CHEMOCOMMUNICATION IN PHYLLONORYCTER ULMIFOLIELLA (HBN) (LEPIDOPTERA,GRACILLARIIDAE) - PERIODICITY, SEX-PHEROMONE, AND INHIBITORS

(Z)-10-Tetradecenyl acetate (Z10-14:OAc) from abdominal tip extracts o f virgin females of the tentiform leafminer moth Phyllonorycter ulmifo liella (Lepidoptera: Gracillariidae) was identified by gas chromatogra phy and mass spectrometry. The biological activity of the component wa s confirmed by field tests with synthetic compounds. As a sex pheromon e component this ester is novel both in the family Gracillariidae and in the superfamily Gracillarioidea. Field trapping of P. ulmifoliella with synthetic Z10-14:OAc at dosages of 1 and 0.2 mg/dispenser led to catches of approximately 9000 and 3000 male moths, respectively. The a ttractivity of the Z10-14:OAc was strongly inhibited by a 10% admixtur e of either (Z)-9-tetradecenyl acetate (Z9-14:OAc), (E)-9-tetradecenyl acetate (E9-14:OAc), or (E)-11-tetradecenyl acetate (E11-14:OAc). Add ition of 10% (E)-10-tetradecenyl acetate (E10-14:OAc) to the sex phero mone reduced attractivity, but significantly less than the inhibitors previously mentioned. The pheromone releasing (or ''calling'') behavio r of virgin P. ulmifoliella females was recorded under laboratory cond itions. Calling activity started about half an hour before lights-on a nd the maximum number of calling females was registered half an hour a fter the start of photophase. A high level of pheromone releasing acti vity lasted for about 2 hr and ceased about 5 hr after the start of ph otophase. Chemocommunication activity in the light period of day is as sumed to be an adaptation which allows this phyllonoryctid to avoid in hibitors emitted as pheromones by many other species. A scheme of prob able interactions by means of semiochemicals between P. ulmifoliella a nd other lepidopterans is presented and the appearance of Z10-14:OAc a s a sex pheromone component in Lepidoptera during evolution of the ord er is discussed.