Insect Service and Biodiversity in Agroecological Farming
This project aims at providing a reference test-case with a first quantitative description of relationships between agroecological farming, biodiversity of insect pollinators and pests, and cucurbit crop production in sub-Saharan Africa. We propose to focus on two major functional groups of insects that are of interest in agroecological farming, namely pollinators, particularly bees (Hymenoptera, Apoidea) and flower flies (Diptera, Syrphidae), but also pests, particularly fruit flies (Diptera, Tephritidae) as targets and proxies for the evaluation of pollinator & pest biodiversity in contrasting agroecosystems. Relationships between agroecological farming landscape and insect diversity (including morpho-species and genetic diversity) will be tested by comparing agroecological and conventional farms in the Morogoro region (East-Central Tanzania). We will focus on three cucurbit crops commonly grown in Tanzania, these are watermelon - Citrullus lanatus, cucumber - Cucumis sativus and pumpkin - Cucurbita sp. Insect species composition and abundance will be estimated following well-established trapping protocols for quantitative analyses. Insects will be preliminarily sorted at the Sokoine University of Agriculture (SUA, Tanzania) and identified in collaboration with the reference taxonomists for African bees (Alain Pauly - RBINS), flower flies (Kurt Jordaens – RMCA) and fruit flies (Marc De Meyer - RMCA). Morpho-species diversity will be computed for pollinators and pests. Insect genetic diversity will be quantified via genome skimming. These data will be used for population genetic analyses as well to quantify levels of phylogenetic diversity. Field experiments on the pollination service provided by bees and flower flies to cucurbit crops will be implemented in experimental plots at SUA. Relationships between farming approach (agroecological, conventional), insect morpho-species and genetic diversity of the targeted insect species and functional groups will be tested using a range of statistical tools routinely used by the Agroecology Lab at ULB. We will provide a socio-economic analysis on cucurbit agroecological farming in Tanzania. In this respect, we will on the one hand monitor yields of cucurbits and their economic value at farm gate and at the local markets, and on the other hand we will deploy a Q-Methodology survey to assess the opportunities and “lock-ins” for an agroecological transition in cucurbit production among a range of stakeholders (including farmers, end consumers, local authorities). This project will provide scientific support to policies promoting the protection of biodiversity and ecosystem services and a more sustainable use of natural resources. We believe that the socio-economic analysis produced on cost-benefits, sustainability and productivity of small-scale cucurbit farming will certainly be of interest for the development of a more sustainable agriculture in Africa and will allow exploring alternative ways to traditional food production and consumption. This project will also produce information relevant in a national context, by identifying obstacles and opportunities to the implementation of agroecology as alternative and transition food system.