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Articles 661 - 690 of 1129

Full-Text Articles in Entomology

Effects Of Endophyte Colonization Of Vicia Faba (Fabaceae) Plants On The Life-History Of Leafminer Parasitoids Phaedrotoma Scabriventris (Hymenoptera: Braconidae) And Diglyphus Isaea (Hymenoptera: Eulophidae), Komivi S. Akutse, Komi K.M. Fiaboe, Johnnie Van Den Berg, Sunday Ekesi, Nguya K. Maniania Oct 2014

Effects Of Endophyte Colonization Of Vicia Faba (Fabaceae) Plants On The Life-History Of Leafminer Parasitoids Phaedrotoma Scabriventris (Hymenoptera: Braconidae) And Diglyphus Isaea (Hymenoptera: Eulophidae), Komivi S. Akutse, Komi K.M. Fiaboe, Johnnie Van Den Berg, Sunday Ekesi, Nguya K. Maniania

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Effects of the fungal endophytes Beauveria bassiana (isolates ICIPE 279, G1LU3, S4SU1) and Hypocrea lixii (isolate F3ST1) on the life-history of Phaedrotoma scabriventris and Diglyphus isaea, parasitoids of the pea leafminer Liriomyza huidobrensis, were studied in the laboratory. Parasitoids were allowed to parasitize 2nd and 3rd instar L. huidobrensis larvae reared on endophytically-inoculated faba bean, Vicia faba . In the control, parasitoids were reared on non-inoculated host plants. Parasitism, pupation, adult emergence and survival were recorded. No significant difference was observed between the bcontrol and the endophyte-inoculated plants in terms of parasitism rates of P. scabriventris (p = 0.68) and …

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Stability, Bifurcation And Chaos Analysis Of Vector-Borne Disease Model With Application To Rift Valley Fever, Sansao A. Pedro, Shirley Abelman, Frank T. Ndjomatchoua, Rosemary Sang, Henri E.Z. Tonnang Oct 2014

Stability, Bifurcation And Chaos Analysis Of Vector-Borne Disease Model With Application To Rift Valley Fever, Sansao A. Pedro, Shirley Abelman, Frank T. Ndjomatchoua, Rosemary Sang, Henri E.Z. Tonnang

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This paper investigates a RVF epidemic model by qualitative analysis and numerical simulations. Qualitative analysis have been used to explore the stability dynamics of the equilibrium points while visualization techniques such as bifurcation diagrams, Poincaré maps, maxima return maps and largest Lyapunov exponents are numerically computed to confirm further complexity of these dynamics induced by the seasonal forcing on the mosquitoes oviposition rates. The obtained results show that ordinary differential equation models with external forcing can have rich dynamic behaviour, ranging from bifurcation to strange attractors which may explain the observed fluctuations found in RVF empiric outbreak data, as well …

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Microclimate Modification And Insect Pest Exclusion Using Agronet Improve Pod Yield And Quality Of French Bean, Elisha Otieno Gogo, Mwanarusi Saidi, Jacob Mugwa Ochieng, Thibaud Martin, Vance Baird, Mathieu Ngouajio Oct 2014

Microclimate Modification And Insect Pest Exclusion Using Agronet Improve Pod Yield And Quality Of French Bean, Elisha Otieno Gogo, Mwanarusi Saidi, Jacob Mugwa Ochieng, Thibaud Martin, Vance Baird, Mathieu Ngouajio

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French bean [Phaseolus vulgaris (L.)] is among the leading export vegetable in Africa, mostly produced by small-scale farmers. Unfavorable environmental conditions and heavy infestations by insect pests are among the major constraints limiting production of the crop. Most French bean producers grow their crop in open fields outdoors subject to harsh environmental conditions and repeatedly spray insecticides in a bid to realize high yield. This has led to rejection of some of the produce at the export market as a result of stringent limits on maximum residue levels. Two trials were conducted at the Horticulture Research and Teaching Field, Egerton …

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Colonization Of Onions By Endophytic Fungi And Their Impacts On The Biology Of Thrips Tabaci, Alexander M. Muvea, Rainer Meyhöfer, Sevgan Subramanian, Hans Michael Poehling, Sunday Ekesi, Nguya K. Maniania Sep 2014

Colonization Of Onions By Endophytic Fungi And Their Impacts On The Biology Of Thrips Tabaci, Alexander M. Muvea, Rainer Meyhöfer, Sevgan Subramanian, Hans Michael Poehling, Sunday Ekesi, Nguya K. Maniania

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Endophytic fungi, which live within host plant tissues without causing any visible symptom of infection, are important mutualists that mediate plant-herbivore interactions. Thrips tabaci (Lindeman) is one of the key pests of onion, Allium cepa L., an economically important agricultural crop cultivated worldwide. However, information on endophyte colonization of onions, and their impacts on the biology of thrips feeding on them, is lacking. We tested the colonization of onion plants by selected fungal endophyte isolates using two inoculation methods. The effects of inoculated endophytes on T. tabaci infesting onion were also examined. Seven fungal endophytes used in our study were …

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Predicting The Impact Of Climate Change On Regional And Seasonal Abundance Of The Mealybug Phenacoccus Solenopsis Tinsley (Hemiptera: Pseudococcidae) Using Temperature-Driven Phenology Model Linked To Gis, Babasaheb B. Fand, Henri E.Z. Tonnang, Mahesh Kumar, Santanu K. Bal, Naveen P. Singh, D. V.K.N. Rao, Ankush L. Kamble, Dhananjay D. Nangare, Paramjit S. Minhas Sep 2014

Predicting The Impact Of Climate Change On Regional And Seasonal Abundance Of The Mealybug Phenacoccus Solenopsis Tinsley (Hemiptera: Pseudococcidae) Using Temperature-Driven Phenology Model Linked To Gis, Babasaheb B. Fand, Henri E.Z. Tonnang, Mahesh Kumar, Santanu K. Bal, Naveen P. Singh, D. V.K.N. Rao, Ankush L. Kamble, Dhananjay D. Nangare, Paramjit S. Minhas

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The mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is a highly invasive and polyphagous pest of global incidence. The fundamental hypothesis of the present study was that the temperature variations due to global climate change may affect seriously the future distribution and abundance of P. solenopsis, which might further aggravate the crop yield losses. We employed a temperature-based phenology model of P. solenopsis in a geographic information system for mapping population growth potentials of P. solenopsis. The three risk indices viz., establishment risk index, generation index and activity index were computed using interpolated temperature data from worldclim database for current (2000) …

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Field Evaluation Of Natural Human Odours And The Biogent-Synthetic Lure In Trapping Aedes Aegypti, Vector Of Dengue And Chikungunya Viruses In Kenya, Eunice A. Owino, Rosemary Sang, Catherine L. Sole, Christian Pirk, Charles Mbogo, Baldwyn Torto Sep 2014

Field Evaluation Of Natural Human Odours And The Biogent-Synthetic Lure In Trapping Aedes Aegypti, Vector Of Dengue And Chikungunya Viruses In Kenya, Eunice A. Owino, Rosemary Sang, Catherine L. Sole, Christian Pirk, Charles Mbogo, Baldwyn Torto

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Background: Methods currently used in sampling adult Aedes aegypti, the main vector of dengue and chikungunya viruses are limited for effective surveillance of the vector and accurate determination of the extent of virus transmission during outbreaks and inter - epidemic periods. Here, we document the use of natural human skin odours in baited traps to improve sampling of adult Ae. aegypti in two different endemic areas of chikungunya and dengue in Kenya - Kilifi and Busia Counties. The chemistry of the volatiles released from human odours and the Biogent (BG)-commercial lure were also compared.

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Vector Competence Of Aedes Aegypti Populations From Kilifi And Nairobi For Dengue 2 Virus And The Influence Of Temperature, Edith Chepkorir, Joel Lutomiah, James Mutisya, Francis Mulwa, Konongoi Limbaso, Benedict Orindi, Zipporah Ng'ang'a, Rosemary Sang Sep 2014

Vector Competence Of Aedes Aegypti Populations From Kilifi And Nairobi For Dengue 2 Virus And The Influence Of Temperature, Edith Chepkorir, Joel Lutomiah, James Mutisya, Francis Mulwa, Konongoi Limbaso, Benedict Orindi, Zipporah Ng'ang'a, Rosemary Sang

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Background: Susceptibility of Ae. aegypti mosquito to dengue virus (DENV) varies geographically and can be influenced by climatic factors such as temperature, which affect the incidence, seasonality and distribution of vector-borne diseases. The first outbreak of dengue fever (DF) in Kenya occured in 1982 in the coastal towns of Malindi and Kilifi. Unlike Nairobi where no active dengue transmission has been reported, DF is currently re-emerging at the Coast causing major outbreaks. This study investigated the vector competence of Ae. aegypti populations from two urban areas, Kilifi (Coast of Kenya) and Nairobi (Central Kenya), for DEN-2 virus and the influence …

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Push-Pull: A Novel Ipm Strategy For The Green Revolution In Africa, Zeyaur R. Khan, Charles A.O. Midega, Jimmy O. Pittchar, John A. Pickett Aug 2014

Push-Pull: A Novel Ipm Strategy For The Green Revolution In Africa, Zeyaur R. Khan, Charles A.O. Midega, Jimmy O. Pittchar, John A. Pickett

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Africa faces serious challenges in feeding its population, mainly due to poor yields of cereals that serve as both staple and cash crops occasioned by insect pests, weeds, and poor soil fertility, and more recently effects of climate change. A novel IPM approach dubbed push-pull has been developed and implemented in eastern Africa, based on locally available companion plants, that effectively addresses these constraints resulting in substantial grain yield increases. The technology involves intercropping cereal crops with stemborer moth repellent crops (push), the forage legume desmodium or molasses grass, and planting the attractive Napier grass (pull) as a border crop. …

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Similar Differentiation Patterns Between Pbp Expression Levels And Pheromone Component Ratios In Two Populations Of Sesamia Nonagrioides, Nicolas Glaser, Brigitte Frérot, Ene Leppik, Christelle Monsempes, Claire Capdevielle-Dulac, Bruno Le Ru, Thomas Lecocq, Myriam Harry, Emmanuelle Jacquin-Joly, Paul Andre Calatayud Aug 2014

Similar Differentiation Patterns Between Pbp Expression Levels And Pheromone Component Ratios In Two Populations Of Sesamia Nonagrioides, Nicolas Glaser, Brigitte Frérot, Ene Leppik, Christelle Monsempes, Claire Capdevielle-Dulac, Bruno Le Ru, Thomas Lecocq, Myriam Harry, Emmanuelle Jacquin-Joly, Paul Andre Calatayud

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Pheromone-binding proteins (PBPs) are thought to contribute to the specificity of the pheromone detection system through an initial selective binding with pheromone molecules. Here, we report different expression levels of PBP transcripts in the antennae of two populations of the stemborer Sesamia nonagrioides (Lepidoptera: Noctuidae), one collected in Europe and one in sub-Saharan Africa. The three PBP transcripts previously identified in this species were found to be expressed in both male and female antennae. Whereas PBP3 did not show any differential expression, PBP1 and PBP2 appeared to be expressed differently according to the population origin and sex. Simultaneously, we measured …

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Development And Optimization Of The Suna Trap As A Tool For Mosquito Monitoring And Control, Alexandra Hiscox, Bruno Otieno, Anthony Kibet, Collins K. Mweresa, Philemon Omusula, Martin Geier, Andreas Rose, Wolfgang R. Mukabana, Willem Takken Jul 2014

Development And Optimization Of The Suna Trap As A Tool For Mosquito Monitoring And Control, Alexandra Hiscox, Bruno Otieno, Anthony Kibet, Collins K. Mweresa, Philemon Omusula, Martin Geier, Andreas Rose, Wolfgang R. Mukabana, Willem Takken

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Background: Monitoring of malaria vector populations provides information about disease transmission risk, as well as measures of the effectiveness of vector control. The Suna trap is introduced and evaluated with regard to its potential as a new, standardized, odour-baited tool for mosquito monitoring and control. Methods. Dual-choice experiments with female Anopheles gambiae sensu lato in a laboratory room and semi-field enclosure, were used to compare catch rates of odour-baited Suna traps and MM-X traps. The relative performance of the Suna trap, CDC light trap and MM-X trap as monitoring tools was assessed inside a human-occupied experimental hut in a semi-field …

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Pyriproxyfen For Mosquito Control: Female Sterilization Or Horizontal Transfer To Oviposition Substrates By Anopheles Gambiae Sensu Stricto And Culex Quinquefasciatus, Oscar Mbare, Steven W. Lindsay, Ulrike Fillinger Jun 2014

Pyriproxyfen For Mosquito Control: Female Sterilization Or Horizontal Transfer To Oviposition Substrates By Anopheles Gambiae Sensu Stricto And Culex Quinquefasciatus, Oscar Mbare, Steven W. Lindsay, Ulrike Fillinger

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Background: The use of gravid mosquitoes as vehicles to auto-disseminate larvicides was recently demonstrated for the transfer of pyriproxyfen (PPF) by container-breeding Aedes mosquitoes and presents an appealing idea to explore for other disease vectors. The success of this approach depends on the female's behaviour, the time of exposure and the amount of PPF that can be carried by an individual. We explore the effect of PPF exposure at seven time points around blood feeding on individual Anopheles gambiae sensu stricto and Culex quinquefasciatus fecundity and ability to transfer in laboratory assays. Method. Mosquitoes were exposed to 2.6 mg PPF …

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Evaluation Of The Influence Of Electric Nets On The Behaviour Of Oviposition Site Seeking Anopheles Gambiae S.S, Sisay Dugassa, Jenny M. Lindh, Steve J. Torr, Steven W. Lindsay, Ulrike Fillinger Jun 2014

Evaluation Of The Influence Of Electric Nets On The Behaviour Of Oviposition Site Seeking Anopheles Gambiae S.S, Sisay Dugassa, Jenny M. Lindh, Steve J. Torr, Steven W. Lindsay, Ulrike Fillinger

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Background: Electric nets (e-nets) are used to analyse the flight behaviour of insects and have been used extensively to study the host-oriented flight of tsetse flies. Recently we adapted this tool to analyse the oviposition behaviour of gravid malaria vectors, Anopheles gambiae s.s., orienting towards aquatic habitats and traps by surrounding an artificial pond with e-nets and collecting electrocuted mosquitoes on sticky boards on the ground next to the nets. Here we study whether e-nets themselves affect the responses of gravid An. gambiae s.s. Methods. Dual-choice experiments were carried out in 80 m2 screened semi-field systems where 200 gravid An. …

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Exploiting Phytochemicals For Developing Sustainable Crop Protection Strategies To Withstand Climate Change: Example From Africa, Zeyaur R. Khan, Charles A.O. Midega, Jimmy O. Pittchar, John A. Pickett Jun 2014

Exploiting Phytochemicals For Developing Sustainable Crop Protection Strategies To Withstand Climate Change: Example From Africa, Zeyaur R. Khan, Charles A.O. Midega, Jimmy O. Pittchar, John A. Pickett

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Africa suffers chronic food insecurity resulting from ravaging effects of insect pests, weeds and poor soil fertility, with rising poverty and increasingly dry and hot weather conditions associated with climate change further aggravating this situation. Scientists at the International Centre of Insect Physiology and Ecology (icipe) together with national and international partners have developed a platform technology, 'push-pull', based on locally available companion plants for integrated management of these constraints by exploiting innate plant defence systems including secondary metabolism. This involves intercropping cereal crops, the main staple and cash crops for millions of smallholder farmers in the continent, with forage …

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Folding Wings Like A Cockroach: A Review Of Transverse Wing Folding Ensign Wasps (Hymenoptera: Evaniidae: Afrevania And Trissevania), István Mikó, Robert S. Copeland, James P. Balhoff, Matthew J. Yoder, Andrew R. Deans May 2014

Folding Wings Like A Cockroach: A Review Of Transverse Wing Folding Ensign Wasps (Hymenoptera: Evaniidae: Afrevania And Trissevania), István Mikó, Robert S. Copeland, James P. Balhoff, Matthew J. Yoder, Andrew R. Deans

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We revise two relatively rare ensign wasp genera, whose species are restricted to Sub-Saharan Africa: Afrevania and Trissevania. Afrevania longipetiolata sp. nov., Trissevania heatherae sp. nov., T. hugoi sp. nov., T. mrimaensis sp. nov. and T. slideri sp. nov. are described, males and females of T. anemotis and Afrevania leroyi are redescribed, and an identification key for Trissevaniini is provided. We argue that Trissevania mrimaensis sp. nov. and T. heatherae sp. nov. populations are vulnerable, given their limited distributions and threats from mining activities in Kenya. We hypothesize that these taxa together comprise a monophyletic lineage, Trissevaniini, tr. nov., the …

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Evaluation Of The Distribution And Impacts Of Parasites, Pathogens, And Pesticides On Honey Bee (Apis Mellifera) Populations In East Africa, Elliud Muli, Harland Patch, Maryann Frazier, James Frazier, Baldwyn Torto, Tracey Baumgarten, Joseph Kilonzo, James Ng Ang A. Kimani, Fiona Mumoki, Daniel Masiga, James Tumlinson, Christina Grozinger Apr 2014

Evaluation Of The Distribution And Impacts Of Parasites, Pathogens, And Pesticides On Honey Bee (Apis Mellifera) Populations In East Africa, Elliud Muli, Harland Patch, Maryann Frazier, James Frazier, Baldwyn Torto, Tracey Baumgarten, Joseph Kilonzo, James Ng Ang A. Kimani, Fiona Mumoki, Daniel Masiga, James Tumlinson, Christina Grozinger

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In East Africa, honey bees (Apis mellifera) provide critical pollination services and income for small-holder farmers and rural families. While honey bee populations in North America and Europe are in decline, little is known about the status of honey bee populations in Africa. We initiated a nationwide survey encompassing 24 locations across Kenya in 2010 to evaluate the numbers and sizes of honey bee colonies, assess the presence of parasites (Varroa mites and Nosema microsporidia) and viruses, identify and quantify pesticide contaminants in hives, and assay for levels of hygienic behavior. Varroa mites were present throughout Kenya, except in the …

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Effects Of Landscape Complexity And Habitat Management On Stemborer Colonization, Parasitism And Damage To Maize, Charles A.O. Midega, Mattias Jonsson, Zeyaur R. Khan, Barbara Ekbom Apr 2014

Effects Of Landscape Complexity And Habitat Management On Stemborer Colonization, Parasitism And Damage To Maize, Charles A.O. Midega, Mattias Jonsson, Zeyaur R. Khan, Barbara Ekbom

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Lepidopteran stemborers are a serious constraint to efficient production of maize in sub-Saharan Africa. One of the most effective ways of managing these pests is through a habitat management system called push-pull. Landscape complexity has been shown to enhance biological control of insect pests, and therefore may influence effectiveness of habitat management systems designed to control pests. We studied the relative importance of the push-pull cropping system as a local effect and proportional cover of grassland as a landscape effect on (i) stemborer population density and damage to maize, and (ii) parasitism and mortality of stemborer life stages in western …

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Human African Trypanosomiasis Research Gets A Boost: Unraveling The Tsetse Genome, Serap Aksoy, Geoffrey Attardo, Matt Berriman, Alan Christoffels, Mike Lehane, Dan Masiga, Yeya Toure Apr 2014

Human African Trypanosomiasis Research Gets A Boost: Unraveling The Tsetse Genome, Serap Aksoy, Geoffrey Attardo, Matt Berriman, Alan Christoffels, Mike Lehane, Dan Masiga, Yeya Toure

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Human African trypanosomiasis (HAT), also known as sleeping sickness, is a neglected disease that impacts 70 million people distributed over 1.55 million km2 in sub-Saharan Africa [1]. Trypanosoma brucei gambiense accounts for almost 90% of the infections in central and western Africa, the remaining infections being from T. b. rhodesiense in eastern Africa [1]. Furthermore, the animal diseases caused by related parasites inflict major economic losses to countries already strained [2]. The parasites are transmitted to the mammalian hosts through the bite of an infected tsetse fly.

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Comparison Of Food-Based Attractants For Bactrocera Invadens (Diptera: Tephritidae) And Evaluation Of Mazoferm - Spinosad Bait Spray For Field Suppression In Mango, Sunday Ekesi, Samira Mohamed, Chrysantus M. Tanga Feb 2014

Comparison Of Food-Based Attractants For Bactrocera Invadens (Diptera: Tephritidae) And Evaluation Of Mazoferm - Spinosad Bait Spray For Field Suppression In Mango, Sunday Ekesi, Samira Mohamed, Chrysantus M. Tanga

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Catches of Bactrocera invadens Drew, Tsuruta, & White (Diptera: Tephritidae) in Multi-lure traps baited with six commercial food-based attractants, Mazoferm E802, Torula yeast, GF-120, Hymlure, Biolure, and Nulure were compared in mango orchards in Kenya. In 2007, Mazoferm E802 and Torula yeast were the most effective attractants and captured 2.4-2.6 times more females and 3.4-4.0 times more males than the standard Nulure. All attractants captured more females than males (ranging from 63 to 74%). In 2008, Mazoferm E802 was the most effective bait capturing 5.6 and 9.1 times more females and males, respectively, than the standard Nulure. Among all the …

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Plasmodium Falciparum Infection Increases Anopheles Gambiae Attraction To Nectar Sources And Sugar Uptake, Vincent O. Nyasembe, Peter E.A. Teal, Patrick Sawa, James H. Tumlinson, Christian Borgemeister, Baldwyn Torto Jan 2014

Plasmodium Falciparum Infection Increases Anopheles Gambiae Attraction To Nectar Sources And Sugar Uptake, Vincent O. Nyasembe, Peter E.A. Teal, Patrick Sawa, James H. Tumlinson, Christian Borgemeister, Baldwyn Torto

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Plasmodium parasites are known to manipulate the behavior of their vectors so as to enhance transmission [1-4]. From an evolutionary standpoint, behavior manipulation by the parasite should expose the vector to limited risk of early mortality while ensuring sufficient energy supply for both it and the vector [5, 6]. However, it is unknown whether this vector manipulation also affects vector-plant interaction and sugar uptake. Here, we show that the attraction of Anopheles gambiae s.s. to plant odors increased by 30% and 24% after infection with the oocyst and sporozoite stages of Plasmodium falciparum, respectively, while probing activity increased by 77% …

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Integrative Taxonomy Of Acrapex Stem Borers (Lepidoptera: Noctuidae: Apameini): Combining Morphology And Poisson Tree Process Analyses, Bruno P. Le Ru, Claire Capdevielle-Dulac, Emmanuel F.A. Toussaint, Desmond Conlong, Johnnie Van Den Berg, Beatrice Pallangyo, George Ong'amo, Gilson Chipabika, Richard Molo, William A. Overholt, James P. Cuda, Gael J. Kergoat Jan 2014

Integrative Taxonomy Of Acrapex Stem Borers (Lepidoptera: Noctuidae: Apameini): Combining Morphology And Poisson Tree Process Analyses, Bruno P. Le Ru, Claire Capdevielle-Dulac, Emmanuel F.A. Toussaint, Desmond Conlong, Johnnie Van Den Berg, Beatrice Pallangyo, George Ong'amo, Gilson Chipabika, Richard Molo, William A. Overholt, James P. Cuda, Gael J. Kergoat

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Ten morphologically similar species of Acrapex from eastern and south-eastern Africa belonging to the A. stygiata and A. albivena groups are reviewed. Six species are described as new: A. brunneella, A. mitiwa, A. mpika, A. salmona, A. sporobola and A. yakoba. The Poaceae host plants of eight species are recorded; four species, A. mitiwa. A. subalbissima, A. syscia and A. yakoba, were found developing exclusively on Imperata cylindrica (L.) Beauv., (Andropogoneae); two species, A. sporobola and A. salmona, on I. cylindrica and Sporobolus macranthelus Chiov. (Zoysieae); and A. albivena on I. cylindrica, Miscanthus capensis (Nees) Andersson (Andropogoneae) and Cymbopogon sp. …

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Molecular Markers Reveal Narrow Genetic Base And Culturing-Associated Genetic Drift In Teretrius Nigrescens Lewis Populations Released For The Biological Control Of The Larger Grain Borer In Africa, B. A. Omondi, J. Van Den Berg, D. Masiga, F. Schulthess Jan 2014

Molecular Markers Reveal Narrow Genetic Base And Culturing-Associated Genetic Drift In Teretrius Nigrescens Lewis Populations Released For The Biological Control Of The Larger Grain Borer In Africa, B. A. Omondi, J. Van Den Berg, D. Masiga, F. Schulthess

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In biological control, successful establishment of a natural enemy species depends on its adaptability in the introduced range including its ability to re-establish desired ecological interactions with the pest. These are affected by genetic parameters hitherto largely unresolved in biological control. The larger grain borer (LGB), Prostephanus truncatus, an invasive species from meso-America, is the most important post-harvest pest of maize in Africa. We studied the genetic structure of Teretrius nigrescens, a predatory beetle previously released for the control of the pest in Africa, to test the hypothesis that establishment patterns were a result of ecotype-environment mismatch and to follow …

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Odorant And Gustatory Receptors In The Tsetse Fly Glossina Morsitans Morsitans, George F.O. Obiero, Paul O. Mireji, Steven R.G. Nyanjom, Alan Christoffels, Hugh M. Robertson, Daniel K. Masiga Jan 2014

Odorant And Gustatory Receptors In The Tsetse Fly Glossina Morsitans Morsitans, George F.O. Obiero, Paul O. Mireji, Steven R.G. Nyanjom, Alan Christoffels, Hugh M. Robertson, Daniel K. Masiga

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Tsetse flies use olfactory and gustatory responses, through odorant and gustatory receptors (ORs and GRs), to interact with their environment. Glossina morsitans morsitans genome ORs and GRs were annotated using homologs of these genes in Drosophila melanogaster and an ab initio approach based on OR and GR specific motifs in G. m. morsitans gene models coupled to gene ontology (GO). Phylogenetic relationships among the ORs or GRs and the homologs were determined using Maximum Likelihood estimates. Relative expression levels among the G. m. morsitans ORs or GRs were established using RNA-seq data derived from adult female fly. Overall, 46 and …

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Volatile Phytochemicals As Mosquito Semiochemicals, Vincent O. Nyasembe, Baldwyn Torto Jan 2014

Volatile Phytochemicals As Mosquito Semiochemicals, Vincent O. Nyasembe, Baldwyn Torto

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Plant biochemical processes result in the release of an array of volatile chemical substances into the environment, some of which are known to play important plant fitness enhancing functions, such as attracting pollinators, thermal tolerance of photosynthesis, and defense against herbivores. Cunningly, phytophagous insects have evolved mechanisms to utilize these volatiles to their own advantage, either to colonize a suitable host for feeding, reproduction and oviposition or avoid an unsuitable one. The volatile compounds involved in plant-insect chemical interactions have been widely exploited in the management of agricultural pests. On the other hand, use of plant volatiles in the management …

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Aquaporins Are Critical For Provision Of Water During Lactation And Intrauterine Progeny Hydration To Maintain Tsetse Fly Reproductive Success, Joshua B. Benoit, Immo A. Hansen, Geoffrey M. Attardo, Veronika Michalková, Paul O. Mireji, Joel L. Bargul, Lisa L. Drake, Daniel K. Masiga, Serap Aksoy Jan 2014

Aquaporins Are Critical For Provision Of Water During Lactation And Intrauterine Progeny Hydration To Maintain Tsetse Fly Reproductive Success, Joshua B. Benoit, Immo A. Hansen, Geoffrey M. Attardo, Veronika Michalková, Paul O. Mireji, Joel L. Bargul, Lisa L. Drake, Daniel K. Masiga, Serap Aksoy

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Tsetse flies undergo drastic fluctuations in their water content throughout their adult life history due to events such as blood feeding, dehydration and lactation, an essential feature of the viviparous reproductive biology of tsetse. Aquaporins (AQPs) are transmembrane proteins that allow water and other solutes to permeate through cellular membranes. Here we identify tsetse aquaporin (AQP) genes, examine their expression patterns under different physiological conditions (blood feeding, lactation and stress response) and perform functional analysis of three specific genes utilizing RNA interference (RNAi) gene silencing. Ten putative aquaporins were identified in the Glossina morsitans morsitans (Gmm) genome, two more than …

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Laboratory Colonisation And Genetic Bottlenecks In The Tsetse Fly Glossina Pallidipes, Marc Ciosi, Daniel K. Masiga, Charles M.R. Turner Jan 2014

Laboratory Colonisation And Genetic Bottlenecks In The Tsetse Fly Glossina Pallidipes, Marc Ciosi, Daniel K. Masiga, Charles M.R. Turner

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Background:The IAEA colony is the only one available for mass rearing of Glossina pallidipes, a vector of human and animal African trypanosomiasis in eastern Africa. This colony is the source for Sterile Insect Technique (SIT) programs in East Africa. The source population of this colony is unclear and its genetic diversity has not previously been evaluated and compared to field populations.Methodology/Principal Findings:We examined the genetic variation within and between the IAEA colony and its potential source populations in north Zimbabwe and the Kenya/Uganda border at 9 microsatellites loci to retrace the demographic history of the IAEA colony. We performed classical …

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Whole Genome Phylogenetic Investigation Of A West Nile Virus Strain Isolated From A Tick Sampled From Livestock In North Eastern Kenya, Olivia Wesula Lwande, Marietjie Venter, Joel Lutomiah, George Michuki, Cecilia Rumberia, Francis Gakuya, Vincent Obanda, Caroline Tigoi, Collins Odhiambo, Fredrick Nindo, Samwel Symekher, Rosemary Sang Jan 2014

Whole Genome Phylogenetic Investigation Of A West Nile Virus Strain Isolated From A Tick Sampled From Livestock In North Eastern Kenya, Olivia Wesula Lwande, Marietjie Venter, Joel Lutomiah, George Michuki, Cecilia Rumberia, Francis Gakuya, Vincent Obanda, Caroline Tigoi, Collins Odhiambo, Fredrick Nindo, Samwel Symekher, Rosemary Sang

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Background: West Nile virus (WNV) has a wide geographical distribution and has been associated to cause neurological disease in humans and horses. Mosquitoes are the traditional vectors for WNV; however, the virus has also been isolated from tick species in North Africa and Europe which could be a means of introduction and spread of the virus over long distances through migratory birds. Although WNV has been isolated in mosquitoes in Kenya, paucity of genetic and pathogenicity data exists. We previously reported the isolation of WNV from ticks collected from livestock and wildlife in Ijara District of Kenya, a hotspot for …

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Storage Of Mung Bean (Vigna Radiata [L.] Wilczek) And Pigeonpea Grains (Cajanus Cajan [L.] Millsp) In Hermetic Triple-Layer Bags Stops Losses Caused By Callosobruchus Maculatus (F.) (Coleoptera: Bruchidae), C. M. Mutungi, H. Affognon, A. W. Njoroge, D. Baributsa, L. L. Murdock Jan 2014

Storage Of Mung Bean (Vigna Radiata [L.] Wilczek) And Pigeonpea Grains (Cajanus Cajan [L.] Millsp) In Hermetic Triple-Layer Bags Stops Losses Caused By Callosobruchus Maculatus (F.) (Coleoptera: Bruchidae), C. M. Mutungi, H. Affognon, A. W. Njoroge, D. Baributsa, L. L. Murdock

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Dry mung bean and pigeonpea grains that had sustained some insect damage but fumigated before the start of the experiment were stored in triple-layer hermetic bags (Purdue Improved Crop Storage (PICS™ bags) or woven polypropylene (PP) bags for 6 months. Some of the bags were artificially infested with cowpea bruchid Callosobruchus maculatus (F.) (PICS1, PP1) while others were not (PICS0, PP0). In an additional trial, PP bags containing the grains were treated with Actellic Super® dust before being artificially infested (PP1Ac). Moisture content, live adult C.maculatus count, grain damage, weight loss, and seed germination were determined on a monthly basis. …

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Triple Bag Hermetic Storage Delivers A Lethal Punch To Prostephanus Truncatus (Horn) (Coleoptera: Bostrichidae) In Stored Maize, A. W. Njoroge, H. D. Affognon, C. M. Mutungi, J. Manono, P. O. Lamuka, L. L. Murdock Jan 2014

Triple Bag Hermetic Storage Delivers A Lethal Punch To Prostephanus Truncatus (Horn) (Coleoptera: Bostrichidae) In Stored Maize, A. W. Njoroge, H. D. Affognon, C. M. Mutungi, J. Manono, P. O. Lamuka, L. L. Murdock

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Clean shelled maize was stored in woven polypropylene (PP) or triple layer polyethylene (PICS™) bags in the presence of Prostephanus truncatus Horn (PP1; PICS1) or absence of it (PP0; PICS0) at ambient conditions for six months. Moisture content, live insect population, grain damage, weight loss, and germination were analyzed on a monthly basis. Temperature and relative humidity in both PICS- and PP-bag setups were monitored, as well as the oxygen and carbon dioxide levels in the PICS bags. Overall, maize stored in PICS bags had significantly lower (P<0.05) moisture content than maize stored in PP bags. Storage in PICS bag slowed growth of P.truncatus populations and blocked infestation from the surrounding storage environment. On the contrary, PP bags permitted profuse build-up of insect population and cross-infestation. At six months, grain damage was 0.0%, 3.4%, 50.5% and 73.9%, corresponding to weight loss of 0.0%, 2.0%, 36.3%, and 47.7% in PICS0, PICS1, PP0 and PP1, respectively. Germination of maize stored in PP bags dropped from 91.1% to 37.0% and 12.7% in PP0 and PP1, respectively, whereas germination of maize stored in PICS bags dropped only marginally and reached 78.1% and 71.0% in PICS0 and PICS1, respectively, in six months. Without extreme loss of grain viability, a huge decrease in insect infestation, grain damage and weight loss is achieved by storing maize in PICS bag even under P.truncatus endemic conditions. © 2014 Elsevier Ltd.

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Chemosensory Receptors In Tsetse Flies Provide Link Between Chemical And Behavioural Ecology, Daniel Masiga, George Obiero, Rosaline Macharia, Paul Mireji, Alan Christoffels Jan 2014

Chemosensory Receptors In Tsetse Flies Provide Link Between Chemical And Behavioural Ecology, Daniel Masiga, George Obiero, Rosaline Macharia, Paul Mireji, Alan Christoffels

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Tsetse flies survive in a variety of environments across tropical Africa, often rising to large numbers, despite their low birth rate of one offspring every seven to nine days. They use olfactory receptors to process chemical signals in their environments to find food, escape from predators, and locate suitable larviposition sites. We discuss the identification of odorant and gustatory receptors in Glossina morsitans morsitans and the role genomics could play in management of nuisance insects. © 2014 Elsevier Ltd.

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Resistance To Iris Yellow Spot Virus And Onion Thrips Among Onion Varieties Grown In Kenya, R. K. Birithia, S. Subramanian, J. W. Muthomi, R. D. Narla Jan 2014

Resistance To Iris Yellow Spot Virus And Onion Thrips Among Onion Varieties Grown In Kenya, R. K. Birithia, S. Subramanian, J. W. Muthomi, R. D. Narla

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Iris yellow spot virus (IYSV) vectored by Thrips tabaci threatens profitable onion production in eastern Africa. Host plant resistance is considered to be the first line of defence against insect-transmitted virus diseases. Hence, information on resistance to IYSV and T. tabaci among common onion cultivars in Kenya is crucial for the development of integrated pest management strategies. This study evaluated the resistance to thrips and IYSV among widely grown onion cultivars in Kenya, viz. Red Pinoy, Red Creole, Bombay Red, Green Bunching and Texas Grano, over two growing seasons. Straw-coloured, diamond-shaped necrotic lesions typical of IYSV infection were observed 2 …

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