A phylogenetic assessment of the polyphyletic nature and intraspecific color polymorphism in the Bactrocera dorsalis complex (Diptera, Tephritidae)

The Bactrocera dorsalis complex (Tephritidae) comprises 85 species of fruit flies, including five highly destructive polyphagous fruit pests. Despite significant work on a few key pest species within the complex, little has been published on the majority of non-economic species in the complex, other than basic descriptions and illustrations of single specimens regarded as typical representatives. To elucidate the species relationships within the Bactrocera dorsalis complex, we used 159 sequences from one mitochondrial (COI) and two nuclear (elongation factor-1α and period) genes to construct a phylogeny containing 20 described species from within the complex, four additional species that may be new to science, and 26 other species from Bactrocera and its sister genus Dacus. The resulting concatenated phylogeny revealed that most of the species placed in the complex appear to be unrelated, emerging across numerous clades. This suggests that they were placed in the Bactrocera dorsalis complex based on the similarity of convergent characters, which does not appear to be diagnostic. Variations in scutum and abdomen color patterns within each of the non-economic species are presented and demonstrate that distantly-related, cryptic species overlap greatly in traditional morphological color patterns used to separate them in keys. Some of these species may not be distinguishable with confidence by means other than DNA data.