Vol. 31, no. 2 Journal of Vector Ecology 319 Urban agricultural land use and characterization of mosquito larval habitats in a medium-sized town of Côte d’Ivoire Barbara Matthys 1,2 , Eliézer K. N’Goran 2,3 , Moussa Koné 4 , Benjamin G. Koudou 2 , Penelope Vounatsou 1 , Guéladio Cissé 2 , Andres B. Tschannen 2 , Marcel Tanner 1 , and Jürg Utzinger 1 1 Department of Public Health and Epidemiology, Swiss Tropical Institute, P.O. Box, CH-4002 Basel, Switzerland 2 Centre Suisse de Recherches Scientifiques, 01 BP 1303, Abidjan 01, Côte d’Ivoire 3 UFR Biosciences, Université d’Abidjan-Cocody, 22 PB 770, Abidjan 22, Côte d’Ivoire 4 Centre d’Entomologie Médicale et Vétérinaire, Université de Bouaké, 27 BP 529, Abidjan 27, Côte d’Ivoire Received 30 March 2006; Accepted 19 July 2006 ABSTRACT: Urban agriculture is common across Africa and contributes to the livelihoods of urban dwellers. Some crop systems create suitable mosquito breeding sites and thus might affect malaria transmission. The purpose of this study was to identify, map, and characterize potential mosquito breeding sites in agricultural land use zones in a medium-sized town of western Côte d’Ivoire and to assess risk factors for productive Anopheles breeding sites. Two surveys were carried out; one toward the end of the rainy season and the second one during the dry season. In all identified potential mosquito breeding sites, two experienced entomologists searched for the presence of Anopheles larvae and pupae with a standardized technique. Totals of 369 and 589 sites were found in the rainy and dry seasons, respectively, mainly in vegetable gardens and irrigated rice fields. Anopheles larvae were present in 50.7% and 42.4% of the sites investigated during the rainy and dry seasons, respectively. Typical Anopheles larval habitats were characterized by the presence of algae, the absence of floating vegetation, and the co-occurrence of Culex larvae. The highest Anopheles larval productivity was observed in rice paddies, agricultural trenches between vegetable patches, and irrigation wells. An indirect link could be established between the occurrence of productive Anopheles breeding sites and agricultural land use through specific man-made habitats, in particular agricultural trenches, irrigation wells, and rice paddies. Our findings have important bearings for the epidemiology and control of urban malaria in sub-Saharan Africa. Journal of Vector Ecology 31 (2): 319-333. 2006. Keyword Index: Malaria, urban agriculture, breeding sites, Anopheles, Culex. INTRODUCTION Malaria causes social and economic hardship and impedes progress toward achieving several of the Millennium Development Goals, particularly in sub- Saharan Africa (Sachs and Malaney 2002, Keiser et al. 2005, Snow et al. 2005). Due to rapid urbanization, malaria in urban settings is a growing, albeit overlooked, problem and requires more emphasis (Robert et al. 2003, Keiser et al. 2004, Donnelly et al. 2005, Hay et al. 2005, Wang et al. 2005). Urbanization often results in profound demographic, ecological, and socio-economic changes that are characterized by a high degree of spatial and temporal heterogeneity (Utzinger and Keiser 2006). The adaptation of malaria vectors to urban ecosystems has been documented and warrants close attention (Chinery 1984, Klinkenberg et al. 2005). Importantly, a high proportion of the urban population at any age is at risk of malaria due to lack of acquired immunity (Castro et al. 2004). Since malaria transmission in urban settings is usually lower and more focal than in rural settings (Staedke et al. 2003), urban areas hold promise for vector control and integrated vector management (WHO 2004). Most of the previous research pertaining to urban malaria in sub-Saharan Africa has focused on large cities, including Brazzaville, Congo (Trape and Zoulani 1987), Dar es Salaam, Tanzania (Castro et al. 2004, Wang et al. 2006a), and Abidjan, Côte d’Ivoire (Wang et al. 2006b). In view of the rapidly growing number of small- and medium-sized towns, there is a pressing need to improve our understanding of the epidemiology of malaria in these settings. As the human population density is usually lower in smaller towns, a higher fraction of open space is available for agriculture, which in turn may create productive mosquito breeding sites and might affect malaria transmission. Urban agriculture encompasses the production, processing, and distribution of food, comprising vegetable and animal products in intra- and peri-urban areas (Baumgartner and Belevi 2001). In African countries, urban agriculture plays an important role in food security and improving local livelihoods. On the other hand, irrigated urban agriculture might affect malaria transmission intensity and dynamics through the creation of suitable breeding sites, as has been documented recently in urban settings of Ghana (Afrane et al. 2004, Klinkenberg et al. 2005). The purpose of the current study was to investigate factors that govern the presence of Anopheles larvae in urban agricultural zones and to derive typical features