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Full-Text Articles in Life Sciences

Control Of Invasive Liriomyza Leafminer Species And Compliance With Food Safety Standards By Small Scale Snow Pea Farmers In Kenya, Zachary Maina Gitonga, Adenirin Chabi-Olaye, Dagmar Mithöfer, Julius Juma Okello, Cecilia Nyawira Ritho Dec 2010

Control Of Invasive Liriomyza Leafminer Species And Compliance With Food Safety Standards By Small Scale Snow Pea Farmers In Kenya, Zachary Maina Gitonga, Adenirin Chabi-Olaye, Dagmar Mithöfer, Julius Juma Okello, Cecilia Nyawira Ritho

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The Kenyan horticultural industry faces a new challenge following invasion by the quarantine Liriomyza leafminer species Liriomyza huidobrensis, Liriomyza sativae and Liriomyza trifolii which have recently become pests of economic importance. Controlling Liriomyza leafminers poses serious difficulties due to their biology and quarantine status. This paper examines farmers' awareness of the pests and difficulties faced in controlling them. (1) A questionnaire survey showed that snow pea farmers in Kenya rely mainly on pesticides for control of invasive Liriomyza leafminers; (2) Sixty five percent of respondents perceived pesticides to be ineffective; (3) As a result, 74% of respondents increased the frequency …

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Genome-Wide Patterns Of Gene Expression During Aging In The African Malaria Vector Anopheles Gambiae, Mei Hui Wang, Osvaldo Marinotti, Anthony A. James, Edward Walker, John Githure, Guiyun Yan Oct 2010

Genome-Wide Patterns Of Gene Expression During Aging In The African Malaria Vector Anopheles Gambiae, Mei Hui Wang, Osvaldo Marinotti, Anthony A. James, Edward Walker, John Githure, Guiyun Yan

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The primary means of reducing malaria transmission is through reduction in longevity in days of the adult female stage of the Anopheles vector. However, assessing chronological age is limited to crude physiologic methods which categorize the females binomially as either very young (nulliparous) or not very young (parous). Yet the epidemiologically relevant reduction in life span falls within the latter category. Age-grading methods that delineate chronological age, using accurate molecular surrogates based upon gene expression profiles, will allow quantification of the longevity-reducing effects of vector control tools aimed at the adult, female mosquito. In this study, microarray analyses of gene …

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Ovaries And Germline Cysts And Their Evolution In Dermaptera (Insecta), Wacław Tworzydło, Szczepan M. Biliński, Petr Kočárek, Fabian Haas Sep 2010

Ovaries And Germline Cysts And Their Evolution In Dermaptera (Insecta), Wacław Tworzydło, Szczepan M. Biliński, Petr Kočárek, Fabian Haas

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We studied the ovary structure and initial stages of oogenesis in 15 representatives of several dermapteran taxa, including the epizoic Arixeniina. In all examined species, the ovaries are meroistic-polytrophic. The ovaries of the basal taxa ('Pygidicranidae', 'Diplatyidae', and Labiduridae) are composed of elongated ovarioles, attached to short lateral oviducts. In these groups, ovarioles contain several (more than 30) ovarian follicles in a linear arrangement. In the Eudermaptera, the ovaries are composed of 1-6 (Spongiphoridae) or 20-40 (Forficulidae, Chelisochidae) short ovarioles (containing 2 ovarian follicles only) that open to strongly elongated lateral oviducts. In all investigated dermapterans, the ovarian follicles are …

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Arm-In-Cage Testing Of Natural Human-Derived Mosquito Repellents, James G. Logan, Nina M. Stanczyk, Ahmed Hassanali, Joshua Kemei, Antônio E.G. Santana, Karlos A.L. Ribeiro, John A. Pickett, A. Jennifer Mordue Aug 2010

Arm-In-Cage Testing Of Natural Human-Derived Mosquito Repellents, James G. Logan, Nina M. Stanczyk, Ahmed Hassanali, Joshua Kemei, Antônio E.G. Santana, Karlos A.L. Ribeiro, John A. Pickett, A. Jennifer Mordue

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Background. Individual human subjects are differentially attractive to mosquitoes and other biting insects. Previous investigations have demonstrated that this can be attributed partly to enhanced production of natural repellent chemicals by those individuals that attract few mosquitoes in the laboratory. The most important compounds in this respect include three aldehydes, octanal, nonanal and decanal, and two ketones, 6-methyl-5-hepten-2-one and geranylacetone [(E)-6,10-dimethylundeca-5,9-dien-2-one]. In olfactometer trials, these compounds interfered with attraction of mosquitoes to a host and consequently show promise as novel mosquito repellents. Methods. To test whether these chemicals could provide protection against mosquitoes, laboratory repellency trials were carried out to …

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Anopheles Larval Abundance And Diversity In Three Rice Agro-Village Complexes Mwea Irrigation Scheme, Central Kenya, Joseph M. Mwangangi, Josephat Shililu, Ephantus J. Muturi, Simon Muriu, Benjamin Jacob, Ephantus W. Kabiru, Charles M. Mbogo, John Githure, Robert J. Novak Aug 2010

Anopheles Larval Abundance And Diversity In Three Rice Agro-Village Complexes Mwea Irrigation Scheme, Central Kenya, Joseph M. Mwangangi, Josephat Shililu, Ephantus J. Muturi, Simon Muriu, Benjamin Jacob, Ephantus W. Kabiru, Charles M. Mbogo, John Githure, Robert J. Novak

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Background. The diversity and abundance of Anopheles larvae has significant influence on the resulting adult mosquito population and hence the dynamics of malaria transmission. Studies were conducted to examine larval habitat dynamics and ecological factors affecting survivorship of aquatic stages of malaria vectors in three agro-ecological settings in Mwea, Kenya. Methods. Three villages were selected based on rice husbandry and water management practices. Aquatic habitats in the 3 villages representing planned rice cultivation (Mbui Njeru), unplanned rice cultivation (Kiamachiri) and non-irrigated (Murinduko) agro-ecosystems were sampled every 2 weeks to generate stage-specific estimates of mosquito larval densities, relative abundance and diversity. …

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Landmarks In The Evolution Of Technologies For Identifying Trypanosomes In Tsetse Flies, John C. Enyaru, Johnson O. Ouma, Imna I. Malele, Enock Matovu, Daniel K. Masiga Aug 2010

Landmarks In The Evolution Of Technologies For Identifying Trypanosomes In Tsetse Flies, John C. Enyaru, Johnson O. Ouma, Imna I. Malele, Enock Matovu, Daniel K. Masiga

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Understanding what the trypanosome pathogens are, their vectors and mode of transmission underpin efforts to control the disease they cause in both humans and livestock. The risk of transmission is estimated by determining what proportion of the vector population is carrying the infectious pathogens. This risk also depends on the infectivity of the trypanosomes to humans and livestock. Most livestock pathogens are not infective to humans, whereas the two sub-species that infect humans also infect livestock. As with other infectious diseases, we can therefore trace the foundation of many continuing disease control programs for trypanosomiasis to the discovery of the …

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Geographic Distribution, Host Range And Perennation Of Cotesia Sesamiae And Cotesia Flavipes Cameron In Cultivated And Natural Habitats In Kenya, Duna Madu Mailafiya, Bruno Pierre Le Ru, Eunice Waitherero Kairu, Paul André Calatayud, Stéphane Dupas Jul 2010

Geographic Distribution, Host Range And Perennation Of Cotesia Sesamiae And Cotesia Flavipes Cameron In Cultivated And Natural Habitats In Kenya, Duna Madu Mailafiya, Bruno Pierre Le Ru, Eunice Waitherero Kairu, Paul André Calatayud, Stéphane Dupas

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Field surveys were carried out in four agroecological zones to assess the geographic distribution, host range and perennation of Cotesia sesamiae and Cotesia flavipes in cultivated and natural habitats in Kenya. The distribution of the two Cotesia species in different ecological regions was most affected by the suitability of the local stem borer species for parasitoid development, and temperature, as both species were found in localities dominated by their suitable host(s) where temperature favoured their occurrence. Fourteen years after its release, C. flavipes has maintained a high level of specificity to its target host Chilo partellus on maize and sorghum …

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Novel Cross-Stage Solitarising Effect Of Gregarious-Phase Adult Desert Locust (Schistocerca Gregaria (Forskål)) Pheromone On Hoppers, Magzoub O. Bashir, Ahmed Hassanali Jun 2010

Novel Cross-Stage Solitarising Effect Of Gregarious-Phase Adult Desert Locust (Schistocerca Gregaria (Forskål)) Pheromone On Hoppers, Magzoub O. Bashir, Ahmed Hassanali

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Previous studies had demonstrated stage differentiation in the cohesion (aggregation) pheromone systems of the desert locust, Schistocerca gregaria. In laboratory arena, the nymphal and adult stages responded aggregatively to their own pheromone, but dispersed evenly within the arena in the presence of the other. In the present study, we explored the effects of longer-term contact of field gregarious hopper bands and laboratory crowd-reared nymphs with the major constituent of the adult pheromone. During the first few days, hoppers in treated bands became relatively hyperactive. Over the next few days, their movements became random and they stopped marching as coherent groups, …

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Isoschaftoside, A C-Glycosylflavonoid From Desmodium Uncinatum Root Exudate, Is An Allelochemical Against The Development Of Striga, Antony M. Hooper, Muniru K. Tsanuo, Keith Chamberlain, Kay Tittcomb, Julie Scholes, Ahmed Hassanali, Zeyaur R. Khan, John A. Pickett Jun 2010

Isoschaftoside, A C-Glycosylflavonoid From Desmodium Uncinatum Root Exudate, Is An Allelochemical Against The Development Of Striga, Antony M. Hooper, Muniru K. Tsanuo, Keith Chamberlain, Kay Tittcomb, Julie Scholes, Ahmed Hassanali, Zeyaur R. Khan, John A. Pickett

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In East African small-holder farming of maize, the cattle forage legume, Desmodium uncinatum is used as an intercrop due to its allelopathic inhibition of parasitism by Striga hermonthica, an obligate parasitic weed that can devastate the maize crop. Bioassay-guided fractionation of the root extract of D. uncinatum revealed isoschaftoside to be the main compound in the most potent fraction inhibiting growth of germinated S. hermonthica radicles. Bioassays repeated with isoschaftoside isolated from a different plant source, Passiflora incarnata, proved it to be a biologically active component. Analysis of the root exudates produced by hydroponically grown D. uncinatum showed isoschaftoside to …

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Participatory Evaluation Of Integrated Pest And Soil Fertility Management Options Using Ordered Categorical Data Analysis, Hugo De Groote, Esther Rutto, George Odhiambo, Fred Kanampiu, Zeyaur Khan, Richard Coe, Bernard Vanlauwe Jun 2010

Participatory Evaluation Of Integrated Pest And Soil Fertility Management Options Using Ordered Categorical Data Analysis, Hugo De Groote, Esther Rutto, George Odhiambo, Fred Kanampiu, Zeyaur Khan, Richard Coe, Bernard Vanlauwe

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Maize is becoming the major food crop around Lake Victoria. Major constraints to its production are Striga, stem borer, and declining soil fertility. Innovative integrated technologies have been developed: the 'push-pull' system (intercropping with Desmodium and surrounded by Napier grass), soybean and Crotalaria rotations, and imidazolinone-resistant (IR) maize seed. In 12 demonstration trials in four villages in Siaya and Vihiga districts (Kenya) and two villages in Busia (Uganda) in 2003 and 2004, 504 farmers evaluated all cropping systems and a mono-cropped continuous maize, each cropped with IR or local maize, and supplemented or not with fertilizer, totaling 16 treatments. Farmers …

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Population Structure Of Anopheles Gambiae Along The Kenyan Coast, Janet T. Midega, Ephantus J. Muturi, Frederick N. Baliraine, Charles M. Mbogo, John Githure, John C. Beier, Guiyun Yan May 2010

Population Structure Of Anopheles Gambiae Along The Kenyan Coast, Janet T. Midega, Ephantus J. Muturi, Frederick N. Baliraine, Charles M. Mbogo, John Githure, John C. Beier, Guiyun Yan

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In the tropics, Anopheles mosquito abundance is greatest during the wet season and decline significantly during the dry season as larval habitats shrink. Population size fluctuations between wet and dry seasons may lead to variation in distribution of specific alleles within natural Anopheles populations, and a possible effect on the population genetic structure. We used 11 microsatellite markers to examine the effect of seasonality on population genetic structure of Anopheles gambiae s.s. at two sites along the Kenyan coast. All loci were highly polymorphic with the total number of alleles for pooled samples ranging from 7 (locus ND36) to 21 …

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Effect Of Seasons And Larval Food Plants On The Quality Of Gonometa Postica Cocoons, Ken O. Fening, Esther N. Kioko, Suresh K. Raina, Jones M. Mueke Apr 2010

Effect Of Seasons And Larval Food Plants On The Quality Of Gonometa Postica Cocoons, Ken O. Fening, Esther N. Kioko, Suresh K. Raina, Jones M. Mueke

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The effect of food plants [Acacia elatior Brenan, A. tortilis (Forssk.) and A. nilotica (L.) Del.] on the development time of Gonometa postica Walker (Lepidoptera: Lasiocampidae) larvae and the quality of their cocoons was studied in the Imba and Mumoni forests of Mwingi, Eastern Kenya, during the long (March-May) and short (October-December) rainy seasons of 2006 and 2007. Larvae were reared in semi-captivity in net sleeves attached to branches of the plants. The period between hatching of eggs and spinning of cocoons, as well as their weight, as determinants of cocoon quality were recorded. In addition, collections of cocoons from …

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Effect Of African Nightshade Species (Solanaceae) On Developmental Time And Life Table Parameters Of Tetranychus Evansi (Acari: Tetranychidae), Lucy Kananu Murungi, Aggrey Nyende, John Wesonga, Peter Masinde, Markus Knapp Mar 2010

Effect Of African Nightshade Species (Solanaceae) On Developmental Time And Life Table Parameters Of Tetranychus Evansi (Acari: Tetranychidae), Lucy Kananu Murungi, Aggrey Nyende, John Wesonga, Peter Masinde, Markus Knapp

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The effect of five African nightshade (Solanum sp.) species on the biological and demographic parameters of the tomato spider mite, Tetranychus evansi Baker and Pritchard, was examined in the laboratory at 25 ± 1°C, 70-80% RH and 12L:12D photoperiod. Duration of each development stage, reproduction rate, longevity, intrinsic rate of natural increase (rm), and doubling time (DT) of the tomato spider mite on the five nightshade species were calculated. The results indicated that S. villosum, S. scabrum, S. tarderemotum and S. americanum are more suitable for T. evansi due to a shorter developmental period, longer adult longevity, higher reproduction and …

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Molecular Diagnosis Of A Previously Unreported Predator-Prey Association In Coffee: Karnyothrips Flavipes Jones (Thysanoptera: Phlaeothripidae) Predation On The Coffee Berry Borer, Juliana Jaramillo, Eric G. Chapman, Fernando E. Vega, James D. Harwood Mar 2010

Molecular Diagnosis Of A Previously Unreported Predator-Prey Association In Coffee: Karnyothrips Flavipes Jones (Thysanoptera: Phlaeothripidae) Predation On The Coffee Berry Borer, Juliana Jaramillo, Eric G. Chapman, Fernando E. Vega, James D. Harwood

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The coffee berry borer, Hypothenemus hampei, is the most important pest of coffee throughout the world, causing losses estimated at US 500 million/year. The thrips Karnyothrips flavipes was observed for the first time feeding on immature stages of H. hampei in April 2008 from samples collected in the Kisii area of Western Kenya. Since the trophic interactions between H. hampei and K. flavipes are carried out entirely within the coffee berry, and because thrips feed by liquid ingestion, we used molecular gut-content analysis to confirm the potential role of K. flavipes as a predator of H. hampei in an organic …

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Prospects For The Development Of Odour Baits To Control The Tsetse Flies Glossina Tachinoidesand G. Palpalis S.L., J. B. Rayaisse, I. Tirados, D. Kaba, S. Y. Dewhirst, J. G. Logan, A. Diarrassouba, E. Salou, M. O. Omolo, P. Solano, M. J. Lehane, J. A. Pickett, G. A. Vale, S. J. Torr, J. Esterhuizen Mar 2010

Prospects For The Development Of Odour Baits To Control The Tsetse Flies Glossina Tachinoidesand G. Palpalis S.L., J. B. Rayaisse, I. Tirados, D. Kaba, S. Y. Dewhirst, J. G. Logan, A. Diarrassouba, E. Salou, M. O. Omolo, P. Solano, M. J. Lehane, J. A. Pickett, G. A. Vale, S. J. Torr, J. Esterhuizen

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Field studies were done of the responses of Glossina palpalis palpalis in Côte d'Ivoire, and G. p. gambiensis and G. tachinoides in Burkina Faso, to odours from humans, cattle and pigs. Responses were measured either by baiting (1.) biconical traps or (2.) electrocuting black targets with natural host odours. The catch of G. tachinoides from traps was significantly enhanced (∼5x) by odour from cattle but not humans. In contrast, catches from electric targets showed inconsistent results. For G. p. gambiensis both human and cattle odour increased (>2x) the trap catch significantly but not the catch from electric targets. For …

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Ecological Niche And Potential Geographic Distribution Of The Invasive Fruit Fly Bactrocera Invadens (Diptera, Tephritidae), M. De Meyer, M. P. Robertson, M. W. Mansell, S. Ekesi, K. Tsuruta, W. Mwaiko, J. F. Vayssières, A. T. Peterson Feb 2010

Ecological Niche And Potential Geographic Distribution Of The Invasive Fruit Fly Bactrocera Invadens (Diptera, Tephritidae), M. De Meyer, M. P. Robertson, M. W. Mansell, S. Ekesi, K. Tsuruta, W. Mwaiko, J. F. Vayssières, A. T. Peterson

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Two correlative approaches to the challenge of ecological niche modeling (genetic algorithm, maximum entropy) were used to estimate the potential global distribution of the invasive fruit fly, Bactrocera invadens, based on associations between known occurrence records and a set of environmental predictor variables. The two models yielded similar estimates, largely corresponding to Equatorial climate classes with high levels of precipitation. The maximum entropy approach was somewhat more conservative in its evaluation of suitability, depending on thresholds for presence/absence that are selected, largely excluding areas with distinct dry seasons; the genetic algorithm models, in contrast, indicate that climate class as partly …

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Chemical Ecology Of Animal And Human Pathogen Vectors In A Changing Global Climate, John A. Pickett, Michael A. Birkett, Sarah Y. Dewhirst, James G. Logan, Maurice O. Omolo, Baldwyn Torto, Julien Pelletier, Zainulabeuddin Syed, Walter S. Leal Feb 2010

Chemical Ecology Of Animal And Human Pathogen Vectors In A Changing Global Climate, John A. Pickett, Michael A. Birkett, Sarah Y. Dewhirst, James G. Logan, Maurice O. Omolo, Baldwyn Torto, Julien Pelletier, Zainulabeuddin Syed, Walter S. Leal

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Infectious diseases affecting livestock and human health that involve vector-borne pathogens are a global problem, unrestricted by borders or boundaries, which may be exacerbated by changing global climate. Thus, the availability of effective tools for control of pathogen vectors is of the utmost importance. The aim of this article is to review, selectively, current knowledge of the chemical ecology of pathogen vectors that affect livestock and human health in the developed and developing world, based on key note lectures presented in a symposium on "The Chemical Ecology of Disease Vectors" at the 25th Annual ISCE meeting in Neuchatel, Switzerland. The …

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Host Recognition And Acceptance Behaviour In Cotesia Sesamiae And C. Flavipes (Hymenoptera: Braconidae), Parasitoids Of Gramineous Stemborers In Africa, Meshack Obonyo, Fritz Schulthess, Bruno Le Ru, Johnnie Van Den Berg, Paul André Calatayud Jan 2010

Host Recognition And Acceptance Behaviour In Cotesia Sesamiae And C. Flavipes (Hymenoptera: Braconidae), Parasitoids Of Gramineous Stemborers In Africa, Meshack Obonyo, Fritz Schulthess, Bruno Le Ru, Johnnie Van Den Berg, Paul André Calatayud

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The host recognition and acceptance behaviour of two braconid larval parasitoids (Cotesia sesamiae and C. flavipes) were studied using natural stemborer hosts (i.e., the noctuid Busseola fusca for C. sesamiae, and the crambid Chilo partellus for C. flavipes) and a non-host (the pyralid Eldana saccharina). A single larva was introduced into an arena together with a female parasitoid and the behaviour of the wasp recorded until it either stung the larva or for a maximum of 5 min if it did not sting the larva. There was a clear hierarchy of behavioural steps, which was similar for both parasitoid species. …

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Nestmate Recognition And The Role Of Cuticular Hydrocarbons In The African Termite Raiding Ant Pachycondyla Analis, Abdullahi A. Yusuf, Christian W.W. Pirk, Robin M. Crewe, Peter G.N. Njagi, Ian Gordon, Baldwyn Torto Jan 2010

Nestmate Recognition And The Role Of Cuticular Hydrocarbons In The African Termite Raiding Ant Pachycondyla Analis, Abdullahi A. Yusuf, Christian W.W. Pirk, Robin M. Crewe, Peter G.N. Njagi, Ian Gordon, Baldwyn Torto

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Cuticular hydrocarbons (CHCs) are used for chemical communication among nestmates in many ant species, and they may play a role in the discrimination of nestmates and non-nestmates. Using the mandible opening response (MOR) bioassay, we tested the response of the African termite raiding ant, Pachycondyla analis, to CHC extracts of nestmates and non-nestmates. The ants were able to distinguish control chemical cues, from nestmate CHCs, and from non-nestmate CHCs, and, based on a CHC recognition threshold, aggression was demonstrated toward non-nestmates. Gas chromatography (GC) and GC-mass spectrometric analyses showed that CHC components of different ant colonies had chain lengths ranging …

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Expression Of Metallothionein And Α-Tubulin In Heavy Metal-Tolerant Anopheles Gambiae Sensu Stricto (Diptera: Culicidae), Paul O. Mireji, Joseph Keating, Ahmed Hassanali, Daniel E. Impoinvil, Charles M. Mbogo, Martha N. Muturi, Hudson Nyambaka, Eucharia U. Kenya, John I. Githure, John C. Beier Jan 2010

Expression Of Metallothionein And Α-Tubulin In Heavy Metal-Tolerant Anopheles Gambiae Sensu Stricto (Diptera: Culicidae), Paul O. Mireji, Joseph Keating, Ahmed Hassanali, Daniel E. Impoinvil, Charles M. Mbogo, Martha N. Muturi, Hudson Nyambaka, Eucharia U. Kenya, John I. Githure, John C. Beier

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Anopheles mosquitoes have been shown to adapt to heavy metals in their natural habitats. In this study we explored the possibility of using Anopheles gambiae sensu stricto as bio-reporters for environmental heavy metal pollution through expressions of their metal-responsive metallothionein and α-tubulin genes. The study was undertaken with third instar larvae after selection by cadmium, copper, or lead at LC30 through five successive generations. Expression levels were determined in the 5th generation by semi-quantitative RT-PCR on the experimental and control populations. The data were analyzed using one-way ANOVA. The highest metallothionein (F3, 11=4.574, P=0.038) and α-tubulin (F3, 11=12.961, P=0.002) responses …

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Importance Of Contact Chemical Cues In Host Recognition And Acceptance By The Braconid Larval Endoparasitoids Cotesia Sesamiae And Cotesia Flavipes, Meshack Obonyo, Fritz Schulthess, Bruno Le Ru, Johnnie Van Den Berg, Jean François Silvain, Paul André Calatayud Jan 2010

Importance Of Contact Chemical Cues In Host Recognition And Acceptance By The Braconid Larval Endoparasitoids Cotesia Sesamiae And Cotesia Flavipes, Meshack Obonyo, Fritz Schulthess, Bruno Le Ru, Johnnie Van Den Berg, Jean François Silvain, Paul André Calatayud

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The ability of the congeneric braconid parasitoids Cotesia sesamiae (Cameron) and Cotesia flavipes Cameron to discriminate between stemborer larval cues upon contact was studied using their natural hosts, namely the noctuid Busseola fusca (Fuller) and the crambid Chilo partellus (Swinhoe), respectively, and the pyralid non-host Eldana saccharina (Walker). When the natural host larvae were washed in distilled water, parasitoid behavior was similar to that displayed when in contact with E. saccharina, characterized by the absence of ovipositor insertion. When washed host or non-host larvae were bathed with water extracts of their natural host, the parasitoids showed a significant increase in …

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Geographic And Breed Distribution Patterns Of An A/G Polymorphism Present In The Mx Gene Suggests Balanced Selection In Village Chickens, S. Ommeh, L. N. Jin, H. Eding, F. C. Muchadeyi, S. Sulandari, M. S.A. Zein, G. Danbaro, C. E. Wani, S. G. Zhao, Q. H. Nie, X. Q. Zhang, M. Ndila, R. Preisinger, G. H. Chen, I. A. Yousif, K. N. Heo, S. J. Oh, M. Tapio, D. Masiga, O. Hanotte, H. Jianlin, S. Weigend Jan 2010

Geographic And Breed Distribution Patterns Of An A/G Polymorphism Present In The Mx Gene Suggests Balanced Selection In Village Chickens, S. Ommeh, L. N. Jin, H. Eding, F. C. Muchadeyi, S. Sulandari, M. S.A. Zein, G. Danbaro, C. E. Wani, S. G. Zhao, Q. H. Nie, X. Q. Zhang, M. Ndila, R. Preisinger, G. H. Chen, I. A. Yousif, K. N. Heo, S. J. Oh, M. Tapio, D. Masiga, O. Hanotte, H. Jianlin, S. Weigend

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An A/G Single Nucleotide Polymorphism (SNP) at position 1,892 of the Mx gene coding sequence has been linked to susceptibility/resistance to avian viral infection in vitro. Using PCR-RFLP and sequencing methods, 1,946 samples from 109 populations from Asia, Africa and Europe; grouped as indigenous village, commercial, fancy chicken as well as wild junglefowl were genotyped for the polymorphism. Allele and genotype frequencies were calculated. Only the G allele was present in Ceylon junglefowl Gallus lafayetti. Using the wild red junglefowl G. gallus population as reference, we assessed if the A/G alleles and genotypes frequencies have been affected by the breeding …

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Non-Target Effects Of The 'Push-Pull' Habitat Management Strategy: Parasitoid Activity And Soil Fauna Abundance, Charles A.O. Midega, Zeyaur R. Khan, Johnnie Van Den Berg, Callistus K.P.O. Ogol, Toby J. Bruce, John A. Pickett Dec 2009

Non-Target Effects Of The 'Push-Pull' Habitat Management Strategy: Parasitoid Activity And Soil Fauna Abundance, Charles A.O. Midega, Zeyaur R. Khan, Johnnie Van Den Berg, Callistus K.P.O. Ogol, Toby J. Bruce, John A. Pickett

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We assessed the non-target effects of a habitat management system ('push-pull') on maize stemborer specialist natural enemy activity and soil Collembola. Two study sites in western Kenya were sampled. There were two treatments at each site, maize monocrop and 'push-pull'. The latter comprised an intercrop of maize and Desmodium, Desmodium uncinatum Jacq., with Napier grass, Pennisetum purpureum (Schumach), as a trap crop planted around the edge of the plot (spaced 1 m from main crop). Trichogramma spp. were recovered from stemborer eggs while Cotesia sesamiae and Cotesia flavipes were recovered from stemborer larvae, and Dentichasmias busseolae from pupae. Mean number …

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Proximity To A Forest Leads To Higher Honey Yield: Another Reason To Conserve, Susan O. Sande, Robin M. Crewe, Suresh K. Raina, Susan W. Nicolson, Ian Gordon Nov 2009

Proximity To A Forest Leads To Higher Honey Yield: Another Reason To Conserve, Susan O. Sande, Robin M. Crewe, Suresh K. Raina, Susan W. Nicolson, Ian Gordon

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Although tropical forest conservation is a top priority for human and environmental health, deforestation persists, mainly because of food and economic needs. No community will totally give up economic activities for the sake of ecological integrity, unless it is given alternative economic activities from which to draw its livelihood. Beekeeping in the forest buffer zone instead of traditional destructive honey-harvesting from forest trees is one such option at Arabuko Sokoke Forest (ASF) in Kenya. ASF is a dry coastal forest which is home to endangered and threatened fauna and is a hotspot considered a priority for conservation. In order to …

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Integration Of Edible Beans (Phaseolus Vulgaris L.) Into The Push-Pull Technology Developed For Stemborer And Striga Control In Maize-Based Cropping Systems, Zeyaur R. Khan, Charles A.O. Midega, Japhether M. Wanyama, David M. Amudavi, Ahmed Hassanali, Jimmy Pittchar, John A. Pickett Nov 2009

Integration Of Edible Beans (Phaseolus Vulgaris L.) Into The Push-Pull Technology Developed For Stemborer And Striga Control In Maize-Based Cropping Systems, Zeyaur R. Khan, Charles A.O. Midega, Japhether M. Wanyama, David M. Amudavi, Ahmed Hassanali, Jimmy Pittchar, John A. Pickett

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Smallholder farming systems in eastern Africa are characterized by cereal/edible legume intercrops in fields severely constrained by parasitic weed, Striga hermonthica, cereal stemborers and declining soil fertility. The push-pull technology concurrently addresses these constraints. It involves intercropping maize with stemborer repellent fodder legume, Desmodium spp. (push), with an attractant crop, Napier grass, Pennisetum purpureum (pull), planted around this intercrop, thus making it difficult to interplant edible legumes. We assessed farmers' practice and perceptions on intercropping and willingness to integrate beans in their push-pull plots from a sample of 300 farmers in six districts in western Kenya. All the respondents traditionally …

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Fungal Entomopathogens: New Insights On Their Ecology, Fernando E. Vega, Mark S. Goettel, Meredith Blackwell, David Chandler, Mark A. Jackson, Siegfried Keller, Masanori Koike, Nguya K. Maniania, Arnulfo Monzón, Bonnie H. Ownley, Judith K. Pell, Drauzio E.N. Rangel, Helen E. Roy Nov 2009

Fungal Entomopathogens: New Insights On Their Ecology, Fernando E. Vega, Mark S. Goettel, Meredith Blackwell, David Chandler, Mark A. Jackson, Siegfried Keller, Masanori Koike, Nguya K. Maniania, Arnulfo Monzón, Bonnie H. Ownley, Judith K. Pell, Drauzio E.N. Rangel, Helen E. Roy

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An important mechanism for insect pest control should be the use of fungal entomopathogens. Even though these organisms have been studied for more than 100 y, their effective use in the field remains elusive. Recently, however, it has been discovered that many of these entomopathogenic fungi play additional roles in nature. They are endophytes, antagonists of plant pathogens, associates with the rhizosphere, and possibly even plant growth promoting agents. These findings indicate that the ecological role of these fungi in the environment is not fully understood and limits our ability to employ them successfully for pest management. In this paper, …

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A Heteroskedastic Error Covariance Matrix Estimator Using A First-Order Conditional Autoregressive Markov Simulation For Deriving Asympotical Efficient Estimates From Ecological Sampled Anopheles Arabiensis Aquatic Habitat Covariates, Benjamin G. Jacob, Daniel A. Griffith, Ephantus J. Muturi, Erick X. Caamano, John I. Githure, Robert J. Novak Oct 2009

A Heteroskedastic Error Covariance Matrix Estimator Using A First-Order Conditional Autoregressive Markov Simulation For Deriving Asympotical Efficient Estimates From Ecological Sampled Anopheles Arabiensis Aquatic Habitat Covariates, Benjamin G. Jacob, Daniel A. Griffith, Ephantus J. Muturi, Erick X. Caamano, John I. Githure, Robert J. Novak

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Background. Autoregressive regression coefficients for Anopheles arabiensis aquatic habitat models are usually assessed using global error techniques and are reported as error covariance matrices. A global statistic, however, will summarize error estimates from multiple habitat locations. This makes it difficult to identify where there are clusters of An. arabiensis aquatic habitats of acceptable prediction. It is therefore useful to conduct some form of spatial error analysis to detect clusters of An. arabiensis aquatic habitats based on uncertainty residuals from individual sampled habitats. In this research, a method of error estimation for spatial simulation models was demonstrated using autocorrelation indices and …

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Odorants That Induce Hygienic Behavior In Honeybees: Identification Of Volatile Compounds In Chalkbrood-Infected Honeybee Larvae, Jodi A.I. Swanson, Baldwyn Torto, Stephen A. Kells, Karen A. Mesce, James H. Tumlinson, Marla Spivak Oct 2009

Odorants That Induce Hygienic Behavior In Honeybees: Identification Of Volatile Compounds In Chalkbrood-Infected Honeybee Larvae, Jodi A.I. Swanson, Baldwyn Torto, Stephen A. Kells, Karen A. Mesce, James H. Tumlinson, Marla Spivak

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Social insects that live in large colonies are vulnerable to disease transmission due to relatively high genetic relatedness among individuals and high rates of contact within and across generations. While individual insects rely on innate immune responses, groups of individuals also have evolved social immunity. Hygienic behavior, in which individual honeybees detect chemical stimuli from diseased larvae and subsequently remove the diseased brood from the nest, is one type of social immunity that reduces pathogen transmission. Three volatile compounds, collected from larvae infected with the fungal pathogen Ascosphaera apis and detected by adult honey bees, were identified by coupled gas …

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Relationship Between Virulence And Repellency Of Entomopathogenic Isolates Of Metarhizium Anisopliae And Beauveria Bassiana To The Termite Macrotermes Michaelseni, D. M. Mburu, L. Ochola, N. K. Maniania, P. G.N. Njagi, L. M. Gitonga, M. W. Ndung'u, A. K. Wanjoya, A. Hassanali Sep 2009

Relationship Between Virulence And Repellency Of Entomopathogenic Isolates Of Metarhizium Anisopliae And Beauveria Bassiana To The Termite Macrotermes Michaelseni, D. M. Mburu, L. Ochola, N. K. Maniania, P. G.N. Njagi, L. M. Gitonga, M. W. Ndung'u, A. K. Wanjoya, A. Hassanali

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Termites encounter a diverse array of potentially useful and harmful fungi in their subterranean habitats. These vary from symbiotic to harmful species with varying levels of virulence. How these hemiedaphic insects survive in habitats with infective fungi is not well understood. Possible mediation of olfactory signals in avoiding contact with entomopathogenic fungi has been explored by a number of workers. In the present study, we initially found that Macrotermes michaelseni detected a virulent isolate of Metarhizium anisopliae from some distance and avoided direct physical contact. We hypothesized that there may be a relationship between virulence and repellency of different isolates …

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Olfactory Attraction Of Egg Parasitoids To Virgin Females Of Noctuid Stemborers, Anani Yaovi Bruce, Fritz Schulthess, Jones Mueke, Paul André Calatayud Aug 2009

Olfactory Attraction Of Egg Parasitoids To Virgin Females Of Noctuid Stemborers, Anani Yaovi Bruce, Fritz Schulthess, Jones Mueke, Paul André Calatayud

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To locate hosts, egg parasitoids rely on infochemicals of the adult host stage, e.g. pheromones, rather than cues emitted by the inconspicuous egg themselves. Here, we show that three different egg parasitoid species the scelionids Telenomus busseolae Gahan and Telenomus isis Polaszek and the trichogrammatid Trichogramma bournieri Pintureau & Babault were attracted to both calling and non-calling females of the noctuids Busseola fusca (Fuller), Sesamia calamistis (Hampson) and Sesamia nonagrioides (Lefebvre). In Y-tube olfactometer experiments this study revealed a preference of all three parasitoids for non-calling (general odors of virgin females) and calling moth (sex pheromone) over the control (clean …

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