Abou Togola

Parasitoid biodiversity conservation for sustainable management of the African rice gall midge, Orseolia oryzivora (Diptera: Cecidomyiidae) in lowland rice

Abstract Platygaster diplosisae and Aprostocetus procerae attack both the African rice gall midge (AfRGM), Orseolia oryzivora, and Orseolia bonzii, a closely related gall midge that feeds on Paspalum scrobiculatum. Recent research has shown that managing this weed at the edge of rice fields offers African farmers, low-cost non-chemical control of AfRGM.

International Trade and Exotic Pests: The Risks for Biodiversity and African Economies

Trade is important for economic development and growth; however, it is also the principal means of introducing invasive pests and disease vectors that can cause environmental damage and economic losses and pose a serious risk to biodiversity. Invasive pests and trade have created a two-way linkage, leading to perceptions that African countries are becoming a source of invasive pests in other countries via trade. What phytosanitary measures do African countries have to take therefore to reduce losses in economic and trade opportunities? Another important issue is the ability of African countries to reduce trade-related pest invasions from other countries and the impact of such invasions on African economies and the environment. Management strategies that can reduce the introduction of exotic pests, while not restricting the benefits of trade or causing protective trade barriers, are desirable. This paper reviews linkages between trade and invasive pests and the resulting effects on African agricultural exports, the economy, environment and biodiversity. Strategies and policies to deal with invasive pests, trade and trade barriers and protectionism are reviewed to assess how they may affect or can be used by African countries to address these problems.

Insect Vectors of Rice Yellow Mottle Virus

Rice yellow mottle virus (RYMV) is the major viral constraint to rice production in Africa. RYMV was first identified in 1966 in Kenya and then later in most African countries where rice is grown. Several studies have been conducted so far on its evolution, pathogenicity, resistance genes, and especially its dissemination by insects. Many of these studies showed that, among RYMV vectors, insects especially leaf-feeders found in rice fields are the major source of virus transmission. Many studies have shown that the virus is vectored by several insect species in a process of a first ingestion of leaf material and subsequent transmission in following feedings. About forty insect species were identified as vectors of RYMV since 1970 up to now. They were essentially the beetles, grasshoppers, and the leafhoppers. For this review, we presented the chronology of their identification. Also, the biology, ecology, host range, distribution, and caused damage of these insects were briefly summarized.

Effect of fungi–termite interaction on the chlorophyll content of three rice varieties grown on ultisol soil of Ikenne, south-west Nigeria

The effect of fungi–termite interaction on three rice varieties was conducted in a screen house at the Africa Rice Center (AfricaRice) Ibadan, Nigeria. Of the 10 fungi species (Fusarium verticilloides, Trichoderma sp., Aspergillus niger, Aspergillus flavus, Macrophoma sp., Neurospora sp., Botryodiplodia theobromae, Penicillum sp., Rhizopus sp. and Sclerotium rolfsii) isolated from termites, soil and rice plants, F. verticilloides, Trichoderma sp. and B. theobromae were used for the interaction study. Each fungus was inoculated singly and in combinations with termite into the root of each rice variety in potted soil. Leaf samples were taken to measure the chlorophyll content which is a major parameter to estimate effect of termite–fungi interaction. The chlorophyll content of the inoculated rice plants was significantly reduced when compared with the control. Fungi interaction with termite had significant reduction on the chlorophyll content. The synergistic relationship between the fungi and the termite was discussed.