Isolation and Identification of Volatile Substances with Attractive Effects on Wohlfahrtia magnifica from Vagina of Bactrian Camel

SIMPLE SUMMARY: Vaginal myiasis is one of the most serious parasitic diseases in Bactrian camels, and the disease has brought serious economic impacts to local herdsmen. Wohlfahrtia magnifica is the main pathogen causing hemorrhagic trauma and myiasis in the natural openings of humans and animals. The study showed that methylheptenone, 1-octen-3-ol, and propyl butyrate can all cause an antennae reaction of Wohlfahrtia magnifica. Moreover, except for propyl butyrate, the higher the concentrations of the other two compounds, the stronger the attractivity to the Wohlfahrtia magnifica, and the mixture of them at the ratio of 1:1 can enhance the attractivity. This study laid a foundation for biological control of vaginal myiasis in Bactrian camels. ABSTRACT: Vaginal myiasis is one of the most serious parasitic diseases in Bactrian camels. At present, there are no reports on biological control measures of the disease. In this paper, the metabolomic analysis of vaginal secretions from susceptible and non-susceptible camels was performed by ACQUITY UPLC H-Class Ultra Performance Liquid Chromatograph. The results matched in 140 vaginal compounds. Methylheptenone, 1-octen-3-ol, and propyl butyrate and their mixtures were selected for gas chromatography-electroantennography (GC-EAD), electroantennography (EAG), behavioral experiments and trapping experiments of Wohlfahrtia magnifica (W. magnifica). Results showed that the W. magnifica had EAG responses to the three compounds, respectively. The EAG responses of female flies to different concentrations of methylheptenone were significantly different, but to the others had no significant difference, and there was no significant difference in the same compounds between the different sexes. Behavioral and trapping experiments showed that methylheptenone and 1-octen-3-ol have significant attraction to W. magnifica, but there was no significant difference to propyl butyrate. When methylheptenone and 1-octen-3-ol were mixed in different proportions, it was found that a mixture at the ratio of 1:1 and 0.5:1 had extremely significant and significant attraction, respectively, to both male and female W. magnifica. The study showed that, except for propyl butyrate, the higher the concentrations of the other two compounds, the stronger the attractivity to the W. magnifica, and a mixture at the ratio of 1:1 could enhance the attractivity to the W. magnifica.