Pheromones of the boll weevil, Anthonomus grandis Boheman, cotton bollworm, Heliothis zea (Boddie), and tobacco budworm, Heliothis virescens (F.), used in traps are becoming increasingly useful for detecting and monitoring these pests (1,3,7,8,10). However, there are many variables that influence trap captures and a better understanding of all of these variables is needed in order to increase the accuracy of trap captures in the determinate on of the density of insects. One of the more important variables is the quantity of insect pheromone that is emitted from the dispensers that are placed in traps. Although a number of important studies related to design of dispensers have been conducted (2,4,5,6,9), additional information is needed. Therefore, cooperative efforts were undertaken to chemically define a variety of available controlled release dispensers for the boll weevil, bollworm, and tobacco budworm and to evaluate selected dispensers under field conditions. Dispensers from seven different sources were studied (Table 1).