DECREASED ATTRACTION OF ANASTREPHA LUDENS TO COMBINATIONS OF 2 TYPES OF SYNTHETIC LURES IN A CITRUS ORCHARD

Combinations of the previously developed attractants CEHO from host fr uit aroma and AMPu from volatile metabolites of amino acids were evalu ated for attractiveness to gamma-irradiated Mexican fruit flies, Anast repha ludens, in a citrus orchard. In one experiment, McPhail traps wi th polyvinyl chloride (PVC) lures loaded with CEHO (10:1:1:50 mixture of 1,8-cineole, ethyl hexanoate, hexanol, and ethyl octanoate) were mo re attractive than blank traps. McPhail traps with AMPu (10:10:1 mixtu re of ammonium bicarbonate, methylamine HCl, and putrescine) were more attractive than blank and CEHO traps. Traps containing both AMPu and CEHO lures were less attractive than traps containing AMPu alone. In a nother experiment, sticky yellow panels and spheres were used to compa re attractiveness of the same two attractants in different formulation s. Sticky traps baited with membrane formulations of CEHO (10:1:1:10 m ixture of the chemicals listed above) were not significantly attractiv e. Sticky traps with polypropylene tubes containing an agar formulatio n of AMPu (6:10:1 mixture of ammonium carbonate, methylamine HCl, and putrescine) were more attractive than blank and CEHO baited traps. As in the first experiment, traps with both AMPu and CEHO lures were less attractive than traps with AMPu alone. Results indicate that attracti ve host-odor volatiles and attractive amino-acid metabolites interact negatively with regard to attractiveness to the Mexican fruit fly.