BACKGROUND: Insect olfactory organs possess many olfactory receptor neurons, which detect many different sets of odorants in nature. In order to feed on blood meals, stable flies locate host animals and humans using chemical cues such as 1-octen-3-ol and butyric acid. In the present study, behavioural and electroantennogram (EAG) response patterns to repellent volatiles from essential oils (EOs) of Zanthoxylum piperitum and Z. armatum in combination with the attractants were investigated. RESULTS: Components of the EOs such as cuminaldehyde, citronellal, neral, linalool, linalool oxide, terpinen-4-ol, 1,8-cineole, and piperitone induced remarkable repellent behaviours in the stable fly. EAG responses in the fly antenna to these chemicals showed a dose-dependent manner. The patterns of behavioural and EAG responses were significantly altered depending on the ratios of 1-octen-3-ol or butyric acid to the EOs or compounds in the air mixtures. CONCLUSION: The present study demonstrated that the Zanthoxylum EOs decreased the levels of response of flight behaviours of the stable fly towards host volatile compounds. The combinations of odorant mixtures of the attractants with the EOs and their components affect the representation of behavioural and EAG responses of the flies. The summation and integration patterns of olfactory responses measured by the EAG indicated that the peripheral olfactory networks in antennae could process the odorant complexity of different odorant mixtures between attractants and repellents.
BACKGROUND: Insect olfactory organs possess many olfactory receptor neurons, which detect many different sets of odorants in nature. In order to feed on blood meals, stable flies locate host animals and humans using chemical cues such as 1-octen-3-ol and butyric acid. In the present study, behavioural and electroantennogram (EAG) response patterns to repellent volatiles from essential oils (EOs) of Zanthoxylum piperitum and Z. armatum in combination with the attractants were investigated. RESULTS: Components of the EOs such as cuminaldehyde, citronellal, neral, linalool, linalool oxide, terpinen-4-ol, 1,8-cineole, and piperitone induced remarkable repellent behaviours in the stable fly. EAG responses in the fly antenna to these chemicals showed a dose-dependent manner. The patterns of behavioural and EAG responses were significantly altered depending on the ratios of 1-octen-3-ol or butyric acid to the EOs or compounds in the air mixtures. CONCLUSION: The present study demonstrated that the ZanthoxylumEOs decreased the levels of response of flight behaviours of the stable fly towards host volatile compounds. The combinations of odorant mixtures of the attractants with the EOs and their components affect the representation of behavioural and EAG responses of the flies. The summation and integration patterns of olfactory responses measured by the EAG indicated that the peripheral olfactory networks in antennae could process the odorant complexity of different odorant mixtures between attractants and repellents.