The effects of human volatiles produced by skin microbiota on Forcipomyia (Lasiohelea) taiwana host preference

BACKGROUND Midges are widely distributed globally. They can transmit numerous serious diseases when biting hosts. It is crucial for developing more effective midge monitoring and control methods to better understand how host volatiles attract and repel these blood‐sucking insects. RESULTS In this work, volatile substances from human skin were detected by means of gas chromatography–mass spectrometry (GC–MS). A total of 25 compounds in relatively high contents were identified from the gauzes adsorbing volatiles of eight volunteers, including ketones, aldehydes, alcohols and acids. Nonanal, 6‐methyl‐5‐hepten‐2‐one and decyl aldehyde were all present in the skin volatiles of the volunteers, at relatively stable and high levels. Our results showed that 0.001% geranylacetone exhibited the highest attraction rate for midges, at ≤72.1%, and that 10% 3‐methyl‐1‐butanol has the highest repellent rate towards midges, reaching 70.7% by behavioral experiments. Thirty‐five types of bacteria from the skin surface of the volunteers were identified. It was discovered that 3‐methyl‐1‐butanol was mainly produced by Staphylococcus hominis subsp. novobiosepticus (R2A01–07) with a high rate of 81.898%. CONCLUSION In summary, volatile substances can attract or repel midges in the appropriate concentration ranges. Differences in human volatile compounds are mainly regulated by the skin microbiota, which indirectly changes the olfactory behavior of midges by regulating human odor. This work is very helpful for understanding the specific mechanisms underlying the host preference of midges.