Bee Pollinators and Economic Importance of Pollination in Crop Production : Case of Kakamega, Western Kenya

Bees are the main animal pollinators of crops worldwide. In Kakamega, Western Kenya, farmers do not manage them for pollination but rely on feral pollinators from the nearby habitats. The ability of these habitats to continuously support bees depends on how they are managed by the adjacent communities. Therefore, the overall aim of this study was to elucidate strategies that can be used to improve bee pollination in the Kakamega farmland. The following objectives were defined: i) determine whether the presence of Kakamega forest affects bee pollinator diversity and foraging activity density in crops in the farmland, ii) establish the contribution of bee pollination to crop productivity, iii) assess the knowledge of farmers about bees and pollination, and iv) quantify the economic benefit that farmers derive from pollination of their crops by bees. The data were collected: i) through observation of bees along a transect from fields near the forest to fields 8 km away, ii) in experimental plots with crops with and without bee-pollination, iii) through questionnaire administration to 352 farmers, and iv) through secondary data, mainly sourced from the Ministry of Agriculture. The number of bee species recorded in the fields near and far from the forest was not statistically different, implying that bee diversity in the farmland does not necessarily depend on the forest. However, the activity density of some bee populations (e.g., Xylocopa calens) was significantly higher in fields near the forest, indicating that the forest might be an important element in providing sufficient pollination services in the system, while the presence of a sufficient number of bees for pollination will depend on how the farmland landscape is managed. The increase in crop yield due to bee pollination, tested on nine crops (beans, cowpeas, green grams, bambara nuts, tomatoes, capsicum, passion fruit, sunflower and squash) ranged from 25% (tomatoes) to more than 99% (squash). Thus, although some crops can produce without bee pollination, presence of bees is important to increase yields, and hence, food security and income. Similarly, bee pollination is essential for reproduction in other crops. There was a significant increase in the quality of seeds (e.g., 21%; sunflower oil) and fruit sizes (e.g., capsicum by 29%, leading to a higher market price). The contribution of bee pollination to the farmers’ income in Kakamega in 2005 was about 50% of the annual value of the selected crops (except squash). This was an almost 40% net benefit, suggesting that bee pollination economically benefits crop producers. More than 98% of the farmers knew different bee species but only about 50% knew of the function of bee pollination in crop production. However, after informing them of the role of pollination, more than 98% were willing to pay an estimated US$90 per household annually for pollination of their crops by bees. Both the knowledge of pollination and willingness to pay amount correlated significantly with the education of the farmers. This suggests that education of farmers on issues of bees and pollination can have an impact on bee conservation in the Kakamega farmland. Therefore, farmers and other stakeholders should be trained on the role of bee pollination and its contribution to their welfare and on the use of cost-effective strategies for bee conservation, taking into consideration the locally available resources. For example, landscape management strategies are possible, e.g., proper utilization of hedgerows, which are unique in the farmland and connects it with the forest. Other methods such as use of trap nests for cavity nesting bees and integrated farm management systems, e.g., pest management, should also be considered. Research should be done to provide guidance on how best these strategies can be adopted for bee conservation in the region.Bienenbestäuber und die wirtschaftliche Bedeutung der Bestäubung in der landwirtschaftlichen Produktion - Beispiel Kakamega, West-Kenia Bienen sind die wichtigsten tierischen Best äuber von Nutzpflanzen weltweit. In Kakamega, West-Kenia, betreiben die Bauern keine Bienenhaltung, sondern verlassen sich ausschließlich auf wilde Bestäuber aus den nahe liegenden Habitaten. Die Fähigkeit dieser Habitate, dauerhaft als Lebensraum für die Bienen zu dienen, hängt davon ab, wie diese durch die angrenzenden lokalen Dorfgemeinschaften bewirtschaftet werden. Das Gesamtziel dieser Studie war daher, Strategien zur Verbesserung der Bienenbestäubung im Farmland in Kakamega herauszuarbeiten. Die Ziele im einzelnen waren: i) herauszufinden, ob die Existenz des Kakamega-Waldes die Diversität der Bienenbestäuber sowie die Aktivitätsdichte der futtersuchenden Bienen in den Nutzpflanzen beeinflusst, ii) den Beitrag der Bienenbestäubung zur Produktivität der Nutzpflanzen zu bestimmen, iii) die Kenntnisse der Bauer über Bienen und Bestäubung zu ermitteln, und iv) den wirtschaftlichen Nutzen für die Bauern durch die Bestäubung ihrer Nutzpflanzen durch die Bienen zu quantifizieren. Die Daten wurden erhoben durch: i) Beobachtung der Bienen entlang eines Transekts von Feldern nahe dem Wald bis zu Feldern in 8 km Entfernung, ii) in Versuchsflächen mit Nutzpflanzen mit und ohne Bienenbestäubung, iii) durch Befragungen (Fragebogen) von 352 Bauern, und iv) durch Sekundärdaten, hauptsächlich vom Landwirtschaftsministerium. Die Anzahl der Bienenarten in den Feldern in der Nähe und weiter entfernt vom Wald unterschied sich nicht signifikant. Dies deutet darauf hin, dass die Bienendiversität in den Feldern nicht notwendigerweise von der Nähe des Waldes abhängt. Jedoch war die Aktivitätsdichte einiger Bienenvölker (z.B. Xylocopa calens) signifikant höher in Feldern nahe am Wald, was darauf hindeutet, dass der Wald ein wichtiges Element in der Bereitstellung von Bestäubungsdiensten durch diese Bienenarten darstellen könnte. Der Mehrertrag der Pflanzen durch Bienenbestäubung wurde an neun Anbaupflanzen (Bohne, Kuhbohne, Kichererbse, Bambaranuss, Tomate, Paprika, Passionsfrucht, Sonnenblume und Kürbis) gemessen und lag zwischen 25$ 90 jährlich pro Haushalt zu bezahlen. Sowohl die Kenntnisse über die Bestäubung als auch die Höhe der Summe, die sie bereit waren zu bezahlen, korrelierte signifikant mit der Bildung der Bauern. Dies deutet darauf hin, dass eine entsprechende Ausbildung zum Schutz der Bienen im Farmland in Kakamega beitragen würde. Daher sollten die Bauern und andere Beteiligte eine Ausbildung hinsichtlich der Rolle der Bienenbestäubung und deren Beitrag zu ihrem Wohlergehen sowie über kosteneffektive Bienenschutzstrategien erhalten, wobei die lokalen Gegebenheiten berücksichtigt werden sollten. Strategien zur Bewirtschaftung der Landschaft wären u.a. möglich durch die richtige Nutzung der dort einzigartigen Hecken, die die Felder mit dem Wald verbinden. Andere Maßnahmen wie die Nutzung von Fallennestern für höhlennistende Bienen und integrierte Farmbewirtschaftung, z.B. in der Schädlingsbekämpfung, sollten ebenfalls in Erwägung gezogen werden. Weitere Forschung sollte aufzeigen, wie diese Strategien für den Bienenschutz in dieser Region umgesetzt werden können

Bee pollination enhances crop yield and fruit quality in Kakamega, Western Kenya

Kasina M, Hagen M, Kraemer M, Nderitu J, Martius C, Wittmann D. Bee pollination enhances crop yield and fruit quality in Kakamega, Western Kenya. East African agricultural and Forestry Journal. 2009;75(1):1-11

Diversity and abundance of native bees foraging on hedgerow plants in the Kakamega farmlands, western Kenya

Mwangi D, Kasina M, Nderitu J, Hagen M, Gikungu M, Kraemer M. Diversity and abundance of native bees foraging on hedgerow plants in the Kakamega farmlands, western Kenya. Journal Of Apicultural Research. 2012;51(4):298-305.We determined the diversity and abundance of native bees foraging on hedgerow flowers, and documented the plant species composition of those hedgerows, from October 2008 to March 2009 at Kakamega, western Kenya. We made observations on hedgerow sectors located in five different land use types: Kakamega forest; roads; sugarcane plantations; maize / bean fields; and grazing land. Our findings show that a high diversity of bees is supported by the hedgerows, and that bee diversity and abundance significantly (P < 0.05) differed across the five land use types. A total of 82 bee species belonging to three families (Apidae, Megachilidae and Halictidae) were recorded, with Apidae having the highest species richness and abundance. The suitability of hedgerow plants as bee forage sources differed greatly, except for Megachilid bees. Most important bee plants belonged to the families Acanthaceae, Asteraceae and Fabaceae. We conclude that hedgerow plants play an important role in providing bee food resources and can be used for managing bees in Kakamega farmed areas. We also suggest the inclusion of hedgerows in community based management of bees in areas where hedgerows are present or have viability to succeed, as they can support bee life and hence the pollination of crops in agricultural ecosystems

Enhancing legume crop pollination and natural pest regulation for improved food security in changing African landscapes

Legumes are important crops for food security, consumed by millions of people especially in Africa where they are an essential protein source and provide key vitamins and minerals. Most legumes depend on insect pollination and natural pest regulation for sufficient yields, however, there is emerging evidence that yield gaps caused by lack of pollination and/or pest pressure may be common. Here we review the literature reporting on pollinators and natural enemies contributing to legume crop yields, and the impact of land-use change on the services provided by these beneficial organisms. We identify strategies for enhancing the benefits of pollination and natural pest control in legumes and propose policy and practice interventions for better utilization of pollinators and natural enemies in legume cropping systems in Africa

Farmers’ Knowledge, Perceptions, and Management Practices of False Codling Moth (<i>Thaumatotibia leucotreta</i>) in Smallholder <i>Capsicum</i> sp. Cropping Systems in Kenya

False codling moth (FCM) Thaumatotibia leucotreta Meyrick (Lepidoptera: Tortricidae) is currently the main pest of phytosanitary concern in international trade, causing rejection and decline of horticultural produce from Kenya exported to the European Union (EU). Overreliance on synthetic insecticides to control this pest is ineffective and unsustainable in the long run, whereas continuous use of pesticides results in high levels of residues in the produce. To gather farmers’ knowledge, attitudes, and practices used by smallholder farmers to manage this pest, a field survey was carried out in 10 Capsicum sp. (Solanales: Solanaceae)-producing counties in Kenya. Data were collected using semi-structured questionnaires administered through face-to-face interviews and focus group discussions involving 108 individual farmers, 20 key informants, and 10 focus group discussions. The majority of the respondents (83.33%) were aware of the FCM infesting Capsicum sp. About three quarters of the farmers (76.85%) reported yield losses and unmarketable quality of FCM-infested Capsicum sp. Most farmers interviewed (99.07%) used insecticides as a management tool. In contrast, only 39.81% of the farmers applied integrated pest management strategies including use of biological control agents and intercropping with repellent plants to control this pest. The results show that FCM is perceived as a significant threat to the horticultural industry of Kenya. Training needs for smallholder farmers and key informants to avoid overreliance on synthetic chemical pesticides and to maintain export goals to the EU where identified