Malaria control in British Guiana.

Anopheles darlingi-the sole malaria vector in British Guiana-was eradicated from the coastal areas by means of house-spraying with residual DDT. Between the seaward zone, where the conditions are ideal for the breeding of this anopheline, and the hinterland, there is a belt of very acid, peaty soil in which the vector cannot exist, and which therefore forms a natural barrier against it. Consequently, extensive routine spraying with DDT has not been necessary to prevent the reinvasion of the coastal areas; satisfactory protection has been obtained simply by concentrating the control operations on the gaps in this barrier.