Identification and Field Evaluation of the Female Sex Pheromone of the Sand Salix Carpenterworm, Holcocerus arenicola Staudinger (Lepidoptera: Cossidae)

Abstract

Extracts of female sex pheromone glands of the sand Salix carpenterworm moth, Holcocerus arenicola, a serious pest of desert thicket, were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Based on comparison of retention times and mass spectra of synthetic standards, four compounds were identified as cis-7-tetradecen-1-ol (Z7-14:OH), cis-5-tetradecen-1-yl acetate (Z5-14:OAc), cis-7-tetradecen-1-yl acetate (Z7-14:OAc), and cis-9-hexadecen-1-yl acetate (Z9-16:OAc) with the ratio of 24:39:100:43. Electroantennographic (EAG) analyses of these standard chemicals and their analogues showed that Z7-14:OAc elicited the largest male EAG response, followed by Z5-14:OAc and Z9-16:OAc. In field trials, traps baited with either Z7-14:OAc or Z5-14:OAc captured males while Z7-14:OH-, Z9-16:OAc- or solvent-baited traps caught no males. Z7-14:OAc as a single component was significantly more attractive than Z5-14:OAc alone. The combination of Z7-14:OAc and Z5-14:OAc showed an evidently synergistic effect and attracted much more males than the individual compounds in the field. Addition of Z7-14:OH to the blend of Z7-14:OAc and Z5-14:OAc enhanced slightly the trap catches. We conclude that the major components of the sex pheromone of H. arenicola are Z7-14:OAc and Z5-14:OAc. Currently, a triangle trap baited with the synthetic compounds Z7-14:OAc, Z5-14:OAc, and Z7-14:OH in a 1:0.4:0.25 ratio at 825 microg/trap dosage can be effectively used to monitor the H. arenicola population level and catch the males within the desert regions in China.