Polyphylla diffracta Casey Materials examined. MEXICO, Chihuahua: 86 km NE Nácori Chico (Sonora), Rancho Arroyo El Cocono, 1660m, 7.VIII.1982, S. McCleve, G.E., K.E. Ball [12 males, not examined, depository unknown]. USA, Colorado: Bent County, 3.5 mi S of Caddoa, 3.VII.1990, B. Kondratieff, M. Kippenhan, H.E. Evans (1 male, DALC). Remarks. The Mexico locality was previously reported by Young (1988) as from the state of Sonora. Revised locality data cited by McCleve and Kohlmann (2005) indicate this locality is actually within the southwestern border of the state of Chihuahua. This species was not listed from Colorado by Young (1967, 1988). Krell (2010) cites “Mesa County, Colorado.” Records of its occurrence in California (Young 1967, 1988; Evans 1992) certainly represent misidentified or mislabeled specimens. For example, examination of a male specimen in the SBMNH determined as this species and labeled “Calif: San Bernardino Co., San Bernardino NF, nr. Deer Crk. 34.1741 -116.9844, July 2, 2005, specimen #CBP0031851, M. Caterino collector” shows that, in fact, it represents P. crinita with fragmented elytral vittae (see comments regarding this character under P. rugosipennis below).

Published as part of La Rue, Delbert A., 2016, Natural history, ecology, and conservation of the genus Polyphylla Harris, 1841. 1. New species from the southwestern United States and Baja California, Mexico, with notes on distribution and synonymy (Coleoptera: Scarabaeidae: Melolonthinae), pp. 1-41 in Insecta Mundi 2016 (491) on page 28, DOI: 10.5281/zenodo.5353384