Higher classification of mealybugs (Hemiptera: Coccomorpha) inferred from molecular phylogeny and their endosymbionts

Mealybugs (Hemiptera: Pseudococcidae, Rhizoecidae and Xenococcidae) are important organisms for understanding processes of evolution, especially microbial symbiotic systems and interactions with host plants. Molecular phylogenetic trees were reconstructed for 128 species of mealybug using DNA fragments of eight loci, namely a mitochondrial (COI), nuclear ribosomal RNA (18S and 28S D2 and D10) and nuclear protein-encoding genes (EF-1α 5′ and 3′, Dynamin and wingless). In addition, data on the types of obligate endosymbionts were used to test the monophyly of major groups resulting from this molecular phylogeny. Based on the data from DNA sequences, morphology and obligate endosymbionts, we present a phylogeny supporting the families Rhizoecidae and Xenococcidae separate from Pseudococcidae, and the separation of Rastrococcus Ferris from Phenacoccinae and Pseudococcinae. Consequently, Rastrococcus is excluded from Phenacoccinae and elevated to subfamily Rastrococcinae subfam. nov. We also found support for Putoidae as a family distinct from the true mealybugs. Phenacoccus rubicola Kwon, Danzig & Park is transferred to Coccura Šulc.