Field attraction of Mediterranean fruit fly, Ceratitis capitata (Wiedemann) to synthetic stereoselective enantiomers of the ceralure B1 isomer.

Stereoselectively synthesized enantiomers of ethyl cis-5-iodotrans-2-methylcyclohexane-1-carboxylate (ceralure B1), a potent lure for male Mediterranean fruit flies, were tested in the laboratory and the field against laboratory reared sterile flies. The (-)-ceralure B1 enantiomer was significantly more attractive than the (+)-ceralure B1 antipode. Dose-response studies of the above compounds demonstrated that (-)-ceralure B1 and to a lesser extent, racemic ceralure B1, captured consistently more male flies than trimedlure, the current male attractant used in detection programs. Longevity tests demonstrated that, over a three-week period, both (-)-ceralure B1 and racemic ceralure B1 caught significantly more flies than trimedlure. The synthesis of specific enantiomers of ceralure B1 shows great promise as a male attractant that could replace trimedlure for detection and delimitation in action programs aimed at this exotic pest.