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Articles 931 - 960 of 1443

Full-Text Articles in Life Sciences

Composition Of Stem Borer Communities In Selected Vegetation Mosaics In Kenya, G. O. Ong'amo, B. P. Le Ru, P. A. Calatayud, J. F. Silvain Jun 2013

Composition Of Stem Borer Communities In Selected Vegetation Mosaics In Kenya, G. O. Ong'amo, B. P. Le Ru, P. A. Calatayud, J. F. Silvain

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Busseola fusca (Fuller), Sesamia calamistis Hampson, Chilo partellus (Swinhoe) and Chilo orichalcociliellus (Strand) are important stem borer pests of maize and sorghum in East Africa. Persistence of these pests in crop fields is blamed on the influx of diaspore populations from the neighbouring natural habitats. In addition to pest species, natural habitats support numerous non-economic stem borer species, some not known to science. However, due to growing human populations and accompanying global change, some of the natural habitats are undergoing rapid changes, a process that may result in the evolution of "new" pest species. In this study, we investigated stem …

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Transfer Of Inoculum Of Metarhizium Anisopliae Between Adult Glossina Morsitans Morsitans And Effects Of Fungal Infection On Blood Feeding And Mating Behaviors, Nguya K. Maniania, Matilda A. Okech, James O. Adino, Jacob O. Opere, Sunday Ekesi Jun 2013

Transfer Of Inoculum Of Metarhizium Anisopliae Between Adult Glossina Morsitans Morsitans And Effects Of Fungal Infection On Blood Feeding And Mating Behaviors, Nguya K. Maniania, Matilda A. Okech, James O. Adino, Jacob O. Opere, Sunday Ekesi

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The transfer of conidia of Metarhizium anisopliae between tsetse flies Glossina morsitans and the effects of fungal inoculation on mating and blood meal feeding behaviors were investigated in the laboratory. Male or female flies were inoculated with fungal conidia ("donors") and allowed to pair with fungus-free mate of opposite sex ("recipients") at 1-day-interval up to three mates. Fungus-treated male or female "donor" flies as well as their mates "recipients" died from fungal infection. However, mortality in male "recipient" flies declined with successive mating, from 82.5 to 32.5 %. Fungus-treated males readily located female flies and mating was successful in most …

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Adaptive Selection On Bracovirus Genomes Drives The Specialization Of Cotesia Parasitoid Wasps, Séverine Jancek, Annie Bézier, Philippe Gayral, Corentin Paillusson, Laure Kaiser, Stéphane Dupas, Bruno Pierre Le Ru, Valérie Barbe, Georges Periquet, Jean Michel Drezen, Elisabeth A. Herniou May 2013

Adaptive Selection On Bracovirus Genomes Drives The Specialization Of Cotesia Parasitoid Wasps, Séverine Jancek, Annie Bézier, Philippe Gayral, Corentin Paillusson, Laure Kaiser, Stéphane Dupas, Bruno Pierre Le Ru, Valérie Barbe, Georges Periquet, Jean Michel Drezen, Elisabeth A. Herniou

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The geographic mosaic of coevolution predicts parasite virulence should be locally adapted to the host community. Cotesia parasitoid wasps adapt to local lepidopteran species possibly through their symbiotic bracovirus. The virus, essential for the parasitism success, is at the heart of the complex coevolutionary relationship linking the wasps and their hosts. The large segmented genome contained in the virus particles encodes virulence genes involved in host immune and developmental suppression. Coevolutionary arms race should result in the positive selection of particular beneficial alleles. To understand the global role of bracoviruses in the local adaptation or specialization of parasitoid wasps to …

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Mosquito-Borne Arbovirus Surveillance At Selected Sites In Diverse Ecological Zones Of Kenya; 2007 - 2012, Caroline Ochieng, Joel Lutomiah, Albina Makio, Hellen Koka, Edith Chepkorir, Santos Yalwala, James Mutisya, Lillian Musila, Samoel Khamadi, Jason Richardson, Joshua Bast, David Schnabel, Eyako Wurapa, Rosemary Sang May 2013

Mosquito-Borne Arbovirus Surveillance At Selected Sites In Diverse Ecological Zones Of Kenya; 2007 - 2012, Caroline Ochieng, Joel Lutomiah, Albina Makio, Hellen Koka, Edith Chepkorir, Santos Yalwala, James Mutisya, Lillian Musila, Samoel Khamadi, Jason Richardson, Joshua Bast, David Schnabel, Eyako Wurapa, Rosemary Sang

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Abstract. Background: Increased frequency of arbovirus outbreaks in East Africa necessitated the determination of distribution of risk by entomologic arbovirus surveillance. A systematic vector surveillance programme spanning 5 years and covering 11 sites representing seven of the eight provinces in Kenya and located in diverse ecological zones was carried out. Methods. Mosquitoes were sampled bi-annually during the wet seasons and screened for arboviruses. Mosquitoes were identified to species, pooled by species, collection date and site and screened for arboviruses by isolation in cell culture and/or RT-PCR screening and sequencing. Results: Over 450,000 mosquitoes in 15,890 pools were screened with 83 …

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Parasitological Prevalence Of Bovine Trypanosomosis In Kubo Division Of Kwale County Of Coastal: Baseline Survey, N. Mbahin, H. Affognon, J. Andoke, M. Tiberius, D. Mbuvi, J. Otieno, P. Muasa, R. K. Saini Apr 2013

Parasitological Prevalence Of Bovine Trypanosomosis In Kubo Division Of Kwale County Of Coastal: Baseline Survey, N. Mbahin, H. Affognon, J. Andoke, M. Tiberius, D. Mbuvi, J. Otieno, P. Muasa, R. K. Saini

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Prior to field trials of large scale tsetse repellent technology validation in July 2011, a cross-sectional survey of bovine trypanosomosis and its vectors was carried out to know the disease level in Kwale County of Coastal Kenya. A total of 584 adult cattle were examined at ten different Locations. The trypanosome prevalence in cattle with regard to age, sex, location and apparent tsetse density was investigated. The overall trypanosome prevalence in cattle in Kubo Division of Kwale County was 33.9%. Two types of infections were recorded in various parts of the Division in the following proportions: T. congolense 61.1%, T. …

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Differences In Essential Oil Content Of Berries And Leaves Of Solanum Sarrachoides (Solanaceae) And The Effects On Oviposition Of The Tomato Spider Mite (Tetranychus Evansi), Lucy K. Murungi, Hillary Kirwa, Baldwyn Torto Apr 2013

Differences In Essential Oil Content Of Berries And Leaves Of Solanum Sarrachoides (Solanaceae) And The Effects On Oviposition Of The Tomato Spider Mite (Tetranychus Evansi), Lucy K. Murungi, Hillary Kirwa, Baldwyn Torto

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Essential oils from leaves and berries of Solanum sarrachoides were obtained by hydro-distillation, analyzed by GC-MS and tested for oviposition deterrence against Tetranychus evansi. Plant oils comprised mainly of monoterpenes and fatty acids, but differed in terms of their relative abundance. The leaf oil contained mainly camphor (34.1%), limonene (8%), decanoic acid (9.3%) and hexadecanoic acid (7.3%). The berry oil contained mainly fatty acids (>20%) including hexadecanoic acid (9.8%) and dodecanoic acid (5.9%), hydrocarbons (>10%) and (E)-β-linalool (3.1%). In oviposition deterrence assays, the leaf essential oil and individual major monoterpenes compared favorably with the two positive controls, neem …

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Sex-Specific Induction Of Cyp6 Cytochrome P450 Genes In Cadmium And Lead Tolerant Anopheles Gambiae, Fauzia K. Musasia, Alfred O. Isaac, Daniel K. Masiga, Irene A. Omedo, Ramadhan Mwakubambanya, Richard Ochieng, Paul O. Mireji Mar 2013

Sex-Specific Induction Of Cyp6 Cytochrome P450 Genes In Cadmium And Lead Tolerant Anopheles Gambiae, Fauzia K. Musasia, Alfred O. Isaac, Daniel K. Masiga, Irene A. Omedo, Ramadhan Mwakubambanya, Richard Ochieng, Paul O. Mireji

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Background: Anopheles gambiae, one of the main Afro-tropical mosquito vector of malaria, has adapted to heavy metals in its natural habitat, and developed resistance to most conventional insecticides. Investigations were conducted to establish an association between tolerance to cadmium or lead-heavy metals, and expression of specific genes for cytochrome p450 enzymes associated with pyrethroid resistance in the mosquito. Methods. Juvenile aquatic stages of the mosquito were selected for tolerance to cadmiun or lead through chronic exposure of the stages to maximum acceptable toxicant concentrations (MATCs) of the metals. Using real-time quantitative polymerase chain reaction (qPCR), three replicates each of male …

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Improving Sterile Insect Technique (Sit) For Tsetse Flies Through Research On Their Symbionts And Pathogens, Adly M.M. Abd-Alla, Max Bergoin, Andrew G. Parker, Nguya K. Maniania, Just M. Vlak, Kostas Bourtzis, Drion G. Boucias, Serap Aksoy Mar 2013

Improving Sterile Insect Technique (Sit) For Tsetse Flies Through Research On Their Symbionts And Pathogens, Adly M.M. Abd-Alla, Max Bergoin, Andrew G. Parker, Nguya K. Maniania, Just M. Vlak, Kostas Bourtzis, Drion G. Boucias, Serap Aksoy

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Tsetse flies (Diptera: Glossinidae) are the cyclical vectors of the trypanosomes, which cause human African trypanosomosis (HAT) or sleeping sickness in humans and African animal trypanosomosis (AAT) or nagana in animals. Due to the lack of effective vaccines and inexpensive drugs for HAT, and the development of resistance of the trypanosomes against the available trypanocidal drugs, vector control remains the most efficient strategy for sustainable management of these diseases. Among the control methods used for tsetse flies, Sterile Insect Technique (SIT), in the frame of area-wide integrated pest management (AW-IPM), represents an effective tactic to suppress and/or eradicate tsetse flies. …

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The Functioning Of Species-Specific Olfactory Pheromones In The Biology Of A Mosquito-Eating Jumping Spider From East Africa, Fiona R. Cross, Robert R. Jackson Mar 2013

The Functioning Of Species-Specific Olfactory Pheromones In The Biology Of A Mosquito-Eating Jumping Spider From East Africa, Fiona R. Cross, Robert R. Jackson

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Having unique, complex eyes and vision based on exceptional spatial acuity, salticid spiders are known for their vision-based predatory and mating strategies. Yet Evarcha culicivora, the salticid we consider here, is known for predatory and mating strategies based strongly on the interplay of vision and olfaction. This unusual East African species feeds indirectly on vertebrate blood by choosing blood-carrying female mosquitoes as preferred prey, which it can identify by sight and by smell. Moreover, E. culicivora's mating strategy is unusual because, unlike the prevailing general pattern among spiders, where males are more active in courtship and females are more active …

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Repellent, Irritant And Toxic Effects Of 20 Plant Extracts On Adults Of The Malaria Vector Anopheles Gambiae Mosquito, Emilie Deletre, Thibaud Martin, Pascal Campagne, Denis Bourguet, Andy Cadin, Chantal Menut, Romain Bonafos, Fabrice Chandre Feb 2013

Repellent, Irritant And Toxic Effects Of 20 Plant Extracts On Adults Of The Malaria Vector Anopheles Gambiae Mosquito, Emilie Deletre, Thibaud Martin, Pascal Campagne, Denis Bourguet, Andy Cadin, Chantal Menut, Romain Bonafos, Fabrice Chandre

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Pyrethroid insecticides induce an excito-repellent effect that reduces contact between humans and mosquitoes. Insecticide use is expected to lower the risk of pathogen transmission, particularly when impregnated on long-lasting treated bednets. When applied at low doses, pyrethroids have a toxic effect, however the development of pyrethroid resistance in several mosquito species may jeopardize these beneficial effects. The need to find additional compounds, either to kill disease-carrying mosquitoes or to prevent mosquito contact with humans, therefore arises. In laboratory conditions, the effects (i.e., repellent, irritant and toxic) of 20 plant extracts, mainly essential oils, were assessed on adults of Anopheles gambiae, …

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Effects Of Mulching, N-Fertilization And Intercropping With Desmodium Uncinatum On Striga Hermonthica Infestation In Maize, Charles A.O. Midega, Jimmy Pittchar, Daisy Salifu, John A. Pickett, Zeyaur R. Khan Feb 2013

Effects Of Mulching, N-Fertilization And Intercropping With Desmodium Uncinatum On Striga Hermonthica Infestation In Maize, Charles A.O. Midega, Jimmy Pittchar, Daisy Salifu, John A. Pickett, Zeyaur R. Khan

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The parasitic weed Striga hermonthica is a major constraint to maize production in sub-Saharan Africa and causes serious food insecurity. We discovered serendipitously an effective control method for the weed that involves intercropping cereals with the fodder legume, silverleaf desmodium, Desmodium uncinatum (Jacq.) DC., through mechanisms that involve soil shading and nitrogen fixation. In the current study we investigated long-term effects of inorganic nitrogen (N), mulching and D. uncinatum, singly and in combinations, on S. hermonthica infestation, maize plant growth and grain yields. Treatments comprised sole maize with and without 120 kg N/ha; sole maize plots covered with maize straw …

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Diversity Of Stem Borer Parasitoids And Their Associated Wild Host Plants In South Africa And Mozambique, H. J. Moolman, J. Van Den Berg, D. Conlong, D. Cugala, S. J. Siebert, B. P. Le Ru Feb 2013

Diversity Of Stem Borer Parasitoids And Their Associated Wild Host Plants In South Africa And Mozambique, H. J. Moolman, J. Van Den Berg, D. Conlong, D. Cugala, S. J. Siebert, B. P. Le Ru

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The diversity of lepidopterous stem borers, their parasitoids and their associated wild host plants was studied in South Africa between 2006 and 2009 and in Mozambique between 2005 and 2010. In South Africa, 20 species of parasitoids were recovered from 17 stem borer species collected on 16 wild host plant species. From Mozambique, 14 parasitoid species were recorded from 16 stem borer species collected on 14 wild host plant species. The highest diversity of parasitoids was recorded on stem borers that attacked the host plants Phragmites australis (7 spp.) and Panicum maximum (6 spp.), in South Africa and Mozambique, respectively. …

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Two Sugar Isomers Influence Host Plant Acceptance By A Cereal Caterpillar Pest, G. Juma, M. Thiongo, L. Dutaur, K. Rharrabe, F. Marion-Poll, B. Le Ru, G. Magoma, J. F. Silvain, P. A. Calatayud Feb 2013

Two Sugar Isomers Influence Host Plant Acceptance By A Cereal Caterpillar Pest, G. Juma, M. Thiongo, L. Dutaur, K. Rharrabe, F. Marion-Poll, B. Le Ru, G. Magoma, J. F. Silvain, P. A. Calatayud

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Abstract Plant sugars are often considered as primary feeding stimuli, conditioning host plant acceptance by herbivorous insects. Of the nine sugars identified from methanolic extracts of seven grass species, only turanose, a sucrose isomer, was negatively correlated with the survival and growth of the noctuid larva of cereal stemborer, Busseola fusca. Sucrose was the most abundant sugar, although it did not vary significantly in concentration among the plant species studied. Using Styrofoam™ cylinders impregnated with increasing concentrations of turanose or sucrose, the two sugars had opposing effects: turanose appeared phagodeterrent while sucrose was phagostimulatory. Electrophysiological studies indicated that B. fusca …

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Climate Change Or Urbanization? Impacts On A Traditional Coffee Production System In East Africa Over The Last 80 Years, Juliana Jaramillo, Mamoudou Setamou, Eric Muchugu, Adenirin Chabi-Olaye, Alvaro Jaramillo, Joseph Mukabana, Johnson Maina, Simon Gathara, Christian Borgemeister Jan 2013

Climate Change Or Urbanization? Impacts On A Traditional Coffee Production System In East Africa Over The Last 80 Years, Juliana Jaramillo, Mamoudou Setamou, Eric Muchugu, Adenirin Chabi-Olaye, Alvaro Jaramillo, Joseph Mukabana, Johnson Maina, Simon Gathara, Christian Borgemeister

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Global environmental changes (GEC) such as climate change (CC) and climate variability have serious impacts in the tropics, particularly in Africa. These are compounded by changes in land use/land cover, which in turn are driven mainly by economic and population growth, and urbanization. These factors create a feedback loop, which affects ecosystems and particularly ecosystem services, for example plant-insect interactions, and by consequence agricultural productivity. We studied effects of GEC at a local level, using a traditional coffee production area in greater Nairobi, Kenya. We chose coffee, the most valuable agricultural commodity worldwide, as it generates income for 100 million …

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Comparison Of The Effects Of Extracts From Three Vitex Plant Species On Anopheles Gambiae S.S. (Diptera: Culicidae) Larvae, Mokua G. Nyamoita, Innocent Ester, Mbwambo H. Zakaria, Lwande Wilber, Ochola J. Bwire, Hassanali Ahmed Jan 2013

Comparison Of The Effects Of Extracts From Three Vitex Plant Species On Anopheles Gambiae S.S. (Diptera: Culicidae) Larvae, Mokua G. Nyamoita, Innocent Ester, Mbwambo H. Zakaria, Lwande Wilber, Ochola J. Bwire, Hassanali Ahmed

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Acetone and methanol extracts of different parts of three Vitex species (leaves and stem bark of Vitex trifolia, leaves, stem bark and root bark of Vitex schiliebenii and stem and root bark of Vitex payos) were evaluated for their potential to control Anopheles gambiae Giles s.s. larvae (Diptera: Culicidae). The extracts gave different levels and rate of mortality of the larvae. Some (methanol extract of V. trifolia leaves, acetone extracts of stem bark and leaves of V. schiliebenii, acetone extract of root bark of V. payos) caused 100% mortality at 100ppm in 72h, with those of V. schiliebenii and V. …

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Occurrence, Diversity And Pattern Of Damage Of Oplostomus Species (Coleoptera: Scarabaeidae), Honey Bee Pests In Kenya, Ayuka T. Fombong, Fiona N. Mumoki, Elliud Muli, Daniel K. Masiga, Richard T. Arbogast, Peter E.A. Teal, Baldwyn Torto Jan 2013

Occurrence, Diversity And Pattern Of Damage Of Oplostomus Species (Coleoptera: Scarabaeidae), Honey Bee Pests In Kenya, Ayuka T. Fombong, Fiona N. Mumoki, Elliud Muli, Daniel K. Masiga, Richard T. Arbogast, Peter E.A. Teal, Baldwyn Torto

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Several arthropod pests including the hive beetles Aethina tumida and Oplostomus haroldi and the ectoparasite Varroa destructor have recently been identified as associated with honey bee colonies in Kenya. Here, we report the first documentation of Oplostomus fuligineus in Kenya, a related scarab of O. haroldi, and distribution, diversity and pattern of damage of the two scarab species on honey bee colonies. Sequence analyses of mitochondrial cytochrome oxidase I gene revealed that there was sufficient sequence divergence to separate both Oplostomus beetles. The same molecular marker separated O. haroldi according to place of origin in Kenya. We further show from …

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Development Of A Gravid Trap For Collecting Live Malaria Vectors Anopheles Gambiae S.L, Sisay Dugassa, Jenny M. Lindh, Florence Oyieke, Wolfgang R. Mukabana, Steven W. Lindsay, Ulrike Fillinger Jan 2013

Development Of A Gravid Trap For Collecting Live Malaria Vectors Anopheles Gambiae S.L, Sisay Dugassa, Jenny M. Lindh, Florence Oyieke, Wolfgang R. Mukabana, Steven W. Lindsay, Ulrike Fillinger

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BACKGROUND: Effective malaria vector control targeting indoor host-seeking mosquitoes has resulted in fewer vectors entering houses in many areas of sub-Saharan Africa, with the proportion of vectors outdoors becoming more important in the transmission of this disease. This study aimed to develop a gravid trap for the outdoor collection of the malaria vector Anopheles gambiae s.l. based on evaluation and modification of commercially available gravid traps. METHODS: Experiments were implemented in an 80 m(2) semi-field system where 200 gravid Anopheles gambiae s.s. were released nightly. The efficacy of the Box, CDC and Frommer updraft gravid traps was compared. The Box …

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Mycoplasma Feriruminatoris Sp. Nov., A Fast Growing Mycoplasma Species Isolated From Wild Caprinae, Joerg Jores, Anne Fischer, Pascal Sirand-Pugnet, Andreas Thomann, Elisabeth M. Liebler-Tenorio, Christiane Schnee, Ivette Santana-Cruz, Martin Heller, Joachim Frey Jan 2013

Mycoplasma Feriruminatoris Sp. Nov., A Fast Growing Mycoplasma Species Isolated From Wild Caprinae, Joerg Jores, Anne Fischer, Pascal Sirand-Pugnet, Andreas Thomann, Elisabeth M. Liebler-Tenorio, Christiane Schnee, Ivette Santana-Cruz, Martin Heller, Joachim Frey

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Five Mycoplasma strains from wild Caprinae were analyzed: four from Alpine ibex (Capra ibex) which died at the Berlin Zoo between 1993 and 1994, one from a Rocky Mountain goat collected in the USA prior to 1987. These five strains represented a population different from the populations belonging to the 'Mycoplasma mycoides cluster' as tested using multi locus sequence typing, Matrix-assisted laser desorption/ionization time of flight mass spectrometry analysis and DNA-DNA hybridization. Analysis of the 16S rRNA gene (rrs), genomic sequence based in silico as well as laboratory DNA-DNA hybridization, and the analysis of phenotypic traits in particular their exceptionally …

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First Record Of Calophya Schini (Hemiptera: Calophyidae) In Ethiopia And Kenya, William A. Overholt, Robert S. Copeland, Susan E. Halbert Jan 2013

First Record Of Calophya Schini (Hemiptera: Calophyidae) In Ethiopia And Kenya, William A. Overholt, Robert S. Copeland, Susan E. Halbert

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A South American leaf galling psyllid, Calophya schini Tuthill, has recently been discovered attacking the South American tree Schinus molle L. in Kenya and Ethiopia. This represents the first record of the psyllid in each country and the only record of C. schini in Africa outside of South Africa. In Kenya, the psyllid was parasitized by an unidentified tetrastichine (Eulophidae), probably of the genus Tamarixia, while in Ethiopia C. schini nymphs were heavily parasitized by an unidentified hymenopteran. Copyright © icipe 2013.

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Comparison Of Volatile Blends And Nucleotide Sequences Of Two Beauveria Bassiana Isolates Of Different Virulence And Repellency Towards The Termite Macrotermes Michealseni, D. M. Mburu, N. K. Maniania, A. Hassanali Jan 2013

Comparison Of Volatile Blends And Nucleotide Sequences Of Two Beauveria Bassiana Isolates Of Different Virulence And Repellency Towards The Termite Macrotermes Michealseni, D. M. Mburu, N. K. Maniania, A. Hassanali

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Isolates of the fungus Beauveria bassiana have different levels of virulence and repellency against the termite Macrotermes michaelseni. In the present study, we compared the volatile profiles and gene sequences of two isolates of the fungus with different levels of virulence and repellence to the termite. Gas chromatography-mass spectrometric analyses showed quantitative and qualitative differences in the composition of volatiles of the two isolates. The repellencies of synthetic blends of 10 prominent components that mimicked the volatiles of each of the two isolates were significantly different. Subtractive bioassays showed that the repellency of each isolate was due to synergistic effects …

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Common Host-Derived Chemicals Increase Catches Of Disease-Transmitting Mosquitoes And Can Improve Early Warning Systems For Rift Valley Fever Virus, David P. Tchouassi, Rosemary Sang, Catherine L. Sole, Armanda D.S. Bastos, Peter E.A. Teal, Christian Borgemeister, Baldwyn Torto Jan 2013

Common Host-Derived Chemicals Increase Catches Of Disease-Transmitting Mosquitoes And Can Improve Early Warning Systems For Rift Valley Fever Virus, David P. Tchouassi, Rosemary Sang, Catherine L. Sole, Armanda D.S. Bastos, Peter E.A. Teal, Christian Borgemeister, Baldwyn Torto

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Rift Valley fever (RVF), a mosquito-borne zoonosis, is a major public health and veterinary problem in sub-Saharan Africa. Surveillance to monitor mosquito populations during the inter-epidemic period (IEP) and viral activity in these vectors is critical to informing public health decisions for early warning and control of the disease. Using a combination of field bioassays, electrophysiological and chemical analyses we demonstrated that skin-derived aldehydes (heptanal, octanal, nonanal, decanal) common to RVF virus (RVFV) hosts including sheep, cow, donkey, goat and human serve as potent attractants for RVFV mosquito vectors. Furthermore, a blend formulated from the four aldehydes and combined with …

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Love Is In The Air: Olfaction-Based Mate-Odour Identification By Jumping Spiders From The Genus Cyrba, Ana M. Cerveira, Robert R. Jackson Jan 2013

Love Is In The Air: Olfaction-Based Mate-Odour Identification By Jumping Spiders From The Genus Cyrba, Ana M. Cerveira, Robert R. Jackson

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Jumping spiders (Salticidae) are known for having good eyesight, but the extent to which they rely on olfaction is poorly understood. Here we demonstrate for the first time that olfactory pheromones are used by two species from the salticid genus Cyrba (C. algerina and C. ocellata). Using a Y-shape olfactometer, we investigated the ability of adult males and females of both species to discriminate between mate and non-mate odour. A hidden spider or a spider's draglines (no spider present) were used as odour sources. There was no evident response by females of either Cyrba species to any tested odour. Males …

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Chemical Communication In The Honey Bee Scarab Pest Oplostomus Haroldi: Role Of (Z)-9-Pentacosene, Ayuka T. Fombong, Peter E.A. Teal, Richard T. Arbogast, Paul N. Ndegwa, Lucy W. Irungu, Baldwyn Torto Dec 2012

Chemical Communication In The Honey Bee Scarab Pest Oplostomus Haroldi: Role Of (Z)-9-Pentacosene, Ayuka T. Fombong, Peter E.A. Teal, Richard T. Arbogast, Paul N. Ndegwa, Lucy W. Irungu, Baldwyn Torto

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Oplostomus haroldi Witte belongs to a unique genus of afro-tropical scarabs that have associations with honey bee colonies, from which they derive vital nutrients. Although the attributes of the honey bee nest impose barriers to communication among nest invaders, this beetle still is able to detect conspecific mates for reproduction. Here, we show, through behavioral studies, that cuticular lipids serve as mate discrimination cues in this beetle. We observed five steps during mating: arrestment, alignment, mounting, and copulation, and a post-copulatory stage, lasting ~40-70 % of the total mating duration, that suggested mate guarding. Chemical analysis identified the same nine …

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Farmers' Perceptions Of Cotton Pests And Their Management In Western Kenya, Charles A.O. Midega, Isaac M. Nyang'au, Jimmy Pittchar, Michael A. Birkett, John A. Pickett, Miguel Borges, Zeyaur R. Khan Dec 2012

Farmers' Perceptions Of Cotton Pests And Their Management In Western Kenya, Charles A.O. Midega, Isaac M. Nyang'au, Jimmy Pittchar, Michael A. Birkett, John A. Pickett, Miguel Borges, Zeyaur R. Khan

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Cotton (Gossypium hirsutum L.) production in western Kenya is severely affected by insect pests, resulting in poor yields in spite of the growing demand for the commodity. One of the key constraints to establishing effective pest management approaches for smallholder farmers is the lack of adequate information about farmers' knowledge, perceptions and practices in pest management. This study was therefore conducted to (1) evaluate farmers' knowledge and perceptions of cotton pests; (2) examine farmers' current practices in managing cotton pests; (3) identify pest management challenges and intervention opportunities in order to develop efficient integrated pest management (IPM) approaches. A total …

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Semiochemicals From Herbivory Induced Cotton Plants Enhance The Foraging Behavior Of The Cotton Boll Weevil, Anthonomus Grandis, D. M. Magalhães, M. Borges, R. A. Laumann, E. R. Sujii, P. Mayon, J. C. Caulfield, C. A.O. Midega, Z. R. Khan, J. A. Pickett, M. A. Birkett, M. C. Blassioli-Moraes Dec 2012

Semiochemicals From Herbivory Induced Cotton Plants Enhance The Foraging Behavior Of The Cotton Boll Weevil, Anthonomus Grandis, D. M. Magalhães, M. Borges, R. A. Laumann, E. R. Sujii, P. Mayon, J. C. Caulfield, C. A.O. Midega, Z. R. Khan, J. A. Pickett, M. A. Birkett, M. C. Blassioli-Moraes

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The boll weevil, Anthonomus grandis, has been monitored through deployment of traps baited with aggregation pheromone components. However, field studies have shown that the number of insects caught in these traps is significantly reduced during cotton squaring, suggesting that volatiles produced by plants at this phenological stage may be involved in attraction. Here, we evaluated the chemical profile of volatile organic compounds (VOCs) emitted by undamaged or damaged cotton plants at different phenological stages, under different infestation conditions, and determined the attractiveness of these VOCs to adults of A. grandis. In addition, we investigated whether or not VOCs released by …

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Species Richness And Nest Dispersion Of Some Tropical Meliponine Bees (Apidae: Meliponinae) In Six Habitat Types In The Kakamega Forest, Western Kenya, Kiatoko Nkoba, Suresh Kumar Raina, Elluid Muli, Klaus Mithofer, Jones Mueke Dec 2012

Species Richness And Nest Dispersion Of Some Tropical Meliponine Bees (Apidae: Meliponinae) In Six Habitat Types In The Kakamega Forest, Western Kenya, Kiatoko Nkoba, Suresh Kumar Raina, Elluid Muli, Klaus Mithofer, Jones Mueke

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A study to determine the species richness and spatial distribution of five meliponine bee species in three different habitats in the Kakamega forest was undertaken for the first time. Two forest (indigenous and mixed indigenous) and two grassland (with Eucalyptus spp. trees and indigenous trees) types, along with homesteads (in the vicinity of mixed indigenous forest and indigenous forest, respectively), were surveyed. Line transect methods were used in the nest survey in each habitat. The highest number of species was recorded in the indigenous forest, while no nest was discovered in the grassland with Eucalyptus spp. trees. The mean number …

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Disentangling Dispersal, Vicariance And Adaptive Radiation Patterns: A Case Study Using Armyworms In The Pest Genus Spodoptera (Lepidoptera: Noctuidae), Gael J. Kergoat, Dorothy P. Prowell, Bruno P. Le Ru, Andrew Mitchell, Pascaline Dumas, Anne Laure Clamens, Fabien L. Condamine, Jean François Silvain Dec 2012

Disentangling Dispersal, Vicariance And Adaptive Radiation Patterns: A Case Study Using Armyworms In The Pest Genus Spodoptera (Lepidoptera: Noctuidae), Gael J. Kergoat, Dorothy P. Prowell, Bruno P. Le Ru, Andrew Mitchell, Pascaline Dumas, Anne Laure Clamens, Fabien L. Condamine, Jean François Silvain

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Thanks to the recent development of integrative approaches that combine dated phylogenies with models of biogeographic evolution, it is becoming more feasible to assess the roles of dispersal and vicariance in creating complex patterns of geographical distribution. However, the historical biogeography of taxa with good dispersal abilities, like birds or flying insects, still remains largely unknown because of the lack of complete phylogenies accompanied by robust estimates of divergence times. In this study, we investigate the evolution and historical biogeography of the globally distributed pest genus Spodoptera (Lepidoptera: Noctuidae) using complete taxon sampling and an extensive set of analyses. Through …

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Secondary Contact And Admixture Between Independently Invading Populations Of The Western Corn Rootworm, Diabrotica Virgifera Virgifera In Europe, Gérald Bermond, Marc Ciosi, Eric Lombaert, Aurélie Blin, Marco Boriani, Lorenzo Furlan, Stefan Toepfer, Thomas Guillemaud Nov 2012

Secondary Contact And Admixture Between Independently Invading Populations Of The Western Corn Rootworm, Diabrotica Virgifera Virgifera In Europe, Gérald Bermond, Marc Ciosi, Eric Lombaert, Aurélie Blin, Marco Boriani, Lorenzo Furlan, Stefan Toepfer, Thomas Guillemaud

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The western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae), is one of the most destructive pests of corn in North America and is currently invading Europe. The two major invasive outbreaks of rootworm in Europe have occurred, in North-West Italy and in Central and South-Eastern Europe. These two outbreaks originated from independent introductions from North America. Secondary contact probably occurred in North Italy between these two outbreaks, in 2008. We used 13 microsatellite markers to conduct a population genetics study, to demonstrate that this geographic contact resulted in a zone of admixture in the Italian region of Veneto. We show …

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Sheep Skin Odor Improves Trap Captures Of Mosquito Vectors Of Rift Valley Fever, David P. Tchouassi, Rosemary Sang, Catherine L. Sole, Armanda D.S. Bastos, Klaus Mithoefer, Baldwyn Torto Nov 2012

Sheep Skin Odor Improves Trap Captures Of Mosquito Vectors Of Rift Valley Fever, David P. Tchouassi, Rosemary Sang, Catherine L. Sole, Armanda D.S. Bastos, Klaus Mithoefer, Baldwyn Torto

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In recent years, the East African region has seen an increase in arboviral diseases transmitted by blood-feeding arthropods. Effective surveillance to monitor and reduce incidence of these infections requires the use of appropriate vector sampling tools. Here, trapped skin volatiles on fur from sheep, a known preferred host of mosquito vectors of Rift Valley fever virus (RVFV), were used with a standard CDC light trap to improve catches of mosquito vectors. We tested the standard CDC light trap alone (L), and baited with (a) CO2 (LC), (b) animal volatiles (LF), and (c) CO2 plus animal volatiles (LCF) in two highly …

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The Impact Of Desmodium Spp. And Cutting Regimes On The Agronomic And Economic Performance Of Desmodium-Maize Intercropping System In Western Kenya, M. Kifuko-Koech, P. Pypers, J. R. Okalebo, C. O. Othieno, Z. R. Khan, J. A. Pickett, A. K. Kipkoech, B. Vanlauwe Oct 2012

The Impact Of Desmodium Spp. And Cutting Regimes On The Agronomic And Economic Performance Of Desmodium-Maize Intercropping System In Western Kenya, M. Kifuko-Koech, P. Pypers, J. R. Okalebo, C. O. Othieno, Z. R. Khan, J. A. Pickett, A. K. Kipkoech, B. Vanlauwe

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Low soil fertility, stemborers (particularly, Chilo partellus) and Striga weeds (Striga hermonthica and Striga asiatica) are major limitations to production of maize in western Kenya. The " Push-Pull" technology ("PPT") has been described as an appropriate innovative technology capable of addressing these constraints. The technology involves intercropping maize with Desmodium and planting Napier grass (Pennisetum purpureum) around the intercrop, but in the current study a modified PPT was used and Napier grass was not included. Field trials were conducted in two locations in western Kenya during 4 subsequent seasons to test the hypothesis that maize yield, the degree of Striga …

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