The Ohio State University Acarology Laboratory (OSAL) collection includes about 117,000 slides (about 67,000 of which incorporated in the main collection) and 17,400 fluid lots (about 15,200 of which part of the main collection), which makes it one of the largest university based mite collections in North America. The collection had its origin in the Acarology Summer Program, and its intensive use in teaching has been a major factor in its development. Rather than focussing on a given taxon, the collection acquisition emphasis has always been on diversity. As a result, almost 75% of the roughly 470 recognized families of Acari are represented, making it one of the most taxonomically diverse collections in the world. Donations by various acarologists over the last 50 years have made the collection particularly rich in secondary (para-) types, of which the collection houses over 3,200.
Major efforts are being made to database this collection at the specimen level in order to make the information contained in it more easily available for both researchers and the general public. Initial retroactive databasing of the main collection of slides and fluid lots (approximately 85,000 slides and fluid lots) was made possible by a National Science Foundation grant (DBI0544963). Current expansion of that effort, including adding images of slide labels, is made possible by another National Science Foundation grant (NSF1115005).
In addition to the mite collection, OSAL also houses a substantial collection of spiders, including the Barrows collection and the holdings of the Ohio spider survey. This part of the collection is managed by Dr. Richard Bradley. Part of the scorpion collection (total ~770 lots), focused on North America, has recently been revised, but the smaller holdings of other Arachnid groups (Opiliones, Pseudoscorpiones, Ricinulei, etc.), have not (yet) been organized.