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Full-Text Articles in Life Sciences

Whole Genome Comparisons Reveal Panmixia Among Fall Armyworm (Spodoptera Frugiperda) From Diverse Locations, Katrina A. Schlum, Kurt Lamour, Caroline Placidi De Bortoli, Rahul Banerjee, Robert Meagher, Eliseu Pereira, Maria Gabriela Murua, Gregory A. Sword, Ashley E. Tessnow, Diego Viteri Dillon, Angela M. Linares Ramirez, Komivi S. Akutse, Rebecca Schmidt-Jeffris, Fangneng Huang, Dominic Reisig, Scott J. Emrich, Juan Luis Jurat-Fuentes Dec 2021

Whole Genome Comparisons Reveal Panmixia Among Fall Armyworm (Spodoptera Frugiperda) From Diverse Locations, Katrina A. Schlum, Kurt Lamour, Caroline Placidi De Bortoli, Rahul Banerjee, Robert Meagher, Eliseu Pereira, Maria Gabriela Murua, Gregory A. Sword, Ashley E. Tessnow, Diego Viteri Dillon, Angela M. Linares Ramirez, Komivi S. Akutse, Rebecca Schmidt-Jeffris, Fangneng Huang, Dominic Reisig, Scott J. Emrich, Juan Luis Jurat-Fuentes

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Background: The fall armyworm (Spodoptera frugiperda (J.E. Smith)) is a highly polyphagous agricultural pest with long-distance migratory behavior threatening food security worldwide. This pest has a host range of > 80 plant species, but two host strains are recognized based on their association with corn (C-strain) or rice and smaller grasses (R-strain). The population genomics of the United States (USA) fall armyworm remains poorly characterized to date despite its agricultural threat. Results: In this study, the population structure and genetic diversity in 55 S. frugiperda samples from Argentina, Brazil, Kenya, Puerto Rico and USA were surveyed to further our understanding of …

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Satellite-Based Modelling Of Potential Tsetse (Glossina Pallidipes) Breeding And Foraging Sites Using Teneral And Non-Teneral Fly Occurrence Data, Stella Gachoki, Thomas Groen, Anton Vrieling, Michael Okal, Andrew Skidmore, Daniel Masiga Dec 2021

Satellite-Based Modelling Of Potential Tsetse (Glossina Pallidipes) Breeding And Foraging Sites Using Teneral And Non-Teneral Fly Occurrence Data, Stella Gachoki, Thomas Groen, Anton Vrieling, Michael Okal, Andrew Skidmore, Daniel Masiga

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Background: African trypanosomiasis, which is mainly transmitted by tsetse flies (Glossina spp.), is a threat to public health and a significant hindrance to animal production. Tools that can reduce tsetse densities and interrupt disease transmission exist, but their large-scale deployment is limited by high implementation costs. This is in part limited by the absence of knowledge of breeding sites and dispersal data, and tools that can predict these in the absence of ground-truthing. Methods: In Kenya, tsetse collections were carried out in 261 randomized points within Shimba Hills National Reserve (SHNR) and villages up to 5 km from the reserve …

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Global Population Genetic Structure And Demographic Trajectories Of The Black Soldier Fly, Hermetia Illucens, Cengiz Kaya, Tomas N. Generalovic, Gunilla Ståhls, Martin Hauser, Ana C. Samayoa, Carlos G. Nunes-Silva, Heather Roxburgh, Jens Wohlfahrt, Ebenezer A. Ewusie, Marc Kenis, Yupa Hanboonsong, Jesus Orozco, Nancy Carrejo, Satoshi Nakamura, Laura Gasco, Santos Rojo, Chrysantus M. Tanga, Rudolf Meier, Clint Rhode, Christine J. Picard, Chris D. Jiggins, Florian Leiber, Jeffery K. Tomberlin, Martin Hasselmann, Wolf U. Blanckenhorn, Martin Kapun, Christoph Sandrock Dec 2021

Global Population Genetic Structure And Demographic Trajectories Of The Black Soldier Fly, Hermetia Illucens, Cengiz Kaya, Tomas N. Generalovic, Gunilla Ståhls, Martin Hauser, Ana C. Samayoa, Carlos G. Nunes-Silva, Heather Roxburgh, Jens Wohlfahrt, Ebenezer A. Ewusie, Marc Kenis, Yupa Hanboonsong, Jesus Orozco, Nancy Carrejo, Satoshi Nakamura, Laura Gasco, Santos Rojo, Chrysantus M. Tanga, Rudolf Meier, Clint Rhode, Christine J. Picard, Chris D. Jiggins, Florian Leiber, Jeffery K. Tomberlin, Martin Hasselmann, Wolf U. Blanckenhorn, Martin Kapun, Christoph Sandrock

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Background: The black soldier fly (Hermetia illucens) is the most promising insect candidate for nutrient-recycling through bioconversion of organic waste into biomass, thereby improving sustainability of protein supplies for animal feed and facilitating transition to a circular economy. Contrary to conventional livestock, genetic resources of farmed insects remain poorly characterised. We present the first comprehensive population genetic characterisation of H. illucens. Based on 15 novel microsatellite markers, we genotyped and analysed 2862 individuals from 150 wild and captive populations originating from 57 countries on seven subcontinents. Results: We identified 16 well-distinguished genetic clusters indicating substantial global population structure. The data …

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Molecular Prevalence And Risk Factors Associated With Tick-Borne Pathogens In Cattle In Western Kenya, Tatenda Chiuya, Jandouwe Villinger, Daniel K. Masiga, Dickens O. Ondifu, Maurice K. Murungi, Lillian Wambua, Armanda D.S. Bastos, Eric M. Fèvre, Laura C. Falzon Dec 2021

Molecular Prevalence And Risk Factors Associated With Tick-Borne Pathogens In Cattle In Western Kenya, Tatenda Chiuya, Jandouwe Villinger, Daniel K. Masiga, Dickens O. Ondifu, Maurice K. Murungi, Lillian Wambua, Armanda D.S. Bastos, Eric M. Fèvre, Laura C. Falzon

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Background: Tick-borne pathogens (TBPs) are of global importance, especially in sub-Saharan Africa where they represent a major constraint to livestock production. Their association with human disease is also increasingly recognized, signalling their zoonotic importance. It is therefore crucial to investigate TBPs prevalence in livestock populations and the factors associated with their presence. We set out to identify TBPs present in cattle and to determine associated risk factors in western Kenya, where smallholder livestock production is important for subsistence and market-driven income. Results: Tick-borne pathogen infections in blood samples collected from cattle at livestock markets and slaughterhouses between May 2017 and …

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Global Overview Of Locusts As Food, Feed And Other Uses, J. P. Egonyu, S. Subramanian, C. M. Tanga, T. Dubois, S. Ekesi, S. Kelemu Dec 2021

Global Overview Of Locusts As Food, Feed And Other Uses, J. P. Egonyu, S. Subramanian, C. M. Tanga, T. Dubois, S. Ekesi, S. Kelemu

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The term 'locusts' refers to insect species which can aggregate into migratory swarms that cause wide-scale destruction of crops and pasture, causing significant effect to food security. This review assesses the potential of harnessing locust swarms for beneficial uses. Among 21 known locusts, ~10 species have been traditionally consumed by humans or fed to animals for millennia in 65 countries. Their nutritional composition is comparable or superior to that of conventional meat. However, insecticide residues, microbial contaminants and allergens may compromise their safety. Some countries have developed regulations on edible insects, locusts inclusive. Safe and efficient harvest of locusts could …

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Distribution And Mating Type Characterization Of Chickpea Blight (Didymella Rabiei (Kov.) V. Arx) In Ethiopia, Gezahegne Getaneh, Tadele Tefera, Fikre Lemessa, Seid Ahmed, Jandouwe Villinger Dec 2021

Distribution And Mating Type Characterization Of Chickpea Blight (Didymella Rabiei (Kov.) V. Arx) In Ethiopia, Gezahegne Getaneh, Tadele Tefera, Fikre Lemessa, Seid Ahmed, Jandouwe Villinger

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We have assessed the distribution and mating type of chickpea blight (Didymella rabiei (Kov.) v. Arx) from a total of 350 and 272 fields in major chickpea (Cicer arietinum L.) growing areas of Ethiopia for two consecutive cropping seasons 2017 and 2018, respectively. The prevalence of D. rabiei was 20 % for the year 2017 and 7% for 2018. Severity range of 2−9 and incidence of 10–100 % were recorded for both seasons in only 7–20 % of the assed fields. Field prevalence of 2017 and 2018 seasons were significantly different (df = 31; p < 0.001 and df = 31; p < 0.001, respectively). Similarly, the disease prevalence of both seasons was significantly different (df = 31; p < 0.001). The disease prevalence ratio frequency was highly deviated from (1:1) for both seasons (X2 = 213.62 p= <0.001; X2 = 144.36 p = 0.01). Genomic DNA of Representative samples were extracted from single spore culture and Mating type 1 (MAT1-1) specific primer SP21, Mating type 2 (MAT1-2) specific primer Tail 5, and a flanking region-specific primer Com1 assay were multiplexed in a single PCR reaction to determine the occurrence of D. rabiei mating type in Ethiopia. Out of 156 samples, only 15 samples were positive to MAT1-1 (∼10 %) with the ratio of 9:1. MAT 1−2 type was the most dominant and possibly the asexual reproduction of D. rabiei is the major type in Ethiopia. The result is important for Ascochyta blight management in breeding strategy.

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An Update On The Distribution Of Glossina (Tsetse Flies) At The Wildlife-Human-Livestock Interface Of Akagera National Park, Rwanda, Richard S. Gashururu, Samuel M. Githigia, Methode N. Gasana, Richard Habimana, Ndichu Maingi, Giuliano Cecchi, Massimo Paone, Weining Zhao, Daniel K. Masiga, James Gashumba Dec 2021

An Update On The Distribution Of Glossina (Tsetse Flies) At The Wildlife-Human-Livestock Interface Of Akagera National Park, Rwanda, Richard S. Gashururu, Samuel M. Githigia, Methode N. Gasana, Richard Habimana, Ndichu Maingi, Giuliano Cecchi, Massimo Paone, Weining Zhao, Daniel K. Masiga, James Gashumba

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Background: Glossina (tsetse flies) biologically transmit trypanosomes that infect both humans and animals. Knowledge of their distribution patterns is a key element to better understand the transmission dynamics of trypanosomosis. Tsetse distribution in Rwanda has not been well enough documented, and little is known on their current distribution. This study determined the current spatial distribution, abundance, diversity, and seasonal variations of tsetse flies in and around the Akagera National Park. Methods: A longitudinal stratified sampling following the seasons was used. Biconical traps were deployed in 55 sites for 6 consecutive days of each study month from May 2018 to June …

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Water Immersion Tolerance By Larval Instars Of Stable Fly, Stomoxys Calcitrans, L1758 (Diptera: Muscidae) Impairs The Fitness Performance Of Their Subsequent Stages, Steve B.S. Baleba Dec 2021

Water Immersion Tolerance By Larval Instars Of Stable Fly, Stomoxys Calcitrans, L1758 (Diptera: Muscidae) Impairs The Fitness Performance Of Their Subsequent Stages, Steve B.S. Baleba

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Background: In holometabolous insects, environmental factors experienced in pre-imaginal life stages affect the life-history traits within that stage and can also influence subsequent life stages. Here, I assessed tolerance to water immersion by the larval instars of the stable fly, Stomoxys calcitrans L. (Diptera: Muscidae) and its impact on the life-history traits of their subsequent life stages. Results: After submerging the three larval instars of S. calcitrans in distilled water, I found that the first instar larvae remained active for longer as compared to the second and third instar larvae. Also, the first instar larvae took a longer period to …

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Mitogenomic Analysis Of Diversity Of Key Whitefly Pests In Kenya And Its Implication To Their Sustainable Management, Fathiya M. Khamis, Fidelis L.O. Ombura, Inusa J. Ajene, Komivi S. Akutse, Sevgan Subramanian, Samira A. Mohamed, Thomas Dubois, Chrysantus M. Tanga, Sunday Ekesi Dec 2021

Mitogenomic Analysis Of Diversity Of Key Whitefly Pests In Kenya And Its Implication To Their Sustainable Management, Fathiya M. Khamis, Fidelis L.O. Ombura, Inusa J. Ajene, Komivi S. Akutse, Sevgan Subramanian, Samira A. Mohamed, Thomas Dubois, Chrysantus M. Tanga, Sunday Ekesi

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Whiteflies (Hemiptera: Aleyrodidae) are devastating agricultural pests of economic importance vectoring pathogenic plant viruses. Knowledge on their diversity and distribution in Kenya is scanty, limiting development of effective sustainable management strategies. The present study is aimed at identifying whitefly pest species present in Kenya across different agroecological zones and establish predictive models for the most abundant species in Africa. Whiteflies were sampled in Kenya from key crops known to be severely infested and identified using 16S rRNA markers and complete mitochondrial genomes. Four whitefly species were identified: Aleyrodes proletella, Aleurodicus dispersus, Bemisia afer and Trialeurodesvaporariorum, the latter being the most …

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Immediate Impacts Of Covid-19 Measures On Bean Production, Distribution, And Food Security In Eastern Africa, Eileen Nchanji, Cosmas Kweyu Lutomia, David Karanja Dec 2021

Immediate Impacts Of Covid-19 Measures On Bean Production, Distribution, And Food Security In Eastern Africa, Eileen Nchanji, Cosmas Kweyu Lutomia, David Karanja

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The outbreak of coronavirus was expected to adversely affect African countries more than any other region in the world. This assertion was based on the existing conditions in sub-Saharan Africa that exposed the region to the dire consequences of the pandemic. Previously existing underlying conditions that affected the food system include a high dependence on trade for inputs supply, the adverse effects of climate change, crop pests and diseases, poverty, low input use, weak institutions and ineffective policies, and insecurity and conflicts. We collected data from farmers, aggregators, bean research coordinators, and urban and peri-urban consumers in five Eastern African …

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Molecular Detection Of Leishmania Donovani, Leishmania Major, And Trypanosoma Species In Sergentomyia Squamipleuris Sand Flies From A Visceral Leishmaniasis Focus In Merti Sub-County, Eastern Kenya, Barrack O. Owino, Jackline Milkah Mwangi, Steve Kiplagat, Hannah Njiriku Mwangi, Johnstone M. Ingonga, Alphine Chebet, Philip M. Ngumbi, Jandouwe Villinger, Daniel K. Masiga, Damaris Matoke-Muhia Dec 2021

Molecular Detection Of Leishmania Donovani, Leishmania Major, And Trypanosoma Species In Sergentomyia Squamipleuris Sand Flies From A Visceral Leishmaniasis Focus In Merti Sub-County, Eastern Kenya, Barrack O. Owino, Jackline Milkah Mwangi, Steve Kiplagat, Hannah Njiriku Mwangi, Johnstone M. Ingonga, Alphine Chebet, Philip M. Ngumbi, Jandouwe Villinger, Daniel K. Masiga, Damaris Matoke-Muhia

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Background: Visceral leishmaniasis (VL) and zoonotic cutaneous leishmaniasis (ZCL) are of public health concern in Merti sub-County, Kenya, but epidemiological data on transmission, vector abundance, distribution, and reservoir hosts remain limited. To better understand the disease and inform control measures to reduce transmission, we investigated the abundance and distribution of sand fly species responsible for Leishmania transmission in the sub-County and their blood-meal hosts. Methods: We conducted an entomological survey in five villages with reported cases of VL in Merti sub-County, Kenya, using CDC miniature light traps and castor oil sticky papers. Sand flies were dissected and identified to the …

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Gene Co-Expression Network Analysis Of Trypanosoma Brucei In Tsetse Fly Vector, Kennedy W. Mwangi, Rosaline W. Macharia, Joel L. Bargul Dec 2021

Gene Co-Expression Network Analysis Of Trypanosoma Brucei In Tsetse Fly Vector, Kennedy W. Mwangi, Rosaline W. Macharia, Joel L. Bargul

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Background: Trypanosoma brucei species are motile protozoan parasites that are cyclically transmitted by tsetse fly (genus Glossina) causing human sleeping sickness and nagana in livestock in sub-Saharan Africa. African trypanosomes display digenetic life cycle stages in the tsetse fly vector and in their mammalian host. Experimental work on insect-stage trypanosomes is challenging because of the difficulty in setting up successful in vitro cultures. Therefore, there is limited knowledge on the trypanosome biology during its development in the tsetse fly. Consequently, this limits the development of new strategies for blocking parasite transmission in the tsetse fly. Methods: In this study, RNA-Seq …

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Plant Nutrient Quality Impacts Survival And Reproductive Fitness Of The Dengue Vector Aedes Aegypti, Vincent Odhiambo Nyasembe, David Poumo Tchouassi, Martha Njeri Muturi, Christian W.W. Pirk, Catherine L. Sole, Baldwyn Torto Dec 2021

Plant Nutrient Quality Impacts Survival And Reproductive Fitness Of The Dengue Vector Aedes Aegypti, Vincent Odhiambo Nyasembe, David Poumo Tchouassi, Martha Njeri Muturi, Christian W.W. Pirk, Catherine L. Sole, Baldwyn Torto

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Background: In a recent study using DNA barcoding, we identified the plants fed upon by four Afro-tropical mosquito species that vector dengue, malaria, and Rift Valley fever. Herein, we have expanded on this study by investigating the role of three of the plants, Pithecellobium dulce (Fabaceae), Leonotis nepetifolia (Lamiaceae), and Opuntia ficus-indica (Cactaceae), on the survival, fecundity, and egg viability of the dengue vector Aedes aegypti. Methods: We tested these effects using females that received (i) an initial three rations of blood meals and (ii) no blood meal at all. Two controls were included: age-matched females fed on glucose solution …

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Transcriptomic Response Of Anopheles Gambiae Sensu Stricto Mosquito Larvae To Curry Tree (Murraya Koenigii) Phytochemicals, Clarence M. Mang’Era, Fathiya M. Khamis, Erick O. Awuoche, Ahmed Hassanali, Fidelis Levi Odhiambo Ombura, Paul O. Mireji Dec 2021

Transcriptomic Response Of Anopheles Gambiae Sensu Stricto Mosquito Larvae To Curry Tree (Murraya Koenigii) Phytochemicals, Clarence M. Mang’Era, Fathiya M. Khamis, Erick O. Awuoche, Ahmed Hassanali, Fidelis Levi Odhiambo Ombura, Paul O. Mireji

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Background: Insect growth regulators (IGRs) can control insect vector populations by disrupting growth and development in juvenile stages of the vectors. We previously identified and described the curry tree (Murraya koenigii (L.) Spreng) phytochemical leaf extract composition (neplanocin A, 3-(1-naphthyl)-l-alanine, lumiflavine, terezine C, agelaspongin and murrayazolinol), which disrupted growth and development in Anopheles gambiae sensu stricto mosquito larvae by inducing morphogenetic abnormalities, reducing locomotion and delaying pupation in the mosquito. Here, we attempted to establish the transcriptional process in the larvae that underpins these phenotypes in the mosquito. Methods: We first exposed third-fourth instar larvae of the mosquito to the …

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Endophytic Colonisation Of Solanum Lycopersicum And Phaseolus Vulgaris By Fungal Endophytes Promotes Seedlings Growth And Hampers The Reproductive Traits, Development, And Survival Of The Greenhouse Whitefly, Trialeurodes Vaporariorum, Vongai M. Paradza, Fathiya M. Khamis, Abdullahi A. Yusuf, Sevgan Subramanian, Sunday Ekesi, Komivi S. Akutse Nov 2021

Endophytic Colonisation Of Solanum Lycopersicum And Phaseolus Vulgaris By Fungal Endophytes Promotes Seedlings Growth And Hampers The Reproductive Traits, Development, And Survival Of The Greenhouse Whitefly, Trialeurodes Vaporariorum, Vongai M. Paradza, Fathiya M. Khamis, Abdullahi A. Yusuf, Sevgan Subramanian, Sunday Ekesi, Komivi S. Akutse

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In the scope of mitigating the negative impacts of pesticide use and managing greenhouse whiteflies, Trialeurodes vaporariorum sustainably, 16 endophytic fungal isolates from five different genera (Beauveria, Trichoderma, Hypocrea, Bionectria, and Fusarium) were screened for their ability to colonise two preferred host plant species, namely, tomato (Solanum lycopersicum L.) and French bean (Phaseolus vulgaris L.), through seed inoculation. Seven and nine isolates were endophytic to P. vulgaris and S. lycopersicum, respectively, where significant differences in the endophytic colonisation rates were observed among the fungal isolates in P. vulgaris and its plant parts, with a significant interaction between the isolates and …

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Prevalence Of Trypanosome Species In Cattle Near Ruma National Park, Lambwe Valley, Kenya: An Update From The Historical Focus For African Trypanosomosis, Shewit Kalayou, Michael Nyang Anga Okal, Peter Otieno Odhiambo, Kawira Mathenge, Daniel Ochieng Gamba, Edward Kariuki, Francis Mcodimba, Daniel Masiga Nov 2021

Prevalence Of Trypanosome Species In Cattle Near Ruma National Park, Lambwe Valley, Kenya: An Update From The Historical Focus For African Trypanosomosis, Shewit Kalayou, Michael Nyang Anga Okal, Peter Otieno Odhiambo, Kawira Mathenge, Daniel Ochieng Gamba, Edward Kariuki, Francis Mcodimba, Daniel Masiga

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The effective control of diseases in areas shared with wildlife depends on the validity of the epidemiologic parameters that guide interventions. Epidemiologic data on animal trypanosomosis in Lambwe valley are decades old, and the recent suspected outbreaks of the disease in the valley necessitate the urgent bridging of this data gap. This cross-sectional study estimated the prevalence of bovine trypanosomosis, identified risk factors, and investigated the occurrence of species with zoonotic potential in Lambwe valley. The area is ~324 km2, of which 120 km2 is the Ruma National Park. Blood was sampled from the jugular and marginal ear veins of …

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Virulence And Horizontal Transmission Of Metarhizium Anisopliae By The Adults Of The Greenhouse Whitefly Trialeurodes Vaporariorum (Hemiptera: Aleyrodidae) And The Efficacy Of Oil Formulations Against Its Nymphs, Vongai M. Paradza, Fathiya M. Khamis, Abdullahi A. Yusuf, Sevgan Subramanian, Komivi S. Akutse Nov 2021

Virulence And Horizontal Transmission Of Metarhizium Anisopliae By The Adults Of The Greenhouse Whitefly Trialeurodes Vaporariorum (Hemiptera: Aleyrodidae) And The Efficacy Of Oil Formulations Against Its Nymphs, Vongai M. Paradza, Fathiya M. Khamis, Abdullahi A. Yusuf, Sevgan Subramanian, Komivi S. Akutse

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The pathogenicity of dry conidia and fungal suspensions of 16 entomopathogenic fungal isolates (10 Metarhizium anisopliae and six Beauveria bassiana) was evaluated against adults and second instar nymphs of the greenhouse whitefly, Trialeurodes vaporariorum respectively. All the tested isolates were pathogenic to T. vaporariorum and caused mortality of 45–93% against the adults and 24–89% against the nymphs. However, M. anisopliae strains showed higher virulence to both developmental stages as compared to B. bassiana strains. The three most virulent isolates that caused high mortalities in adults were M. anisopliae ICIPE 18, ICIPE 62 and ICIPE 69, with cumulative mortalities of 82, …

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Mating Frequency Of Female False Codling Moth, Thaumatotibia Leucotreta (Lepidoptera: Tortricidae): Trade-Off Between Fecundity And Longevity, Abdelmutalab G.A. Azrag, Shepard Ndlela, Abdullah M. Mkiga, Samira Abuelgasim Mohamed Nov 2021

Mating Frequency Of Female False Codling Moth, Thaumatotibia Leucotreta (Lepidoptera: Tortricidae): Trade-Off Between Fecundity And Longevity, Abdelmutalab G.A. Azrag, Shepard Ndlela, Abdullah M. Mkiga, Samira Abuelgasim Mohamed

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Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) is a polyphagous insect pest native to sub-Saharan Africa. The larvae burrow into the fruit and feed on the pulp, thus inflicting huge direct (yield) and indirect losses (markets). Nevertheless, little is known about the mating frequency, behavior, and trade-off between fecundity and longevity of this pest. Therefore, this study aimed to determine the effect of mating status and frequency on fecundity, fertility, and female longevity of T. leucotreta; evaluate the trade-off between the female fecundity and longevity, and evaluate the spermatophore degradation in the bursa copulatrix. The first mating occurred 13 h on average …

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Socioeconomic And Health Impacts Of Fall Armyworm In Ethiopia, Zewdu Abro, Emily Kimathi, Hugo De Groote, Tadele Tefera, Subramanian Sevgan, Saliou Niassy, Menale Kassie Nov 2021

Socioeconomic And Health Impacts Of Fall Armyworm In Ethiopia, Zewdu Abro, Emily Kimathi, Hugo De Groote, Tadele Tefera, Subramanian Sevgan, Saliou Niassy, Menale Kassie

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Since 2016, fall armyworm (FAW) has threatened sub-Saharan ‘Africa’s fragile food systems and economic performance. Yet, there is limited evidence on this transboundary pest’s economic and food security impacts in the region. Additionally, the health and environmental consequences of the insecticides being used to control FAW have not been studied. This paper presents evidence on the impacts of FAW on maize production, food security, and human and environmental health. We use a combination of an agroecology-based community survey and nationally representative data from an agricultural household survey to achieve our objectives. The results indicate that the pest causes an average …

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Pollinator Supplementation Mitigates Pollination Deficits In Smallholder Avocado (Persea Americana Mill.) Production Systems In Kenya, Rose Nyakemiso Sagwe, Marcell K. Peters, Thomas Dubois, Ingolf Steffan-Dewenter, H. Michael G. Lattorff Nov 2021

Pollinator Supplementation Mitigates Pollination Deficits In Smallholder Avocado (Persea Americana Mill.) Production Systems In Kenya, Rose Nyakemiso Sagwe, Marcell K. Peters, Thomas Dubois, Ingolf Steffan-Dewenter, H. Michael G. Lattorff

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Avocado (Persea americana Mill.) is a major horticultural crop that relies on insect mediated pollination. In avocado production, a knowledge gap exists as to the importance of insect pollination, especially in East African smallholder farms. In this study, conducted in a leading smallholder avocado production region in Kenya, we assessed the dependence of avocado fruit set on insect pollination and whether current smallholder production systems suffer from a deficit in pollination services. Furthermore, we assessed if supplementation with colonies of the Western honey bee (Apis mellifera L.) to farms mitigated potential pollination deficits. Our results revealed a very high reliance …

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Efficiencies Of Stationary Sampling Tools For The Tsetse Fly Glossina Fuscipes Fuscipes In Western Kenya, Njelembo J. Mbewe, Catherine L. Sole, Christian W.W. Pirk, Daniel K. Masiga, Abdullahi A. Yusuf Nov 2021

Efficiencies Of Stationary Sampling Tools For The Tsetse Fly Glossina Fuscipes Fuscipes In Western Kenya, Njelembo J. Mbewe, Catherine L. Sole, Christian W.W. Pirk, Daniel K. Masiga, Abdullahi A. Yusuf

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Monitoring the effectiveness of tsetse fly control interventions that aim to reduce transmission of African trypanosomiasis requires highly efficient sampling tools that can catch flies at low densities. The sticky small target (StS-target) has previously been shown to be more effective in sampling Glossina fuscipes fuscipes compared to the biconical trap. However, its efficiency in terms of the proportion of flies it catches out of those that visit it has not been reported. Furthermore, there are no reports on whether tsetse samples caught using the StS-target can be used for subsequent processes such as molecular tests. In this study, we …

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Perennial Legume Intercrops Provide Multiple Belowground Ecosystem Services In Smallholder Farming Systems, Laurie E. Drinkwater, Charles A.O. Midega, Rachel Awuor, Dickens Nyagol, Zeyaur R. Khan Oct 2021

Perennial Legume Intercrops Provide Multiple Belowground Ecosystem Services In Smallholder Farming Systems, Laurie E. Drinkwater, Charles A.O. Midega, Rachel Awuor, Dickens Nyagol, Zeyaur R. Khan

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Soil degradation is a major underlying cause of poverty and malnutrition in smallholder agrarian communities across the globe. Legume diversification, through polyculture or intercropping, is a strategy that increases yields and income while improving family nutrition. However, the potential for these legume-cereal intercrops to restore soil functions in smallholder fields remains uncertain, with many studies failing to detect increases in soil organic matter (SOM). In sub-Saharan Africa, smallholders typically grow maize either intercropped with short-lived annual food legumes or as a monoculture. Recently, a novel maize system which includes perennial legumes in the genus Desmodium as intercrops, known as “push-pull” …

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Beyond Sperm And Male Accessory Gland Proteins: Exploring Insect Reproductive Metabolomes, Francesca Scolari, Fathiya M. Khamis, Diana Pérez-Staples Oct 2021

Beyond Sperm And Male Accessory Gland Proteins: Exploring Insect Reproductive Metabolomes, Francesca Scolari, Fathiya M. Khamis, Diana Pérez-Staples

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Insect seminal fluid, the non-sperm component of the ejaculate, comprises a variegated set of molecules, including, but not limited to, lipids, proteins, carbohydrates, salts, hormones, nucleic acids, and vitamins. The identity and functional role of seminal fluid proteins (SFPs) have been widely investigated, in multiple species. However, most of the other small molecules in insect ejaculates remain uncharacterized. Metabolomics is currently adopted to deepen our understanding of complex biological processes and in the last 15years has been applied to answer different physiological questions. Technological advances in high-throughput methods for metabolite identification such as mass spectrometry and nuclear magnetic resonance (NMR) …

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Integration Of Invasive Tree, Black Locust, Into Agro-Ecological Flower Visitor Networks Induces Competition For Pollination Services, Gerald Chikowore, Sandy Lynn Steenhuisen, Reyard Mutamiswa, Grant D. Martin, Frank Chidawanyika Oct 2021

Integration Of Invasive Tree, Black Locust, Into Agro-Ecological Flower Visitor Networks Induces Competition For Pollination Services, Gerald Chikowore, Sandy Lynn Steenhuisen, Reyard Mutamiswa, Grant D. Martin, Frank Chidawanyika

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Invasion of ecosystems by alien species is a global concern. Robinia pseudoacacia L. (Fabaceae) is one such species which impacts on native diversity and ecosystem functioning. We assessed how R. pseudoacacia affects flower visitation by arthropods in commercial apple orchards in eastern Free State, South Africa. We used paired observations to compare the abundance and diversity of flower visitors and their interactions with the two plant species. Our results showed that R. pseudoacacia flowers attract African honey bees (Apis mellifera) more than apple flowers. However, flower visitation by Diptera, particularly March flies (Bibionidae) was higher in apple flowers. Arthropods of …

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Neurotoxic Zanthoxylum Chalybeum Root Constituents Invoke Mosquito Larval Growth Retardation Through Ecdysteroidogenic Cyp450s Transcriptional Perturbations, Jackson M. Muema, Joel L. Bargul, James M. Mutunga, Meshack A. Obonyo, George O. Asudi, Sospeter N. Njeru Oct 2021

Neurotoxic Zanthoxylum Chalybeum Root Constituents Invoke Mosquito Larval Growth Retardation Through Ecdysteroidogenic Cyp450s Transcriptional Perturbations, Jackson M. Muema, Joel L. Bargul, James M. Mutunga, Meshack A. Obonyo, George O. Asudi, Sospeter N. Njeru

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Intracellular effects exerted by phytochemicals eliciting insect growth-retarding responses during vector control intervention remain largely underexplored. We studied the effects of Zanthoxylum chalybeum Engl. (Rutaceae) (ZCE) root derivatives against malaria (Anopheles gambiae) and arbovirus vector (Aedes aegypti) larvae to decipher possible molecular targets. We report dose-dependent biphasic effects on larval response, with transient exposure to ZCE and its bioactive fraction (ZCFr.5) inhibiting acetylcholinesterase (AChE) activity, inducing larval lethality and growth retardation at sublethal doses. Half-maximal lethal concentrations (LC50) for ZCE against An. gambiae and Ae. aegypti larvae after 24-h exposure were 9.00 ppm and 12.26 ppm, respectively. The active fraction …

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Odor Composition Of Field Versus Laboratory Desert Locust Populations, Baldwyn Torto, Hillary Kirwa, Ruth Kihika, Saliou Niassy Oct 2021

Odor Composition Of Field Versus Laboratory Desert Locust Populations, Baldwyn Torto, Hillary Kirwa, Ruth Kihika, Saliou Niassy

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Olfaction plays an important role in the behavioural ecology of the desert locust Schistocerca gregaria (Orthoptera:Acrididae). Different locust life stages and sexes use olfactory cues for different behaviours such as grouping, mating, oviposition, feeding, maturation and gregarization, which can be exploited for management of the desert locust. However, the full spectrum of the chemistry of volatiles released by the desert locust remains unknown. Here, we compared the volatile emissions of different life stages of a natural wild population reared in the laboratory for one generation with those of a population that has been reared in the laboratory for seven generations. …

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Effect Of Moisture Stress On The Development Of False Codling Moth Thaumatotibia Leucotreta (Lepidoptera: Tortricidae) On Two Tomato Varieties, Esther Museo Patrick, Irene Koomen, Shepard Ndlela, John Mwibanda Wesonga Oct 2021

Effect Of Moisture Stress On The Development Of False Codling Moth Thaumatotibia Leucotreta (Lepidoptera: Tortricidae) On Two Tomato Varieties, Esther Museo Patrick, Irene Koomen, Shepard Ndlela, John Mwibanda Wesonga

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False codling moth Thaumatotibia leucotreta (Meyrick) is a pest native to sub-Saharan Africa infesting over 100 plant species including tomato. Its survival and performance are influenced by changes in precipitation and stress-related biochemical changes in the host plant. Water availability for agricultural production continues to decline due to climate change affecting drought-sensitive crops like tomatoes. Little is known on host plant–insect interactions of T. leucotreta and tomato as influenced by moisture stress. Hence, our study tested the impact of different water holding capacities (WHC) (40%, 50%, 60%, 70%, and 90%) of plant growing media on the growth of Anna F1 …

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Long-Term Maize-Desmodium Intercropping Shifts Structure And Composition Of Soil Microbiome With Stronger Impact On Fungal Communities, Aneth David Mwakilili, Kilaza Samson Mwaikono, Sebastian Larsson Herrera, Charles A.O. Midega, Francis Magingo, Beatrix Alsanius, Teun Dekker, Sylvester Leonard Lyantagaye Oct 2021

Long-Term Maize-Desmodium Intercropping Shifts Structure And Composition Of Soil Microbiome With Stronger Impact On Fungal Communities, Aneth David Mwakilili, Kilaza Samson Mwaikono, Sebastian Larsson Herrera, Charles A.O. Midega, Francis Magingo, Beatrix Alsanius, Teun Dekker, Sylvester Leonard Lyantagaye

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Purpose: Push–pull is an intercropping technology that is rapidly spreading among smallholder farmers in Sub-Saharan Africa. The technology intercrops cereals with Desmodium to fight off stem borers, eliminate parasitic weeds, and improve soil fertility and yields of cereals. The above-ground components of push–pull cropping have been well investigated. However, the impact of the technology on the soil microbiome and the subsequent role of the microbiome on diverse ecosystem benefits are unknown. Here we describe the soil microbiome associated with maize—Desmodium intercropping in push–pull farming in comparison to long-term maize monoculture. Methods: Soil samples were collected from long-term maize—Desmodium intercropping and …

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Functional Land Cover Scale For Three Insect Pests With Contrasting Dispersal Strategies In A Fragmented Coffee-Based Landscape In Central Kenya, Gladys Mosomtai, Abdelmutalab G.A. Azrag, Régis Babin, Elfatih M. Abdel-Rahman, John Odindi, Onisimo Mutanga, Henri E.Z. Tonnang, Tobias Landmann, Guillaume David Oct 2021

Functional Land Cover Scale For Three Insect Pests With Contrasting Dispersal Strategies In A Fragmented Coffee-Based Landscape In Central Kenya, Gladys Mosomtai, Abdelmutalab G.A. Azrag, Régis Babin, Elfatih M. Abdel-Rahman, John Odindi, Onisimo Mutanga, Henri E.Z. Tonnang, Tobias Landmann, Guillaume David

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In the Eastern Africa highlands, the gradual transformation of natural ecosystems to smallholding coffee-based agrosystems has resulted in more fragmented landscapes. Major pests of coffee find appropriate living conditions leading to high infestation rates and the need for smallholder farmers to implement pest control measures. This study aims to understand the influence of landscapes on the ecology of three major coffee pests: the coffee berry borer (CBB), Hypothenemus hampei, and the Antestia bugs Antestiopsis thunbergii (ABT) and A. facetoides (ABF). The study was conducted on a typical smallholder coffee-based landscape in central Kenya. The pest abundance was assessed monthly for …

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Mitochondrial Genomes Reveal Diverse Lineages Of Diaphorina Citri Kuwayama (Hemiptera: Sternorrhyncha: Psyllidae) In Kenya And La Réunion, Yanjing Wang, Susan Halbert, Samira Mohamed, Hélène Delatte, Bernard Reynaud, George A.C. Beattie, Paul Holford, Jinming Lu, Yijing Cen Oct 2021

Mitochondrial Genomes Reveal Diverse Lineages Of Diaphorina Citri Kuwayama (Hemiptera: Sternorrhyncha: Psyllidae) In Kenya And La Réunion, Yanjing Wang, Susan Halbert, Samira Mohamed, Hélène Delatte, Bernard Reynaud, George A.C. Beattie, Paul Holford, Jinming Lu, Yijing Cen

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The Asian citrus psyllid, Diaphorina citri, is a major threat to citrus production worldwide, as it transmits ‘Candidatus Liberibacter asiaticus’, the pathogen associated with the devastating Asian form of huanglongbing. The psyllid has spread widely from its native South Asia during the past 300 years, most recently to Africa. We report the first population genomic analyses of D. citri in Kenya and La Réunion based on next-generation sequencing of their mitochondrial genomes. We analyzed mitochondrial sequences of 264 D. citri individuals to establish genetic relationships among accessions from D. citri populations from Asia, North America and Africa. Haplotype network analysis …

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