Figure 1

Proportion of infected male versus female D. magna hosts after exposure to P. ramosa spores. (a) The data correspond to Experiment 1, with long exposure time (for 11 days) of sexually dimorphic hosts (three-day-old). The proportion of infected increased with spore dose in both sexes (factor "Dose", df = 3, deviance = 34.9, P < 0.00001) and was always higher in females than in males (factor "Sex", df = 1, deviance = 27.4, P < 0.00001; interaction "Sex × Dose", df = 1, deviance = 1.35, P = 0.45). (b) The data correspond to Experiment 2, with short-exposure time (for two days) hosts to young to show sexual dimorphism (one-day-old). The infection rate increased with spore dose in both sexes (factor "Dose", df = 1, deviance = 26.5, P < 0.00001; interaction "Sex × Dose", df = 1, deviance = 1.33, P = 0.24). We did not observe a difference in the proportion of infected females versus males (factor "Sex", df = 1, deviance = 1.6, P = 0.21). We pooled the three host clones used in this experiment as they were not significantly different (factor "Host", df = 6, deviance = 8.1, P = 0.23). Numbers of replicates are given on top of each bar.