Sex pheromone of orange wheat blossom midge, Sitodiplosis mosellana

Pheromone extract of the female orange wheat blossom midge, Sitodiplosis mo sellana (Gehin) (SM) (Diptera: Cecidomyiidae), was analyzed by coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectr ometry (MS), employing fused silica columns coated with DB-5, DB-210, DB-23 or SP-1000. These analyses revealed a single, LAD-active candidate pheromo ne which was identified as 2,7-nonanediyl dibutyrate. In experiments in whe at fields in Saskatchewan, traps baited with (2S,7S)-2,7-nonanediyl dibutyr ate attracted significant numbers of male SM. The presence of other stereoi somers did not adversely affect trap captures. Facile synthesis of stereois omeric 2,7-nonanediyl dibutyrate will facilitate the development of pheromo ne-based monitoring or even control of SM populations.