Skip to main content Accessibility help

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

  • M. E. Hassan Shazali (a1)


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.

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.



Hide All
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.
Bellows, T. S. Jr (1982) Analytical model for laboratory populations of Callosobruchus chinensis and C. maculatus (Coleoptera, Bruchidae). J. Arum. Ecol. 51, 263287.
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.
Crombie, A. C. (1944) On intraspecific and interspecific competition in larvae of graminivorous insects, J. exp. Biol. 20, 135151.
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.
Elton, C. (1946) Competition and the structure of ecological communities, J. Anim. Ecol. 15, 5463.
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.
Hassell, M. P. (1976) The dynamics of competition and predation. Studies in Biology No. 72. Edward Arnold Publishers.
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.
Maclagan, D. S. (1932) The effect of population density upon rate of reproduction with special reference to insects. Proc. R. Soc. Lond. IIIB, 437454.
Markham, R. H. (1981) The ecology of insect pest population in maize storage cribs in Nigeria. PhD Thesis, University of London.
Ricker, W. E. (1954) Effects of compensatory mortality upon population abundance, J. Wildlife Manage. 18, 4551.
Sharifi, S. and Mills, R. B. (1971) Development activities and behaviour of the rice weevil inside wheat kernels, J. Econ. Entomol. 64, 11141118.
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.
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.
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.
Solomon, M. E. (1953) The population dynamics of storage pests. IC int. Congr. Ent. Amsterdam 2, 235248.
Varley, G. C., Gradwell, G. R. and Hassell, M. P. (1973) Insect Population Ecology. Blackwell Scientific Publications, Oxford.


Related content

Powered by UNSILO

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

  • M. E. Hassan Shazali (a1)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.