The authors presented in the paper a very nice and interesting piece of work on the long-term impact of queen infection at the time of colony foundation. The authors exposed freshly mated queen of the ant Lasius niger to a low dose of a fungal sympatric pathogen. They first compared the effect of this infection on colony dynamics. They show that queen infection affects colony dynamics with a slower growth before hibernation but a compensatory growth afterwards. This experiment also provides interesting life history results independently of the infection treatment, especially on hibernation success. Low brood to care by workers and a low worker activity level before hibernation are associated to a higher hibernation success. Second, they tested for a transgenerational immunity transmission from queen to workers using again low doses of queen infection and showed a better worker survival one year after when exposed to high doses of the same pathogen. By following infection prevalence using qPCR, they showed that the highest prevalence level was found just after the production of the first pupae probably reflecting a cost of reproduction on immunity and no more infection was found once the first workers emerged.
The paper reads very well, the statistical analysis are well conducted, clearly explained in the supplementary materials. The data are very interesting and nicely presented. I only have minor comments.
Minor comments:
Abstract: may be useful to give the species name in the abstract.
Line 135: not clear whether the strain was established from the sympatric natural population?
Line 139-140: because the infection dose was low, I am wondering whether the authors can be sure that the queen indeed got infected? I understand that they cannot test it in their experiment, but they might have conducted other experiments at this low dose that could give an idea of the percentage of queens that indeed got infected with a persistent sub-lethal infection.
Line 164: not clear at this stage why is the sample size so unbalanced between pathogen and sham treated queens? I guess it is because some colonies were killed to monitor pathogen in the queen at different steps of the life cycle?
Line 281 & 284: the authors should explicitly state the direction of the prediction.
Figure 4: If I get it right, the grey line of figure 4A is only based on the three naturally infected queens? This merits to be explicitly stated in the legend.
Line 350: I am just curious to know what is the natural variation in worker to brood ratio just before entering hibernation? Given that this a parameter with a strong impact on hibernation success, I would expect it to be under strong selection. Why would some colonies produced more pupae than the worker force can really sustain?

the authors thoroughly revised the manuscript according to my comments and those of other referees. The new version of the manuscript can now be accepted