Calophya 16S microbiomes Targeted Locus (Loci)

Bacteria associated with sap-feeding insect herbivores include not only symbionts that may increase their hosts’ fitness but also harmful plant pathogens. Calophya spp. gall- inducing psyllids (Hemiptera: Calophyidae) are being investigated for their potential as biological control agents of the noxious weed, Brazilian peppertree (Schinus terebinthifolia), in Florida. Although there are no examples of plant pathogen transmission by members of the family Calophyidae, several insects in the superfamily Psylloidea are known to transmit pathogenic Liberibacters and Phytoplasmas. To determine whether Calophya spp. harbor potentially harmful plant pathogenic bacteria, we sequenced the 16S ribosomal RNA gene of individuals from four Calophya spp. populations. All rRNA sequences fell into the bacterial domain, with 98-99% belonging to the Proteobacteria. The Calophya microbiomes were a relatively simple community, with 49-79 Operational Taxonomic Units (OTUs), and 5-8 OTUs with greater than 1% in abundance. Candidatus Carsonella was the most abundant group, with OTUs representing between 51 – 65% of the total community. The next most abundant clade was affiliated with an unclassified Enterobacteriacae group similar to Buchnera that ranged from 20-31% in abundance. Wolbachia populations were the third most abundant group and represented 7-27% of the diversity in microbial OTUs. We did not detect any Liberibacters or Phytoplasmas in the microbiomes of the four Calophya populations. Our study suggests that releasing Calophya spp. in United States possess no risk of introducing plant pathogenic bacteria into Florida.