Monocrepidius Eschscholtz, 1829 .

This genus appears in older checklists as Conoderus Eschscholtz, 1829 (see Kundrata et al. 2019 for generic change justification). Conoderus is still retained by some authors (e.g., Mathison 2021), but we follow Kundrata et al. (2019). This checklist documents a slight westward range extension for Monocrepidius vespertinus (Fabricius) .Although both Montana species, Monocrepidius auritus (Herbst) and M. vespertinus, are often considered economically important in other states (e.g., Jewett 1940 and Willis et al. 2010, respectively), their status in Montana is unclear. Monocrepidius auritus larvae are often confused with Aeolus livens larvae, so their presence in agricultural fields may be under-reported.