Longitarsus melanurus (Melsheimer) was first associated with Onosmodium Michx. by Popenoe (1877) in Kansas where the sole species is O. molle Michx. (Great Plains Flora Assn. 1986). Recent field observations over several years showed that adults of L. melanurus feed on leaves of O. molle in Wisconsin, where these beetles were collected at 43 of the 59 sites where O. molle was found growing naturally (Williams 1996).
Williams, Andrew H.
"Longitarsus Melanurus (Coleoptera: Chrysomelidae) Reproduces on Onosmodium Molle (Boraginaceae),"
The Great Lakes Entomologist, vol 35
Available at: https://scholar.valpo.edu/tgle/vol35/iss1/7