Identification
From user Joe, Entomologist (in training):
Here's the key to Neartic species:
1a. Pedicel < 3X length of scape (2)
1b. Pedicel > 3X length of Scape (5)
2a. Frons/Occiput enitrely pruinose (3)
2b. Glossy band dorsal of antennae (4)
3a. Metacoxa w/ anteromedial tubercle; Northeast X. nitidis
3b. Metacoxa w/o anteromedial tubercle; West Coast to Alaska X. gracilis
4a. Sternopleuron/Hypopleuron glossy; Eastern X. lugens
4b. Sternopleuron/Hypopleuron w/ pruinosity; Widespread X. cinctus
5a. Frons/Occiput glossy; Boreal/Northeast/Colorado X. fulgidus
5b. Frons pruinose (6)
6a. Pedicel 1.5X ocellar distance; Eastern X. reflectens
6b. Pedicel < 1.5X ocellar distance; West Coast X. decorus
Print References
Webb, D. 1979. Journal of the Kansas Entomological Society. 52:448-463