Hostname: page-component-76fb5796d-9pm4c Total loading time: 0 Render date: 2024-04-30T03:25:31.523Z Has data issue: false hasContentIssue false
  • English
  • Français

The influence of salinity on larval development and population dynamics of Anopheles merus Dönitz (Diptera: Culicidae)

Published online by Cambridge University Press:  10 July 2009

F. W. Mosha  and
C. M. Mutero
F. W. Mosha
Affiliation:
The International Centre of Insect Physiology and Ecology, Coastal Field Station, P.O. Box 80804, Mombasa, Kenya
C. M. Mutero
Affiliation:
The International Centre of Insect Physiology and Ecology, Coastal Field Station, P.O. Box 80804, Mombasa, Kenya
Get access Rights & Permissions [Opens in a new window]

Abstract

Variations in density of adults of Anopheles merus Dön. in Jimbo Village on the Kenya Coast were found to be correlated both with rainfall and with salinity at their breeding sites. Densities started to increase at the beginning of the rains when several breeding sites were formed. This was followed by a decline in numbers resulting mainly from the decrease in salinity in the semi-permanent breeding sites. A second rise occurred after the end of the rains, corresponding with an increase in salinity in the semi-permanent breeding sites due to evaporation. Peak density coincided with salinities of 30–50% sea water in the breeding sites. Laboratory breeding experiments showed that the larvae were usually capable of completing development in 0–100% sea water, with optimum development at 0, 40 and 60% sea water. Failure to complete development in 100% sea water at certain periods of the year indicated that there could be some seasonal variation in salt tolerance. The larvae were also found to complete development in alkaline saline water collected from an inland location around Lake Jipe in Kenya. The LC50s of sea water for first and fourth-instar larvae after exposure for 2 h were 135·0 and 930·0%, respectively. First-instar larvae were less to lerant of sodium chloride than of sea water of equivalent strength. The LC50 of sodium chloride for first-instar larvae was only 102·5%, sea water equivalent. In tests against first-instar larvae of other soluble chemical salts normally present in sea water, the highest LC50 (122·0g/litre) was of sodium sulphate and the lowest (10·5g/litre) of potassium carbonate.

Type
Research Paper
Information
Bulletin of Entomological Research , Volume 72 , Issue 1 , March 1982 , pp. 119 - 128
Copyright
Copyright © Cambridge University Press 1982

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

Bates, M. (1939). The use of salt solutions for the demonstration of physiological differences between the larvae of certain European anopheline mosquitoes.—Am. J. trap. Med. 19, 357–384.Google Scholar
Gebert, S. (1936). The breeding of Anopheles costalis in sea-water, in Mauritius.—Trans. R. Soc. trap. Med. Hyg. 30, 255–257.CrossRefGoogle Scholar
Gelfand, H. M. (1955). Anopheles gambiae Giles and Anopheles melas Theobald in a coastal area of Liberia, West Africa.—Trans. R. Soc. trap. Med. Hyg. 49, 508–527.CrossRefGoogle Scholar
Giglioli, M. E. C. (1964). Tides, salinity and the breeding of Anopheles melas (Theobald, 1903) during the dry season in the Gambia.—Riv. Malar. 43, 245–263.Google Scholar
Gillies, M. T. & De Meillon, B. (1968). The Anophelinae of Africa south of the Sahara.—Publs s. Afr. Inst. med. Res. no. 54, 203–224.Google Scholar
Halcrow, J. G. (1957). A new sub-species of Anopheles gambiae Giles from Mauritius.—E. Ajr. med. J. 34, 133–135.Google Scholar
Iyengar, R. (1962). The bionomics of salt-water Anopheles gambiae in East Africa.—Bull. Wld Hlth Org. 27, 223–229.Google ScholarPubMed
Jepson, W. F., Moutia, A. & Courtois, C. (1947). The malaria problem in Mauritius: the bionomics of Mauritian Anopheles.—Bull. ent. Res. 38, 177–208.Google Scholar
Kuhlow, F. (1962). Studies on the bionomics and the morphology of the saltwater breeding Anopheles gambiae on the coast of Tanganyika.—Riv. Malar. 41, 187–197.Google Scholar
Mackay, R. (1938). Second (final) report of the Malaria Unit, Dar es Salaam, for the period November 1934 to December 1936.—61 pp. Dar es Salaam, Govt. Printer.Google Scholar
Maffi, M. (1960). Focolaio larvale di A. gambiae e di A. squamosus in raccolta d'acqua salata, a Busc Busc (fascia costiera del basso Oltre Giuba). Primo reperto in Somalia.—Riv. Malar. 39, 131–133.Google Scholar
Muirhead, Thomson R. C. (1951). Studies on salt-water and fresh-water Anopheles gambiae on the East African coast.—Bull. ent. Res. 41, 487–502.Google Scholar
Njogu, A. R. & Kinoti, G. K. (1971). Observations on the breeding sites of mosquitoes in Lake Manyara, a saline lake in the East African Rift Valley.—Bull. ent. Res. 60, 473–479.CrossRefGoogle Scholar
Oketch, L. M. & White, G. B. (in press). Reliability of superoxide dismutase isoenzyme for distinguishing A. merus from other members of the Anopheles gambiae complex.—Trans. R. Soc. trap. Med. Hyg.Google Scholar
Paterson, H. E. (1964). “SaltwaterAnopheles gambiae” on Mauritius.—Bull. Wld Hlth Org. 31, 635–644.Google Scholar
Paterson, H. E., Paterson, J. S. & Van Eeden, G. J. (1964). Records of the breeding of “saltwaterAnopheles gambiae ” at inland localities in southern Africa.—Nature, Lond. 201, 524–525.Google Scholar
Ribbands, C. R. (1944). Differences between Anopheles melas and Anopheles gambiae. II.—Salinity relations of larvae and maxillary palp banding of adult females.—Ann. trap. Med. Parasit. 38, 87–99.CrossRefGoogle Scholar
Sverdrup, H. U., Johnson, M. W. & Fleming, R. H. (1942). The oceans.—1087 pp. London, Prentice-Hill.Google Scholar
Swaroop, S. (1966). Statistical methods in malaria.—164 pp. Geneva, Wld Hlth Org.Google ScholarPubMed
WHO (1975). Manual on practical entomology in malaria prepared by the WHO Division of Malaria and other Parasitic Diseases. Part II. Methods and techniques.—191 pp. Geneva, Wld Hlth Org. (WHO offset Publication No. 13).Google Scholar