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Articles 781 - 810 of 1129

Full-Text Articles in Entomology

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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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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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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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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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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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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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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Thermal Tolerance Of The Coffee Berry Borer Hypothenemus Hampei: Predictions Of Climate Change Impact On A Tropical Insect Pest, Juliana Jaramillo, Adenirin Chabi-Olaye, Charles Kamonjo, Alvaro Jaramillo, Fernando E. Vega, Hans Michael Poehling, Christian Borgemeister Aug 2009

Thermal Tolerance Of The Coffee Berry Borer Hypothenemus Hampei: Predictions Of Climate Change Impact On A Tropical Insect Pest, Juliana Jaramillo, Adenirin Chabi-Olaye, Charles Kamonjo, Alvaro Jaramillo, Fernando E. Vega, Hans Michael Poehling, Christian Borgemeister

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Coffee is predicted to be severely affected by climate change. We determined the thermal tolerance of the coffee berry borer , Hypothenemus hampei, the most devastating pest of coffee worldwide, and make inferences on the possible effects of climate change using climatic data from Colombia, Kenya, Tanzania, and Ethiopia. For this, the effect of eight temperature regimes (15, 20, 23, 25, 27, 30, 33 and 35°C) on the bionomics of H. hampei was studied. Successful egg to adult development occurred between 20-30°C. Using linear regression and a modified Logan model, the lower and upper thresholds for development were estimated at …

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Recilia Banda Kramer (Hemiptera: Cicadellidae), A Vector Of Napier Stunt Phytoplasma In Kenya, Evans Obura, Charles A.O. Midega, Daniel Masiga, John A. Pickett, Mohamed Hassan, Shinsaku Koji, Zeyaur R. Khan Jul 2009

Recilia Banda Kramer (Hemiptera: Cicadellidae), A Vector Of Napier Stunt Phytoplasma In Kenya, Evans Obura, Charles A.O. Midega, Daniel Masiga, John A. Pickett, Mohamed Hassan, Shinsaku Koji, Zeyaur R. Khan

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Napier grass (Pennisetum purpureum) is the most important fodder crop in smallholder dairy production systems in East Africa, characterized by small zero-grazing units. It is also an important trap crop used in the management of cereal stemborers in maize in the region. However, production of Napier grass in the region is severely constrained by Napier stunt disease. The etiology of the disease is known to be a phytoplasma, 16SrXI strain. However, the putative insect vector was yet unknown. We sampled and identified five leafhopper and three planthopper species associated with Napier grass and used them as candidates in pathogen transmission …

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Anti-Mosquito And Antimicrobial Nor-Halimanoids, Isocoumarins And An Anilinoid From Tessmannia Densiflora, Charles Kihampa, Mayunga H.H. Nkunya, Cosam C. Joseph, Stephen M. Magesa, Ahmed Hassanali, Matthias Heydenreich, Erich Kleinpeter Jul 2009

Anti-Mosquito And Antimicrobial Nor-Halimanoids, Isocoumarins And An Anilinoid From Tessmannia Densiflora, Charles Kihampa, Mayunga H.H. Nkunya, Cosam C. Joseph, Stephen M. Magesa, Ahmed Hassanali, Matthias Heydenreich, Erich Kleinpeter

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The nor-halimane diterpenoid tessmannic acid and its methyl, 2-methylisopropyl and 1-methylbutyl esters, the unusual isocoumarins 8-hydroxy-6-methoxy-3-pentylisocoumarin and 7-chloro-8-hydroxy-6-methoxy-3-pentylisocoumarin, and 5-pentyl-3-methoxy-N-butylaniline were isolated from the stem and root bark extracts of Tessmannia densiflora Harms (Caesalpiniaceae) that showed mosquito larvicidal activity. The structures were determined on interpretation of spectroscopic data. Tessmannic acid and its methyl ester exhibited antibacterial and antifungal activity. The compounds also caused high larvae and adult Anopheles gambiae mosquitoe mortality effects, and stronger mosquito repellency than that shown by the standard repellent DEET, hence indicating Tessmannia species to be potential sources of bioactive natural products. © 2009 Elsevier Ltd. …

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Where To Sample? Ecological Implications Of Sampling Strata In Determining Abundance And Impact Of Natural Enemies Of The Coffee Berry Borer, Hypothenemus Hampei, Juliana Jaramillo, Adenirin Chabi-Olaye, Christian Borgemeister, Charles Kamonjo, Hans Michael Poehling, Fernando E. Vega Jun 2009

Where To Sample? Ecological Implications Of Sampling Strata In Determining Abundance And Impact Of Natural Enemies Of The Coffee Berry Borer, Hypothenemus Hampei, Juliana Jaramillo, Adenirin Chabi-Olaye, Christian Borgemeister, Charles Kamonjo, Hans Michael Poehling, Fernando E. Vega

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Several parasitoids of African origin have been introduced to coffee producing areas of the Americas and Asia as biological control agents of the coffee berry borer (CBB) Hypothenemus hampei (Coleoptera: Curculionidae). These parasitoids have become established in the field but their effect on the CBB has been limited. A two-year field study in Western Kenya has found Prorops nasuta (Hymenoptera: Bethylidae) to be the predominant parasitoid emerging from CBB-infested coffee berries collected on coffee trees or from the ground. P. nasuta comprises more than 75% of the total natural enemies collected. The density of P. nasuta was 90% higher in …

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Diversity, Distribution And Role Of Wild Crucifers In Major Cabbage And Kale Growing Areas Of Kenya, R. Kahuthia-Gathu, B. Löhr, H. M. Poehling, P. K. Mbugua Jun 2009

Diversity, Distribution And Role Of Wild Crucifers In Major Cabbage And Kale Growing Areas Of Kenya, R. Kahuthia-Gathu, B. Löhr, H. M. Poehling, P. K. Mbugua

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An investigation of the diversity and distribution of wild crucifer species and their importance for cultivated crucifers was conducted during 2005 and 2006 in the highland and mid-altitude semi-arid areas of Kenya. Thirteen species of wild crucifers in nine genera were recorded: Raphanus raphanistrum, Erucastrum arabicum, Sisymbrium officinale, Crambe kilimandscharica, Capsella bursa-pastoris, Rorippa nudiuscula, Ro. micrantha, Ro. microphylla, Lepidium bonariense, Coronopus didymus, Brassica rapa, B. juncea and an unidentified Brassica species. Highland areas had significantly higher species diversity and species richness than mid-altitude semi-arid areas. Species richness, diversity and evenness varied with season and location. Raphanus raphanistrum was the dominant …

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Predation And Reproductive Output Of The Ladybird Beetle Stethorus Tridens Preying On Tomato Red Spider Mite Tetranychus Evansi, Erika P.J. Britto, Manoel G.C. Gondim, Jorge B. Torres, Komi K.M. Fiaboe, Gilberto J. Moraes, Markus Knapp Jun 2009

Predation And Reproductive Output Of The Ladybird Beetle Stethorus Tridens Preying On Tomato Red Spider Mite Tetranychus Evansi, Erika P.J. Britto, Manoel G.C. Gondim, Jorge B. Torres, Komi K.M. Fiaboe, Gilberto J. Moraes, Markus Knapp

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Predatory behaviour and reproductive output of the ladybird beetle Stethorus tridens Gordon as function of the tomato red spider mite (TRSM), Tetranychus evansi Baker & Pritchard, densities was investigated in the laboratory. Adult female of S. tridens were isolated in cylindrical plastic arenas, containing a leaf disc of Solanum americanum Mill. with 5, 20, 40, 60, 80 or 100 T. evansi nymphs. The number of prey consumed and eggs laid were evaluated daily for ten consecutive days, starting at the oviposition. Oviposition of S. tridens was positively correlated with prey consumption and lower threshold prey consumption for S. tridens laying …

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Prospects For Developing Odour Baits To Control Glossina Fuscipes Spp., The Major Vector Of Human African Trypanosomiasis, Maurice O. Omolo, Ahmed Hassanali, Serge Mpiana, Johan Esterhuizen, Jenny Lindh, Mike J. Lehane, Philippe Solano, Jean Baptiste Rayaisse, Glyn A. Vale, Steve J. Torr, Inaki Tirados May 2009

Prospects For Developing Odour Baits To Control Glossina Fuscipes Spp., The Major Vector Of Human African Trypanosomiasis, Maurice O. Omolo, Ahmed Hassanali, Serge Mpiana, Johan Esterhuizen, Jenny Lindh, Mike J. Lehane, Philippe Solano, Jean Baptiste Rayaisse, Glyn A. Vale, Steve J. Torr, Inaki Tirados

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We are attempting to develop cost-effective control methods for the important vector of sleeping sickness, Glossina fuscipes spp. Responses of the tsetse flies Glossina fuscipes fuscipes (in Kenya) and G. f. quanzensis (in Democratic Republic of Congo) to natural host odours are reported. Arrangements of electric nets were used to assess the effect of cattle-, human- and pig-odour on (1) the numbers of tsetse attracted to the odour source and (2) the proportion of flies that landed on a black target (1 × 1 m). In addition responses to monitor lizard (Varanus niloticus) were assessed in Kenya. The effects of …

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Variability In Pheromone Communication Among Different Haplotype Populations Of Busseola Fusca, A. E. Félix, G. Genestier, C. Malosse, P. A. Calatayud, B. Le Rü, J. F. Silvain, B. Frérot May 2009

Variability In Pheromone Communication Among Different Haplotype Populations Of Busseola Fusca, A. E. Félix, G. Genestier, C. Malosse, P. A. Calatayud, B. Le Rü, J. F. Silvain, B. Frérot

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The relationship between pheromone composition and mitochondrial haplotype clades was investigated by coupling DNA analyses with pheromone identification and male mate searching behavior among different geographic populations of Busseola fusca. The within-population variations in pheromone blend were as great as those observed between geographic populations, suggesting that the female sex pheromone blend was not the basis of reproductive isolation between the geographic clades. Furthermore, while data from wind tunnel experiments demonstrated that most of the tested males were sensitive to small variations in pheromone mixture, there was considerable within-population variability in the observed response. The study identified a new pheromone …

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Spatiotemporal Dynamics Of Immature Culicines (Subfamily Culicinae) And Their Larval Habitats In Mwea Rice Scheme, Kenya, Ephantus J. Muturi, Joseph M. Mwangangi, Benjamin G. Jacob, Josephat I. Shililu, Charles M. Mbogo, John I. Githure, Robert J. Novak Mar 2009

Spatiotemporal Dynamics Of Immature Culicines (Subfamily Culicinae) And Their Larval Habitats In Mwea Rice Scheme, Kenya, Ephantus J. Muturi, Joseph M. Mwangangi, Benjamin G. Jacob, Josephat I. Shililu, Charles M. Mbogo, John I. Githure, Robert J. Novak

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An ecological study was conducted at three study sites in Mwea Rice Scheme, Kenya to identify the diverse aquatic habitats in which culicine mosquitoes thrived and to explore the best strategies for mosquito control in the area. During the 11-month study period, ten habitat categories and 11 culicine species mainly dominated by Culex quinquefasciatus (72.0%) and Culex annulioris (17.9%) were identified from pupae and late instars larval samples. Two of the 11 culicine species, Ficalbia (Mimomyia) plumosa and Uranotaenia spp., have not been reported previously in the study area. Rurumi had more habitat types than either of the other study …

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Submicroscopic Gametocytes And The Transmission Of Antifolate-Resistant Plasmodium Falciparum In Western Kenya, Mayke J.A.M. Oesterholt, Michael Alifrangis, Colin J. Sutherland, Sabah A. Omar, Patrick Sawa, Christina Howitt, Louis C. Gouagna, Robert W. Sauerwein, Teun Bousema Feb 2009

Submicroscopic Gametocytes And The Transmission Of Antifolate-Resistant Plasmodium Falciparum In Western Kenya, Mayke J.A.M. Oesterholt, Michael Alifrangis, Colin J. Sutherland, Sabah A. Omar, Patrick Sawa, Christina Howitt, Louis C. Gouagna, Robert W. Sauerwein, Teun Bousema

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Background: Single nucleotide polymorphisms (SNPs) in the dhfr and dhps genes are associated with sulphadoxine-pyrimethamine (SP) treatment failure and gametocyte carriage. This may result in enhanced transmission of mutant malaria parasites, as previously shown for chloroquine resistant parasites. In the present study, we determine the association between parasite mutations, submicroscopic P. falciparum gametocytemia and malaria transmission to mosquitoes. Methodology/Principal Findings: Samples from children treated with SP alone or in combination with artesunate (AS) or amodiaquine were genotyped for SNPs in the dhfr and dhps genes. Gametocytemia was determined by microscopy and Pfs25 RNA-based quantitative nucleic acid sequence-based amplification (Pfs25 QT-NASBA). …

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Parasitoids Associated With Mussidia Spp. (Lepidoptera: Pyralidae) In Kenya, Benjamin Kimwele Muli, Fritz Schulthess, Johnnie Van Den Berg Feb 2009

Parasitoids Associated With Mussidia Spp. (Lepidoptera: Pyralidae) In Kenya, Benjamin Kimwele Muli, Fritz Schulthess, Johnnie Van Den Berg

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The pyralid Mussidia nigrivenella, a pest of cotton, maize and Phaseolus bean in West Africa, has never been reported as a crop pest in East and Southern Africa, although reportedly it exists in the wild. It is hypothesized that the difference in pest status of M. nigrivenella between western and eastern Africa was either due to differences in natural enemy compositions or that there exist several populations and/or species of Mussidia, which vary in their host plant range. Thus, a catalogue of parasitoids of Mussidia spp. was established through surveys in mid-altitude and coastal Kenya, between 2006 and 2007. Mussidia …

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Describing Anopheles Arabiensis Aquatic Habitats In Two Riceland Agro-Ecosystems In Mwea, Kenya Using A Negative Binomial Regression Model With A Non-Homogenous Mean, Benjamin G. Jacob, Daniel Griffith, Ephantus Muturi, Erick X. Caamano, Josephat Shililu, John I. Githure, Robert J. Novak Jan 2009

Describing Anopheles Arabiensis Aquatic Habitats In Two Riceland Agro-Ecosystems In Mwea, Kenya Using A Negative Binomial Regression Model With A Non-Homogenous Mean, Benjamin G. Jacob, Daniel Griffith, Ephantus Muturi, Erick X. Caamano, Josephat Shililu, John I. Githure, Robert J. Novak

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This research illustrates a geostatistical approach for modeling the spatial distribution patterns of Anopheles arabiensis Patton (Patton) aquatic habitats in two riceland environments. QuickBird 0.61m data, encompassing the visible bands and the near-infra-red (NIR) band, were selected to synthesize images of An. arabiensis aquatic habitats. These bands and field sampled data were used to determine ecological parameters associated with riceland larval habitat development. SAS® was used to calculate univariate statistics, correlations and Poisson regression models. Global autocorrelation statistics were generated in ArcGIS® from georeferenced Anopheles aquatic habitats in the study sites. The geographic distribution of Anopheles gambiae s.l. aquatic habitats …

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Larvicidal Activity Of Extracts From Three Plumbago Spp Against Anopheles Gambiae, Barasa M. Maniafu, Lwande Wilber, Isaiah O. Ndiege, Cornelius C. Wanjala, Teresa Ayuko Akenga Jan 2009

Larvicidal Activity Of Extracts From Three Plumbago Spp Against Anopheles Gambiae, Barasa M. Maniafu, Lwande Wilber, Isaiah O. Ndiege, Cornelius C. Wanjala, Teresa Ayuko Akenga

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Three Plumbago spp have been tested for mosquito larvicidal activity. The crude extracts exhibiting the highest larvicidal activity against Anopheles gambiae were hexane (LC50 = 6.4 μg/mL) and chloroform (LC50 = 6.7 μg/mL) extracts from Plumbago zeylanica Linn, chloroform (LC50 = 6.7 ug/mL) extract from Plumbago stenophylla Bull and ethyl acetate (LC50 = 4.1 μg/mL) extract from Plumbago dawei Rolfe. These LC50 values were within 95% confidence limits. 5-hydroxy-2-methyl-1,4-naphthoquinone (plumbagin) 1 (LC50 = 1.9 μg/mL) and β-sitosterol 2 were characterised from ethyl acetate extract of root bark of P. dawei, a native medicinal plant growing in Kenya, based on spectral …

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Effect Of Common Wild Crucifer Species Of Kenya On Fitness Of Two Exotic Diamondback Moth Parasitoids, Cotesia Plutellae And Diadegma Semiclausum, R. Kahuthia-Gathu, B. Löhr, H. M. Poehling Dec 2008

Effect Of Common Wild Crucifer Species Of Kenya On Fitness Of Two Exotic Diamondback Moth Parasitoids, Cotesia Plutellae And Diadegma Semiclausum, R. Kahuthia-Gathu, B. Löhr, H. M. Poehling

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Plutella xylostella is the most abundant and damaging pest of cruciferous crops in Kenya and has gained economic importance over the years. During a survey conducted in the major crucifer areas of Kenya a number of wild crucifers recorded in the region were found infested with diamondback moth. As a result, research was conducted in the laboratory and greenhouse to investigate whether exotic parasitoids recently introduced would develop and survive on the wild crucifers. Experiments were conducted on development, survival, reproductive potential and parasitism of Cotesia plutellae and Diadegma semiclausum on cultivated Brassica (Brassica oleracea var. capitata and B. oleracea …

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Regulation Of Oviposition In Anopheles Gambiae S.S.: Role Of Inter- And Intra-Specific Signals, Leunita A. Sumba, C. Brandon Ogbunugafor, Arop L. Deng, Ahmed Hassanali Nov 2008

Regulation Of Oviposition In Anopheles Gambiae S.S.: Role Of Inter- And Intra-Specific Signals, Leunita A. Sumba, C. Brandon Ogbunugafor, Arop L. Deng, Ahmed Hassanali

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Females of Anopheles gambiae Giles normally oviposit in a large number of fresh, small, sunlit, and spatially spread temporary pools. Such pools are associated with lower levels of predation compared to large, longer-lasting habitats. We compared oviposition levels on preferred (water collected from natural anopheline larval habitats) and non-preferred (distilled water) aqueous substrates by gravid females that contained different densities of conspecific eggs or early and late instar larvae. The presence of conspecific larvae, but not eggs, had a positive or negative effect on the ovipositional responses of gravid An. gambiae females, depending on the quality (preferred or non-preferred by …

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Cross Mating Studies Among Five Fruit Fly Parasitoid Populations: Potential Biological Control Implications For Tephritid Pests, Maxwell K. Billah, Susan W. Kimani-Njogu, Robert A. Wharton, William A. Overholt, David D. Wilson, Millicent A. Cobblah Oct 2008

Cross Mating Studies Among Five Fruit Fly Parasitoid Populations: Potential Biological Control Implications For Tephritid Pests, Maxwell K. Billah, Susan W. Kimani-Njogu, Robert A. Wharton, William A. Overholt, David D. Wilson, Millicent A. Cobblah

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The reproductive compatibility between four different species/populations of the tephritid parasitoid Psyttalia (Walker) species from Kenya and individuals of the morphologically identical Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae) from a laboratory culture in Italy used in augmentative biological control of olive fly, Bactrocera oleae (Gmelin) (Diptera: Tephritidae) was assessed through cross mating tests using single-pair and group mating methods. Reciprocal crosses among the species resulted in the production of viable offsprings up to the second generation. In spite of the successful production of viable offspring in the laboratory, Psyttalia species are known to have specific host fruit and/or host fly preferences …

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