Sierra Leone IPM project 05: Controlling African rice gall midge, Orseolia oryzivora (Diptera: Cecidomyiidae) in lowland rice environments by integrating host plant resistance, cropping pattern, crop residue management, biological control and  nursery application of low persistent chemical pesticide (Carbamates)

Project Duration:  2 Years (2006 – 2008)

Purpose of the project:  To develop and test at farm level IPM packages based on an understanding of the interaction of host plant resistance, cropping patterns, crop residue management, natural enemies and nursery application of carbofuran for the control of O. oryzivora in lowland rice habitats in West Africa

Background/description:  The WARDA/CABI Project on Management of the African rice gall midge (AfRGM) has conducted an extensive survey on the distribution, host range and natural enemies of the African rice gall midge.  Two parasitoids, viz, a polyembryonic endoparasitoid, Platygaster diplosisae Risbec and a solitary ectoparasitoid, Aprocetus procerae were identified as potential biocontrol agents for AfRGM.  The project also screened 600 rice accessions and several improved rice genotypes were identified but manageable resistance levels were not achieved for AfRGM.  It is likely that a combination of IPM components including host plant resistance, biological control, habitat management and nursery application of low persistence insecticides will be needed to provide adequate suppression of O. oryzivora in West Africa.

Agro-ecological zones and locations:  Northern savana grassland and Southern tropical rain forest in Sierra Leone

Expected Output: 1) Relationship between O. oryzivora incidence and natural enemy population dynamics in different rice-based cropping systems in lowland environments is established and this can help identify new and more effective natural enemies that can be introduced in new areas, 2) Host plant–insect–natural enemy interactions are assessed and improved as both components can effectively control O. oryzivora, especially in low input subsistence farming systems, 3) Efficient crop residue management that suppress AfRGM populations and enhance natural enemy activity is developed and recommended for use, 4) The effectiveness of selective systemic insecticides and optimum dose and time of application are known, an information critical for developing IPM appropriate to different agroecosystems.

Potential impact and beneficiaries:  Small-scale lowland rice farmers, who constitute the majority of rice producers in West Africa will be the beneficiaries of the results, notably, host plant resistance, cultural practices and biological control–having many advantages such as sustainability and environmental safety.  In addition, the technologies will reduce quantitative losses due to rice gall midge damage, increase rice yields leading to increased farmers’ incomes and rural family well being.  All of these would eventually lead to food security and poverty alleviation in Sub-Saharan Africa.

Partners:  a) Njala University; b) West Africa Rice Development Association (WARDA)

Principal investor(s):  Gatsby Charitable Foundation

Project Contact Person(s)/Principal Investigator(s): Samuel I. Kamara, sikamara2001@ yahoo.com, S.S. Harding, rokupr@sierratel.sl and C. K. Charles, rokupr@sierratel.sl