Vector control is fundamental to the suppression and/or eradication of many endemic and epidemic diseases affecting man. The discovery and widespread application of insecticides in vector control programs focused early attention on studies revealing ecological and behavioral characteristics of arthropod vectors. As a consequence of this emphasis, few attempts were made to investigate arthropod cytogenetics. However, recent recognition of the deleterious effects of highly persistent insecticides on the environment and the development of insecticide resistance by vectors of human disease have established the importance of cytogenetics as a base on which programs for control of vector populations may be built (Wrigth and Pal, 1967).