Data from: Ancient symbiosis confers desiccation resistance to stored grain pest beetles

Microbial symbionts of insects provide a range of ecological traits to
their hosts that are beneficial in the context of biotic interactions.
However, little is known about insect symbiont-mediated adaptation to the
abiotic environment, e.g. temperature and humidity. Here we report on an
ancient clade of intracellular, bacteriome-located Bacteroidetes symbionts
that are associated with grain and wood pest beetles of the
phylogenetically distant families Silvanidae and Bostrichidae. In the
saw-toothed grain beetle Oryzaephilus surinamensis, we demonstrate that
the symbionts affect cuticle thickness, melanization and hydrocarbon
profile, enhancing desiccation resistance and thereby strongly improving
fitness under dry conditions. Together with earlier observations on
symbiont contributions to cuticle biosynthesis in weevils, our findings
indicate that convergent acquisitions of bacterial mutualists represented
key adaptations enabling diverse pest beetle groups to survive and
proliferate under the low ambient humidity that characterizes dry grain
storage facilities.