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Egg parasitoids for augmentative biological control of lepidopteran vegetable pests in Africa: Research status and needs

Published online by Cambridge University Press:  19 September 2011

S. Sithanantham ,
T. H. Abera ,
J. Baumgärtner ,
S. A. Hassan ,
B. Löhr ,
J. C. Monje ,
W. A. Overholt ,
A. V. N. Paul ,
Fang Hao Wan  and
C. P. W. Zebitz
S. Sithanantham
Affiliation:
International Centre of Insect Physiology and Ecology (ICIPE), P. O. Box 30772, Nairobi, Kenya
T. H. Abera
Affiliation:
International Centre of Insect Physiology and Ecology (ICIPE), P. O. Box 30772, Nairobi, Kenya
J. Baumgärtner
Affiliation:
International Centre of Insect Physiology and Ecology (ICIPE), P. O. Box 30772, Nairobi, Kenya
S. A. Hassan
Affiliation:
Institute for Biological Pest Control, Heinrichstr. 243, D-64287 Darmstadt, Germany
B. Löhr
Affiliation:
International Centre of Insect Physiology and Ecology (ICIPE), P. O. Box 30772, Nairobi, Kenya
J. C. Monje
Affiliation:
Institute of Phytomedicine, University of Hohenheim, D-70593 Stuttgart, Germany
W. A. Overholt
Affiliation:
International Centre of Insect Physiology and Ecology (ICIPE), P. O. Box 30772, Nairobi, Kenya
A. V. N. Paul
Affiliation:
Indian Agricultural Research Institute, New Delhi - 110012, India
Fang Hao Wan
Affiliation:
Chinese Academy of Agricultural Sciences, CAAS, Beijing 100081, China
C. P. W. Zebitz
Affiliation:
Institute of Phytomedicine, University of Hohenheim, D-70593 Stuttgart, Germany
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Abstract

Among the important constraints to vegetable production in Africa are the lepidopteran pests, in particular Helicoverpa armigera (Hb.) and Plutella xylostella (L.) which cause direct yield loss as well as cosmetic damage. Egg parasitoids, especially Trichogramma spp., shown promise as biocontrol agents against both species in previous studies. In Africa, surveys have so far recorded 18 species of Trichogramma, eight of Trichogrammatoidea and seven of Telenomus besides one species each of Baryscopus and Oencyrtus. For effective utilisation of egg parasitoids in vegetable ecosystems in Africa, the experience gained elsewhere should be suitably utilised, and complementary research undertaken. This paper examines the scope for use of egg parasitoids in Africa, focusing on five research areas. Firstly, surveys should be undertaken to collect, characterise, and catalogue the different species and strains of egg parasitoids occurring in the region. Secondly, the pest status of target Lepidoptera and the potential demand for use of egg parasitoids in the major ecologies should be assessed. Thirdly, the local and/or exotic species/strains with good potential to control H. armigera and P. xylostella need to be identified, and fourthly, analyses aimed at selecting appropriate mass production and delivery systems for Trichogramma use in major vegetable crops should be undertaken. Finally, optimisation of inundative release strategies should be researched on. The scope for research collaboration within Africa and internationally is discussed.

Résumé

Les Lépidoptères ravageurs, en particulier Helicoverpa armigera (Hb.) et Plutella xylostella (L.), responsables de pertes directes de récoltes et de dégâts esthétiques, sont l'une des contraintes majeures de la production maraîchère en Afrique. Lors d'études antérieures, les parasitoïdes d'oeufs, notamment Trichogramma spp., ont montré des potentialités comme agent de régulation biologique contre ces deux espèces. En Afrique, des enquêtes ont à ce jour permis de recenser 18 espèces de trichogrammes, huit espèces de Trichogrammatoidea, sept de Telenomus et, une de Baryscopus et d'Oencyrtus. Afin d'utiliser efficacement les parasitoïdes d'oeufs dans les écosystèmes maraîchers en Afrique, l'expérience acquise ailleurs pourrait être avantageusement utilisée, et des recherches complémentaires entreprises. Cet article examinera possibilité d'utiliser les parasitoïdes d'oeufs en Afrique, en s'intéressant à 5 domaines de recherches. Premièrement, des enquêtes pourraient être entreprises afin de collecter, identifier et inventorier les différentes espèces et souches de parasitoïdes d'oeufs présents dans la région. Deuxièmement, le statut de ravageur des Lépidoptères cibles et l'intérêt d'utiliser des parasitoïdes d'oeufs dans les principales conditions écologiques devraient être évalués. Troisièmement, les espèces ou les souches indigènes et/ou exotiques avec un bon potentiel de contrôle d'H. armigera et P. xylostella devront être identifiées. Quatrièmement, il serait souhaitable d'entreprendre des analyses destinées à sélectionner une production de masse et des systèmes de livraison appropriés pour l'utilisation des trichogrammes dans les principales productions maraîchères. Finalement, l'optimisation des stratégies de lâchers inondatifs devrait être approfondie. Il est également recommandé d'établir des collaborations de recherches internationales.

Keywords

vegetable productionegg parasitoidsTrichogrammaTrichogrammatoideaHelicoverpa armigeraPlutella xylostellabiological diversityproduction maraîchèreparasitoïdes d'oeufsTrichogrammaTrichogrammatoideaHelicoverpa armigeraPlutella xylostelladiversité biologique
Type
Mini Review
Information
International Journal of Tropical Insect Science , Volume 21 , Issue 3 , September 2001 , pp. 189 - 205
Copyright
Copyright © ICIPE 2001

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