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The penetration of pyrethrum through the cuticle of the tick, Ornithodorus moubata Murray (Argasidae)

Published online by Cambridge University Press:  06 April 2009

G. G. Robinson
Affiliation:
London School of Hygiene and Tropical Medicine

Extract

1. Experiments are described in which various concentrations of pyrethrum in oil are tested for speed of stimulation of Ornithodorus larvae. There is a logarithmic relation between concentration and speed of stimulation, except with concentrated solutions (stronger than 0·015% by weight of pyrethrin I) in which there is a relative retardation of response.

2. As larvae grow older they respond more slowly, and this is probably due to an increase in thickness of the cuticle in natural growth.

3. Mineral oils induce much swifter penetration of the pyrethrum than any of the vegetable oils tested.

My thanks are due to Prof. Buxton in whose department the work was done, and also, to Dr J. T. Martin of Rothamsted Experimental Station, who kindly analysed samples of Pyremist ‘L’ for pyrethrin I.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1942

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References

REFERENCES

Bliss, C. I. & Broadbent, B. M. (1935). A comparison of criteria of susceptibility in the response of Drosophila to hydrocyanic acid gas. I. Stupefaction time and mortality. J. Econ. Ent. 28, 989.CrossRefGoogle Scholar
Campbell, F. L. (1926). Speed of toxic action of arsenic in the silkworm. J. Gen. Physiol. 9, 433.CrossRefGoogle ScholarPubMed
Clark, A. J. (1933). The Mode of Action of Drugs upon Cells. London: Edward Arnold.Google Scholar
Dutton, J. E. & Todd, J. L. (1905). The nature of human tick fever in the eastern part of the Congo Free State. Mem. Lpool Sch. Trop. Med. no. 17.Google Scholar
Hartzell, A. & Wilcoxon, F. (1933). Experiments on the mode of action of pyrethrum and its effects on insect tissues. Vth Congr. int. Ent. Paris, 1932, p. 289.Google Scholar
Hoskins, W. M. (1932). Toxicity and permeability. I. The toxicity of acid and basic solutions of sodium arsenite to mosquito pupae. J. Econ. Ent. 25, 1212.CrossRefGoogle Scholar
Richardson, H. H. (1932). Insecticidal studies of mid-continent distillates as bases for pyrethrum extracts. Industr. Engng Chem. 24, 1394.CrossRefGoogle Scholar
Shackell, L. F. (1922). Studies in protoplasm poisoning. I. Phenol. J. Gen. Physiol. 5, 783.CrossRefGoogle Scholar
Sullivan, W. N., Haller, H. L., McGovran, E. R. & Phillips, G. L. (1938). Knockdown in flysprays. Soap, 14, 101.Google Scholar
Wigglesworth, V. B. (1933). The physiology of the cuticle and of ecdysis in Rhodnius prolixus (Triatomidae, Hemiptera); with special reference to the function of the oenocytes and of the dermal glands. Quart. J. Micr. Set. 76, 269.Google Scholar
Wioglesworth, V. B. (1939). The Principles of Insect Physiology. London: Methuen.Google Scholar
Wigglesworth, V. B. (1941). The effect of pyrethrum on the spiracular mechanism of insects. Proc. R. Ent. Soc. Lond. A, 16, 11.Google Scholar