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Full-Text Articles in Life Sciences

Is It Possible To Discern Striga Weed (Striga Hermonthica) Infestation Levels In Maize Agro-Ecological Systems Using In-Situ Spectroscopy?, Bester Tawona Mudereri, Timothy Dube, Saliou Niassy, Emily Kimathi, Tobias Landmann, Zeyaur Khan, Elfatih M. Abdel-Rahman Mar 2020

Is It Possible To Discern Striga Weed (Striga Hermonthica) Infestation Levels In Maize Agro-Ecological Systems Using In-Situ Spectroscopy?, Bester Tawona Mudereri, Timothy Dube, Saliou Niassy, Emily Kimathi, Tobias Landmann, Zeyaur Khan, Elfatih M. Abdel-Rahman

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The invasion by Striga in most cereal crop fields in Africa has posed a significant threat to food security and has caused substantial socioeconomic losses. Hyperspectral remote sensing is an effective means to discriminate plant species, providing possibilities to track such weed invasions and improve precision agriculture. However, essential baseline information using remotely sensed data is missing, specifically for the Striga weed in Africa. In this study, we investigated the spectral uniqueness of Striga compared to other co-occurring maize crops and weeds. We used the in-situ FieldSpec® Handheld 2™ analytical spectral device (ASD), hyperspectral data and their respective narrow-band indices …

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Influence Of Seeing A Red Face During The Male–Male Encounters Of Mosquito-Specialist Spiders, Fiona R. Cross, Robert R. Jackson, Lisa A. Taylor Mar 2020

Influence Of Seeing A Red Face During The Male–Male Encounters Of Mosquito-Specialist Spiders, Fiona R. Cross, Robert R. Jackson, Lisa A. Taylor

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Males of Evarcha culicivora, an East African jumping spider (Salticidae), have bright red faces. Here, we investigated how seeing a red face might influence a male’s behaviour during encounters with another male. We applied black eyeliner to conceal the red on a male’s face and measured the spectral properties of male faces with and without the eyeliner. Only the faces without eyeliner reflected in the long-wavelength range corresponding to red. In experiments over 2 days, where eyeliner was absent on the first day and present on the second, we compared how two groups of males responded to their mirror images. …

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The Impact Of Conventional And Organic Farming On Soil Biodiversity Conservation: A Case Study On Termites In The Long-Term Farming Systems Comparison Trials In Kenya, John J. Anyango, David Bautze, Komi K.M. Fiaboe, Zipporah O. Lagat, Anne W. Muriuki, Sibylle Stöckli, Judith Riedel, Gladys K. Onyambu, Martha W. Musyoka, Edward N. Karanja, Noah Adamtey Feb 2020

The Impact Of Conventional And Organic Farming On Soil Biodiversity Conservation: A Case Study On Termites In The Long-Term Farming Systems Comparison Trials In Kenya, John J. Anyango, David Bautze, Komi K.M. Fiaboe, Zipporah O. Lagat, Anne W. Muriuki, Sibylle Stöckli, Judith Riedel, Gladys K. Onyambu, Martha W. Musyoka, Edward N. Karanja, Noah Adamtey

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Background: A long-term experiment at two trial sites in Kenya has been on-going since 2007 to assess the effect of organic and conventional farming systems on productivity, profitability and sustainability. During these trials the presence of significant numbers of termites (Isoptera) was observed. Termites are major soil macrofauna and within literature they are either depict as 'pests' or as important indicator for environmental sustainability. The extent by which termites may be managed to avoid crop damage, but improve sustainability of farming systems is worthwhile to understand. Therefore, a study on termites was added to the long-term experiments in Kenya. The …

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Modelling And Manipulation Of Aphid-Mediated Spread Of Non-Persistently Transmitted Viruses, John P. Carr, Trisna Tungadi, Ruairí Donnelly, Ana Bravo-Cazar, Sun Ju Rhee, Lewis G. Watt, J. Musembi Mutuku, Francis O. Wamonje, Alex M. Murphy, Warren Arinaitwe, Adrienne E. Pate, Nik J. Cunniffe, Christopher A. Gilligan Feb 2020

Modelling And Manipulation Of Aphid-Mediated Spread Of Non-Persistently Transmitted Viruses, John P. Carr, Trisna Tungadi, Ruairí Donnelly, Ana Bravo-Cazar, Sun Ju Rhee, Lewis G. Watt, J. Musembi Mutuku, Francis O. Wamonje, Alex M. Murphy, Warren Arinaitwe, Adrienne E. Pate, Nik J. Cunniffe, Christopher A. Gilligan

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Aphids vector many plant viruses in a non-persistent manner i.e., virus particles bind loosely to the insect mouthparts (stylet). This means that acquisition of virus particles from infected plants, and inoculation of uninfected plants by viruliferous aphids, are rapid processes that require only brief probes of the plant's epidermal cells. Virus infection alters plant biochemistry, which causes changes in emission of volatile organic compounds and altered accumulation of nutrients and defence compounds in host tissues. These virus-induced biochemical changes can influence the migration, settling and feeding behaviours of aphids. Working mainly with cucumber mosaic virus and several potyviruses, a number …

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High Risk For Human Exposure To Rift Valley Fever Virus In Communities Living Along Livestock Movement Routes: A Cross-Sectional Survey In Kenya, Caroline Tigoi, Rosemary Sang, Edith Chepkorir, Benedict Orindi, Samuel Okello Arum, Francis Mulwa, Gladys Mosomtai, Samson Limbaso, Osama A. Hassan, Zephania Irura, Clas Ahlm, Magnus Evander Feb 2020

High Risk For Human Exposure To Rift Valley Fever Virus In Communities Living Along Livestock Movement Routes: A Cross-Sectional Survey In Kenya, Caroline Tigoi, Rosemary Sang, Edith Chepkorir, Benedict Orindi, Samuel Okello Arum, Francis Mulwa, Gladys Mosomtai, Samson Limbaso, Osama A. Hassan, Zephania Irura, Clas Ahlm, Magnus Evander

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Introduction Multiple outbreaks of Rift Valley Fever (RVF) with devastating effects have occurred in East Africa. These outbreaks cause disease in both livestock and humans and affect poor households most severely. Communities living in areas practicing nomadic livestock movement may be at higher risk of infection. This study sought to i) determine the human exposure to Rift Valley fever virus (RVFV) in populations living within nomadic animal movement routes in Kenya; and ii) identify risk factors for RVFV infection in these communities. Methods A cross-sectional descriptive study design was used. Samples were collected from the year 2014 to 2015 in …

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Plant Community Composition And Functional Characteristics Define Invasion And Infestation Of Termites In Cocoa Agroforestry Systems, T. C.L. Djuideu, D. H.B. Bisseleua, S. Kekeunou, M. J. Meupia, F. G. Difouo, C. F. Ambele Feb 2020

Plant Community Composition And Functional Characteristics Define Invasion And Infestation Of Termites In Cocoa Agroforestry Systems, T. C.L. Djuideu, D. H.B. Bisseleua, S. Kekeunou, M. J. Meupia, F. G. Difouo, C. F. Ambele

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The effects of farm management on non-native species and the structure and function of native communities and ecosystems on crop yield is poorly documented especially in the cocoa agroforestry systems of West Africa. We assessed termite damages, cocoa plantations structural characteristic and local farmer knowledge to refine the critical role of shade trees management on subterranean crops pests and the consequences on marketable yield in five cocoa agroforestry systems. Farmers recognized termites as the most damaging subterranean pests and clearly described the type of damages they cause on cocoa trees and seedlings. Complete shade removal or very heavy shade on …

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Different Plant Viruses Induce Changes In Feeding Behavior Of Specialist And Generalist Aphids On Common Bean That Are Likely To Enhance Virus Transmission, Francis O. Wamonje, Ruairí Donnelly, Trisna D. Tungadi, Alex M. Murphy, Adrienne E. Pate, Christine Woodcock, John Caulfield, J. Musembi Mutuku, Toby J.A. Bruce, Christopher A. Gilligan, John A. Pickett, John P. Carr Jan 2020

Different Plant Viruses Induce Changes In Feeding Behavior Of Specialist And Generalist Aphids On Common Bean That Are Likely To Enhance Virus Transmission, Francis O. Wamonje, Ruairí Donnelly, Trisna D. Tungadi, Alex M. Murphy, Adrienne E. Pate, Christine Woodcock, John Caulfield, J. Musembi Mutuku, Toby J.A. Bruce, Christopher A. Gilligan, John A. Pickett, John P. Carr

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Bean common mosaic virus (BCMV), bean common mosaic necrosis virus (BCMNV), and cucumber mosaic virus (CMV) cause serious epidemics in common bean (Phaseolus vulgaris), a vital food security crop in many low-to-medium income countries, particularly in Sub-Saharan Africa. Aphids transmit these viruses “non-persistently,” i.e., virions attach loosely to the insects' stylets. Viruses may manipulate aphid-host interactions to enhance transmission. We used direct observation and electrical penetration graph measurements to see if the three viruses induced similar or distinct changes in feeding behaviors of two aphid species, Aphis fabae and Myzus persicae. Both aphids vector BCMV, BCMNV, and CMV but A. …

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Stable Flies, Stomoxys Calcitrans L. (Diptera: Muscidae), Improve Offspring Fitness By Avoiding Oviposition Substrates With Competitors Or Parasites, Steve B.S. Baleba, Baldwyn Torto, Daniel Masiga, Merid N. Getahun, Christopher W. Weldon Jan 2020

Stable Flies, Stomoxys Calcitrans L. (Diptera: Muscidae), Improve Offspring Fitness By Avoiding Oviposition Substrates With Competitors Or Parasites, Steve B.S. Baleba, Baldwyn Torto, Daniel Masiga, Merid N. Getahun, Christopher W. Weldon

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Oviposition site selection by gravid female insects is an important determinant in species distribution, abundance, and population dynamics. Females may assess the suitability of a potential oviposition substrate by using cues from conspecific or heterospecific individuals already present. Here, we assessed whether the presence of conspecific or heterospecific larvae and parasites influenced oviposition decisions by the stable fly, Stomoxys calcitrans (Linneaus). Using dual and multiple-choice oviposition bioassays, we found that gravid female S. calcitrans avoided substrates with conspecific larvae, the larvae of house flies, Musca domestica (Linneaus), and the mite Macrocheles muscaedomesticae (Scopoli). Avoidance of conspecific and heterospecific larvae persisted …

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Essential Oils Of Tagetes Minuta And Tithonia Diversifolia Affect Host Location Behaviour And On-Host Attachment Site Preference Of The Brown Ear Tick, Rhipicephalus Appendiculatus In The Semi-Field Studies, Wycliffe Wanzala, Ahmed Hassanali, Wolfgang Richard Mukabana, Willem Takken, Sheila Iminza Minyoso Jan 2020

Essential Oils Of Tagetes Minuta And Tithonia Diversifolia Affect Host Location Behaviour And On-Host Attachment Site Preference Of The Brown Ear Tick, Rhipicephalus Appendiculatus In The Semi-Field Studies, Wycliffe Wanzala, Ahmed Hassanali, Wolfgang Richard Mukabana, Willem Takken, Sheila Iminza Minyoso

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Effects of essential oils of Tagetes minuta and Tithonia diversifolia (Asteraceae) on orientation behaviour and on-host attachment site preference of newly hatched adult Rhipicephalus appendiculatus were evaluated. Host animals were treated at the ear pinna (by smearing the oil directly on the ear or suspending a tube containing the oil on the ear pinna) and legs + tail in semi-field plots. The legs + tail sites of the essential oil application showed the lowest mean percentage of ticks observed on host body (16.5 ± 1.9% and 26.0 ± 2.8%) and the highest mean percentage reduction of attaching ticks (76.5 ± …

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Mineral Fertilizer Use In Land-Scarce Conditions: Case Of Rwanda, Josaphat Rusisiro Mugabo, Eric Tollens, Jonas Nwankwo Chianu, Bernard Vanlauwe Jan 2020

Mineral Fertilizer Use In Land-Scarce Conditions: Case Of Rwanda, Josaphat Rusisiro Mugabo, Eric Tollens, Jonas Nwankwo Chianu, Bernard Vanlauwe

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This study was undertaken to investigate the use of mineral fertilizer by smallholder farmers in order to understand the set of factors influencing the decisions of smallholder farmers to use fertilizers in land-scarce conditions. Using descriptive analysis and the Cragg's double-hurdle model, the study identified and analyzed factors that determine smallholder farmer adoption of mineral fertilizers and those that affect the intensity of household mineral fertilizer use. From factors that only influence the decision of smallholder farmers to use mineral fertilizers, distance to fertilizer market and livestock affects it negatively; while farmer association membership, landholding per capita, access to extension …

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Population Genetics Of The Mediterranean Corn Borer (Sesamia Nonagrioides) Differs Between Wild And Cultivated Plants, Abdel Kader Naino Jika, B. Le Ru, C. Capdevielle-Dulac, F. Chardonnet, J. F. Silvain, L. Kaiser, S. Dupas Jan 2020

Population Genetics Of The Mediterranean Corn Borer (Sesamia Nonagrioides) Differs Between Wild And Cultivated Plants, Abdel Kader Naino Jika, B. Le Ru, C. Capdevielle-Dulac, F. Chardonnet, J. F. Silvain, L. Kaiser, S. Dupas

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The population genetic structure of crop pest populations gives information about their spatial ecology, which helps in designing management strategies. In this paper, we investigated the genetic structure of the Mediterranean Corn Borer (MCB), Sesamia nonagrioides Lefèbvre (Lepidoptera: Noctuidae), one of the most important maize pests in the Mediterranean countries, using microsatellite markers for the first time in this species. Insects were collected in twenty-five locations in southwest and southeast France from cultivated and wild host plants (Zea mays, Sorghum halepense and Typha domingensis). Contrary to what has been reported so far in France, we found that MCB populations could …

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Morphology, Development And Reproduction Of Atractomorpha Acutipennis (Guérin-Méneville, 1844) (Orthoptera: Pyrgomorphidae), Sévilor Kekeunou, Marcelle Mbadjoun-Nziké, Alain Christel Wandji, Steve Bernard Soh-Baleba, Alfiery Laurel Djomnang-Nkwala, Alain Simeu-Noutchom, Charly Oumarou-Ngoute, Philene Corine Aude Um-Nyobe, Linda Gaelle Guiadem-Simo, Patrick Ntonga Akono Jan 2020

Morphology, Development And Reproduction Of Atractomorpha Acutipennis (Guérin-Méneville, 1844) (Orthoptera: Pyrgomorphidae), Sévilor Kekeunou, Marcelle Mbadjoun-Nziké, Alain Christel Wandji, Steve Bernard Soh-Baleba, Alfiery Laurel Djomnang-Nkwala, Alain Simeu-Noutchom, Charly Oumarou-Ngoute, Philene Corine Aude Um-Nyobe, Linda Gaelle Guiadem-Simo, Patrick Ntonga Akono

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For a better knowledge of Atractomorpha acutipennis bio-ecology and to facilitate its identification, we studied the morphology, development and reproduction of this grasshopper on Manihot esculenta under laboratory conditions. Five hundred and fifty-one first nymphal stages obtained in the laboratory were reared in cages. Some body parts allowed a clear identification of different nymphal instars. Post-embryonic development passed through six stages (males) and seven stages (females). Mean nymphal development time was 17.14 ± 0.62, 12.91 ± 0.62, 13.45 ± 0.69, 13.80 ± 0.68, 15.23 ± 0.55 days respectively in males nymphal instars 1 to 5 and 16.18 ± 0.54, 13.13 …

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Occurrence Of Plant-Parasitic Nematodes On Enset (Ensete Ventricosum) In Ethiopia With Focus On Pratylenchus Goodeyi As A Key Species Of The Crop, Selamawit A. Kidane, Beira H. Meressa, Solveig Haukeland, Trine Hvoslef-Eide, Christer Magnusson, Marjolein Couvreur, Wim Bert, Danny L. Coyne Jan 2020

Occurrence Of Plant-Parasitic Nematodes On Enset (Ensete Ventricosum) In Ethiopia With Focus On Pratylenchus Goodeyi As A Key Species Of The Crop, Selamawit A. Kidane, Beira H. Meressa, Solveig Haukeland, Trine Hvoslef-Eide, Christer Magnusson, Marjolein Couvreur, Wim Bert, Danny L. Coyne

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Summary - Enset (Ensete ventricosum) is an important starch staple crop, cultivated primarily in south and southwestern Ethiopia. Enset is the main crop of a sustainable indigenous African system that ensures food security in a country that is food deficient. Related to the banana family, enset is similarly affected by plant-parasitic nematodes. Plant-parasitic nematodes impose a huge constraint on agriculture. The distribution, population density and incidence of plant-parasitic nematodes of enset was determined during August 2018. A total of 308 fields were sampled from major enset-growing zones of Ethiopia. Eleven plant-parasitic nematode taxa were identified, with Pratylenchus (lesion nematode) being …

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Unlocking Maize Crop Productivity Through Improved Management Practices In Northern Tanzania, Kihara J, Kizito F, Jumbo M, Kinyua M, M. Bekunda Jan 2020

Unlocking Maize Crop Productivity Through Improved Management Practices In Northern Tanzania, Kihara J, Kizito F, Jumbo M, Kinyua M, M. Bekunda

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Addressing the problem of low crop productivity and food insecurity can be accelerated through community-centered implementation of good agricultural management practices. This study was conducted in Babati, Northern Tanzania. The objective of the study was to determine nitrogen (N) and phosphorus (P) application requirements for maize, and demonstrate economically viable best bet yield-improving management technologies under three ecozones namely; ‘low elevation low rainfall', ‘medium elevation high rainfall' and ‘medium elevation low rainfall' ecozone. Two sets of trials were conducted: N (0, 45, 90, 120 and 150 kg ha-1) and P (0, 15, 30, 40 kg ha-1) response trials in 16 …

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Impact Of Integrated Fruit Fly Management Strategy On Food Security Among Smallholder Mango Farmers In Kenya, P. N. Nyang'au, B. W. Muriithi, J. M. Nzuma, P. Irungu, H. M. Gichungi, G. Diiro Jan 2020

Impact Of Integrated Fruit Fly Management Strategy On Food Security Among Smallholder Mango Farmers In Kenya, P. N. Nyang'au, B. W. Muriithi, J. M. Nzuma, P. Irungu, H. M. Gichungi, G. Diiro

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Adoption of agricultural innovations is perceived as a key avenue for poverty reduction and improved food and nutritional security in developing countries. The International Centre for Insect Physiology and Ecology (icipe) has developed and implemented a set of Integrated Pest Management (IPM) strategies in several sub-Saharan African countries aimed at controlling mango infesting fruit flies (Bactrocera dorsalis). Although positive returns from the use of fruit fly IPM have already been documented, the impact of these technologies on food security is not well understood. This study evaluated the impact of the IPM strategy on food security with the help of a …

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Smallholder Farmers' Knowledge And Willingness To Pay For Insect-Based Feeds In Kenya, Shaphan Y. Chia, John Macharia, Gracious M. Diiro, Menale Kassie, Sunday Ekesi, Joop J.A. Van Loon, Marcel Dicke, Chrysantus M. Tanga Jan 2020

Smallholder Farmers' Knowledge And Willingness To Pay For Insect-Based Feeds In Kenya, Shaphan Y. Chia, John Macharia, Gracious M. Diiro, Menale Kassie, Sunday Ekesi, Joop J.A. Van Loon, Marcel Dicke, Chrysantus M. Tanga

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Edible insects are increasingly being considered as sustainable alternatives to fish and soybean meals in animal feed because of their high nutritional quality and environmental benefits. However, successful introduction of a new product to the market depends on the target user's acceptance. Thus, evaluating the potential demand of insect-based feeds would provide relevant information for policy development. The present study assessed farmers' knowledge on edible insects as feed, their acceptance of integrating insect meals in animal feeds and willingness to pay (WTP) for insect-based feed (IBF) using a contingent valuation method. A household survey was conducted among 957 randomly selected …

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Role Of Egg-Laying Behavior, Virulence And Local Adaptation In A Parasitoid's Chances Of Reproducing In A New Host, R. Benoist, S. Paquet, F. Decourcelle, J. Guez, R. Jeannette, P. A. Calatayud, B. Le Ru, F. Mougel, L. Kaiser Jan 2020

Role Of Egg-Laying Behavior, Virulence And Local Adaptation In A Parasitoid's Chances Of Reproducing In A New Host, R. Benoist, S. Paquet, F. Decourcelle, J. Guez, R. Jeannette, P. A. Calatayud, B. Le Ru, F. Mougel, L. Kaiser

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Understanding the ability of parasitoid insects to succeed in new host populations is a relevant question for biological control and adaptive mechanisms. Cotesia typhae is an African parasitoid specialized on the moth Sesamiae nonagrioides, also called the Mediterranean corn borer. Two Kenyan strains of C. typhae differ in their virulence against a new host population from France. We explored behavioral and physiological hypotheses about this differentiation. Cotesia genus belongs to a group of Hymenoptera in which females inject a domesticated virus in their host to overcome its resistance. Since viral particles are injected along with eggs and since the strain …

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Changes In Chemical And Microbiological Quality Of Semi-Processed Black Soldier Fly (Hermetia Illucens L.) Larval Meal During Storage, E. Kamau, C. Mutungi, J. Kinyuru, S. Imathiu, S. Ekesi, S. Ekesi, D. Nakimbugwe, K. K.M. Fiaboe Jan 2020

Changes In Chemical And Microbiological Quality Of Semi-Processed Black Soldier Fly (Hermetia Illucens L.) Larval Meal During Storage, E. Kamau, C. Mutungi, J. Kinyuru, S. Imathiu, S. Ekesi, S. Ekesi, D. Nakimbugwe, K. K.M. Fiaboe

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Edible insects are receiving attention as a protein source in the food and feed sector. However, successful commercialisation requires mass production matched with appropriate processing and storage techniques. The quality of dried and pulverised black soldier fly larvae stored in woven polypropylene (PP) sacks, polyethylene (PE) bags and plastic containers with screw lid (PL) in ambient and refrigerated environments was monitored over six months. Chemical indicators (oxidation, fatty acid profile), microbiological parameters (total viable counts, yeast and moulds, Enterobacteriaceae, presumptive coliforms, Salmonella) and colour change were examined. Temperature and relative humidity of the storage environments were monitored. In the ambient …

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Seed Quality And Mycoflora Associated With Chickpea (Cicer Arientinum L.) Seed In Ethiopia, G. Getaneh, T. Tefera, F. Lemmessa, S. Ahmed, A. Zewudie Jan 2020

Seed Quality And Mycoflora Associated With Chickpea (Cicer Arientinum L.) Seed In Ethiopia, G. Getaneh, T. Tefera, F. Lemmessa, S. Ahmed, A. Zewudie

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The study was conducted at Ethiopian Institute of Agricultural Research, Haramaya University and Jimma University, Ethiopia. Crop yield is directly associated with the physical and biological quality of planting material or seed. Ninety-nine (99) chickpea seed lot samples were collected for physical purity, seed health and germination tests from major chickpea growing areas in Ethiopia in the 2016/17 cropping season to assess the status of chickpea seed health and quality among subsistence farmers, research stations and seed growers. The seed lots were grouped as researcher saved, farmers saved and seed growers’ saved seed. The maximum physical purity of 97.5% was …

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A Cross-Sectional Observational Study Investigating The Association Between Sedges (Swamp Grasses, Cyperaceae) And The Prevalence Of Immature Malaria Vectors In Aquatic Habitats Along The Shore Of Lake Victoria, Western Kenya, Getachew E. Bokore, Paul Ouma, Patrick O. Onyango, Tullu Bukhari, Ulrike Fillinger Jan 2020

A Cross-Sectional Observational Study Investigating The Association Between Sedges (Swamp Grasses, Cyperaceae) And The Prevalence Of Immature Malaria Vectors In Aquatic Habitats Along The Shore Of Lake Victoria, Western Kenya, Getachew E. Bokore, Paul Ouma, Patrick O. Onyango, Tullu Bukhari, Ulrike Fillinger

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Background: Strategies that involve manipulations of the odour-orientation of gravid malaria vectors could lead to novel attract-and-kill interventions. Recent work has highlighted the potential involvement of graminoid plants in luring vectors to oviposition sites. This study aimed to analyse the association between water-indicating graminoid plants (Cyperaceae, sedges), other abiotic and biotic factors and the presence and abundance of early instar Anopheles larvae in aquatic habitats as a proxy indicator for oviposition. Methods: A cross-sectional survey of 110 aquatic habitats along the shores of Lake Victoria was done during the rainy season. Habitats were sampled for mosquito larvae using the sweep-net …

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Gendered Analysis Of The Demand For Poultry Feed In Kenya, John Njenga Macharia, Gracious Malton Diiro, John Rono Busienei, Kimpei Munei, Hippolyte D. Affognon, Sunday Ekesi, Beatrice Muriithi, Dorothy Nakimbugwe, Chrysantus Mbi Tanga, Komi K.M. Fiaboe Jan 2020

Gendered Analysis Of The Demand For Poultry Feed In Kenya, John Njenga Macharia, Gracious Malton Diiro, John Rono Busienei, Kimpei Munei, Hippolyte D. Affognon, Sunday Ekesi, Beatrice Muriithi, Dorothy Nakimbugwe, Chrysantus Mbi Tanga, Komi K.M. Fiaboe

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This paper uses a translog cost function approach to study the farm-level demand for poultry feed in Kenya. The study estimates the demand elasticities of the three common types of poultry feed; mixed feed, grain, and leafy vegetables. The estimated model was used to obtain estimates of Marshallian demand elasticities for poultry feed in Kenya for male-headed and female-headed households. The elasticities reported can be used by researchers and policy analysts to evaluate policy effects of changes in feed demand quantities within the livestock economy in Kenya. Moreover, these parameters can provide more reliable estimates of the total change in …

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Diversity Of Fall Armyworm, Spodoptera Frugiperda And Their Gut Bacterial Community In Kenya, Joseph Gichuhi, Subramanian Sevgan, Fathiya Khamis, Johnnie Van Den Berg, Hannalene Du Plessis, Sunday Ekesi, Jeremy K. Herren Jan 2020

Diversity Of Fall Armyworm, Spodoptera Frugiperda And Their Gut Bacterial Community In Kenya, Joseph Gichuhi, Subramanian Sevgan, Fathiya Khamis, Johnnie Van Den Berg, Hannalene Du Plessis, Sunday Ekesi, Jeremy K. Herren

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Background: The invasive fall armyworm, Spodoptera frugiperda (J.E. Smith) is a polyphagous pest that causes widespread damage particularly to maize and sorghum in Africa. The microbiome associated with S. frugiperda could play a role in the insects' success and adaptability. However, bacterial communities in S. frugiperda remain poorly studied. Methods: We investigated the composition, abundance and diversity of microbiomes associated with larval and adult specimens of S. frugiperda collected from four maize growing regions in Kenya through high throughput sequencing of the bacterial 16S rRNA gene. The population structure of S. frugiperda in Kenya was assessed through amplification of the …

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Tuta Absoluta (Lepidoptera: Gelechiidae) Invasion In Nigeria: First Report Of Its Distribution, Pascal Osa Aigbedion-Atalor, Abiola O. Oke, Abiola A. Oladigbolu, Adejumo A. Layade, Igho B. Igbinosa, Samira A. Mohamed Dec 2019

Tuta Absoluta (Lepidoptera: Gelechiidae) Invasion In Nigeria: First Report Of Its Distribution, Pascal Osa Aigbedion-Atalor, Abiola O. Oke, Abiola A. Oladigbolu, Adejumo A. Layade, Igho B. Igbinosa, Samira A. Mohamed

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The South America tomato pinworm Tuta absoluta is a serious invasive species in Nigeria. Its impacts on crop production are well understood, but its distribution in the country is unclear. Here, between March 2017 and July 2018, mapping surveys of the distribution of T. absoluta were conducted in 528 different locations across 11 states in Nigeria. Results showed that T. absoluta is present and established in all 360 sites surveyed in the northern and south-western parts of Nigeria. However, it was not recorded at all locations surveyed in two states, Edo and Delta, further south of the country. The implications …

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The Nutritive Value Of Black Soldier Fly Larvae Reared On Common Organic Waste Streams In Kenya, Marwa Shumo, Isaac M. Osuga, Fathiya M. Khamis, Chrysantus M. Tanga, Komi K.M. Fiaboe, Sevgan Subramanian, Sunday Ekesi, Arnold Van Huis, Christian Borgemeister Dec 2019

The Nutritive Value Of Black Soldier Fly Larvae Reared On Common Organic Waste Streams In Kenya, Marwa Shumo, Isaac M. Osuga, Fathiya M. Khamis, Chrysantus M. Tanga, Komi K.M. Fiaboe, Sevgan Subramanian, Sunday Ekesi, Arnold Van Huis, Christian Borgemeister

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In Africa, livestock production currently accounts for about 30% of the gross value of agricultural production. However, production is struggling to keep up with the demands of expanding human populations, the rise in urbanization and the associated shifts in diet habits. High costs of feed prevent the livestock sector from thriving and to meet the rising demand. Insects have been identified as potential alternatives to the conventionally used protein sources in livestock feed due to their rich nutrients content and the fact that they can be reared on organic side streams. Substrates derived from organic by-products are suitable for industrial …

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Abc Transporter Genes Abc-C6 And Abc-G33 Alter Plant-Microbe-Parasite Interactions In The Rhizosphere, Deborah Elizabeth Cox, Steven Dyer, Ryan Weir, Xavier Cheseto, Matthew Sturrock, Danny Coyne, Baldwyn Torto, Aaron G. Maule, Johnathan J. Dalzell Dec 2019

Abc Transporter Genes Abc-C6 And Abc-G33 Alter Plant-Microbe-Parasite Interactions In The Rhizosphere, Deborah Elizabeth Cox, Steven Dyer, Ryan Weir, Xavier Cheseto, Matthew Sturrock, Danny Coyne, Baldwyn Torto, Aaron G. Maule, Johnathan J. Dalzell

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Plants are master regulators of rhizosphere ecology, secreting a complex mixture of compounds into the soil, collectively termed plant root exudate. Root exudate composition is highly dynamic and functional, mediating economically important interactions between plants and a wide range of soil organisms. Currently we know very little about the molecular basis of root exudate composition, which is a key hurdle to functional exploitation of root exudates for crop improvement. Root expressed transporters modulate exudate composition and could be manipulated to develop beneficial plant root exudate traits. Using Virus Induced Gene silencing (VIGS), we demonstrate that knockdown of two root-expressed ABC …

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Towards A Global Dna Barcode Reference Library For Quarantine Identifications Of Lepidopteran Stemborers, With An Emphasis On Sugarcane Pests, Timothy R.C. Lee, Stacey J. Anderson, Lucy T.T. Tran-Nguyen, Nader Sallam, Bruno P. Le Ru, Desmond Conlong, Kevin Powell, Andrew Ward, Andrew Mitchell Dec 2019

Towards A Global Dna Barcode Reference Library For Quarantine Identifications Of Lepidopteran Stemborers, With An Emphasis On Sugarcane Pests, Timothy R.C. Lee, Stacey J. Anderson, Lucy T.T. Tran-Nguyen, Nader Sallam, Bruno P. Le Ru, Desmond Conlong, Kevin Powell, Andrew Ward, Andrew Mitchell

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Lepidopteran stemborers are among the most damaging agricultural pests worldwide, able to reduce crop yields by up to 40%. Sugarcane is the world’s most prolific crop, and several stemborer species from the families Noctuidae, Tortricidae, Crambidae and Pyralidae attack sugarcane. Australia is currently free of the most damaging stemborers, but biosecurity efforts are hampered by the difficulty in morphologically distinguishing stemborer species. Here we assess the utility of DNA barcoding in identifying stemborer pest species. We review the current state of the COI barcode sequence library for sugarcane stemborers, assembling a dataset of 1297 sequences from 64 species. Sequences were …

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Species-Specific Transcriptional Profiles Of The Gut And Gut Microbiome Of Ceratitis Quilicii And Ceratitis Rosa Sensu Stricto, Fathiya M. Khamis, Paul O. Mireji, Fidelis L.O. Ombura, Anna R. Malacrida, Erick O. Awuoche, Martin Rono, Samira A. Mohamed, Chrysantus M. Tanga, Sunday Ekesi Dec 2019

Species-Specific Transcriptional Profiles Of The Gut And Gut Microbiome Of Ceratitis Quilicii And Ceratitis Rosa Sensu Stricto, Fathiya M. Khamis, Paul O. Mireji, Fidelis L.O. Ombura, Anna R. Malacrida, Erick O. Awuoche, Martin Rono, Samira A. Mohamed, Chrysantus M. Tanga, Sunday Ekesi

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The fruit fly species, Ceratitis rosa sensu stricto and Ceratitis quilicii, are sibling species restricted to the lowland and highland regions, respectively. Until recently, these sibling species were considered as allopatric populations of C. rosa with distinct bionomics. We used deep Next Generation Sequencing (NGS) technology on intact guts of individuals from the two sibling species to compare their transcriptional profiles and simultaneously understand gut microbiome and host molecular processes and identify distinguishing genetic differences between the two species. Since the genomes of both species had not been published previously, the transcriptomes were assembled de novo into transcripts. Microbe-specific transcript …

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Differential Response To Plant- And Human-Derived Odorants In Field Surveillance Of The Dengue Vector, Aedes Aegypti, Wyckliff P. Omondi, Eunice A. Owino, David Odongo, Joseph M. Mwangangi, Baldwyn Torto, David P. Tchouassi Dec 2019

Differential Response To Plant- And Human-Derived Odorants In Field Surveillance Of The Dengue Vector, Aedes Aegypti, Wyckliff P. Omondi, Eunice A. Owino, David Odongo, Joseph M. Mwangangi, Baldwyn Torto, David P. Tchouassi

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Linalool oxide (LO) and hexanoic acid (HA) represent plant- and human-derived odorants, respectively, previously found as attractants for the dengue vector Aedes aegypti. Here, we investigated if a blend of both compounds can improve captures of this mosquito species in field trials in two dengue endemic sites, Kilifi and Busia Counties in Kenya. Ae. aegypti captures were significantly higher in Kilifi than Busia (χ21,142 = 170.63, P < 0.0001) and varied by treatments (χ25,137 = 151.19, P = 0.002). We found that CO2-baited BG Sentinel traps combined with a blend of both odorants decreased Ae. aegypti captures about 2- to 4-fold compared to captures with the individual compounds (LO or HA) used as positive controls. This was the case for all blends of LO and HA, irrespective of the doses tested. Our findings indicate that combining plant- and human-derived odors may elicit a masking effect in trapping Ae. aegypti. These results partly corroborate previous findings for malaria mosquitoes which showed that combining lures from both host sources either decreases or increases trap catches depending on the dose. Further investigations in the usefulness of combining plant and animal odorants in mosquito trapping are therefore necessary.

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Ethylene Response Factor (Erf) Genes Modulate Plant Root Exudate Composition And The Attraction Of Plant Parasitic Nematodes, Steven Dyer, Ryan Weir, Deborah Cox, Xavier Cheseto, Baldwyn Torto, Johnathan J. Dalzell Dec 2019

Ethylene Response Factor (Erf) Genes Modulate Plant Root Exudate Composition And The Attraction Of Plant Parasitic Nematodes, Steven Dyer, Ryan Weir, Deborah Cox, Xavier Cheseto, Baldwyn Torto, Johnathan J. Dalzell

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Plant root exudates are compositionally diverse, plastic and adaptive. Ethylene signalling influences the attraction of plant parasitic nematodes, presumably through the modulation of root exudate composition. Understanding this pathway could lead to new sources of crop parasite resistance. Here we used Virus-Induced Gene Silencing to knock down the expression of two Ethylene Response Factor (ERF) genes, ERF-E2 and ERF-E3, in tomato. Root exudates were significantly more attractive to the PPNs Meloidogyne incognita and Globodera pallida following knockdown of ERF-E2, which had no impact on the attraction of Meloidogyne javanica. Knockdown of ERF-E3 had no impact on the attraction of Meloidogyne …

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Insects For Sustainable Animal Feed: Inclusive Business Models Involving Smallholder Farmers, Shaphan Y. Chia, Chrysantus M. Tanga, Joop Ja Van Loon, Marcel Dicke Dec 2019

Insects For Sustainable Animal Feed: Inclusive Business Models Involving Smallholder Farmers, Shaphan Y. Chia, Chrysantus M. Tanga, Joop Ja Van Loon, Marcel Dicke

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Global population growth, an increasing demand for animal products and scarcity of conventional feed ingredients drive the search for alternative protein sources for animal feed. Extensive research indicates that insects provide good opportunities as a sustainable, high quality and low-cost component of animal feed. Here, we discuss how insect farming can promote inclusive business for smallholder farmers in the agribusiness value chain. Inclusive business models involving insects as ingredients in feed may contribute to solving socio-economic and environmental problems in developing countries, aligning with the United Nations’ Sustainable Development Goals. With low initial capital investments, smallholder insect farmers have good …

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