Multipartite microbial symbiosis in neotropical treehoppers

Neotropical treehoppers, or membracids, are insects in the order Hemiptera that specialize in consuming plant sap. This limited nutrient diet requires supplantation by symbionts. Membracids, in the suborder Auchenorrhyncha, which includes insects such as cicadas, planthoppers, spittlebugs, treehoppers, and leafhoppers, usually harbor at least 2 obligate endosymbionts within a specialized organ called the bacteriome. However, a detailed study of membracids from Brazil in the 1940’s showed neotropical treehoppers can harbor up to 6 symbionts within their bacteriomes. Additionally, although other hemipterans in infraorder Flugoromorpha and family Cicadellidae have been well established as plant pathogen vectors, membracids remain understudied. To investigate how these complex microbial symbioses cooperate metabolically to produce missing nutrients as well as their interactions with plant pathogens, we collected 47 species of membracid from Brazil and 7 from the US. To date, we have performed dissection, DNA and RNA isolation, library preparation, Illumina sequencing, and bioinformatic analyses on 16 species. Among these species’ metagenomic assemblies were 12 insect endosymbionts including primary symbionts Sulcia and Nasuia as well as potentially secondary or replacement symbionts Arsenophonus, Sodalis, Bombella, Rickettsia, Wolbachia, Burkholderia, Hamiltonella, Sulfuriferula, Ca. Gullanella, and a yeast- like Ophiocordyceps symbiont. Scaffolds were also matched to 9 potential plant pathogens, as well as various other microbes including bacteriophages, viruses, entomopathogens, and fungi. In addition to continuing with metatranscriptomic analysis and microscopy methods, future directions include exploring how concepts of cooperative game theory such as the Prisoner’s dilemma and Nash Equilibrium can be used to describe the biodiversity of neotropical membracids.