The discovery of heavy infestations in wild cotton and ornamental or door-yard cotton in southern Florida led to a program of eradicating all wild and door-yard cotton plants there. From its inception in 1932 through June 1947, infestation was cut from 40 percent in many sections to less than 0.1 percent. Early in this period, the migration of pink bollworms from the wild cotton to cultivated cotton in northern Florida and southern Georgia was stopped, the incipient infestation in the two areas was ended, and the quarantine was removed.

Federal funds were lacking from July 1, 1947, through June 30, 1949; in that time the wild cotton plants, although present in greatly reduced numbers, fruited and much of the benefits of the eradication work was lost. In the absence of a host-free period, seven or eight generations of pink bollworms were produced each year, and infestation began to climb rapidly in some localities. The work was resumed in July 1949 in time to prevent a new spread from wild cotton to cultivated cotton; inspections in northern Florida and southern Georgia were negative in 1949, 1950, and 1951.

The aim of the program is the complete eradication of all cotton plants in southern Florida. In the meantime, infestation has to be kept at a very low level to prevent natural spread. The various areas are covered from two to four times during the period late September to May when weather conditions permit work in the jungle-like swamp, and existing cotton plants are destroyed. The procedure establishes a host-free period that is effective in holding down infestation. The presence of a single plant in the heavy undergrowth may permit pink bollworm infestation to persist from year to year.

Past experience indicates that infestation would build up sufficiently in 4 or 5 years, in the absence of a vigorous eradication program, to spread the pink bollworm once more to cultivated cotton in northern Florida and southern Georgia.

THE BUREAU of Entomology and Plant Quarantine, through its pink bollworm control organization, cooperates closely with the Mexican Government. The interest of the United States is primarily the prevention of long-distance spread into the uninfested areas of this country. If that is to be accomplished, infestation in Mexico, particularly in border areas, must be held to a very low level. The cooperation consists mainly of technical assistance to officials of the Mexican Department of Agriculture. Regional agricultural committees, farm organizations, and banks also participate in the work. The control programs in Mexico closely parallel those in the United States. Stalk- destruction dates in the lower Rio Grande Valley and adjacent Mexican territory are established annually after conferences among officials of the two Governments.

Regulatory requirements in the two countries are similar and awareness of needs and results is growing. A program that combines sanitation at gins and other processing plants, treatment of cottonseed, cultural practices, and insecticidal applications has been developed; larger yields of cotton per acre have been achieved by it.

The tremendous increase in cotton acreage in the Matamoros region adjacent to the lower Rio Grande Valley makes a continuation of the cooperative program essential. Otherwise much of the work along the border in the United States would be nullified, because the areas are actually one continuous region whose principal crop is cotton. The pink bollworm does not know what an international boundary is.

L. F. CURL, formerly leader of the division of pink bollworm control, is now regional director for several insect control programs of the Bureau of Entomology and Plant Quarantine in the Southwest and Mexico. He is a native of Arkansas and a graduate of Mississippi State College.

R. W. WHITE is in charge of the pink bollworm control project, in which he began work in 1920. He is a native of Texas and a graduate of Cornell University.

Corn earworm in an ear of corn.