Insect Science and its Application (1997) 17, 143-150

Z.R. Khan, P. Chiliswa, K. Ampong-Nyarko, L.E. Smart, A. Polaszek, J. Wandera and M.A. Mulaa (1997)
Utilisation of wild gramineous plants for management of cereal stemborers in Africa
Insect Science and its Application 17 (1), 143-150
Abstract: Field trials in Kenya demonstrated that the forage grass, Sorghum vulgare sudanense (Sudan grass) attracted greater oviposition by stemborers than cultivated maize, resulting in significant increase in maize yield. On the other hand, the non-host forage plant, Melinis minutiflora (molasses grass), when inter-cropped with maize, repelled gravid stemborer females from ovipositing on maize, resulting in significant reduction in stemborer infestation. Using these trap- and repellent gramineous plants, a novel pest management approach based on a 'push-pull' or stimulo-deterrent diversionary strategy is being developed where stemborers are repelled from the food crop and are simultaneously attracted to a discard or trap crop. The plant composition and permanence of habitat surrounding maize fields also influence the abundance of natural enemies that invade agroecosystems once a pest population is present. It may be advantageous to promote the growth of native Gramineae and other wild plants which minimise, or even suppress, population growth of pests during noncropping seasons, but still provide a suitable habitat for natural enemies.

Des essais de terrain au Kenya ont prouve que l'herbe fourragere, Sorghum vulgare sudanense (herbe du Soudan) attirait plus de foreurs de tiges pour la ponte que le mais cultive, entrainant une augmentation significative de la recolte de mais. D'autre part, la plante fourragere non-hote, Melinis minutiflora (herbe melasse), une lois en culture mixte avec le mais, empechait des foreurs de tiges femelles gravides de pondre sur le mays, ce qui reduisait significativement l'infestation du mais par les foreurs de tiges. L'utilisation de ces plantes graminees pieges et repulsives, une approche nouvelle du controle des ravageurs basee sur une strategie diversionniste de 'pousse-tire' ou de 'stimulation-deterrence' est en train d'etre developee la ou les foreurs de tiges sont repousses loin des cultures de consommation et sont simultanement attires vers une plante rebut ou piege. La composition botanique et la permanence de l'habitat entourant les champs de mais influencent aussi l'abondance des ennemis naturels qui envahissent des agroecosystemes des qu'une population de ravageurs est presente. Il serait avantageux de promouvoir la croissance des graminees indigenes et d'autres plantes sauvages qui minimisent ou meme inhibent la croissance des populations des ravageurs durant les saisons de jachere, tout en assurant un habitat favorable pour les ennemis naturels.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Zeyaur R. Khan, Kwesi Ampong-Nyarko, Andrew Polaszek

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Chilo partellus	Maize/corn (Zea mays)	Kenya