Ice crawlers (Insecta: Grylloblattodea) are rarely encountered insects that consist of five genera representing 26 species from North America and Asia. Asian grylloblattids are the most diverse, but North American ice crawlers (genus Grylloblatta) are known for their adaptation to cold conditions. Phylogenetic relationships among grylloblattid species and genera are not known. Late Pleistocene glaciations had a major effect on the current Grylloblatta distribution, because their specific habitat requirements restrict them to small geographical areas. Six genes were sampled in 37 individuals for 18S rRNA, 28S rRNA, histone 3, 12S rRNA, 16S rRNA, and cytochrome oxidase II (COII) from 27 populations of Grylloblatta, three populations from Japan (genus Galloisiana), and three populations from Russia (genus Grylloblattina). An additional 35 individuals from these localities were sampled for COII only. Phylogenetic analysis with two mantophasmid outgroups in POY indicates monophyletic genera, with Grylloblatta as sister to Grylloblattina. Two major lineages exist within Grylloblatta: a clade in Northern California and Oregon and a clade in Washington and Oregon. One new species and up to six candidate spacies are possible based on these data. Fossils and geological events provide little evidence for dating grylloblattid divergence times. At least six Grylloblatta lineages existed before the end of the Pleistocene glaciation. Conservation status for each lineage is proposed, based on IUCN Red List Conservation Criteria.



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Life Sciences; Biology



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Grylloblattodea, entomology, biogeography, conservation, phylogenetics, systematics, DNA, IUCN, insects, fossils, Pleistocene

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