The Pan-Pacific Entomologist
A nesting site of the anthophorid bee Ptilothrix sumichrasti (Cresson) at Marana, Arizona was observed during August 1954. The site was visited from time to time in subsequent years, but no nesting activity was noted until August and September of 1962, when additional observations were made. This paper discusses there observations according to an outline adapted from Linsley et al. (1953). Specimens collected in 1954 were determined by Dr. P. H. Timberlake. The species is apparently widespread in Mexico, but the only known locations within the United States are in the Santa Cruz and Gila River Valleys in southern Arizona.
Butler, George D. Jr., "Biological Observations on Ptilothrix sumichrasti (Cresson) in Southern Arizona" (1967). Bu. Paper 58.
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