Evolutionary relationships of flavobacterial and enterobacterial endosymbionts with their scale insect hosts (Hemiptera: Coccoidea)

Abstract

Flavobacteria and Enterobacteriaceae have been previously reported as scale insect endosymbionts. The purpose of this work was twofold: first, to screen different scale insect families for the presence of these endosymbionts by PCR analyses and second, to elucidate the history of cophylogeny between these bacteria and the insects by analysing a portion of 16S rRNA and 18S rRNA gene sequences by two reconciliation tools, CoRe-PA and Jane. From a survey of 27 scale insects within seven families, we identified Flavobacteria and Enterobacteriaceae as coexisting in ten species that belong to the Ortheziidae, Monophlebidae, Diaspididae and Coccidae families, and we frequently found two closely related enterobacteria harboured in the same individual. Analyses performed with CoRe-PA and Jane suggest that Flavobacteria from the scale insects analysed have a unique origin, except for Candidatus Brownia rhizoecola (Flavobacteria of Pseudococcidae, Phenacoccinae), which seems to come from a nonscale insect. Nevertheless, cospeciation between Flavobacteria and scale insects is suggested only within the families Monophlebidae, Ortheziidae and Diaspididae, and host switches seem to have occurred from the ancestors of Monophlebidae and Ortheziidae to insects from families Coccidae, Lecanodiaspididae, Eriococcidae and Pseudococcidae. Our analyses suggest that Enterobacteriaceae underwent more evolutionary events (losses, duplications and host switches), and their phylogenies showed a lower proportion of congruent nodes between host and bacteria, indicating a more relaxed relationship with scale insects compared with Flavobacteria.

Ciliate species diversity and host-parasitoid codiversification in Pseudocollinia infecting krill, with description of Pseudocollinia similis sp. nov.

“…Parasites often codiversify or coevolve with their hosts, and recently gene sequences and inferred tree topologies have been used to test these hypotheses of codiversification (Johnson et al 2004, Kuo et al 2008, Cruaud et al 2012, Rosenblueth et al 2012, Du Toit et al 2013. While event-based reconciliation tools show some codiversification of Pseudocollinia species with their host euphausiids, the AU/SH tests rejected absolute codiversification.…”

Species in Wolbachia? Proposal for the designation of ‘Candidatus Wolbachia bourtzisii’, ‘Candidatus Wolbachia onchocercicola’, ‘Candidatus Wolbachia blaxteri’, ‘Candidatus Wolbachia brugii’, ‘Candidatus Wolbachia taylori’, ‘Candidatus Wolbachia collembolicola’ and ‘Candidatus Wolbachia multihospitum’ for the different species within Wolbachia supergroups

“…Some insects and their endosymbionts have a parallel evolutionary history, and cospeciation events have been described for both host and bacteria, especially primary endosymbionts [1,10,21,79,87]. For endosymbionts that have cospeciated with their hosts, endosymbionts in different hosts would be distinct species.…”

Bacteria belonging to the genus Burkholderia are obligatory symbionts of the eriococcids Acanthococcus aceris Signoret, 1875 and Gossyparia spuria (Modeer, 1778) (Insecta, Hemiptera, Coccoidea)

“…Gruwell et al (2005) detected Flavobacteria (phylum Bacteroidetes) in the body of Macroporicoccus ulmi (Tang and Hao, 1995) (as Cryptococcus ulmi). Rosenblueth et al (2012) have examined the species Eriococcus euphorbiae (Ferris, 1955) using Bacteroidetes-specific primers but no bacteria were revealed. Taking into account the above facts, the investigations on the symbionts of Eriococcidae seem especially interesting.…”