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Intraspecific Competition in Sitophilus oryzae (L.) and Sitotroga cerealella (Oliv.) in Grain Sorghum

Published online by Cambridge University Press:  19 September 2011

M. E. Hassan Shazali
Affiliation:
Grain Storage Research Unit, Shambat Research Station, P. O. Box 30, Khartoum North, Sudan
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Abstract

Intraspecific competition in the rice weevil, Sitophilus oryzae (L.) and the angoumois grain moth, Sitotroga cerealella (Oliv.) in grain sorghum was studied in laboratory experiments. Progeny production per female of each of the two species when reared separately, decreased as the initial parent population density increased. The number of progeny produced by Sitophilus oryzae increased to a peak, and then declined sharply with a further increase in initial parent population density, characteristic of a scramble competition. In contrast, the progeny produced by Sitotroga cerealella increased with an increase in parental density to reach a fairly constant maximum (flat topped curve), characteristic of a contest competition. It is concluded that intraspecific competition will not limit the potential of the grain moth S. cerealella of becoming a major pest of stored sorghum.

Résumé

La compétition intraspécifique au sein de populations du charançon du riz, Sitophilus oryzae (L.) et de l'alucite des céréales, Sitotroga cerealella (Oliv.) a été étudiée dans des conditions de laboratoire. En élévages separés, la prolificité par femelle de chaque espèce diminuait au fur et a mesuré que la densité de la population parentale initiale augmentait. Le nombre de progénitures de Sitophilus oryzae augmentait jusqu'à un pic, pour ensuite chuter abruptement suite a l'augmentation de la population parentale, un fait caractéristique a une compétition ascendante. Par contre, le nombre de progénitures chez Sitotroga cerealella croissait en même temps que l'augmentation de la densité de la population parentale mais pour atteindre un maximum constant (courbe à un sommet aplani), caractéristique devolue à une compétition concurrente. On a donc conclu que la compétition intraspecifique ne pourra pas limiter la potentialité de S. cerealella, d'infliger des dégâts importants au sorgho emmagasiné.

Type
Research Articles
Copyright
Copyright © ICIPE 1997

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References

REFERENCES

Agha, A. A. (1961) The biology of Sitotroga cerealella with special reference to food and the effect of extreme physical conditions. PhD Thesis, University of London.Google Scholar
Bellows, T. S. Jr (1982) Analytical model for laboratory populations of Callosobruchus chinensis and C. maculatus (Coleoptera, Bruchidae). J. Arum. Ecol. 51, 263287.Google Scholar
Birch, L. C. (1945) The influence of temperature, humidity and density on the oviposition of the small strain of Calandra oryzae (L.) and Rhyzopertha dominica (Fab.) (Coleoptera). Aust. J. Exp. Biol. Med. Sci.. 23, 197203.Google Scholar
Crombie, A. C. (1944) On intraspecific and interspecific competition in larvae of graminivorous insects, J. exp. Biol. 20, 135151.CrossRefGoogle Scholar
De Lima, C. P. F. (1978) A study of the bionomics and control of Sttophilus zeamais (Motchulsky) and Sitotroga cerealella (Oliver) and associated fauna in stored maize under laboratory and field conditions in Kenya. PhD Thesis, Univeristy of London.Google Scholar
Elton, C. (1946) Competition and the structure of ecological communities, J. Anim. Ecol. 15, 5463.CrossRefGoogle Scholar
Giga, D. P. and Smith, R. H. (1991) Intraspecific competition in the bean weevils Callosobruchus maculatus and Callosobruchus rhodesianus (Coleoptera: Bruchidae). J. Appl. Ecol. 28, 918929.CrossRefGoogle Scholar
Hassell, M. P. (1976) The dynamics of competition and predation. Studies in Biology No. 72. Edward Arnold Publishers.Google Scholar
Husted, S. R. and Mills, R. B. (1969) Intraspecific Kernelentry behaviour and competition among larvae of the angoumois grain moth. Transaction Kansas Acad. Sci. 72, 252258.Google Scholar
Maclagan, D. S. (1932) The effect of population density upon rate of reproduction with special reference to insects. Proc. R. Soc. Lond. IIIB, 437454.Google Scholar
Markham, R. H. (1981) The ecology of insect pest population in maize storage cribs in Nigeria. PhD Thesis, University of London.Google Scholar
Ricker, W. E. (1954) Effects of compensatory mortality upon population abundance, J. Wildlife Manage. 18, 4551.Google Scholar
Sharifi, S. and Mills, R. B. (1971) Development activities and behaviour of the rice weevil inside wheat kernels, J. Econ. Entomol. 64, 11141118.Google Scholar
Shazali, M. E. H. (1982) The biology and population ecology of four insect pests of stored sorghum with particular reference to competition and succession. PhD Thesis, University of Reading.Google Scholar
Shazali, M. E. H. (1993) Interspecific competition between larvae of Sitophilus oryzae (L.) and Sitotroga cerealella (Oliv.) in sorghum grains. Insect Sci. Applic. 14, 285288.Google Scholar
Smith, R. H. and Lessells, C. M. (1985) Opposition, ovicide and larval competition in graminivorous insects, pp. 423448. In Behavioural Ecology: Ecological Consequences of Adaptive Behaviour (Edited by Silby, R. M. and Smith, R. H.). Blackwell Scientific Publications, Oxford.Google Scholar
Solomon, M. E. (1953) The population dynamics of storage pests. IC int. Congr. Ent. Amsterdam 2, 235248.Google Scholar
Varley, G. C., Gradwell, G. R. and Hassell, M. P. (1973) Insect Population Ecology. Blackwell Scientific Publications, Oxford.Google Scholar