Species-specific, two-component, volatile signals in two sympatric ant-lion species:Synclysis baetica and Acanthaclisis occitanica (Neuroptera, Myrmeleontidae)

The thoracic glands of males in two ant-lion species Synclysis baetica and Acanthaclisis occitanica, which occur sympatrically in Israel, were found to contain a volatile secretion with two-component blends of nerol oxide and (R,Z)-6-tridecen-2-ol (approx 1:5) and nerol oxide and 10-homonerol oxide (approx. 1:2), respectively. Chemical analyses were performed using gas chromatography-mass spectrometry, chiral gas chromatography, and ozonolysis, and the proposed structures were confirmed by synthesis. The species-specific, few-component volatile signals are thought to function as a reproductive isolation mechanism between the two sympatric species. Biochemical relationships between the nerol derivatives and between the unsaturated secondary alcohols are discussed.