Abstract

                                According to Martin (1947 and 1949), Systemic insecticides are those formulations which are absorbed by the plants and translocated to other parts in such quantities that they have insecticidal action. Based on the decomposition of such chemicals within the plants, three broad categories of systemic poisons have been recognised. The first group includes chemicals like selenium which remain more or less in a stable form and do not undergo any disintegration. The second comprises of compounds like Schradan, Pestox, Hanane, etc,, which even after absorption persist in their original form and act as insecticides until they are decomposed. The last category includes insecticides like Systox and Metasystox, which after absorption get transformed into other toxic substances that also act as insecticides. As a result of this phenomenon, the toxicity of the original formulation is enhanced considerably. Nagaraja Rao and Krishnaswamy (1952), have recorded the usefulness of Schradan, Sytam, Pestox, Tetrax and Isopestox in the control of aphids and mites. Sundaram (1952) after testing a number of organic pesticides, has concluded that BFPO reduces appreciably the incidence of Lecanium viride Gr, on coffee. Ripper (1952) in his paper read at the Third International Congress of Crop Protection held at Serbonne has dealt at considerable length on the work done with systemic insecticides in different countries.

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