Fig. 1

Experimental design. Eight monogynous mother colonies were equally split in two fragments: one containing the queen (queenright: QR) and the other being queenless (QL). After 9 weeks, two workers were sampled from each nest. One was immune-challenged (IC) by pricking with a needle dropped into a 10% lipo-polysaccharide solution (LPS-PGN), while the other non-immune-challenged worker (NIC) received the same manipulation, but the needle only touched the cuticle. Twenty-four hours after the manipulation, the fat body was dissected for RNA extraction, the gut for 16S microbiome sequencing and the ovaries for size measurements. QL workers had longer ovaries than workers from the QR nests (fertile workers F; non-fertile workers NF). The figure was designed by Matteo Negroni using photos of T. rugatulus taken by M. Negroni and S. Foitzik