In addition to be used as a trap plant in the push-pull technology, Napier grass is the most important fodder crop in smallholder dairy production systems in East Africa, characterized by small zero grazing units. The major threat to adoption and expansion of the push-pull technology, and to the smallholder dairy industry, is the stunt disease of Napier grass . The etiology of the disease is known to be a phytoplasma, 16SrXI strain. Although, the putative insect vector was yet unknown, we have recently identified a leafhopper, Recilia banda Kramer (Hemiptera: Cicadellidae) as the vector of Napier stunt phytoplasma in Kenya.

Climate change is anticipated to have far reaching effects on sustainable development of sub-Saharan Africa (SSA), including the ability to attain the Millennium Development Goals (sdgs). Rainfall is becoming progressively more unpredictable in the region, accompanied by increases in atmospheric temperature. Predictions indicate that these trends will continue, together with increased incidences of floods and drought, expanded host and habitat ranges of pests and weeds (and pressure from these). Moreover, Agriculture is expected to intensify during the next few decades to meet the extra food demand from a growing population. These will result into progressively more serious land degradation, increased incidences of crop failure and general increases in food and nutritional insecurity among resource poor farmers in the region.

To adapt to these adverse conditions, the resource-poor smallholder farmers will need to move to more drought resistant cereal crops, such as sorghum and millet, and small ruminants for dairy production. Push-pull technology effectively works with these drought tolerant cereals resulting in significant grain yield increases. However, the trap and intercrop components are rainfall and temperature limited. Therefore, to ensure the technology continues to positively impact food security in the region over the longer term, there is an urgent need to adapt it to drier areas.

Towards this, the project urgently needs to evaluate new drought- and high temperature- tolerant trap and intercrop plants for incorporation in the push-pull technology to ensure its sustainability under the increasingly adverse conditions associated with climate change. It is important that these plants should have correct chemistry in terms of stemborer attractancy for the trap component and stemborer repellence and striga suppression, and ability to improve soil fertility and soil moisture retention, for the intercrop component. In addition, they should also provide other ecosystem services such as biodiversity conservation and organic matter improvement. The science required to identify these new components and understand the underpinning mechanisms will not only help in providing a basis for feedback in case of changes in semiochemical production by the companion plants, but will also provide the underpinning science required for the next generations of high-yield but low-input crops detailed in the recent Royal Society report entitled Reaping the benefits: Science and the sustainable intensification of global agriculture (www.royalsociety.org/Reapingthebenefits)

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The shortage of desmodium seeds is an important limiting factor for much wider dissemination of the 'Push-Pull' technology in sub-Saharan Africa (SSA). Although technology and methods for the production of seeds and development of local markets are now developed in collaboration with farmers, local seed companies and stockists, availability of large quantities of good quality seeds is essential for the planned full scale expansion. Recently an external review of icipe programmes concluded that this problem should be given high priority as it is a major cause of the limited spread of the 'Push-Pull' system. According to the reviewer efforts to select high seed yielding varieties should also be undertaken.