Abstract: | DDT resistance, first observed some thirteen years ago in houseflies, is rapidly spreading in an alarming number of other insects of public health importance, particularly mosquitos. But while much has been learned of the mechanism of this resistance in houseflies, little is known as yet of the corresponding mechanism in mosquitos. A WHO-sponsored study was designed to find out primarily whether, as in houseflies, the breakdown of DDT to DDE—a non-toxic metabolite—in vivo is the predominant factor responsible for the development of resistance in anopheline mosquitos. |