Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-18T08:05:59.172Z Has data issue: false hasContentIssue false
  • English
  • Français

Phase variation and ‘off-season’ survival of the African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae)

Published online by Cambridge University Press:  19 September 2011

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

Abstract

The existence of phase variation in S. exempta has long been known and the possible significance of the phenomenon in terms of the insect's life-system has been discussed previously (Rose, 1979). Present studies carried out on a comparative basis have shown meaningful differences in many attributes of solitary- and gregarious-phase caterpillars.

The solitary-phase caterpillars take longer to develop, possess more protein fractions and higher levels of juvenile hormone in the haemolymph of sixth instars, and their pupae consume more oxygen compared to the gregarious ones. It is suggested that the solitary form of larvae is the normal type for the species, while the gregarious form is able to make maximum use of resources during some parts of the year.

Type
Research Article
Information
International Journal of Tropical Insect Science , Volume 1 , Issue 4 , December 1981 , pp. 357 - 360
Copyright
Copyright © ICIPE 1981

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

REFERENCES

Brown, E. S., Betts, E. and Rainey, R. C. (1969) Seasonal changes in distribution of the African armyworm, Spodoptera exempta (Wlk.) (Lepidoptera: Noetuidae), with special reference to Eastern Africa. Bull. ent. Res. 58, 66–728.CrossRefGoogle Scholar
Cross, G. A. M. (1975) Identification, purification and properties of clone-specific glycoprotein antigens constituting the surface coat of T. brucei. Parasitology 71, 389–418.CrossRefGoogle Scholar
Davies, B. J. (1964) Disc electrophoresis. II. Method and application to human serum proteins. Ann. N.Y. Acad. Sci. 121, 404–427.CrossRefGoogle Scholar
de Wilde, J., Staal, G. B., De Kort, C. A. D., De Loof, A. and Baard, G. (1968) Juvenile hormone titre in the haemolymph as a function of photoperiodic treatment in the adult Colorado beetle (Leptonotarsa decemliniata Say). Proc. K. ned.Akad. Wet. (C) 71, 321–326.Google Scholar
Diezel, W., Kipperschilarger, G. and Hoffman, E. (1972) An improved procedure for protein staining in polyacrylamide gels with a new type of Coomassie Brilliant Blue. Ann. Biochem. 48, 617–620.CrossRefGoogle ScholarPubMed
Faure, J. C. (1946) Phase-variation in the armyworm. Laphygma exempta (Wlk.). Sci. Bull. Dept. Agric. S. Afr. 234, 17pp.Google Scholar
Hattingh, C. C. (1941) The biology and ecology of the armyworm (Laphygma exempta) and its control in South Africa. Sci. Bull. Dept. Agric. S. Afr. 211, 50 pp.Google Scholar
Hayes, D. K., Schechter, M. S., Monsing, E. and Horton, J. (1968) Oxygen uptake of single insects determined with a polarographic oxygen electrode. Anal. Biochem. 26, 51–60.CrossRefGoogle ScholarPubMed
Iwao, S. (1962) Studies on the phase-variation and related phenomenon in some lepidopterous insects. Mem. Coll. Agric, Kyoto Univ. 84, 1–80.Google Scholar
Khasimuddin, S. (1977) On the occurrence of an aestivation/disapause phenomenon in the African armyworm, Spodopteraexempta (Wlk.) (Lepidoptera: Noetuidae). E. Afri. agric. For. J. 42 (3), 350.CrossRefGoogle Scholar
Khasimuddin, S. (1981) Behavioural ecology of the African armyworm, Spodoptera exempta (Walker): observations on population processes during a high-density outbreak. Insect Sci. Applic. 1, 143–146.Google Scholar
Maurer, H. R. (1971) Disc Electrophoresis and Related Techniques of Polyacrylamide Gel Electrophoresis. Walter Gruyter, Berlin.Google Scholar
Rose, D. J. W. (1975) Field development and quality changes in successive generations of Spodoptera exempta (Wlk.), the African armyworm. J. appl. Ecol. 21, 727–739.CrossRefGoogle Scholar
Rose, D. J. W. (1979) The significance of low density populations of the African armyworm, Spodoptera exempta (Walker). Phil. Trans. R. Soc. 287, 393–402.Google Scholar
Yagi, S. (1976) The role of juvenile hormone in diapause and phase-variation in some lepidopterous insects. In The Juvenile Hormones (Ed. by Gilbert, L. I.). Plenum. New York.Google Scholar