This, the second study of the nesting biology of Lithurgus chrysurus Fonscolombe found at Palmerton, Carbon Co., Pennsylvania, describes its nest construction, provisioning, egg deposition, and larval development. The first study (Rozen, 2013) was based on observations on the late-stage nesting biology in early fall, when these activities were no longer being performed. Comparisons are made with activities of the native Lithurgopsis apicalis (Cresson); in general, the two species have similar, but not identical, nesting biologies. Because Lithurgus chrysurus is an adventive bee native to the Mediterranean regions and is capable of constructing nests in both soft wood as well as firmer wood, it is unclear why it has not expanded its range to any great extent in the New World.