Scaling-up Biological Control of the Diamondback Moth on Crucifers in Central and Southern Africa

The diamondback moth (DBM), Plutella xylostella L., is a key pest of cabbage, kale and other brassica vegetables. The pest can cause up to 100% yield loss if control measures are not implemented. To manage the pest, farmers normally rely on the use of chemical insecticides. The insecticides have negative effects to the environment, natural enemies, applicators and consumers of the agricultural produce.

In order to reduce on chemical insecticide use, management strategies based on use of biocontrol agents against the pest were tried in East Africa and yielded varying results. Indigenous natural enemies, for instance, were unable to control DBM. The formal research pursued an initiative of importing a highland specialist parasitiod, Diadegma semiclausum, from Taiwan and using it for management of DBM in East Africa. The parasitoid was mass reared and released in the highland of Limuru and Taita Taveta. Cotesia vestalis was also imported from southern Africa and released in the lowland of Kenya where it was thought to perform well.

The use of parasitoids for management of the DBM was effective and following the success story achieved in Kenya a scaling-up project was developed for Kenya, Tanzania, Uganda, Ethiopia and Cameroon. The current project focuses on sharing the positive outcomes of the phase I activities to central and southern Africa. Capacity building of the farmers, agricultural extension officers, research officers and students is also a key component of the project.

Aims: The project aims at promoting biocontrol-based IPM of crucifer pests in southern and central Africa (Malawi, Mozambique, Rwanda and Zambia); and assessing the impact of Cotesia vestalis in East Africa through a pilot study in Kenya.

How: By introducing biocontrol-based IPM practices in smallholder vegetable production systems.

Means: Combining both participatory methods, technology transfer and communication tools based on success achieved in Kenya, Tanzania and Uganda.

Overarching Goal: Increase rural income of smallholder vegetable producers through improved safety and quality of vegetables in the supply chain for domestic markets.

Beneficiaries: Smallholder vegetable growers (women, men & youth) and NARS in IFAD project countries

Donor: International Fund for Agricultural Development (IFAD)

Collaborators: University of Rwanda; Eduardo Mondlane University; Zambia Agriculture Research Institute (ZARI), Department of Agricultural Research Services (DARS), Malawi

Countries: Rwanda, Malawi, Mozambique and Zambia

Grants Results Sheet: https://www.ifad.org/en/web/knowledge/publication/asset/39700301

Key staff

Dr Sunday Ekesi – Head of Plant Health Division

Dr Sevgan Subramanian – Senior Scientist, Plant Health Division