Phylogenetic assessment of the Metamasius hemipterus species complex (Coleoptera, Curculionidae, Dryophthorinae).

We investigated the phylogenetics of the Metamasius hemipterus species complex, which comprises three weevil subspecies of a widely distributed agricultural pest. Several aspects of this species are uncharacteristic for weevils, such as its broad distribution and its compatibility with a wide array of host plants. Furthermore, the three subspecies of M. hemipterus are distinguishable only by color patterns, which may not constitute reliable indicators of species identity. We tested the validity of this species complex and its three-constituent subspecies, using a RAD-seq genome-skimming approach. Here, we show that Metamasius hemipterus carbonarius is a melanized form of M. h. sericeus; and that these two putative subspecies are genetically distinct from M. h. hemipterus. We revise the species limits of this complex, dividing it into two species (M. sericeus and M. hemipterus) and provide an updated taxonomic key.