Abstract
While contemporary changes in feeding preferences have been documented
in phytophagous insects, the mechanisms behind these processes remain to
be fully clarified. In this context, the insect gut microbiome plays a
central role in adaptation to novel host plants. The cucurbit
frugivorous fruit fly Zeugodacus cucurbitae (Diptera,
Tephritidae) has occasionally been reported on “unconventional” host
plants from different families, including Solanaceae. In this study, we
focus on wild parental (F0) and semi-wild first filial
(F1) samples of Z. cucurbitae from multiple sites
in La Réunion and explore how the gut microbiome composition changes
when this fly is feeding on a non-cucurbit host (Solanum
melongena ). Our analyses show non-obvious microbiome responses
following F0-F1 host shift and the
importance of local effects which heavily affected the diversity and
composition of microbiomes. We identified the main bacterial genera
responsible for differences between treatments and provided a first
overview of the metabolic pathways in which they are involved. These
data further stress the importance of a careful approach when drawing
general inferences based on laboratory populations or from
non-adequately replicated field samples.
Keywords: microbial gut symbionts, wild populations, plant-insect
interactions, host switch