Melanotus Eschscholtz, 1829 .

This checklist provides a considerable westward expansion of the ranges for four Montana species in the genus, Melanotus castanipes (Paykull), Melanotus communis Gyllenhal, Melanotus decumanus (Erichson), and Melanotus emissus (LeConte), which have previously been recorded from South Dakota (Kirk and Balsbaugh 1975; Quate and Thompson 1967). The other two species that occur in the state, Melanotus similis (Kirby) and Melanotus oregonensis (LeConte), are comparatively widespread in Montana and have been reported as economically important in other states, but do not appear so for Montana. Melanotus oregonensis has typically been treated as a subspecies of Melanotus longulus (LeConte), including in Seibert (1993), but we follow Fall (1934), Van Dyke (1943), and Lane (1971) here and recognize it as a distinct species. It should also be noted that in Quate and Thompson (1967), the most recently published key to North American species, species recorded from Montana, except for M. similis and M. oregonensis, are misprinted Missouri records.