AbstractGroup VII of North American Ips contains I. thomasi, new species, I. borealis Swaine and I. swainei R. Hopping. They are less than 4.0 mm. long and females have the front of the head or at least the vertex smooth and shining, impunctate, or with very fine sparse punctures; males are more coarsely granulate-punctate on the frons. The species are described and a key is given. All breed in Picea in Canada and northern United States.
Manual of the botany of the northern United States.