Introduction

Abstract

With the slow development of civilisation, so has man gradually realised the extent to which pests harm his crops, annoy him and transmit diseases, both human and those of domestic animals. The use of chemicals to kill pests is not a new concept; about A.D. 70 Pliny the Elder recommended that arsenic could be used to kill insects, and the Chinese used arsenic sulphide as an insecticide as early as the late sixteenth century. The use of arsenical compounds has continued, and, during the early part of the twentieth century, large quantities of such compounds as lead arsenate were used to control insect pests. Another arsenical compound, Paris green (copper aceto-arsenite), was extensively applied to pools and standing water in the tropics, in attempts to control malaria-transmitting mosquitoes.