AN INHIBITOR OF THE MATING DISRUPTION EFFECT OF (Z)-11-TETRADECENYL ACETATE ON PANDEMIS-HEPARANA (TORTRICIDAE, TORTRICINAE)

Hamaki-con is a mating disruption device containing (Z)-11-tetradeceny l acetate, Z11-14:Ac, as the active ingredient. The mating disruption effect of Hamaki-con on Pandemis heparama was investigated with a labo ratory bioassay. The percentage of mating with Hamakicon treatment was 63%, and this value was significantly higher than that for the treatm ent with purified Z11-14:Ac (23%). This result suggested that an inhib itor against the mating disruption effect of Z11-14:Ac is contained in Hamaki-con. In order to identify the inhibitor, Hamaki-con was chroma tographed on a Florisil column which was eluted successively with hexa ne, 5%, 15% and 50% ether in hexane. The inhibitory activity was obser ved in the 5% fraction. A major impurity in the fraction was (E)-11-te tradecenyl acetate, E11-ldr:Ac, which was contained in 6.2% to Z11-14: Ac. The percentage of mating with the treatment using a blend of Z11-1 4:Ac and 6.2% of E11-14:Ac was significantly higher than that with the Z11-14:Ac treatment. This indicates that E11-14:Ac is the inhibitor t o the activity of Z11-14:Ac. The inhibitory effect of E11-14:Ac was no t observed when the concentration was less than 0.3%. The presence of 6.2% E11-14:Ac in Hamaki-con was considered to be the reason why Hamak i-con did not have a mating disruption effect on this species in some field tests.