Filbertworm sex pheromone : Identification and field tests of (E,E)- and (E,Z)-8,10-dodecadien-1-ol acetates

(E,E)- and (E,Z)-8,10-Dodecadien-1-ol acetates were identified in a 1∶4.3 ratio in the extract of abdominal tips of female filbert-worm moths,Melissopus latiferreanus (Walsingham). The identifications were based on electroantennogram (EAG) analysis, gas chromatography, mass spectrometry, ozonolysis, and synthesis. TheE,Z isomer produced the stronger EAG response. In the field tests of various ratios ofE,E∶E,Z, the ratio found in the extract captured the most males. The pureE,E isomer initially was not attractive by itself (<0.1%E,Z) but became attractive after a few days, presumably because of isomerization. TheE, Z isomer (<0.1%E,E) was attractive initially, but this compound might have isomerized faster than theE,E isomer. A study of the isomerization showed that regardless of the initial mixture of 8,10-dodecadien-1-ol acetate isomers, almost complete equilibration existed after one month. The equilibrium mixture consisted of 9%Z8,E10, 65%E8,E10, 23%E8,Z10, and 3%Z8,Z10. Concentrations in rubber septa (1∶4 ratio ofE,E toE,Z) of 0.03-3.0 mg/septum produced equivalent trap catches.