Project Title: Virus versus virus: 'Plant-vectored' viruses as bio-pesticides against insects and insect-transmitted plant viruses
Host Organisation: International Centre of Insect Physiology and Ecology (ICIPE), Kenya
Aphids and related insects are important plant pests for two reasons: they directly damage many crops and they transmit most plant viruses. For many farmers in sub-Saharan Africa, insecticides are either too expensive or unavailable, and aphid populations are very high, especially in warmer regions. For these reasons, new, inexpensive and sustainable control methods are vitally important. Can ‘good viruses’ such as insect-infecting dicistroviruses help? Dicistroviruses are remarkable in that they use plants as infection 'reservoirs' - these viruses do not reproduce or cause disease in plants but insects that feed on these reservoir plants will become infected and can become diseased and die. We believe that dicistroviruses have important potential as biological control agents that would limit direct insect damage and inhibit transmission of crop-infecting viruses. We propose to use next-generation sequencing, a state-of-the-art genetic 'fingerprinting' technique, to discover the variety of insect-infecting dicistroviruses that use crop plants as reservoirs and identify the aphid pests they infect. We shall characterise pure strains of the dicistroviruses under laboratory conditions to facilitate basic research to understand the effects of the dicistroviruses viruses on aphid survival, their feeding behaviour on plants, and on the ability of these insects to transmit crop-infecting viruses. This will enable us to identify insect-infecting viruses with potential as practical biocontrol agents to protect crops against these insects and inhibit the spread of crop-destroying viruses. This research supports Sustainable Development Goals 1-3 by benefiting smallholder incomes, food security and economic development of people in developing countries of Africa.