Studies made in 1933 by Matheson, Boyd, and Stratman-Thomas (3) have shown that Anopheles walkeri Theobald is an efficient host for Plasmodium vivax, the causative organism of tertian malaria. Infection was demonstrated in 4 out of the 6 mosquito specimens dissected after having fed on a gametocyte carrier, and an attack of malaria was produced in a patient by the bite of one of these mosquitoes. It has recently been found that this mosquito occurs in several localities in central and southern Florida (1, 2) and that the Florida specimens represent a southern race of the species (2). In October, 1935, a number of female A. walkeri collected near Orlando, Fla., were sent by mail to the Division of Malaria Research of the Florida State Board of Health at Tallahassee, where certain of them were tested for their ability to act as hosts for Plasmodium falciparum, the causative agent of aestivo-autumnal malaria.
Of the Station for Malaria Research, Tallahassee, Fla. The studies and observations on which this paper is based were conducted with the support and under the auspices of the International Health Division of the Rockefeller Foundation, in coöperation with the Florida State Board of Health and the Florida State Hospital.
Of the Division of Insects Affecting Man and Animals, Bureau of Entomology and Plant Quarantine, United States Department of Agriculture.