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Behavioural ecology of the african armyworm, Spodoptera exempta (Walker): Observations on population processes during a high-density outbreak

Published online by Cambridge University Press:  19 September 2011

Syed Khasimuddin
Affiliation:
The International Centre of Insect Physiology and Ecology (ICIPE), P.O. Box 30772, Nairobi, Kenya
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Abstract

During sporadic outbreaks of S. exempta, population densities sometimes reach extremely high numbers. Monitoring at one such outbreak revealed that a considerable synchrony exists in the developmental processes of such populations, so that at times up to 97% of the population is represented by only one stage of development. Heavy pupal mortality with symptoms of a cytoplasmic virus infection was noted. Flight behaviour of emerging adults revealed observable differences in the flight activity of the moths. Although a great majority of the emerging moths flew away from the area, some stayed back. Eggs layed by the latter produced a second brood but, due to a more or less total depletion of the food source, this subsequent brood did not survive in any appreciable numbers and finally died out.

Type
Research Article
Copyright
Copyright © ICIPE 1981

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References

REFERENCES

Brown, E. S. (1962) The African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae) A review of literature. Commonwealth Institute of Entomology, London, 57 pp., 11 tables.Google Scholar
Brown, E. S. and Swaine, G. (1966) New evidence on the migration on moths of the African armyworm, Spodoptera exempta (Wik.) (Lep: Noctuidae). Bull. ent. Res. 56. 671684.CrossRefGoogle Scholar
Brown, E. S., Betts, E. and Rainey, R. C. (1969) Seasonal changes in the distribution of the African armyworm, Spodoptera exempta (Wlk.) (Lep: Noctuidae), with special reference to eastern Africa. Bull. ent. Res. 58, 661728.CrossRefGoogle Scholar
Khasimuddin, S. (1978) Courtship and mating behaviour of the African armyworm, Spodoptera exempta (Wlk.) (Lep:Noctuidae). Bull. ent. Res. 68, 195202.CrossRefGoogle Scholar
Khasimuddin, S. and Lubega, M. C. (1979) Behavioural ecology of the African armyworm, Spodoptera exempta (Wik.) (Lep: Noctuidae): Evidence of successive generations from the Lambwe Valley in Kenya. Bull. ent. Res. 69, 275282.CrossRefGoogle Scholar
Rose, D. J. W. (1975) Field development and quality changes in successive generations of Spodoptera exempta (Wlk.), the African armyworm. J. appi. Ecol. 21, 727739.CrossRefGoogle Scholar
Rose, D. J. W. and Dewhurst, C. F. (1979). The African armyworm, Spodoptera exempta (Wlk.): Congregation of moths in trees before flight. Ent. exp. appi. 26, 346348.CrossRefGoogle Scholar