We conducted laboratory experiments to elucidate the influence of barometric pressure on odor discrimination and oviposition and feeding behavior of adult female plum curculios, Conotrachelus nenuphar (Herbst). Barometric pressure had a significant effect on Response Index values (used as a measure of odor discrimination); odor discrimination of hexane-extracted McIntosh fruit volatiles was high when barometric pressure was high. Barometric pressure also had a significant effect on oviposition as females oviposited more during periods of low barometric pressure on a favored host fruit (wild plum). Observed feeding activity of females was not influenced by barometric pressure.