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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  and
G. Karuhize
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.

Keywords

Brevicoryne brassicaeparasitoidsDiaeretiella rapaeBrevicoryne brassicaeparasitoidesDiaeretiella rapae
Type
Research Articles
Information
International Journal of Tropical Insect Science , Volume 7 , Issue 5 , October 1986 , pp. 605 - 609
Copyright
Copyright © ICIPE 1986

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References

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