Cladistic analysis and evolutionary relationships of Xylocopa Latreille, 1802, subgenus Xylocopoides Michener, 1954, a New World lineage of large carpenter bees (Insecta: Hymenoptera: Apidae)

Results of a cladistic analysis of the five currently recognized species of the genus Xylocopa Latreille, 1802, subgenus Xylocopoides Michener, 1954, are reported. Twenty adult morphological characters were coded for the five species of subgenus Xylocopoides, plus two outgroup species from the related subgenus Xylocopa Latreille, 1802. The resulting taxon-character matrix was analyzed with the “TNT” computer software program and a single most parsimonious tree of 21 steps was recovered. Monophyly of subgenus Xylocopoides relative to the outgroup species in subgenus Xylocopa is confirmed. Characters used to establish the subgenus Calloxylocopa Hurd & Moure, 1963, are derived character states in the single species X. tenuata Smith, 1874, and thus Calloxylocopa is maintained in synonymy with subgenus Xylocopoides. Within Xylocopoides, X. tenuata is the sister species to the four other species of the subgenus. Xylocopa cyanea Smith, 1874, and X. californica Cresson, 1864, are sister species, while X. pallidiscopa Hurd, 1961, and X. virginica (Linnaeus, 1771), are also sister species, suggesting the possibility of a Mexican origin for the common and widespread Nearctic species X. virginica. The male of X. pallidiscopa is described for the first time and an identification key that includes both sexes of all species of Xylocopoides is presented.