Phylogeography of Dendroctonus rufipennis Based on mtDNA and Microsatellites

Spruce beetle, Dendroctonus rufipennis (Kirby), is one of the most broadly distributed bark beetles in North America, extending from Alaska to Newfoundland, south to Arizona. It colonizes most species of spruce within its range. Usually it is associated with highly stressed or killed trees, but under certain conditions undergoes landscape level eruptions that kill millions of trees (Werner and others 1977), regardless of their physiological condition (Wallin and Raffa 2004). Populations may be semivoltine or univoltine, depending on temperature (Hansen and others 2001). Spruce beetles show relatively close associations with several species of fungi (Six and Bentz 2003), some of which vary in frequency with beetle population phase (Aukema and others 2005). Adult beetles were collected from sixteen sites extending across the full range of D. rufipennis. DNA was extracted, and approximately 100 beetles were sequenced for mtDNA and approximately 550 beetles were genotyped for microsatellites (Maroja and others subm). Phylogenies were reconstructed by several means, including Maximum Parsimony and Bayesian Posterio