The sex pheromone of female dogwood borers (DWB) Synanthedon scitula (Harris) (Lepidoptera: Sesiidae) was determined to be an 88:6:6 ternary blend of (Z,Z)-3,13-octadecadienyl acetate (Z,Z-3,13-ODDA), (E,Z)-2,13-octadecadienyl acetate (E,Z-2,13-ODDA), and (Z,E)-3,13-octadecadienyl acetate (Z,E-3,13-ODDA) by gas chromatography-electroantennographic detection (GC-EAD) and gas chromatography-mass spectrometry (GC-MS). The major sex pheromone component, Z,Z-3,13-ODDA, was attractive as a single component. A blend of Z,Z-3,13-ODDA with 1-3% of E,Z-2,13-ODDA (binary blend) was more attractive than the single component. A third component, Z,E-3,13-ODDA, was sometimes observed in GC-EAD analyses, and enhanced attraction to the binary blend in some field bioassays. Lures containing 1 mg of binary and ternary blends attracted 18 and 28 times more male DWB moths, respectively, than caged virgin females in field trials. Attraction was strongly antagonized by addition of as little as 0.5% of E,Z-3,13-octadecadienyl acetate (E,Z-3,13-ODDA). In a period of 12 wk in 2004, more than 60,000 males were captured in sticky traps baited with synthetic pheromone blends in six apple orchards in Virginia, West Virginia, and North Carolina. Lure longevity trials showed that approximately 76% of the pheromone remained in rubber septum lures after 12 wk in the field.