16s amplicon sequencing of Jalysus spp. stilt bugs

Many insect species in the superfamilies Lygaeioidea and Coreioidea participate in a symbiotic association with bacteria in the genus Burkholderia. Despite the insects' dependence on the bacterium for normal growth and reproduction, the insects acquire Burkholderia from the environment every generation. We used 16S amplicon sequencing to study the spatial structuring of Burkholderia sequence variants associated with a widespread omnivorous bug genus, Jalysus (Berytidae). We sampled Wickham's stilt bug, Jalysus wickhami, across the USA and performed more limited sampling of its sister species, the spined stilt bug Jalysus spinosus. We asked: (1) What Burkholderia symbiont strains are hosted by different populations of Jalysus? (2) Does geography, host insect species, host plant species, or host plant individual influence the symbiont strain these insects acquire? We found: (1) Over 60 Burkholderia strains were present in a sample of 465 individuals, but one strain dominated, accounting for almost half of all symbiont reads. Most strains were closely related to other hemipteran Burkholderia symbionts. (2) Individual insects could host multiple strains of Burkholderia, though most hosted a single strain. (3) Some J. wickhami-associated Burkholderia strains were geographically widespread, while others were localized. There was a significant difference between strains associated with the Eastern and Western USA. (4) There was no relationship between strains and host plant species, nor did J. wickhami and J. spinosus differ predictably in the strains they hosted. However, there was an apparent association between strain and host plant individual. These results suggest that stilt bugs associate with a highly diverse and spatially structured collection of Burkholderia strains that are acquired from the environment.