statistically supported.