Local management and landscape drivers of pollination and biological control services in a Kenyan agro-ecosystem Mark Otieno a,⇑ , Ben A. Woodcock b , Andrew Wilby c , Ioannis N. Vogiatzakis e , Alice L. Mauchline a , Mary W. Gikungu d , Simon G. Potts a a Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Earley Gate, Reading RG6 6AR, United Kingdom b NERC Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB, United Kingdom c Lancaster Environment Centre, University of Lancaster, Bailrigg, Lancaster LA1 4YQ, United Kingdom d Zoology Department, Invertebrate Zoology Section, P.O. Box 40658, 00100 GPO, Nairobi, Kenya e School of Pure & Applied Sciences, Open University of Cyprus, 13-15 Digeni Akrita Avenue, Adamantio Building, 1055 Nicosia, P.O. Box 24801, 1304 Nicosia, Cyprus article info Article history: Received 18 January 2011 Received in revised form 23 May 2011 Accepted 1 June 2011 Available online 30 July 2011 Keywords: Bio-control Farm management Fruit set Landscape context Pollination The developing world abstract Arthropods that have a direct impact on crop production (i.e. pests, natural enemies and pollinators) can be influenced by both local farm management and the context within which the fields occur in the wider landscape. However, the contributions and spatial scales at which these drivers operate and interact are not fully understood, particularly in the developing world. The impact of both local management and landscape context on insect pollinators and natural enemy communities and on their capacity to deliver related ecosystem services to an economically important tropical crop, pigeonpea was investigated. The study was conducted in nine paired farms across a gradient of increasing distance to semi-native vege- tation in Kibwezi, Kenya. Results show that proximity of fields to semi-native habitats negatively affected pollinator and chewing insect abundance. Within fields, pesticide use was a key negative predictor of pol- linator, pest and foliar active predator abundance. On the contrary, fertilizer application significantly enhanced pollinator and both chewing and sucking insect pest abundance. At a 1 km spatial scale of fields, there were significant negative effects of the number of semi-native habitat patches within fields dominated by mass flowering pigeonpea on pollinators abundance. For service provision, a significant decline in fruit set when insects were excluded from flowers was recorded. This study reveals the inter- connections of pollinators, predators and pests with pigeonpea crop. For sustainable yields and to con- serve high densities of both pollinators and predators of pests within pigeonpea landscapes, it is crucial to target the adoption of less disruptive farm management practices such as reducing pesticide and fertilizer inputs. Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction Historically, there has been a trade-off between achieving sus- tainability in food production and conserving biological diversity, a problem that is particularly pertinent to the developing world where growing populations place ever greater pressure on finite biological resources (Abalu and Hassan, 1998; Steffan-Dewenter et al., 2005). In the context of developing countries, the importance of the relationship between agricultural biodiversity, local man- agement and landscape context is poorly studied, while potentially being of great importance for human livelihoods (Abalu and Hassan, 1998). For many crops, agricultural production benefits from both pollination and natural pest control services that are provided by invertebrates (Landis et al., 2000; Ricketts et al., 2008). Insect pollinators are important in supporting 15–30% of global food production, and are worth an estimated €153 billion p.a. to the world economy (Gallai et al., 2009). Similarly, arthropod natural enemies contribute significantly to pest control, by control- ling herbivorous invertebrate populations in crops, thereby reduc- ing yield losses. The estimated value of this contribution to natural pest control in agricultural crops is $4.5 billion per year in the USA alone (Losey and Vaughan, 2006). Insect pollinators and arthropod natural enemies are major groups of invertebrates that signifi- cantly contribute to the crop production by delivering pollination and natural pest regulation. Insect communities associated with agriculture, whether pollin- ators, natural enemies or pest species, have been shown to be af- fected by both local management practices and the context of the farm in the wider landscape (Bianchi et al., 2006; Ricketts et al., 2008). Here, the term ‘landscape context’ is used to refer to the land cover and land use surrounding a site (Bianchi et al., 2006). The impact of local management practices, such as pesticide application, fertilizer application and tillage, on invertebrates has been well 0006-3207/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.biocon.2011.06.013 ⇑ Corresponding author. E-mail address: m.otieno@pgr.reading.ac.uk (M. Otieno). Biological Conservation 144 (2011) 2424–2431 Contents lists available at ScienceDirect Biological Conservation journal homepage: www.elsevier.com/locate/biocon