Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-26T04:17:00.046Z Has data issue: false hasContentIssue false

Insecticidal Action Studies with Demeton-O and Demeton-S

Published online by Cambridge University Press:  10 July 2009

W. A. L. David
Affiliation:
A. R. C. Unit of Insect Physiology, Cambridge.

Extract

The two isomers demeton-O and demeton-S which occur as a mixture called demeton in the commercial insecticide Systox act on Aphis fabae Scop. as contact and systemic insecticides and as fumigants.

When applied as a contact insecticide or systemically via the roots from solution or from soil, demeton-S was about ten times as toxic to Aphis fabae on broad beans as demeton-O. Using demeton-S containing 32P it was shown that, when applied to the roots, radioactive material passed to all parts of the plants and that the concentration in the aerial parts was higher than in the roots. Leaf samples were more active than stem samples. By radioassay and by the cut tap-root technique it appeared that the lethal dose of demeton-S was equivalent to about 1·0 mg./kg. of fresh plant tissue. The lethal dose of demeton-O by the cut tap-root technique was 3·0 mg./kg. From solutions, the plants first absorbed demeton-S preferentially, then water preferentially. Demeton-S was more rapidly absorbed from sand than from soil.

Both isomers were translocated from older to younger leaves of broad beans usually in sufficient quantities to kill Aphids but the results were more consistent with demeton-S. The quantity translocated downwards was small. A low light intensity before and after treatment reduced the quantity of demeton-S translocated. There was also a reduction in the quantity translocated when the plants were only shaded before treatment. One day of shading was sufficient to cause the maximum reduction.

Solutions of the two isomers gave off toxic vapours and plants treated via the roots gave off toxic vapours from the foliage.

Type
Research Paper
Copyright
Copyright © Cambridge University Press 1957

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

David, W. A. L. (1951). Insecticidal-action studies with bisdimethylaminophosphonous anhydride containing 32phosphorus.—Ann. appl. Biol., 38, pp. 508524.CrossRefGoogle Scholar
David, W. A. L. (1952). Insecticidal-action studies with bisdimethylamino fluorophosphine oxide containing 32phosphorus.—Ann. appl. Biol., 39, pp. 203210.Google Scholar
David, W. A. L. & Gardiner, B. O. C. (1951). Investigations on the systemic insecticidal action of sodium fluoroacetate and of three phosphorus compounds on Aphis fabae Scop.—Ann. appl. Biol., 38, pp. 91110.CrossRefGoogle Scholar
David, W. A. L. & Gardiner, B. O. C. (1954). The action of the systemic insecticide Systox on Aphids.—Bull. ent. Res., 45, pp. 683692.CrossRefGoogle Scholar
Gardner, K. & Heath, D. F. (1953). Quantitative determination of isomers of O,O-diethyl ethylmercaptoethyl thiophosphate.—Analyt. Chem., 25, pp. 18491853.Google Scholar
Heath, D. F. & Llewellyn, M. V. (1953). Systemic insecticides on sprayed surfaces.—Proc. Isotope Tech. Conf., Oxford 1951, 1, pp. 445451.Google Scholar
Heath, D. F., Lane, D. W. J. & Park, P. O. (1955). The decomposition of some organophosphorus insecticides and related compounds in plants.—Philos. Trans., (B) 239, pp. 191214.Google Scholar
Lusis, E. (1952). The effect of “ Systox ” on Drosophila melanogaster Mg.—Höfchen-briefe, (Engl. edn.) 5, pp. 225238.Google Scholar
Metcalf, R. L., March, R. B., Fukuto, T. R. & Maxon, M. (1954). The behavior of Systox-isomers in bean and Citrus plants.—J. econ. Ent., 47, pp. 10451055.CrossRefGoogle Scholar
Schrader, G. (1952). Die Entwicklung neuer Insektizide auf Grundlage organischer Fluor und Phosphor-Verbindungen.—Monogr. angew. Chem. u. Chem.-Ing.-Tech., no. 62, 2nd edn., 96 pp. Weinheim, Verlag-Chemie.Google Scholar
Thomas, W. D. E. & Bennett, S. H. (1954). The absorption, translocation and breakdown of Schradan applied to leaves, using 32P-labelled material. III. Translocation and breakdown.—Ann. appl. Biol., 41, pp. 501519.CrossRefGoogle Scholar
Thomas, W. D. E., Bennett, S. H. & Lloyd-Jones, C. P. (1955). The absorption, breakdown and systemic behaviour in plants of 32P-labelled demeton-S.—Ann. appl. Biol., 43, pp. 569593.CrossRefGoogle Scholar
Tietz, H. (1954). The 32P marked diethyl thionophosphoric ester of β-oxyethyl thioethylether (active ingredient of the systeiflic insecticide “ Systox ”), its absorption and translocation in plants.—Höfchen-briefe, (Engl. edn.) 7, pp. 155.Google Scholar
Unterstenhöfer, G. (1952). Über das innertherapeutische Insektizid Systox.—Meded. LandbHogesch. Opzoekingssta. Gent, 17, pp. 7587.Google Scholar
Veall, N. (1948). A Geiger-Muller counter for measuring the beta ray activity of liquids and its application to medical tracer experiments.—Brit. J. Radiol., 21, pp. 347351.CrossRefGoogle ScholarPubMed