Survival and Development of the African Armyworm Spodoptera exempta (Wlk.) (Lepidoptera, Noctuidae) on Some Grass Species (Gramineae)

  • Jacob G. Yarro


—At 25°C and 70% r.h. larvae of Spodoptera exempta develop faster and pass through five instars on star grass, Cynodon dactylon (L.); Pers. maize, Zea mais L.; and Kikuyu grass, Pennisetum clandestinum Chiov. whereas on guinea grass, Panicum maximum Jacq.; and Setaria plicatilis (Hochst.) Hack, the development is not only slower, but the larvae pass through six and seven instars, respectively. Samples of larvae reared on the former grass species suffer high mortality only at the first and the last instar stages so that the distribution of per cent mortality is U-shaped. On the latter host plants, the mortality during the first instar stage is equally high and continues through the subsequent instars with no obvious peak towards the end of the larval life. The samples on C. dactylon and Z. mais had much higher growth indices than those on P. maximum and S. plicatilis. C. dactylon is a preferred natural food plant of S. exempta in the field, and these investigations demonstrate its value and importance.

Key Words

Spodoptera exempta survival development host plants grass species growth indices 


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  1. Bailey J. L. (1967) Techniques in Protein Chemistry. 2nd revised edition. Elsevier, Amsterdam.Google Scholar
  2. Bogdan A. V. (1963) Notes on the damage by armyworm (Laphygma exempta) to grass species at Kitale Kenya. E. Afr. agric. for. J. 19, 120–121.CrossRefGoogle Scholar
  3. Brown E. S. (1962) The African Armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae). A Review of the Literature. Commonwealth Institute of Entomology, London.Google Scholar
  4. Brown E. S. (1970) Control of the African armyworm, Spodoptera exempta (Walk.)—an appreciation of the problem. E. Afr. agric. for. J. 35, 237–245.CrossRefGoogle Scholar
  5. Brown E. S., Betts E. and Rainey R. C. (1969) Seasonal changes in distribution of the African armyworm, Spodoptera exempta (Wlk.) (Lepidoptera: Noctuidae) with special reference to Eastern Africa. Bull. ent. Res. 58, 661–728.CrossRefGoogle Scholar
  6. Brown E. S. and Dewhurst C. F. (1975) The genus Spodoptera (Lepidoptera, Noctuidae) in Africa and the Near East. Bull. ent. Res. 65, 221–262.CrossRefGoogle Scholar
  7. Brown E. S. and Mohamed A. K. A. (1972) The relation between simulated armyworm damage and crop loss in maize and sorghum. E. Afr. agric. for. J. 37, 237–257.CrossRefGoogle Scholar
  8. Brown E. S. and Swaine G. (1965) Virus disease of the African armyworm, Spodoptera exempta (Wlk.). Bull ent. Res. 56, 95–116.CrossRefGoogle Scholar
  9. Brown E. S. and Swaine G. (1966) New evidence on the migration of moths of the African armyworm, Spodoptera exempta (Lepidoptera, Noctuidae). Bull. ent. Res. 56, 671–684.CrossRefGoogle Scholar
  10. Faure J. C. (1943) Phase variation in the armyworm Laphygma exempta (Wlk.). Sci. Bull. Dep. Agric. 234, 1–17.Google Scholar
  11. Gill J. L. (1978) Design and Analysis of Experiments in the Animal and Medical Sciences, Vol. 1, p. 179. The Iowa State University Press, Ames, Iowa.Google Scholar
  12. Hattingh C. C. (1941) The biology and ecology of the armyworm (Laphygma exempta) and its control in South Africa. Sci. Bull.’Dep. Agric. S. Afr. 217, 1–50.Google Scholar
  13. Howe R. W. (1971) A parameter for expressing suitability of an environment for insect development. I. Stored Prod. Res. 7, 63–64.CrossRefGoogle Scholar
  14. Matthee J. J. (1952) The occurrence of the armyworm in and around Pretoria. J. ent. Soc. Sth. Afr 15, 122–128.Google Scholar
  15. Odindo M. O. (1977) Comparative studies on the histo-pathology and the symptomatology of a nuclear poly-hedrosis of Spodoptera exempta (Wlk.) (Noctuidae, Lepidoptera). E. Afr. agric. for. J. 42, 287–295.CrossRefGoogle Scholar
  16. Odiyo P. O. (1979) Forecasting infestations of a migrant pest: the African armyworm Spodoptera exempta (Walk.). Phil. Trans. R. Soc. (B)287, 403–413.CrossRefGoogle Scholar
  17. Odiyo P. O. (1981) Development of the first outbreaks of the African armyworm, Spodoptera exempta (Walk.) between Kenya and Tanzania during the ‘off-season’ months of July to December. Insect Sci. Application 1, 319–338.Google Scholar
  18. Pant N. C. and Dang K. (1969) Food values of several commodities in the development of Tribolium castenum Hobst. Indian J. Ent. 31, 147–151.Google Scholar
  19. Rose D. J. W. (1979) The significance of low density populations of the African armyworm, Spodoptera exempta (Walk.). Phil. Trans. R. Soc. (B)287, 393–402.CrossRefGoogle Scholar
  20. Slansky F. and Feeny P. P. (1977) Maximization of the rate of nitrogen accumulation by larvae of the cabbage butterfly on wild and cultivated food plants. Ecol. Monogr. 47, 209–228.CrossRefGoogle Scholar
  21. Sokal R. and Rolf F. J. (1969) Biometry. The Principles and Practice of Statistics in Biological Research. W. H. Freeman and Company, 1976 pp.Google Scholar
  22. Soo Hoo C. F. and Fraenkel G. (1966) The consumption, digestion and utilization of food plants by a phytophagous insect Prodenia eridania (Cramer). J. Insect Physiol. 12, 711–730.CrossRefGoogle Scholar
  23. Whellan J. A. (1958) Report of the Chief Entomologist for the year ending 30th September, 1956. Rhodesia Agric. J. 55, 302–313.Google Scholar
  24. Yarro J. G., Otindo B. L., Gatehouse A. G. and Lubega M. C. (1981) Dwarf variety of coconut, Cocos nucifera (Palmae), a host plant for the African armyworm, Spodoptera exempta (Wlk.) (Lepidoptera, Noctuidae). Insect Sci. Application 1, 361–362.Google Scholar

Copyright information

© ICIPE 1984

Authors and Affiliations

  • Jacob G. Yarro
    • 1
  1. 1.International Centre of Insect Physiology and EcologyNairobiKenya

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