Xylocopa sonorina Smith, 1874 from Vancouver, British Columbia, Canada (Hymenoptera: Apidae, Xylocopinae) with comments on its taxonomy

Abstract

Only one species of large carpenter bee, Xylocopa virginica (Linnaeus, 1771), has been recorded from Canada, albeit restricted to southern Ontario and Quebec. However, a single female specimen identified by Hurd in 1954 as X. varipuncta Patton, 1879 from British Columbia is in the C.A. Triplehorn Insect Collection at The Ohio State University (OSUC), suggesting that this species was accidentally introduced into coastal western Canada. As wood-nesters, many large carpenter bees are likely capable of expanding their range great distances by natural and unnatural transport methods while nesting inside suitable substrates, the presumed mode of transport into western Canada, and likely elsewhere. The ease at which the nests are transported has likely contributed to the nomenclatural and distributional ambiguity surrounding this species due to morphological similarities of specimens from North America, Hawaii, and several South Pacific islands. By comparing DNA barcodes of specimens from the western United States to specimens from Hawaii, we confirm the early opinion of P.H. Timberlake (Timberlake 1922) that specimens long established on the Hawaiian Islands are the same X. varipuncta from continental North America. Furthermore, these DNA barcode sequences also match those of specimens identified as X. sonorina Smith, 1874 from the French Polynesian and Samoan Islands, thus fully supporting the opinion of Groom et al. (2017) that all are likely conspecific. As X. sonorina, a species described from and likely introduced to Hawaii is the oldest name available, X. varipuncta is here placed into synonymy. Additional research will be needed to trace the timing and pathway of introduction and establishment of X. sonorina; it is presumed that the species is native to the southwestern United States but has been established in Hawaii since the mid-1800s. It is also established in French Polynesia, the Samoan Islands, and likely other south Pacific islands, with additional records of occurrence from Java, New Zealand, and now Canada.