Excerpt: Berlese or Tullgren funnel methods of extraction of forest litter fauna often produce minute arthropods called pseudoscorpions. These are relatively common but have received little attention. Because of the author's involvement with the Michigan State University soil zoology research project the potential significance of these animals has become a matter of interest. The Pictorial Key (Figs. 1 and 2) has been designed to assist in the identification of Michigan pseudoscorpions, and will be a useful starting point for further study of our species. Because pseudoscorpions are predaceous on many soil arthropods (Hoff, 1949), they are important in soil arthropod population dynamics, food chain and humification-fertility studies, and pesticide residue detoxication.
During this study, collecting was limited mostly to forest situations. Samples were taken from 40 counties throughout Michigan, during four major time periods. During the summer of 1963, a substantial amount of material was collected from Alpena County. In March 1966, forest litter was collected from 20 counties. In the summer of 1966, specimens were collected from Grand Traverse County and surrounding areas. In the spring of 1968, collections were made throughout the northern Lower and Upper Peninsulas.
Manley, Gary V.
"A Pictoral Key and Annotated List of Michigan Pseudoscorpions (Arachnida: Pseudoscorpionida),"
The Great Lakes Entomologist, vol 2
Available at: https://scholar.valpo.edu/tgle/vol2/iss1/1