Evolutionarily recent dual obligatory symbiosis among adelgids indicates a transition between fungus- and insect-associated lifestyles. Bacteriocyte-associated symbionts of Adelges laricis/tardus

Adelgids (Insecta: Hemiptera: Adelgidae) form a small group of insects but harbor a surprisingly diverse set of bacteriocyte-associated symbionts, which suggest multiple replacement and acquisition of symbionts over evolutionary time. Using a metagenomic approach, we investigated the symbiosis of the Adelges laricis/tardus species complex containing betaproteobacterial and gammaproteobacterial symbionts within the bacteriome.