Although only about half of the Lucilia species listed as valid by Aubertin (1933) were included, these results strongly suggest that L. sericata and L. cuprina are indeed sister species. All of the Bayesian inference analyses (Figs 1–3) indicate that L. sericata and L. cuprina are sister taxa with strong support from the nuclear gene (28S & Per) and total data (28S, Per & COI) trees and weaker support from the COI gene alone. Lucilia cuprina is paraphyletic (Fig. 2) with respect to L. sericata in the mitochondrial gene (COI) tree, as has been shown previously (using the same sequences but weaker auxiliary taxon sampling) to be the result of introgressive hybridisation between these two species (Williams & Villet, 2013). In another study, the nuclear gene elongation factor-1 alpha (EF-1α) did not recover L. sericata and L. cuprina as sister-species (McDonagh & Stevens, 2011), but the clade containing L. sericata was poorly resolved and thus the conclusion was not well supported. In the same study, the 28S and COI gene trees both recovered L. sericata and L. cuprina as sister species with strong support (McDonagh & Stevens, 2011).
The Bayesian inference analysis of the COI barcode sequences included 45 L. sericata sequences and 42 L. cuprina sequences. Despite the number of sequences, L. sericata was poorly resolved, which explains the poor node support (0.61) of the L. sericata + L. cuprina + L. taiyuanensis clade. Lucilia taiyuanensis is represented by only one sequence