Browsing by Author "Otieno, Mark"
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Item The Ark of Taste in Kenya(UoEm, 2024-10-17) Michele, F. Fontefrancesco; Mattia Zocchi, Dauro; Barstow, Charles; Kiiru, Samson; Natali, Roberto; Moraa Onyango, Cecilia; O. Ogendo, Joshua; G. Ontita, Edward; Otieno, Mark; Petrini, Carlo; K. Sitati, Gladys; M. Zocchi, Dauroam firmly convinced that our most urgent task is to protect biodiversity as the foundation of our food system. Many local crop varieties are dis- appearing and the widespread use of chemicals in agriculture threatens countless species with extinction. The global food system today is in a more precarious position than ever before due to the intertwined threats of food price inflation, food insecurity resulting from conflicts in many parts of the world, and climate change. These shocks and crises are major alarm bells that signal the fragility of our food systems, and there is no single action more pow- erful than making people aware of the importance of protecting food biodiver- sity. Without biodiversity, there is no foundation for human life on this planet. Biodiversity is the raw material that nourishes our civilizations and cultures and it is essential for human adaptation to Earth’s varied environments. Biodiversity is crucial for every country in the world and its value should never be underestimated. I believe it is especially important to keep this in mind when considering the African context. The people of Africa have long endured unjust seed policies, land grabbing, and the adverse effects of chemicals that are needed to sustain the daily expansion of monocultures. These practices are perpetuated with the promise of feeding the continent’s rapidly growing population; what they’re actually doing is making African food systems less resilient. Biodiversity in food and agriculture is declining, the climate crisis is intensifying, and diet-related diseases are reaching epidemic proportions. We urgently need to break away from imperialistic and extractive production sys- tems to slow down climate change and environmental degradation, and the only way to accomplish this is by preserving biodiversity. The Ark of Taste is the world’s largest living catalogue of biodiverse, delicious, and distinctive gastronomic heritage at risk of extinction. The Atlas you hold in your hands expands on the first edition of The Ark of Taste in Kenya, published in 2018. This new edition is a comprehensive tool for understanding Kenya’s tradi- tional foodscapes and it reiterates the central roles that institutions, producers, and consumers all play in preserving Kenya’s food cultures and biodiversity. I would like to draw your attention to one aspect of this book in particular that I think is fundamental: its ability to actively engage, involve, and empower new generations of professionals in the Kenyan food system. The project that led to the creation of this expanded edition was developed and executed entirely by researchers from the University of Gastronomic Sciences in Italy and the Universities of Egerton, Embu, and Nairobi in Kenya. Fifty students from the three Kenyan universities were taught to identify, describe, and communicate about local food heritage following the Ark of Taste approach, and Kenyan researchers contributed new chapters focused on creating awareness among the general public about the importance of this heritage. This collective, co- operative work enabled us to expand the data set on Kenyan traditional food biodiversity to include products that Western knowledge alone wouldn’t have been able to identify. The products described in this book represent the tangible and intangible knowledge and skills of multitudes of people who, despite difficulties and with great passion, labor every day to grow and safeguard the biodiversity on which we all depend. The gastronomic heritage of every country rests primarily on the shoulders of these people, who care for the environment, keep marginal communities thriving, save soils from erosion, and protect biological, cultural, and food diversity. As consumers, we can choose to incorporate biodiversity into our diets, becoming valuable allies in its preservation. We have the simple but profound power act with care and respect toward the people who cultivate biodiversity, contributing to their wellbeing as well as to our own health and the health of our planet. By sustainably consuming diverse foods and embrac- ing eating as a creative act that simultaneously meets our physiological needs and brings us great pleasure, we can ensure the survival of the extensive and valuable heritage that this book celebrates.Item Assesing the Drivers of Pollinator and Natural Enemy Community in Pigeonpea and Field Bean Crops(The University of Reading, 2010-09) Otieno, Mark1. Arthropods are key components in agro-ecosystems providing critical ecosystem services to crops, such as pollination and natural pest control. The structure and functioning of these arthropod communities can be influenced by farm management practices and the context of the farm within the wider landscape, yet this is poorly understood....Item Combining Host Plant Resistance, Selective Insecticides, and Biological Control Agents for Integrated Management of Tuta absoluta(Hindawi, 2020-08) Nderitu, Peris W; Jonsson, Mattias; Arunga, Ester E.; Otieno, Mark; Muturi, John J.; Wafula, Geoffrey O.Combination of pest management strategies that minimize pesticide use and conserve natural enemies is important for a sustainable environment. Overreliance on synthetic insecticides in the management of Tuta absoluta has led to pesticide resistance leading to difficulties in managing the pest. In this regard, alternative measures need to be put in place to reduce the effects of this pest. ,e objective of this study was, therefore, to assess the effectiveness of host plant resistance, biological control, and selective insecticides when used in combination, in the management of T. absoluta in tomato production. ,e study was set up in a greenhouse in a completely randomized design involving two tomato varieties, an insecticide (chlorantraniliprole), and a biological control agent(Macrolophus pygmaeus), applied singly or in combination. Data were collected on T. absoluta damage from the lower, intermediate, and upper leaves. ,e results from this study show that a combination of insecticide with a moderately resistant variety had a significantly lower T. absoluta damage as compared with a susceptible variety combined with an insecticide. However, the moderately resistant variety when combined with insecticide showed no effect when the biological control agent was added. ,e susceptible variety significantly reduced T. absoluta damage when combined with the biological control agent. ,ese results indicate that treatment combinations in insect pest management can be utilized. ,e present study results indicate that using a moderately resistant variety (Riogrande VF) in combination with the insecticide chlorantraniliprole (Coragen®) and a susceptible variety (Pesa F1) in combination with the biological control agent (M. pygmaeus) can improve T. absoluta management. Under good habitat management, the susceptible variety will perform equally as the moderately resistant variety due to suppression of the T. absoluta populations by natural enemies. ,ese findings show the importance of environmental conservation both by enhancing natural enemy abundance and use of selective insecticide in the management of T. absoluta in tomato production. Combinations in this present study are likely to reduce insecticide doses, thereby reducing the cost of production and enhancing environmental compatibility with natural enemies.Item Comparative Trapping Efficiency to Characterize Bee Abundance, Diversity, and Community Composition in Apple Orchards(Oxford University Press, 2015-07) Joshi, N.K.; Leslie, Timothy; Rajotte, Edwin G.; Kammerer, Melaine A.; Otieno, Mark; Biddinger, David J.Bees are important pollinators of numerous crops, and monitoring their abundance and diversity in commercial agricultural ecosystems is of increasing importance due to pollinator declines. In season-long field studies conducted in Pennsylvania during 2011–2013, we evaluated five different bee monitoring passive traps—three pan traps (blue, yellow, and white) and two vane traps (blue and yellow)—for their effectiveness and utility for monitoring bees in commercial apple orchards. Traps were placed prebloom and were monitored weekly until the end of crop season (mid-October). We recorded 14,770 bees comprising 118 species, 27 genera, and five families. The most abundant species were Augochlora pura (Say) (34.4% of total), Ceratina calcarata Robertson (15.5%), Bombus vagans Smith (7.8%), Bombus impatiens Cresson (6.4%), and Apis mellifera L. (4.3%). Bee abundance was highly variable among trap types across the three years and during the bloom and postbloom period. Blue vane traps were found to be the most effective trap type, with significantly higher rates of per-sample species accumulation than all other traps. Species richness estimates were highest for the blue vane and blue pan traps. This study reveals the utility and effectiveness of various traps for studying abundance and diversity of pollinator bees in commercially managed apple orchards. It also provides baseline information about the bee community found during the bloom and postbloom periods in Pennsylvania apple orchards that can be used to measure changes in bee community structure and abundance due to conservation efforts, such as reduced risk IPM programs, habitat management, and augmentation.Item The Effects of Herbivory on interactions of pollinators and flowers in Acacia SPP. (Fabaceae,mimosoideae) in Laikipia(Kenyatta University, 2005) Otieno, MarkAcacia trees are among the most dominant tree species found in semi arid ecosystems with a vast geographical distribution throughout the savanna habitats. The trees are leguminous and have remarkable ability to fix nitrogen in the soil, thereby, improving fertility. About all parts of an Acacia tree are edible to different types of animals and their leaves provide the only greenery in the dry season, so are bound to be eaten. As such, they support enormous pyramids of biomass in complex food chains with super predators at the apex. Economically, they are used as basic sources of fruits, firewood, medicine and secondary products for daily human livelihoods. Owing to their important, a lot of studies have focused on their growth ecology. Herbivory and reproduction are among the most studied aspects of Acacia. However, the interactive link between these two aspects and their effect on the growth success of Acacias is poorly understood. Understanding the link between herbivory and pollination, would not only provide useful information on the interaction of plants and diversity of visitors but also information on the floral morphometry and rewards to pollinators. The general objective of this study was to determine the effects of herbivory on interactions between pollinators and flowers in Acacia spp. The study was conducted at the Mpala Research Centre in Laikipia District of Kenya (0017'N, 36053'E) on one herbivore excluded plot (70m x 50m) and in the open grazed areas adjacent to the excusion plot. Acacia trees for investigation were randomly selected. Data were recorded on floral morphometric measurements and dehiscence in different browsing levels and simulated herbivory plots. The number and type of visitors to the flowers was also recorded besides determining the species diversity of wild flora within the study site. ANOVA was used to analyze variation in different flower attributes, SNKwas used to separate means with significant differences. Generally, unbrowsed trees produed significantly (P<0.05) more flowers, florets, anthers and larger floral diameters than naturally and heavilly browsed Acacia trees. Similarly, unbrowsed trees attracted more pollinators especially bees than naturally browsed trees. An earlier pollinator peak activity was recorded on unbrowsed trees than browsed trees. A significant shist of inflorescence dehiscence time occurred between unbrowsed and naturally browsed trees of A. nilotica, (KS=0.34, P<0.01), A. brevispica (KS=0.34, P<0.01) across the day. The unbrowsed trees attracted significantly more pollinators than naturally browsed trees probably because the unbrowsed trees had larger flowers thereby becoming more visible to pollinators from a distance than those of browsed trees. The delayed floral dehiscence of naturally browsed trees could have been caused by modification of the microclimate around the flowers making them open later in the day than unbrowsed trees. This study has shown than A. nilotica and A. brevispica vary their floral resources greatly when browsed, whereas A. etbaica tends to show compensatory floral growth. More studies therefore, need to be done on their reproductive success.Item Enhancing legume crop pollination and natural pest regulation for improved food security in changing African landscapes(Elsevier, 2020-09) Otieno, Mark; Dewentera, Ingolf S.; Potts, Simon G.; Kinuthia, Wanja; Kasina, Muo J.; Garrattb, Michael P.D.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.Item Flower visitors of Streptocarpus teitensis: implications for conservation of a critically endangered African violet species in Kenya(PeerJ, 2021-01) Otieno, Mark; Josh, Neelendra; Rutschmann, BenjaminBackground: The African violets are endangered plant species restricted mainly to the Eastern Arc Mountains biodiversity hotspots in Kenya and Tanzania. These plants grow well in shaded environments with high humidity. Given their restricted geographical range and published evidence of dependance on insect vectors to facilitate sexual reproduction, understanding their pollination biology is vital for their survival. Methods: We conducted an empirical study using flower visitor observations, pan trapping and bagging experiments to establish the role of flower visitors in the fruit set of a locally endemic and critically endangered species of African violet in Taita Hills, Kenya, Streptocarpus teitensis. Results: The study found that fruit set is increased by 47.8% in S. teitensis when flowers are visited by insects. However, it is important to note the presence of putative autogamy suggesting S. teitensis could have a mixed breeding system involving self-pollination and cross-pollination since bagged flowers produced 26.9% fruit set. Conclusions: Insects appear to be essential flower visitors necessary for increased fruit set in S. teitensis. However, there is evidence of a mixed breeding system involving putative self-pollination and cross-pollination suggesting that S. teitensis is somewhat shielded from the negative effects of pollinator losses. Consequently, S. teitensis appears to be protected to a degree from the risks such as reproduction failure associated with pollinator losses by the presence of a safety net in putative self-pollination.Item A global quantitative synthesis of local and landscape effects on wild bee pollinators in agroecosystems(Blackwell Publishing Ltd, 2013) Kennedy, Christina M.; Lonsdorf, Erick; Neel, Maile C.; Williams, Neal M.; Ricketts, Taylor H.; Winfree, Rachael; Bommarco, Riccardo; Brittain, Claire; Burley, Alana L.; Cariveau, Daniel; Carvalheiro; Chacoff, Natacha P.; Cunningham, Saul A.; Danforth, Bryan N.; Dudenhoffer, Jan-Hendrick; Elle, Elizabeth; Gaines, Hanna R.; Garibaldi, Lucas A.; Gratton, Claudio; Holzschuh, Andrea; Isaacs, Rufus; Javorek, Steven K.; Jha, Shalene; Klein, Alexandra M.; Krewenka, Kristin; Mandelik, Yael; Mayfield, Margaret M.; Morandin, Lora; Neame, Lisa A.; Otieno, Mark; Park, Mia; Potts, Simon G.; Rundlof, Maj; Saez, Agustin; Steffan-Dewenter, Ingolf; Taki, Hisatomo; Viana, Blandina F.; Westphal, Catrin; Wilson, Julianna K.; Greenleaf, Sara S.; Kremen, Claire; Carvalheiro, Luisa G.Bees provide essential pollination services that are potentially affected both by local farm management and the surrounding landscape. To better understand these different factors, we modelled the relative effects of landscape composition (nesting and floral resources within foraging distances), landscape configuration (patch shape, interpatch connectivity and habitat aggregation) and farm management (organic vs. conventional and local-scale field diversity), and their interactions, on wild bee abundance and richness for 39 crop systems globally. Bee abundance and richness were higher in diversified and organic fields and in landscapes comprising more high-quality habitats; bee richness on conventional fields with low diversity benefited most from high-quality surrounding land cover. Landscape configuration effects were weak. Bee responses varied slightly by biome. Our synthesis reveals that pollinator persistence will depend on both the maintenance of high-quality habitats around farms and on local management practices that may offset impacts of intensive monoculture agriculture.Item A global synthesis of the effects of diversified farming systems on arthropod diversity within fields and across agricultural landscapes. Global Change Biology(Wiley Online Library, 2017-03) Lichtenberg, E.; Otieno, Mark; Christina, Kennedy M.; Kremen, Claire; Batary, Peter; Berendse, Frank; Bommarco, Riccardo; Bosque-Perez, Nilsa A.; Carvalheiro, Luısa G.; Snyder, William E.; Williams, Neal M.Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroecosystems. What remains unclear is the extent to which farm management schemes affect biodiversity components other than species richness, and whether impacts differ across spatial scales and landscape contexts. Using a global metadataset, we quantified the effects of organic farming and plant diversification on abundance, local diversity (communities within fields), and regional diversity (communities across fields) of arthropod pollinators, predators, herbivores, and detritivores. Both organic farming and higher in‐field plant diversity enhanced arthropod abundance, particularly for rare taxa. This resulted in increased richness but decreased evenness. While these responses were stronger at local relative to regional scales, richness and abundance increased at both scales, and richness on farms embedded in complex relative to simple landscapes. Overall, both organic farming and in‐field plant diversification exerted the strongest effects on pollinators and predators, suggesting these management schemes can facilitate ecosystem service providers without augmenting herbivore (pest) populations. Our results suggest that organic farming and plant diversification promote diverse arthropod metacommunities that may provide temporal and spatial stability of ecosystem service provisioning. Conserving diverse plant and arthropod communities in farming systems therefore requires sustainable practices that operate both within fields and across landscapes.Item Local and landscape effects on bee functional guilds in pigeon pea crops in Kenya(Springer, 2015-07) Otieno, Mark; Sidhu, Sheena C.; Woodcock, Ben A.; Wilby, A.; Ioannis, N.; Mauchline, Alice L.; Gikungu, Mary W.; Potts, Simon G.Pollinators face many challenges within agricultural systems due to landscape changes and intensification which can affect resource availability that can impact pollination services. This paper examines pigeon pea pollination and considers how landscape context and agricultural intensification in terms of pesticide use affects the abundance of bees characterized by species guilds on crops. The study was conducted on six paired farms across a gradient of habitat complexity based on the distance of each farm from adjacent semi-natural vegetation in Kibwezi Sub-county, Kenya. The study found that farms which do not use insecticides in farm management, but are in close proximity to natural habitat have greater bee guild abundance, but at further distances, overall abundance is reduced with or without insecticide use. At 1 km landscape radius, the complexity of habitats but not patch size had a positive impact on the abundance of cavity nesting bees and mason bees, which can be attributed to the interspersion of the small-holder farms with semi-natural habitats across the landscapes producing mosaics of heterogeneous habitats. The study revealed the strongest relationships between fruit set and bee abundance to be with the carpenter bee, social bee and solitary bee guilds, which are among the most abundant bees visiting pigeon pea flowers in this system. Our findings provide the foundation for conservation efforts by identifying which bee guilds pollinated pigeon peas. From this study, we suggest managing the floral and nesting resources that would best support the most abundant crop pollinators, and also reducing insecticide application to the crop.Item Local management and landscape drivers of pollination and biological control services in a Kenyan agro-ecosystem(Elsevier, 2011) Otieno, Mark; Woodcock, Ben A.; Wilby, Andrew; Vogiatzakis, Ioannis N.; Mauchline, Alice L.; Gikungu, Mary W.; Potts, Simon G.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 vegetation 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 pollinator, 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 interconnections of pollinators, predators and pests with pigeonpea crop. For sustainable yields and to conserve 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.Item Pollination Ecology of Desmodium Setigerum (Fabaceae) in Uganda; Do Big Bees Do It Better?(2016-08) Stanley, Dara A.; Otieno, Mark; Steijven, Karin; Berlin, Emma Sandler; Piironen, Tiina; Willmer, Pat; Nuttman, CliveExplosive pollen release is documented in many plant families, including the Fabaceae. Desmodium setigerum E. Mey (Fabaceae) is a perennial herb with single trip explosive pollen release found in eastern Africa, and the unique ability to reverse floral colour change if insufficient pollination has occurred. However, little else is known about the pollination ecology of this species, what visitors can trigger explosive pollen release, and whether bee body size is related to pollination efficiency. We investigated: 1) the breeding system of D. setigerum, and whether it is pollen limited; 2) whether flowers are visited early in the day allowing sufficient time for a second opportunity for pollination; and 3) what insect species visit D. setigerum and the relative efficacy of different flower visitors in relation to visitor size and pollination success. We found that although self-compatible, D. setigerum requires insect visitation to set seed as explosive pollen release is needed even for selfing. Most flowers are initially visited before 1400h, and by 1800h nearly all flowers have been tripped. Flowers were not pollen limited in this study, and were visited primarily by bees. We observed 16 visiting species, and there was a wide variation (0-404 grains) in the amount of pollen deposited on stigmas. Although almost all bees deposited some pollen, the mean number of pollen grains deposited in a single visit per species was negatively related to body size. However, one particular megachilid species deposited significantly more pollen grains than any other visitor and so is likely an important pollinator of this species. This provides insights into the pollination biology of this unique plant species, and adds to increasing literature on the relationships between bee body size, explosive pollen release and pollination effectiveness.Item Proximity to Woodland and Landscape Structure Drives Pollinator Visitation in Apple Orchard Ecosystem(Crossmark, 2016-04) Neelendra, Joshi K.; Otieno, Mark; Edwin, Rajotte G.; Shelby, Fleischer J.; David, Biddinge J.Landscapes of farms and adjacent areas are known to influence abundance of various arthropods such as pollinators in commercial agricultural ecosystems. In this context, we examined the effect of heterogeneous landscapes surrounding and including commercial apple orchards on pollinator visitation and foraging distance during bloom period from 2011 to 2013 in Pennsylvania. Our results showed that the frequency of feral honeybees and solitary bee visits within an apple orchard depends on the proximity of the orchard to an unmanaged habitat (primarily comprised of forest). At the landscape scale, we found that the Mean Proximity Index, the Largest Patch Index, and the Number of Patches positively correlated with the visitation rate of dominant bee taxa (Apis mellifera, Bombus spp., and solitary bees) visiting apple flowers at low spatial scales (up to 500 m around the orchards). The Mean Proximity Index at 500 m was related to bee visitation patterns, especially for solitary bees and A. mellifera. Bees in all our study sites preferred to forage in areas with large homogenous patches up to 500 m around an apple orchard. This effect can be attributed to the mass flowering of apples that formed the largest proportion of the 500 m spatial scale. The Number of Patches at 250 m spatial scale was positively correlated with bee visitation, especially Bombus spp., probably because these areas had more habitats and more resources required by these bees. We conclude that retaining unmanaged habitats closer to commercial apple orchards will maintain biodiversity within the landscapes and insure pollination services to apples.Item Item Sustainable Agroecological Practices in Sub-Saharan Africa in the Face of Climate Change(UoEm, 2024-11-11) Otieno, MarkThis book emphasizes the critical importance of agroecological practices as a response to the climate crisis in sub-Saharan Africa. It explores the intricate relationship between agriculture, ecosystems, and climate, advocating for the transformation of farming systems to ensure long-term sustainability. Through research, case studies, and practical examples, the book showcases the potential of agroecology in addressing the impacts of climate change. Sustainable practices such as biodiversity conservation, resource preservation, soil fertility enhancement, and greenhouse gas emission reduction are extensively discussed, providing readers with a comprehensive understanding of the topic. The book also highlights success stories from various countries in sub-Saharan Africa, aiming to inspire farmers, policymakers, and practitioners to adopt and sustain change. It acknowledges the vulnerabilities faced by smallholder farmers in the region and emphasizes the integration of traditional knowledge with scientific advancements. This integration is seen as essential in providing farmers with the necessary resources, information, and capacity-building opportunities to adapt to changing climatic conditions. The book emphasizes the need for collaboration and innovation among governments, research institutions, civil society organizations, and local communities to promote sustainable agricultural development. Ultimately, the book advocates for sustainable agroecological practices as a means to achieve food security, enhance ecosystem resilience, and foster rural development in sub-Saharan Africa. By adopting climate-friendly agricultural approaches and maintaining ecological balance, it envisions a future where communities thrive, ecosystems flourish, and the impacts of climate change are mitigated. The target audience for this book includes students, agroecology experts, farmers, policymakers, and agricultural practitioners who are interested in the subjectmatter.Item Tea breaks: how flower visitors can benefit from unplanned floral buffer strips in a Tanzanian tea plantation(Blackwell Publishing Ltd, 2013) Norfolk, Olivia; Sadiki, Lotha Laisser; Broughton, Brittanie; Otieno, Mark; Nuttman, CliveItem Tomato Leaf miner (Tuta absoluta) (Meyrick 1917) (Lepidoptera: Gelechiidae) prevalence and farmer management practices in Kirinyanga County, Kenya(Academic Journals, 2018-08) Nderitu, Peris Wangari; Muturi, Jamleck; Otieno, Mark; Arunga, Ester E.; Mattias, JonssonPest invasion is one of the limiting factors affecting food production. Tomato leaf miner (Tuta absoluta) (Meyrick 1917) (Lepidoptera: Gelechiidae), is an invasive insect pest of tomato. However, In Kenya, there is limited information on the level of invasion of the pest in tomato producing areas in the country. We assessed the level of invasion of T. absoluta and farmer management practices in Kirinyaga County. Tomato farmers were interviewed using questionnaires aimed at identifying the management practices used by farmers to control T. absoluta and their awareness on the insect pest. Two hundred and eight tomato farmers were interviewed, 90% of the respondents rated T. absoluta as a major pest of tomato. Results show that 94% of the respondents use synthetic chemicals in the control of T. absoluta with an average frequency of 12 times per growing season of three months with the highest frequency being 16 times. Increased use of synthetic insecticides was associated with a negative impact on the natural enemies. Among the interviewed farmers, 52 and 46% of respondents stated that after chemical spraying natural enemies disappear and are killed respectively, while 2% did not know what happened to them. It is therefore imperative to design an integrated pest management program that integrates biological control and environmentally friendly chemicals for sustainable control of T. absoluta populations.Item Trait matching of flower visitors and crops predicts fruit set better than trait diversity(Wiley Online Library, 2015) Garibaldi, Lucas A.; Otieno, Mark; Bartomeus, Ignasi; Bommarco, Riccardo; Klein, Alexandra M.; Cunningham, Saul A.; Aizen, Marcelo A.; Boreux, Virginie; Garratt, Michael P. D.; Carvalheiro, Luısa G.; Kremen, Claire; Morales, Carolina L.; Schuepp, ChristofSummary Understanding the relationships between trait diversity, species diversity and ecosystem functioning is essential for sustainable management. For functions comprising two trophic levels, trait matching between interacting partners should also drive functioning. However, the predictive ability of trait diversity and matching is unclear for most functions, particularly for crop pollination, where interacting partners did not necessarily co‐evolve. World‐wide, we collected data on traits of flower visitors and crops, visitation rates to crop flowers per insect species and fruit set in 469 fields of 33 crop systems. Through hierarchical mixed‐effects models, we tested whether flower visitor trait diversity and/or trait matching between flower visitors and crops improve the prediction of crop fruit set (functioning) beyond flower visitor species diversity and abundance. Flower visitor trait diversity was positively related to fruit set, but surprisingly did not explain more variation than flower visitor species diversity. The best prediction of fruit set was obtained by matching traits of flower visitors (body size and mouthpart length) and crops (nectar accessibility of flowers) in addition to flower visitor abundance, species richness and species evenness. Fruit set increased with species richness, and more so in assemblages with high evenness, indicating that additional species of flower visitors contribute more to crop pollination when species abundances are similar. Synthesis and applications. Despite contrasting floral traits for crops world‐wide, only the abundance of a few pollinator species is commonly managed for greater yield. Our results suggest that the identification and enhancement of pollinator species with traits matching those of the focal crop, as well as the enhancement of pollinator richness and evenness, will increase crop yield beyond current practices. Furthermore, we show that field practitioners can predict and manage agroecosystems for pollination services based on knowledge of just a few traits that are known for a wide range of flower visitor species.Item The Utility of Aerial Pan-Trapping for Assessing Insect Pollinators Across Vertical Strata(2011) Nuttman, Clive; Otieno, Mark; Kwapong, Peter K.; Combey, Rofela; Willmer, Pat; Potts, Simon G.Insect pollinators provide a critical ecosystem service by pollinating many wild flowers and crops. It is therefore essential to be able to effectively survey and monitor pollinator communities across a range of habitats, and in particular, sample the often stratified parts of the habitats where insects are found. To date, a wide array of sampling methods have been used to collect insect pollinators, but no single method has been used effectively to sample across habitat types and throughout the spatial structure of habitats. Here we present a method of ‘aerial pan-trapping’ that allows insect pollinators to be sampled across the vertical strata from the canopy of forests to agro-ecosystems. We surveyed and compared the species richness and abundance of a wide range of insect pollinators in agricultural, secondary regenerating forest and primary forest habitats in Ghana to evaluate the usefulness of this approach. In addition to confirming the efficacy of the method at heights of up to 30 metres and the effects of trap color on catch, we found greatest insect abundance in agricultural land and higher bee abundance and species richness in undisturbed forest compared to secondary forest.