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The role of Diaeretiella rapae (M'cintosh) (Hymenoptera: Braconidae) in the population control of the cabbage aphid, Brevicoryne brassicae L. (Hemiptera: Aphididae) in Kenya

Published online by Cambridge University Press:  19 September 2011

J. Bahana
Affiliation:
Department of Zoology, University of Nairobi, P.O. Box 30197, Nairobi, Kenya
G. Karuhize
Affiliation:
Department of Zoology, University of Nairobi, P.O. Box 30197, Nairobi, Kenya
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Abstract

Diaeretiella rapae (M'cintosh) was the only parasitoid of the cabbage aphid, Brevicoryne brassicae L., during studies reported here.

Percentage parasitism of B. brassicae ranged from 27.1 to 76.1% in studies carried out around Nairobi area during 1978/79. It was highest during the month of September, when the aphid population density had reached maximum, and lowest in May when aphid numbers were low. High parasitism coincided with a decline in aphid population.

Because of these high levels of parasitism and other attributes of the parasitoid, it was concluded that D. rapae played a significant role in suppressing populations of B. brassicae and should be taken into consideration in any control programme aimed at protecting brassica crops against aphid pests in Kenya.

Résumé

Le puceron Diaeretiella rapae (M'cintosh) était l'unique parasitoide de choux Brevicoryne brassicae L. rapporte tout au long de nos études.

Une étude menée dans les environs de Nairobi au cours des années 1978/79 montre un pourcentage de parasitisme de Brevicoryne brassicae de l'ordre de 27.1 a 76.1%. Le parasitisme est trés élere pendant le mois de September, lorsque apparemment la densité de la population de pucerons atteint le maximum, et est tre bas au mois de mai lorsque le nombre de pucerons est bas.

A cause de ces hauts niveaux de parasitisme et autres attributs du parasitoide, il étail concluque D. rapae jouvait un role considerable dans la suppression des populations de B. brassicae et devrait être pris en consideration dans tout programme de lutte ayaôut pour objectif la protection de culture de chaux contre les pucerons, insectes nuisibles au Kenya.

Type
Research Articles
Copyright
Copyright © ICIPE 1986

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References

REFERENCES

Anonymous (1977) Provincial Annual Reports. Kenya, Ministry of Agriculture, 1977–78.Google Scholar
Bohlen, E. (1978) Crop Pests of Tanzania. Parley, Berlin.Google Scholar
Chua, T. H. (1979) A comparative study of the searching efficiencies of a parasite and a hyperparasite. Res. Popul. Ecol. 20, 179187.CrossRefGoogle Scholar
Coppel, H. C. and Mertins, J. W. (1977) Biological Insect Suppression. Springer, Berlin.CrossRefGoogle Scholar
George, K. S. (1957) Preliminary investigation on the biology and ecology of the parasites and predators of Brevicoryne brassicae. Bull. ent. Res. 48, 619629.CrossRefGoogle Scholar
Hill, D. S. (1975) Agricultural Insect Pests of the Tropics and their Control. Cambridge University Press, Cambridge.Google Scholar
Huffaker, C. B. (Ed.) (1971) Biological control. In Proceedings of the AAAS Symposium on Biological Control. Plenum Press, New York.Google Scholar
Hughes, R. D. (1963) Population dynamics of the cabbage aphid. Brevicoryne brassicae L. J. Anim. Ecol. 32, 393424.CrossRefGoogle Scholar
Lammerick, J. and Banfield, L. A. (1980) Effects of aphid control by Disulfoton on seed yield components and seed quality of oil seed rape. N.Z. J. Exp. 8, 4558.Google Scholar
Pimental, D. (1961) Natural control of aphid populations on Cole crops. J. econ. Ent. 54, 885888.CrossRefGoogle Scholar
Schumutterer, H. (1968) Pests of Crops in North-East and Central Africa with Particular Reference to Sudan. Gustar Fischer, Stuttgart.Google Scholar
Solomon, S. E. (1949) The natural control of animal populations. J. Anim. Ecol. 18, 135.CrossRefGoogle Scholar
Strickland, A. H. (1961) Sampling of crop pests and their hosts. A. Rev. Ent. 6, 201220.CrossRefGoogle Scholar
Van Emden, H. F. (1966) Effectiveness of aphidophagous insects in reducing aphid populations. A review. In Ecology of Aphidophagous Insects (Edited by Hodek, I.), pp. 227235. Academica Press, Prague.Google Scholar
Wanjama, J. K. (1978) Survey of insects associated with oil rape (Brassica napus L. and B. campestris) in Kenya with special reference to susceptibility of six rape varieties to insect attack. M.Sc. thesis. University of Nairobi.Google Scholar