Host specificity, seasonality, and urbanicity shape the gut microbiome of a synanthropic insect

The soapberry bug Jadera haematoloma has rapidly adapted to a new host plant, the introduced goldenrain tree, after originally feeding on native herbaceous saplings. This shift has enabled the insect to thrive in urban areas. The gut microbiota of J. haematoloma varies based on its host, the time of year, and the level of urbanization it encounters.

The core microbiome of the bug is made up of a limited number of bacterial species from families such as Rhizobiaceae, Streptococcaceae, Enterobacteriaceae, and Lactobacillaceae. The type of host plant the bug feeds on primarily determines the community composition of its gut microbes. Bugs that feed on the native host have a more diverse and balanced microbial community, while those on the introduced host are dominated by a single Rhizobiaceae species.

Seasonal changes cause significant shifts in the accessory microbial taxa within the bug's gut. Urbanization introduces its own unique impact on the bug's microbiome. Although the presence of local green spaces does not greatly affect the richness of microbial species, it does lead to slight changes in community structure and increases the variability of the microbiome.

Higher levels of urbanization result in greater beta dispersion, suggesting that urban environments create more unpredictable microbiomes, which may signify environmental stress. These findings demonstrate how the rapid dietary host shifts and the pressures of urbanization influence the microbiome of this adaptable insect.