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Articles 241 - 270 of 1443

Full-Text Articles in Life Sciences

Description Of The Immature Stages Of Dacus Bivittatus (Diptera: Tephritidae), The Greater Pumpkin Fruit Fly, Gary J. Steck, Shepard Ndlela, Louis A. Somma, Jessica Diaz, Matthew R. Moore, Jessica Awad Dec 2022

Description Of The Immature Stages Of Dacus Bivittatus (Diptera: Tephritidae), The Greater Pumpkin Fruit Fly, Gary J. Steck, Shepard Ndlela, Louis A. Somma, Jessica Diaz, Matthew R. Moore, Jessica Awad

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We describe the egg, three instars, and pupa of Dacus bivittatus Bigot using optical and scanning electron microscopy and compare them with those of other Dacus Fabricius species for which these stages have been described as well as those of two important pest species of Zeugodacus Hendel that infest cucurbits. A new anatomical term, lateral lips, is introduced to describe a feature of the facial mask. A feature of the egg that has not been reported previously for Tephritidae is described here: a peculiar arrangement of aeropyles in an irregular line partially encircling the egg near the posterior end. A …

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Transcriptomic Profiling Of Trypanosoma Congolense Mouthpart Parasites From Naturally Infected Flies, Sara Silva Pereira, Kawira Mathenge, Daniel Masiga, Andrew Jackson Dec 2022

Transcriptomic Profiling Of Trypanosoma Congolense Mouthpart Parasites From Naturally Infected Flies, Sara Silva Pereira, Kawira Mathenge, Daniel Masiga, Andrew Jackson

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Background: Animal African trypanosomiasis, or nagana, is a veterinary disease caused by African trypanosomes transmitted by tsetse flies. In Africa, Trypanosoma congolense is one of the most pathogenic and prevalent causes of nagana in livestock, resulting in high animal morbidity and mortality and extensive production losses. In the tsetse fly, parasites colonise the midgut and eventually reach the mouthparts, from where they can be transmitted as the fly feeds on vertebrate hosts such as cattle. Despite the extreme importance of mouthpart-form parasites for disease transmission, very few global expression profile studies have been conducted in these parasite forms. Methods: Here, …

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Honey Compositional Convergence And The Parallel Domestication Of Social Bees, Pierre Noiset, Nathalie Cabirol, Marcelo Rojas-Oropeza, Natapot Warrit, Kiatoko Nkoba, Nicolas J. Vereecken Dec 2022

Honey Compositional Convergence And The Parallel Domestication Of Social Bees, Pierre Noiset, Nathalie Cabirol, Marcelo Rojas-Oropeza, Natapot Warrit, Kiatoko Nkoba, Nicolas J. Vereecken

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Honey collection evolved from simple honey hunting to the parallel and independent domestication of different species of bees in various parts of the world. In this study, we investigate the extent to which the composition of Apis and stingless bee honeys has been a driver in the selection of different bee species for domestication in Mesoamerica (Mexico) and Asia (Thailand) using a sampling design that combines peak honey profiling by H1 NMR spectroscopy with the collection of honeys from domesticated and undomesticated bee species. Our results show that, independently of the region of the world considered, domesticated stingless bees produce …

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The Effect Of Climate Variability In The Efficacy Of The Entomopathogenic Fungus Metarhizium Acridum Against The Desert Locust Schistocerca Gregaria, Samuel F. Kamga, Frank T. Ndjomatchoua, Ritter A. Guimapi, Ingeborg Klingen, Clément Tchawoua, Anne Grete Roer Hjelkrem, Karl H. Thunes, Francois M. Kakmeni Dec 2022

The Effect Of Climate Variability In The Efficacy Of The Entomopathogenic Fungus Metarhizium Acridum Against The Desert Locust Schistocerca Gregaria, Samuel F. Kamga, Frank T. Ndjomatchoua, Ritter A. Guimapi, Ingeborg Klingen, Clément Tchawoua, Anne Grete Roer Hjelkrem, Karl H. Thunes, Francois M. Kakmeni

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Despite substantial efforts to control locusts they remain periodically a major burden in Africa, causing severe yield loss and hence loss of food and income. Distribution maps indicating the value of the basic reproduction number R0 was used to identify areas where an insect pest can be controlled by a natural enemy. A dynamic process-based mathematical model integrating essential features of a natural enemy and its interaction with the pest is used to generate R0 risk maps for insect pest outbreaks, using desert locust and the entomopathogenic fungus Metarhizium acridum (Synn. Metarhizium anisoliae var. acridum) as a case study. This …

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Inventory Reveals Wide Biodiversity Of Edible Insects In The Eastern Democratic Republic Of Congo, Jackson Ishara, Rodrigue Ayagirwe, Katcho Karume, Gustave N. Mushagalusa, David Bugeme, Saliou Niassy, Patchimaporn Udomkun, John Kinyuru Dec 2022

Inventory Reveals Wide Biodiversity Of Edible Insects In The Eastern Democratic Republic Of Congo, Jackson Ishara, Rodrigue Ayagirwe, Katcho Karume, Gustave N. Mushagalusa, David Bugeme, Saliou Niassy, Patchimaporn Udomkun, John Kinyuru

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In response to growing food demand, edible insects are perceived as an opportunity to alleviate food insecurity. With its wide edible insects’ biodiversity, the Democratic Republic of Congo is one of Africa’s most critical entomophagous. This study aimed at giving a first insight on inventory showing diversity, perception, consumption, availability, host plants, harvesting techniques and processing techniques of edible insects in South-Kivu, DRC. It recorded twenty-three edible insects belonging to nine families and five orders, some of which are consumed in the larval, adult, egg and pupa stages. Rhyncophorus phoenicis, Alphitobius diaperinus, Macrotermes subhyalinus and Acheta domesticus were the most …

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Potential Distribution Of Fall Armyworm In Africa And Beyond, Considering Climate Change And Irrigation Patterns, Bipana Paudel Timilsena, Saliou Niassy, Emily Kimathi, Elfatih M. Abdel-Rahman, Irmgard Seidl-Adams, Mark Wamalwa, Henri E.Z. Tonnang, Sunday Ekesi, David P. Hughes, Edwin G. Rajotte, Sevgan Subramanian Dec 2022

Potential Distribution Of Fall Armyworm In Africa And Beyond, Considering Climate Change And Irrigation Patterns, Bipana Paudel Timilsena, Saliou Niassy, Emily Kimathi, Elfatih M. Abdel-Rahman, Irmgard Seidl-Adams, Mark Wamalwa, Henri E.Z. Tonnang, Sunday Ekesi, David P. Hughes, Edwin G. Rajotte, Sevgan Subramanian

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The fall armyworm, Spodoptera frugiperda (FAW), first invaded Africa in 2016 and has since become established in many areas across the continent where it poses a serious threat to food and nutrition security. We re-parameterized the existing CLIMEX model to assess the FAW global invasion threat, emphasizing the risk of transient and permanent population establishment in Africa under current and projected future climates, considering irrigation patterns. FAW can establish itself in almost all countries in eastern and central Africa and a large part of western Africa under the current climate. Climatic barriers, such as heat and dry stresses, may limit …

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Urbanization Of Aedes Mosquito Populations And Evolution Of Arboviral Disease Risk In Africa, Sheila B. Agha, David P. Tchouassi Dec 2022

Urbanization Of Aedes Mosquito Populations And Evolution Of Arboviral Disease Risk In Africa, Sheila B. Agha, David P. Tchouassi

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The arboviral diseases dengue, chikungunya, and yellow fever are re-merging and gaining a foothold in Africa, with a significant threat of large outbreaks in urban areas. Although their emergence is intimately linked to the primary vector Aedes aegypti, which thrives in urban environments, the risk of these diseases remains substantially heterogeneous in different geographic areas. Range expansion of invasive mosquito species Aedes albopictus, and colonization of urban habitats by sylvatic and peridomestic Aedes vectors, are likely to alter the diseases’ epidemiology. We discuss how a network of different vector species and perhaps vector subpopulations could interact with associated serotypes/genotypes/lineages of …

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Gut Microbiota Shift In Layer Pullets Fed On Black Soldier Fly Larvae-Based Feeds Towards Enhancing Healthy Gut Microbial Community, Evalyne W. Ndotono, Fathiya M. Khamis, Joel L. Bargul, Chrysantus M. Tanga Dec 2022

Gut Microbiota Shift In Layer Pullets Fed On Black Soldier Fly Larvae-Based Feeds Towards Enhancing Healthy Gut Microbial Community, Evalyne W. Ndotono, Fathiya M. Khamis, Joel L. Bargul, Chrysantus M. Tanga

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Globally, most gut microbiota-related studies have focused on broilers due to their diverse microbial communities compared to that of layer chicken. However, in Africa few studies have been undertaken despite the increasing benefits to the poultry industry. The utilization of Insect-Based diets to improve the gastrointestinal function and gut health in poultry is increasingly gaining global attention. Here, we evaluated the potential roles of commercial black soldier fly larvae-based feeds (BSFLF) in reshaping the abundance, composition and diversity of the gut microbiota of layer chickens using high throughput Oxford nanopore Minion sequencing of the full length bacterial 16S rRNA gene. …

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Nutrient Quality And Maturity Status Of Frass Fertilizer From Nine Edible Insects, Dennis Beesigamukama, Sevgan Subramanian, Chrysantus M. Tanga Dec 2022

Nutrient Quality And Maturity Status Of Frass Fertilizer From Nine Edible Insects, Dennis Beesigamukama, Sevgan Subramanian, Chrysantus M. Tanga

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Globally, there is growing interest to recycle organic waste using insect larvae into high-quality frass fertilizer through circular economy approach. This paper presents the first comparative report on the nutrient concentrations, fertilizing indices, nutrient supply potentials and compost maturity of nine edible insect frass fertilizers. Our results revealed that frass fertilizers from all the insect species had adequate concentrations and contents of macronutrients [nitrogen (N), phosphorus (P), potassium (K)], secondary nutrients (calcium, magnesium, and sulphur) and micro-nutrients (manganese, copper, iron, zinc, boron, and sodium). The fertilizing indices of the frass fertilizers were above 3. However, black soldier fly (BSF) frass …

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Malaria Vector Feeding, Peak Biting Time And Resting Place Preference Behaviors In Line With Indoor Based Intervention Tools And Its Implication: Scenario From Selected Sentinel Sites Of Ethiopia, Alemnesh Hailemariam Bedasso, Abebe Asale Gutto, Abate Waldetensai, Araya Eukubay, Getachew Eticha Bokore, Solomon Kinde, Fekadu Gemechu, Yared Debebe, Mesfin Aklilu, Geremew Tasew, Fekadu Massebo, Abebe Teshome, Tilahun Kebede, Bedri Abdulatif, Achamyelesh Sisay, Hiwot Solomon, Eliningaya J. Kweka Dec 2022

Malaria Vector Feeding, Peak Biting Time And Resting Place Preference Behaviors In Line With Indoor Based Intervention Tools And Its Implication: Scenario From Selected Sentinel Sites Of Ethiopia, Alemnesh Hailemariam Bedasso, Abebe Asale Gutto, Abate Waldetensai, Araya Eukubay, Getachew Eticha Bokore, Solomon Kinde, Fekadu Gemechu, Yared Debebe, Mesfin Aklilu, Geremew Tasew, Fekadu Massebo, Abebe Teshome, Tilahun Kebede, Bedri Abdulatif, Achamyelesh Sisay, Hiwot Solomon, Eliningaya J. Kweka

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In Ethiopia, malaria incidence has significantly reduced in the past decade through the combined use of conventional vector control approaches and treatment using antimalarial drugs. However, the sustainability of this achievement is threatened by the shift in biting and resting behaviors and emergence of insecticide resistance by the primary malaria vector. Therefore, continuous monitoring of the behaviour of malaria mosquitoes in different sentinel sites is crucial to design effective prevention and control methods in the local context. Entomological investigations were conducted in three sentinel sites for five consecutive months during the major malaria transmission season. The species composition, population dynamics, …

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Predicting The Potential Global Distribution Of An Invasive Alien Pest Trioza Erytreae (Del Guercio) (Hemiptera: Triozidae), Owusu Fordjour Aidoo, Philipe Guilherme Corcino Souza, Ricardo Siqueira Da Silva, Paulo Antonio Santana Júnior, Marcelo Coutinho Picanço, Rosina Kyerematen, Mamoudou Sétamou, Sunday Ekesi, Christian Borgemeister Dec 2022

Predicting The Potential Global Distribution Of An Invasive Alien Pest Trioza Erytreae (Del Guercio) (Hemiptera: Triozidae), Owusu Fordjour Aidoo, Philipe Guilherme Corcino Souza, Ricardo Siqueira Da Silva, Paulo Antonio Santana Júnior, Marcelo Coutinho Picanço, Rosina Kyerematen, Mamoudou Sétamou, Sunday Ekesi, Christian Borgemeister

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The impact of invasive alien pests on agriculture, food security, and biodiversity conservation has been worsened by climate change caused by the rising earth’s atmospheric greenhouse gases. The African citrus triozid, Trioza erytreae (Del Guercio; Hemiptera: Triozidae), is an invasive pest of all citrus species. It vectors the phloem-limited bacterium “Candidatus Liberibacter africanus”, a causal agent of citrus greening disease or African Huanglongbing (HLB). Understanding the global distribution of T. erytreae is critical for surveillance, monitoring, and eradication programs. Therefore, we combined geospatial and physiological data of T. erytreae to predict its global distribution using the CLIMEX model. The model’s …

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The Distinctive Bionomics Of Aedes Aegypti Populations In Africa, David P. Tchouassi, Sheila B. Agha, Jandouwe Villinger, Rosemary Sang, Baldwyn Torto Dec 2022

The Distinctive Bionomics Of Aedes Aegypti Populations In Africa, David P. Tchouassi, Sheila B. Agha, Jandouwe Villinger, Rosemary Sang, Baldwyn Torto

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Aedes aegypti is the primary vector of dengue, chikungunya, and Zika viruses of medical importance. Behavioral and biological attributes contribute to its vectorial capacity. The mosquito domestic form, which resides outside Africa (Ae. aegypti aegypti (Aaa)), is considered to breed in artificial containers in and around homes and preferentially feeds on human blood but commonly indulges in a plant diet. Potential divergence in these attributes, in sub-Saharan Africa (SSA) where Aaa coexists with the forest ecotype (Ae. aegypti formosus), should impact the vectoring ability and hence disease epidemiology. A summary of current knowledge on Ae. aegypti blood feeding, oviposition, and …

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The Possibilities Of Explicit Striga (Striga Asiatica) Risk Monitoring Using Phenometric, Edaphic, And Climatic Variables, Demonstrated For Malawi And Zambia, Emily Kimathi, Bester Tawona Mudereri, Elfatih M. Abdel-Rahman, Saliou Niassy, Henri E.Z. Tonnang, Tobias Landmann Dec 2022

The Possibilities Of Explicit Striga (Striga Asiatica) Risk Monitoring Using Phenometric, Edaphic, And Climatic Variables, Demonstrated For Malawi And Zambia, Emily Kimathi, Bester Tawona Mudereri, Elfatih M. Abdel-Rahman, Saliou Niassy, Henri E.Z. Tonnang, Tobias Landmann

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Food insecurity continues to affect more than two-thirds of the population in sub‐Saharan Africa (SSA), particularly those depending on rain-fed agriculture. Striga, a parasitic weed, has caused yield losses of cereal crops, immensely affecting smallholder farmers in SSA. Although earlier studies have established that Striga is a constraint to crop production, there is little information on the spatial extent of spread and infestation severity of the weed in some SSA countries like Malawi and Zambia. This study aimed to use remotely sensed vegetation phenological (n = 11), climatic (n = 3), and soil (n = 4) variables to develop a …

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Leveraging Machine Learning Tools And Algorithms For Analysis Of Fruit Fly Morphometrics, Daisy Salifu, Eric Ali Ibrahim, Henri E.Z. Tonnang Dec 2022

Leveraging Machine Learning Tools And Algorithms For Analysis Of Fruit Fly Morphometrics, Daisy Salifu, Eric Ali Ibrahim, Henri E.Z. Tonnang

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Analysis of landmark-based morphometric measurements taken on body parts of insects have been a useful taxonomic approach alongside DNA barcoding in insect identification. Statistical analysis of morphometrics have largely been dominated by traditional methods and approaches such as principal component analysis (PCA), canonical variate analysis (CVA) and discriminant analysis (DA). However, advancement in computing power creates a paradigm shift to apply modern tools such as machine learning. Herein, we assess the predictive performance of four machine learning classifiers; K-nearest neighbor (KNN), random forest (RF), support vector machine (the linear, polynomial and radial kernel SVMs) and artificial neural network (ANNs) on …

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Genetics And Immunity Of Anopheles Response To The Entomopathogenic Fungus Metarhizium Anisopliae Overlap With Immunity To Plasmodium, Tullu Bukhari, Vishukumar Aimanianda, Emmanuel Bischoff, Emma Brito-Fravallo, Karin Eiglmeier, Michelle M. Riehle, Kenneth D. Vernick, Christian Mitri Dec 2022

Genetics And Immunity Of Anopheles Response To The Entomopathogenic Fungus Metarhizium Anisopliae Overlap With Immunity To Plasmodium, Tullu Bukhari, Vishukumar Aimanianda, Emmanuel Bischoff, Emma Brito-Fravallo, Karin Eiglmeier, Michelle M. Riehle, Kenneth D. Vernick, Christian Mitri

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Entomopathogenic fungi have been explored as a potential biopesticide to counteract the insecticide resistance issue in mosquitoes. However, little is known about the possibility that genetic resistance to fungal biopesticides could evolve in mosquito populations. Here, we detected an important genetic component underlying Anopheles coluzzii survival after exposure to the entomopathogenic fungus Metarhizium anisopliae. A familiality study detected variation for survival among wild mosquito isofemale pedigrees, and genetic mapping identified two loci that significantly influence mosquito survival after fungus exposure. One locus overlaps with a previously reported locus for Anopheles susceptibility to the human malaria parasite Plasmodium falciparum. Candidate gene …

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Innovative Feedstocks For Optimal Mass Production Of The Edible Long-Horned Grasshopper, Ruspolia Differens, Kababu Margaret, Mweresa K. Collins, Sevgan Subramanian, James P. Egonyu, Dorothy Nakimbugwe, Geoffrey Ssepuuya, Nyamu Faith, Sunday Ekesi, Chrysantus M. Tanga Nov 2022

Innovative Feedstocks For Optimal Mass Production Of The Edible Long-Horned Grasshopper, Ruspolia Differens, Kababu Margaret, Mweresa K. Collins, Sevgan Subramanian, James P. Egonyu, Dorothy Nakimbugwe, Geoffrey Ssepuuya, Nyamu Faith, Sunday Ekesi, Chrysantus M. Tanga

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The edible long-horned grasshopper Ruspolia differens Serville (Orthoptera:Tettigoniidae) is a highly nutritious food source consumed in over 20 African countries. Its occurrence is highly seasonal, and wild harvesting is carried out using locally designed and inefficient light traps, thus limiting sustainable utilization as an important food source. To ensure year-round production and availability of R. differens, we evaluated the effects of low-cost and affordable diets based on agricultural by-products on their growth performance, survival, fecundity, and longevity. A total of four diets with varying ratios of agricultural by-products were evaluated: Diet 1 [33.3% maize bran (MB) + 33.3% wheat bran …

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Tephritid Fruit Fly Species Composition, Seasonality, And Fruit Infestations In Two Central African Agro-Ecological Zones, Samuel Nanga Nanga, Rachid Hanna, Apollin Fotso Kuate, Komi K.M. Fiaboe, Ibrahim Nchoutnji, Michel Ndjab, Désiré Gnanvossou, Samira A. Mohamed, Sunday Ekesi, Champlain Djieto-Lordon Nov 2022

Tephritid Fruit Fly Species Composition, Seasonality, And Fruit Infestations In Two Central African Agro-Ecological Zones, Samuel Nanga Nanga, Rachid Hanna, Apollin Fotso Kuate, Komi K.M. Fiaboe, Ibrahim Nchoutnji, Michel Ndjab, Désiré Gnanvossou, Samira A. Mohamed, Sunday Ekesi, Champlain Djieto-Lordon

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Bactrocera dorsalis and several Africa-native Ceratitis species are serious constraints to fruit production in sub-Saharan Africa. A long-term trapping and fruit collection study was conducted (2011–2016) in two contrasting agro-ecological zones (AEZs) of Cameroon to determine fruit fly species composition, seasonality, attraction to various lures and baits, and fruit infestation levels. Ten tephritid species from genera Bactrocera, Ceratitis, Dacus, and Perilampsis were captured in traps. Bactrocera dorsalis was the most dominant of the trapped species and persisted throughout the year, with peak populations in May–June. Ceratitis spp. were less abundant than B. dorsalis, with Ceratitis anonae dominating in the western …

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Influence Of Si In Maize Plants In Kenyan Populations Of Spodoptera Frugiperda (Lepidoptera: Noctuidae), Ovide Nuambote-Yobila, Boaz Musyoka, Elijah Njuguna, Anani Yaovi Bruce, Fathia Khamis, Sevgan Subramanian, Frédéric Marion-Poll, Paul André Calatayud Nov 2022

Influence Of Si In Maize Plants In Kenyan Populations Of Spodoptera Frugiperda (Lepidoptera: Noctuidae), Ovide Nuambote-Yobila, Boaz Musyoka, Elijah Njuguna, Anani Yaovi Bruce, Fathia Khamis, Sevgan Subramanian, Frédéric Marion-Poll, Paul André Calatayud

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The fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), native to the Americas, was confirmed in West and Central Africa in 2016 and reported in almost all countries of sub-Saharan Africa in 2017, becoming thereafter one of the major constraints on the production of maize, the main staple food crop in the region. Cereals depend on silicon (Si)-based defences to fight off herbivores. Both FAW strains, namely rice and corn strains, have been found to be present in Kenya. The present study tested the influence of Si on larval survival and relative growth rate according to the FAW strain, using potted …

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Striving To Be Resilient: The Role Of Crop-Poultry Integrated System As A Climate Change Adaptation Strategy In Semiarid Eastern Kenya, Kelvin Mulungu, Daniel Kangogo Nov 2022

Striving To Be Resilient: The Role Of Crop-Poultry Integrated System As A Climate Change Adaptation Strategy In Semiarid Eastern Kenya, Kelvin Mulungu, Daniel Kangogo

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Climate change continues to pose significant challenges to food security and livelihoods of smallholder farmers specifically in semi-arid regions. One approach that holds prospects for climate risk management is climate-smart agriculture (CSA). CSA has concentrated on crop practices with little attention to livestock especially indigenous (village) chickens as a potential practice that can be combined with crop agriculture. This study considers the adoption of three CSA practices: improved maize seeds (IS), soil management (SM), indigenous chicken (IC) enterprise and their various combinations. Using survey data collected from 300 farming households in semiarid Kenya, we estimate the impact of integrated crop-poultry …

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The Role Of Nitrogen Fixation And Crop N Dynamics On Performance And Legacy Effects Of Maize-Grain Legumes Intercrops On Smallholder Farms In Tanzania, E. Mugi-Ngenga, L. Bastiaans, S. Zingore, N. P.R. Anten, K. E. Giller Nov 2022

The Role Of Nitrogen Fixation And Crop N Dynamics On Performance And Legacy Effects Of Maize-Grain Legumes Intercrops On Smallholder Farms In Tanzania, E. Mugi-Ngenga, L. Bastiaans, S. Zingore, N. P.R. Anten, K. E. Giller

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Maize-grain legume intercrops form an important component of the cropping systems of smallholder farmers in many parts of sub-Saharan Africa. However, the effects of cropping system and fertilizer use on nitrogen fixation and nitrogen uptake of component crops in maize-legume intercrops are not well understood. Our study addressed the questions: (i) What is the capacity of pigeonpea and lablab to fix atmospheric nitrogen (N2) in sole crop and when intercropped with maize on smallholder farms across different agro-ecological conditions?; (ii) How does productivity and N-uptake by sole and intercropped maize and legumes respond to N and P fertilizer?; and (iii) …

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Nitrogen Budgets And Nitrogen Use Efficiency As Agricultural Performance Indicators In Lake Victoria Basin, Winnie Ntinyari, Joseph Gweyi-Onyango, Mekonnen Giweta, James Mutegi, Benson Mochoge, Generose Nziguheba, Cargele Masso Oct 2022

Nitrogen Budgets And Nitrogen Use Efficiency As Agricultural Performance Indicators In Lake Victoria Basin, Winnie Ntinyari, Joseph Gweyi-Onyango, Mekonnen Giweta, James Mutegi, Benson Mochoge, Generose Nziguheba, Cargele Masso

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Too little nitrogen (N) is a threat to crop productivity and soil fertility in sub-Saharan Africa (SSA). Nitrogen budgets (NB) and nitrogen use efficiency (NUE) are critical tools for assessing N dynamics in agriculture and have received little or no attention in the region. Data were collected from smallholder farmers clustered into two categories, farmers applying and farmers not applying N fertilizers. NB were calculated using the Coupled Human and Natural Systems (CHANS) model approach for field and farm spatial scales. The results showed spatial variabilities in NB and NUE at the field level (maize and rice) across all the …

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Immediate And Residual-Effects Of Sole And Intercropped Grain Legumes In Maize Production Systems Under Rain-Fed Conditions Of Northern Tanzania, E. Mugi-Ngenga, L. Bastiaans, N. P.R. Anten, S. Zingore, K. E. Giller Oct 2022

Immediate And Residual-Effects Of Sole And Intercropped Grain Legumes In Maize Production Systems Under Rain-Fed Conditions Of Northern Tanzania, E. Mugi-Ngenga, L. Bastiaans, N. P.R. Anten, S. Zingore, K. E. Giller

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Intercropping of maize with grain-legume crops predominates on smallholder farms in East Africa. However, the growth and development of crops and their interaction with fertilizer in intercropping systems are not well understood. We sought to answer the questions: (i) what are the effects of fertilizer on the growth and development of maize-pigeonpea and maize-lablab intercropping systems under variable agroecological conditions? (ii) what are the residual effects of two seasons of sole and intercrops of maize, pigeonpea and lablab on a succeeding maize crop? We studied pure stands of maize, long-duration pigeonpea, medium-duration pigeonpea and lablab, and additive intercropping combinations on …

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Synthesis Of 1,2,3-Triazole-Thymol Derivatives As Potential Antimicrobial Agents, Justice Kwaku Addo, Ernest Owusu-Ansah, Nicholas T.K.D. Dayie, Xavier Cheseto, Baldwyn Torto Oct 2022

Synthesis Of 1,2,3-Triazole-Thymol Derivatives As Potential Antimicrobial Agents, Justice Kwaku Addo, Ernest Owusu-Ansah, Nicholas T.K.D. Dayie, Xavier Cheseto, Baldwyn Torto

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Background: Thymol as a natural biological template can be modified chemically since the hydroxyl group makes it a candidate for structural modification. Thus, this study incorporated the triazole moiety on thymol and the chlorination of thymol moiety to help improve its biological potency. Materials and methods: A series of ten 1,2,3-triazole-thymol derivatives 1–10 were synthesized from thymol, by a click reaction between O-propargyl terminal alkyne of thymol and its chlorothymol with benzyl azide and substituted benzyl azides. Their structures were confirmed by spectroscopic methods (1H-NMR, 13C-NMR, IR, GC-MS-EI/CI and LC-ESI-QTOF-MS). The Well diffusion method using Müeller-Hinton agar plates was used …

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The Dynamics And Role Of Gender In High-Value Avocado Farming In Kenya, Beatrice Muriithi, Jane Kabubo-Mariara Oct 2022

The Dynamics And Role Of Gender In High-Value Avocado Farming In Kenya, Beatrice Muriithi, Jane Kabubo-Mariara

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We used two-wave panel data obtained from avocado growers in Murang’a County in Kenya to examine, through the perspective of gender, the dynamics of farmers’ participation in avocado production and marketing organizations (PMOs), and test whether understanding group dynamics is important for analyzing contract farming. Using a multinomial logit (MNL) model, we identify the characteristics of men and women participating in PMOs categorized as early adopters, dis-adopters, late adopters, and non-adopters. We focus on dis-adopters and late adopters because these categories are most often ignored in the literature. Moreover, without considering the dynamics, we verify the influencing factors of PMOs …

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Occurrence And Density Of The Stink Bug Antestiopsis Thunbergii Gmelin 1790 (Heteroptera: Pentatomidae) And Related Egg-Parasitoids In Burundi Coffee Agroecosystems, Jean Mugishawimana, Lucy Kananu Murungi, Soter Ndihokubwayo, Anaclet Nibasumba, Julien Haran, Guillaume David Oct 2022

Occurrence And Density Of The Stink Bug Antestiopsis Thunbergii Gmelin 1790 (Heteroptera: Pentatomidae) And Related Egg-Parasitoids In Burundi Coffee Agroecosystems, Jean Mugishawimana, Lucy Kananu Murungi, Soter Ndihokubwayo, Anaclet Nibasumba, Julien Haran, Guillaume David

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Antestiopsis thunbergii is the most important coffee pest in Burundi causing yield losses of up to 30%. The aim of this study was to estimate its occurrence and density and to assess the species diversity of native egg-parasitoids associated to this pest in coffee agroecosystems. Our study was carried out in four coffee growing agro-ecological zones of Burundi namely; the humid west escarpments, the humid central highlands, the sub-humid central highlands and the sub-humid southeastern and northern depressions. In total, 600 coffee trees, randomly selected in 40 coffee plots of 20 communes were investigated at three phenological stages of the …

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Immersion In Hot Water As A Phytosanitary Treatment For Thaumatotibia Leucotreta (Lepidoptera: Tortricidae) In Bell Pepper (Capsicum Annuum L.), Nelson L. Mwando, Shepard Ndlela, Rainer Meyhöfer, Sevgan Subramanian, Samira A. Mohamed Oct 2022

Immersion In Hot Water As A Phytosanitary Treatment For Thaumatotibia Leucotreta (Lepidoptera: Tortricidae) In Bell Pepper (Capsicum Annuum L.), Nelson L. Mwando, Shepard Ndlela, Rainer Meyhöfer, Sevgan Subramanian, Samira A. Mohamed

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The False codling moth (FCM), Thaumatotibia leucotreta is a major quarantine pest that hampers Capsicum production and trade in sub-Saharan Africa (SSA) and may need a postharvest treatment to meet quarantine standards of lucrative overseas markets. In this study, we evaluated the efficacy of hot water treatment (HWT) as a potential nonchemical quarantine control option against T. leucotreta in bell pepper and its effect on the quality parameters of the peppers. Infested bell pepper harboring different immature stages of T. leucotreta were subjected to a hot water treatment of 50 ± 0.2 °C for eight different time-points to determine heat …

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Parasitisation Of Weaver Ants By A Species Of Smicromorpha Girault (Hymenoptera: Chalcididae: Smicromorphinae) And Unequivocal Evidence Of Its Presence In The Afrotropical Region, Robert S. Copeland, Bethelihem Mekonnen, Gerard Delvare Sep 2022

Parasitisation Of Weaver Ants By A Species Of Smicromorpha Girault (Hymenoptera: Chalcididae: Smicromorphinae) And Unequivocal Evidence Of Its Presence In The Afrotropical Region, Robert S. Copeland, Bethelihem Mekonnen, Gerard Delvare

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Smicromorpha Girault (Hymenoptera: Chalcididae) is distributed in the old world tropics and subtropics from Australia through New Guinea, Southeast and South Asia. Since its original description in 1913 conclusive evidence of its host has been lacking although it has been collected in association with weaver ants (Oecophylla spp.; Formicidae: Formicinae) either in proximity to ant nests or, on one occasion, reared from one. In this paper we report the presence of Smicromorpha pupae within the gaster of Oecophylla longinoda workers from a nest collected in coastal Kenya. This discovery extends the distribution of Smicromorpha to the Afrotropical Region and demonstrates …

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Integrated Management Of Spodoptera Frugiperda 6 Years Post Detection In Africa: A Review, Ghislain T. Tepa-Yotto, Peter Chinwada, Ivan Rwomushana, Georg Goergen, Sevgan Subramanian Aug 2022

Integrated Management Of Spodoptera Frugiperda 6 Years Post Detection In Africa: A Review, Ghislain T. Tepa-Yotto, Peter Chinwada, Ivan Rwomushana, Georg Goergen, Sevgan Subramanian

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The introduction of fall armyworm (FAW) Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae) on the African continent has led to paradigm shifts in pest control in maize systems, occasioned by year-round populations. The discovery of resident parasitoid species adapting to the new pest significantly informed decision-making toward avoiding highly hazardous synthetic insecticides to control the pest. A number of biopesticides have shown promise against the fall armyworm, providing a new arsenal for the sustainable management of this invasive pest. However, a few knowledge gaps remain for a fully integrated and sustainable FAW-management approach, particularly on host-resistance potential.

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Integrating A Crop Model With A Greenhouse Gas Calculator To Identify Low Carbon Agricultural Intensification Options For Smallholder Farmers In Rural South Africa, Farirai Rusere, Lynn V. Dicks, Siyabusa Mkuhlani, Olivier Crespo Aug 2022

Integrating A Crop Model With A Greenhouse Gas Calculator To Identify Low Carbon Agricultural Intensification Options For Smallholder Farmers In Rural South Africa, Farirai Rusere, Lynn V. Dicks, Siyabusa Mkuhlani, Olivier Crespo

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Models that enable the estimation of crop yields and greenhouse gas (GHG) emissions concurrently are still lacking. This study develops a biophysical modelling framework encompassing a farm typology, a crop model, and a farm-focused GHG calculator to assess productivity (crop yield) and GHG emissions of crop management practices concurrently. Using this modelling framework, the study developed cropping system scenarios based on the concept of conservation agriculture (CA) to identify and design cropping systems that deliver ecological intensification for different farm types. All farm types were found to be net sources of GHG with cropping system inefficiency across all farm types. …

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Larval Exposure To Parasitic Varroa Destructor Mites Triggers Specific Immune Responses In Different Honey Bee Castes And Species, Yu Fang, Abebe Jenberie Wubie, Mao Feng, Chuan Ma, Boris Baer, Jianke Li Aug 2022

Larval Exposure To Parasitic Varroa Destructor Mites Triggers Specific Immune Responses In Different Honey Bee Castes And Species, Yu Fang, Abebe Jenberie Wubie, Mao Feng, Chuan Ma, Boris Baer, Jianke Li

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Innate immune systems are key defenses of animals and particularly important in species that lack the sophisticated adaptive immune systems as found in vertebrates. Here, we were interested to quantify variation in innate immune responses of insects in hosts that differ in their parasite susceptibility. To do this, we studied immune responses in honey bees, which can host a remarkable number of different parasites, which are major contributors of declining bee health and colony losses. The most significant parasite of honey bees is the mite Varroa destructor, which has infested the majority of global honey bee populations, and its control …

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