Abstract
Hamiki-con is a mating disruption device containing (Z)-11-tetradecenyl acetate, Z11-14:Ac, as the active ingredient. The mating disruption effect of Hamiki-con on Pandemis heparana was investigated with a laboratory bioassay. The percentage of mating with Hamiki-con treatment was 63%, and this value was significantly higher than that for the treatment with purified Z11-14:Ac is contained in Hamiki-con. In order to identify the inhibitor, Hamiki-con was chromatographed on a Florisil column which was eluted successively with hexane, 5%, 15% and 50% ether in hexane. The inhibitor activity was observed in the 5% fraction. A major impurity in the fraction was (E)-11-tetradecenyl acetate, E11-14:Ac, which was contained in 6.2% to Z11-14:Ac. The percentage of mating with the treatment using a blend of Z11-14:Ac and 6.2% of E11-14:Ac is the inhibitor to the activity of Z11-14:Ac. The inhibitory effect of E11-14:Ac was not observed when the concentration was less than 0.3%. The presence of 6.2% E11-14:Ac in Hamiki-con was considered to be the reason why Hamiki-con did not have a mating disruption effect on this species in some field tests.
