Crabro villosus is a species in the order Hymenoptera ("ants, bees, wasps and sawflies"), in the class Insecta ("insects"). It is found in North America.Sharkey M.J. (2007). Hylogeny and Classification of Hymenoptera."Phylogenetic relationships among superfamilies of Hymenoptera", Sharkey M.J., Carpenter J.M., Vilhelmsen L., et al. 2012. Cladistics 28(1): 80-112.
References
Further reading Ross H. Arnett. (2000). American Insects: A Handbook of the Insects of America North of Mexico. CRC Press.