The enzyme from Zea mays, variety B73, gives mainly 7-epi-sesquithujene with (S)-beta-bisabolene and traces of other sesquiterpenoids, cf. EC 18.104.22.168 (S)-beta-bisabolene synthase. It requires Mg2+ or Mn2+. The product ratio is dependent on which metal ion is present. 7-epi-Sesquithujene is an attractant for the emerald ash borer beetle.