IDENTIFICATION OF THE SEX ATTRACTANT PHEROMONE OF THE BROWNTAIL MOTH,EUPROCTIS-SIMILIS (FUESSLY) (LEPIDOPTERA, LYMANTRIIDAE)

Six compounds were identified as sex pheromone candidates from abdomin al tips of the female browntail moth, Euproctis similis (FUESSLY), usi ng coupled gas chromatography-electroantennographic detection, coupled gas chromatography-mass spectrometric analysis, microreaction, and sy nthesis. These compounds were (Z)-7-octadecenyl 2'-methylbutyrate (53. 5%), (Z)-7-octadecenyl isovalerate (32.1%), (Z)-9-octadecenyl 2'-methy lbutyrate (4.3%), (Z)-9-octadecenyl isovalerate (4.8%), (Z)-7-octadece nyl isobutyrate (2.7%) and (Z)-7-octadecenyl butyrate (2.7%). The tota l amount was determined to be ca. 18.7 ng/female. The enantiomeric dis tribution of (Z)-7-octadecenyl 2'-methylbutyrate and (Z)-9-octadecenyl 2'-methylbutyrate was tentatively estimated to be (S): (R)=7: 2. In f light-tunnel bioassays, 7 synthetic components, including optical isom ers of (Z)-7-octadecenyl 2'-methylbutyrate, attracted males. In field bioassays, males were captured with blends of 4 to 6 components. Four components of these seven components, (Z)-7-octadecenyl 2'-methylbutyr ate, (Z)-7-octadecenyl isovalerate, (Z)-7-octadecenyl isobutyrate and (Z)-7-octadecenyl butyrate, seemed to be essential for sex attractant activity in the male moths in flight-tunnel and field bioassays.