Margaiostus Stibick, 1976 .

The species in this genus are considered rare and may be headed toward extinction, as suggested by Stibick (1978). The most recent Montana specimen of Margaiostus glacialis (Van Dyke) (Fig. 1c) was collected in 2013 and the next most recent collection of Montana M. glacialis specimens was in 1990, supporting its rarity and suggesting that it may still exist in highly localized populations.