Optimum maleGrapholitha molesta(Busck) attractancy tocis-8-dodecenyl acetate (c8–12:Ac) required 6–7%transisomer, whereas maleGrapholitha prunivora(Walsh) attractancy to c8–12:Ac was best when 2.2% of thetransisomer was present. Rubber septa containing 200 μg of the attractant mixture (6.6% trans) were the most attractive forG. molestaand this could be synergized with 600 μg of dodecyl alcohol. Dodecyl acetate inhibited attractancy of bothGrapholithaspecies.