One and the same: integrative taxonomic evidence that <i> <scp>B</scp> actrocera invadens </i> ( <scp>D</scp> iptera: <scp>T</scp> ephritidae) is the same species as the <scp>O</scp> riental fruit fly <i> <scp>B</scp> actrocera dorsalis </i>

Abstract

Abstract The invasive fruit fly B actrocera invadens D rew, T suruta &amp; W hite, and the O riental fruit fly B actrocera dorsalis ( H endel) are highly destructive horticultural pests of global significance. Bactrocera invadens originates from the Indian subcontinent and has recently invaded all of sub‐ S aharan A frica, while B . dorsalis principally occurs from the I ndian subcontinent towards southern C hina and South‐east A sia. High morphological and genetic similarity has cast doubt over whether B . invadens is a distinct species from B . dorsalis . Addressing this issue within an integrative taxonomic framework, we sampled from across the geographic distribution of both taxa and: (i) analysed morphological variation, including those characters considered diagnostic (scutum colour, length of aedeagus, width of postsutural lateral vittae, wing size, and wing shape); (ii) sequenced four loci ( ITS1 , ITS2 , cox1 and nad4 ) for phylogenetic inference; and (iii) generated a cox1 haplotype network to examine population structure. Molecular analyses included the closely related species, B actrocera kandiensis D rew &amp; H ancock. Scutum colour varies from red‐brown to fully black for individuals from A frica and the I ndian subcontinent. All individuals east of the I ndian subcontinent are black except for a few red‐brown individuals from C hina. The postsutural lateral vittae width of B . invadens is narrower than B . dorsalis from eastern A sia, but the variation is clinal, with subcontinent B . dorsalis populations intermediate in size. Aedeagus length, wing shape and wing size cannot discriminate between the two taxa. Phylogenetic analyses failed to resolve B . invadens from B . dorsalis , but did resolve B . kandiensis . Bactrocera dorsalis and B . invadens shared cox1 haplotypes, yet the haplotype network pattern does not reflect current taxonomy or patterns in thoracic colour. Some individuals of B . dorsalis/ B . invadens possessed haplotypes more closely related to B . kandiensis than to conspecifics, suggestive of mitochondrial introgression between these species. The combined evidence fails to support the delimitation of B . dorsalis and B . invadens as separate biological species. Consequently, existing biological data for B . dorsalis may be applied to the invasive population in A frica. Our recommendation, in line with other recent publications, is that B . invadens be synonymized with B . dorsalis .