Anopheles quadrimaeulatus, the common malaria mosquito, transmits malaria and is a bad pest otherwise. Aedes aegypti, the yellow-fever mosquito, transmits yellow fever and dengue fever and is a serious house pest. Culex quinquefasciatus, the southern house mosquito, is a serious house pest. It transmits bird malaria and is an intermediate host for some of the filaria. Aedes sollicitans, the salt-marsh mosquito, is the most important salt-marsh species generally in the Eastern and Southern States. Aedes taeniorliynehus, the small, black salt-marsh mosquito, is another saltmarsh species of economic importance, especially in Florida. Psorophora columbiae, the Florida glades mosquito, is an important freshwater species in southern Florida, and is also troublesome in other areas. Mansonia perturbans, the common Mansonia, is a severe pest in areas where suitable breeding conditions occur. (Some of these species may also transmit equine encephalomyelitis or other diseases.) The woods mosquitoes, taken collectively, form a group that is also* of considerable importance as a pest of man and animals. The principal ones in the Southeast are Aedes triseriatus, A. infirmatus, A., atlanticus, A. vexans, Psorophora ferox, and P. ciliata. Culex salinarius and C. restuans are important at times, and various other species, such as Psorophora cyanescens, A. canadensis, and Mansonia, titillans, may become annoying in restricted localities. Of the 47 species taken in Florida, 7 are tropical species, and 6 of 'National Malaeia Committee, Subcommittee on Engineering, malaria control for engineers. U. S. Pub. Health Serv. B-1210, 81 pp., illus. 1936. [Mimeographed.]