Statistical analyses
We ran generalized linear mixed models (GLMMs, Statistica v12, StatSoft InC., Tulsa, OK, United States) to test MHW, FPC effect, and their interaction on reproductive parameters, cumulative faecals and survival. We converted the data of the percentage of females with hatched eggs and survival of males and females to logit form log (x+1) following the recommendation in Warton and Hui (2011). In F2 generation, we ran GLMMs with four fixed effects of F1-MHW, F1-FPC, F2-MHW and F2-FPC and their two-, three- and four-way interactions. Significance is considered withP < 0.5.