Abstract
Scale insects (Hemiptera: Coccoidae) constitute a very diverse group of sap-feeding insects with a large diversity of symbiotic associations with bacteria. Here, we present the complete genome sequence, metabolic reconstruction, and comparative genomics of the flavobacterial endosymbiont of the giant scale insect Llaveia axin axin. The gene repertoire of its 309,299 bp genome was similar to that of other flavobacterial insect endosymbionts though not syntenic. According to its genetic content, essential amino acid biosynthesis is likely to be the flavobacterial endosymbiont's principal contribution to the symbiotic association with its insect host. We also report the presence of a γ-proteobacterial symbiont that may be involved in waste nitrogen recycling and also has amino acid biosynthetic capabilities that may provide metabolic precursors to the flavobacterial endosymbiont. We propose "Candidatus Walczuchella monophlebidarum" as the name of the flavobacterial endosymbiont of insects from the Monophlebidae family.