All four North American species have been associated with Vitaceae.
O. whiteheadi is associated with Vitis (wild grape, Vitaceae) in AZ(2)
Print References
Yoshitake, Hiraku and Robert S. Anderson. 2015. A review of the genus Orchestomerus Dietz (Coleoptera: Curculionidae: Ceutorhynchinae: Cnemogonini) of the USA. The Coleopterists Bulletin 69(4): 565–578.