Fig. 5

Plutella xylostella larvae and adult detect and avoid Cotesia vestalis odorants. A GC/MS analysis of the volatiles produced by C. vestalis. Heptanal could be detected in extracts of C. vestalis. IS internal standard. B Synthetic heptanal. C Preference index of WT and PxylOR16^−/− P. xylostella mutant adults (left) and larvae (right) for filter paper + dichloromethane vs filter paper + C. vestalis body wash in a Y-tube olfactometer and a 10-cm diameter plastic Petri dish, respectively (n = 16, adults; n = 28, larvae). Both sexes of WT larvae and adults of P. xylostella had avoidance responses to a C. vestalis body wash, but the PxylOR16^−/− mutant did not (Welch’s t-test; NS, no significant difference; P > 0.05; * P < 0.05; *** P < 0.001). D Preference index of WT and PxylOR16^−/− mutant adults (left) and larvae (right) for air + 20 live C. vestalis vs air in a Y-tube olfactometer and a screening device, respectively (n = 16, adults; n = 10, larvae). Both sexes of WT larvae and adults of P. xylostella showed avoidance of C. vestalis, but the PxylOR16^−/− mutants did not (Welch’s t-test; NS, no significant difference; P > 0.05; * P < 0.05; ** P < 0.01)