The tarnished plant bug, Lygus lineolaris (Hemiptera, Heteroptera: Miridae) is a serious pest of cotton. The pests' ability to survive on a wide variety of host plant species, numbering at least 400, and its complex biology, involving transition through five different immature stages, are practical obstacles to integrated approaches for control of the pest. Trapping or monitoring for proper timing of insecticidal control is not simple because the behavioral cues, such as sex pheromones and food/oviposition-site odors, have not been identified for the plant bug. In order to develop timely and effective, yet environmentally sound, control measures for this pest, we have undertaken research to understand the physiological and molecular mechanisms of chemical reception in the plant bug.