GC-MS chromatogram of the headspace of S. epidermidis and the behavioural response of An. gambiae. Part of a GC-MS chromatogram of the headspace of a blood agar plate with S. epidermidis and a blood agar plate without skin microbiota indicating the compounds that were present in significantly different amounts (Figure 7). Compound names are indicated when present in significantly higher or lower amount in the treatment compared to the control. Bars represent the average response of released An. gambiae in a dual-port olfactometer to both odour sources. Error bars represent standard errors of the mean; ***: χ2-test P < 0.001.