The INHS Insect Collection, which comprises ca. 7 million prepared specimens as well as noninsect arthropods (e.g., arachnids and myriapods) and miscellaneous invertebrates (bryozoans), is one of the largest and oldest entomological collections in North America.
Specimen holdings emphasize the upper midwestern USA but are global in scope for certain groups, particularly Coleoptera, Collembola, Diptera, Hemiptera (Auchenorrhyncha), Hymenoptera (Apoidea), Lepidoptera, Plecoptera, Psocodea (Psocoptera + Phthiraptera), Thysanoptera and Trichoptera. The collection contains significant historical holdings from Illinois dating to the mid-1800s, including at least 3,079 primary and >10,000 secondary type specimens.