International Journal of Tropical Insect Science

, Volume 2, Issue 3, pp 189–195 | Cite as

Some Laboratory Observations on the Biology of Aedes (Stegomyia) Africanus

  • S. D. K. Sempala


Investigations are reported on oviposition habits, development, and emergence patterns of the pre-adult stages of Aedes (Stegomyia) africanus (Theo.) under laboratory conditions. It was observed that water or at least a wet surface is necessary for oviposition and that the intensity of egg-laying takes place within 2 cm from water surface and is greater in those containers with deeper water levels. Post-oviposition embryonic development lasts an average of 6 days thus conforming with earlier findings (Gillett, 1955). The quantity of water does not affect either the period of post-oviposition embryonic development or the rate of egg hatching. However, an average of 75% of the eggs hatch within the first 13 days after flooding, leaving the rest to hatch in subsequent instalments. At 27°C, the second-instar larvae take the shortest time to develop while the fourth-instar larvae take the longest period. Generally, intra-instar variability in growth rates were observed except in the pupal stage. Emergence of the various pre-imaginal stages and pupation did not appear to have any regular periodicity. Of particular interest was the observation that the number of instars in this species varied from the normal number of four, a finding which is believed not to have been recorded previously in the family Culicidae.

Key Words

Mosquito Aedes (Stegomyia) africanus oviposition embryonic development larval instars flooding periodicity life history 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Christophers S. R. (1960) Aedes aegypti (L.). The Yellow Fever Mosquito. Its Life History, Bionomics and Structure. Cambridge University Press, London.Google Scholar
  2. Clements A. N. (1963) The Physiology of Mosquitoes (International Series of Monographs on Pure and Applied Biology, 17). Pergamon Press, Oxford.Google Scholar
  3. Corbet P. S. (1964) Observations on mosquitoes ovipositing in small containers in Zika Forest, Uganda. J. Anim. Ecol. 33, 141–164.CrossRefGoogle Scholar
  4. Gillett J. D. (1955) Variation in the hatching response of Aedes eggs (Diptera, Culicidae). Bull. ent. Res. 46, 241–254.CrossRefGoogle Scholar
  5. Gillett J. D. (1971) Mosquitoes. Weidenfeld & Nicolson. London.Google Scholar
  6. Gillett J. D. and Haddow A. J. (1957) Laboratory observation on oviposition-cycle in the mosquito Aedes (Stegomyia) africanus Theobald. Ann. trop. Med. Parasit. 51, 170–174.CrossRefGoogle Scholar
  7. Gillett J. D., Ross R. W., Dick G. W. A., Haddow A. J. and Hewitt L. E. (1950) Experiments to test the possibility of trans-ovarial transmission of yellow fever virus in the mosquito Aedes (Stegomyia) africanus Theobold. Ann. trop. Med. Parasit. 44, 342–350.CrossRefGoogle Scholar
  8. Haddow A. J. (1961) Studies on the biting habits and medical importance of East African mosquitoes in the genus Aedes. II. Subgenera Mucidus, Diceromyia, Finlaya, and Stegomyia. Bull. ent. Res. 52, 317–351.CrossRefGoogle Scholar
  9. Haddow A. J. (1964) Observation on the biting habits of mosquitoes in the forest canopy of Zika, Uganda, with special reference to the crepuscular periods. Bull. ent. Res. 55, 589–608.CrossRefGoogle Scholar
  10. Haddow A. and Ssenkubuge Y. (1965) Entomological studies from a high steel tower in Zika Forest, Uganda. Part I. The biting activity of mosquitoes and tabanids as shown by twenty-four hour catches, Trans. R. ent. Soc. Lond. 117, 215–243.CrossRefGoogle Scholar
  11. Lumsden W. H. R. (1952) The crepuscular biting activity of insects in the forest canopy in Bwamba, Uganda. A study in relation to the sylvan epidemiology of yellow fever. Bull. ent. Res. 42, 712–760.CrossRefGoogle Scholar
  12. Marcovitch S. (1960) Experiments on prolongation of the life of mosquito larvae by underfeeding. J. econ Ent. 53, 169.CrossRefGoogle Scholar
  13. McClelland G. A. H. (1970) Subtle periodicity of pupation in rapidly developing mosquitoes with particular reference to Aedes rittatus and Aedes aeqvpti. Bull. Wld Hlth Org. 42, 951–955.Google Scholar
  14. Ross R. W. and Gillett J. D. (1950) The cyclical transmission of yellow fever through the grivet monkey, Cer-copithecus aethiops centralis Neumann, and the mosquito Aedes (Stegomvia) africanus Theobald. Ann. trop. Med. Parasit. 44, 351–356.CrossRefGoogle Scholar
  15. Sempala S. D. K. (1971) Some aspects of the biology of tree-hole breeding mosquitoes with special reference to Aedes (Stegomyia) africanus Theobald and Aedes (Stegomyia) apicoargenteus Theobald (Diptera, Culicidae). M.Sc. thesis, University of East Africa.Google Scholar
  16. Sempala S. D. K. (1976) Studies on the bionomics and ecology of Aedes (Stegomyia) africanus Theobald (Diptera, Culicidae) in a tropical forest in Uganda. Ph.D. thesis, University of Nairobi.Google Scholar
  17. Sempala S. D. K. (1980) The ecology of Aedes (Stegomyia) africanus Theobald in a tropical forest in Uganda: mark-release-recapture studies on a female adult population. Insect Sci. Applic. 1, 211–224.Google Scholar
  18. Trpis M. (1972) Seasonal changes in the larval populations in Aedes aegvpti in two biotopes in Dar es Salaam, Tanzania. Bull. Wld Hlth Org. 47, 245–255.Google Scholar
  19. Wigglesworth V. B. (1961) The Principles of Insect Physiology. Methuen, London.Google Scholar

Copyright information

© ICIPE 1981

Authors and Affiliations

  • S. D. K. Sempala
    • 1
  1. 1.Department of Entomology and Vertebrate ZoologyUganda Virus Research InstituteEntebbeUganda

Personalised recommendations