FIGURE 1.

Schematic representation of experimental workflow. After environmental sampling and cohousing for 7 days, Saccharomyces cerevisiae strains (YP4 and YH1) were administered in foundresses of Polistes dominula wasps collected in different seasons (autumn and spring) and life stages (pre- and post-diapause) and workers collected in summer. At the 11th day, bacterial clearance was compared among treated and control groups. In the pre-diapause foundresses collected in autumn (in blue), gut microbiota analysis was also performed. SS, sterile sugar solution (40% D-glucose). Details were reported in the section “Materials and Methods.”