Results are reported from the first two years of a multi-year study on the distribution of terrestrial isopods (Crustacea: Isopoda) in Michigan. During the first year of the study (1997), intensive investigations were carried out using pitfall traps in a small area of Midland, MI. The study was resumed in 2001 with opportunistic collection and hand-sorting of litter samples for terrestrial isopods throughout 30 Michigan counties. As a result of this data collection, the species Haplophthalmus danicus, previously unrecorded in the state, has been located in seven counties, and 83 new county records have been established for eight other terrestrial isopod species in Michigan. In particular, this study adds extensively to distributional knowledge for four species so far: Hyloniscus riparius, Trichoniscus pusillus, Oniscus asellus, and Armadillidium vulgare. Another species, Armadillidium nasatum, previously reported only inside greenhouses in three somewhat southern locations in the state, was found as clearly well-established outdoor populations in two additional counties further north. Habitat/microhabitat information is presented for all species.
Stoyenoff, Jennifer L.
"Distribution of Terrestrial Isopods (Crustacea: Isopoda) Throughout Michigan: Early Results,"
The Great Lakes Entomologist, vol 34
Available at: https://scholar.valpo.edu/tgle/vol34/iss2/4