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Articles 991 - 1020 of 1443

Full-Text Articles in Life Sciences

Bonobos Fall Within The Genomic Variation Of Chimpanzees, Anne Fischer, Kay Prüfer, Jeffrey M. Good, Michel Halbwax, Victor Wiebe, Claudine André, Rebeca Atencia, Lawrence Mugisha, Susan E. Ptak, Svante Pääbo Jul 2011

Bonobos Fall Within The Genomic Variation Of Chimpanzees, Anne Fischer, Kay Prüfer, Jeffrey M. Good, Michel Halbwax, Victor Wiebe, Claudine André, Rebeca Atencia, Lawrence Mugisha, Susan E. Ptak, Svante Pääbo

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To gain insight into the patterns of genetic variation and evolutionary relationships within and between bonobos and chimpanzees, we sequenced 150,000 base pairs of nuclear DNA divided among 15 autosomal regions as well as the complete mitochondrial genomes from 20 bonobos and 58 chimpanzees. Except for western chimpanzees, we found poor genetic separation of chimpanzees based on sample locality. In contrast, bonobos consistently cluster together but fall as a group within the variation of chimpanzees for many of the regions. Thus, while chimpanzees retain genomic variation that predates bonobo-chimpanzee speciation, extensive lineage sorting has occurred within bonobos such that much …

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Ultra-Prolonged Activation Of Co2-Sensing Neurons Disorients Mosquitoes, Stephanie Lynn Turner, Nan Li, Tom Guda, John Githure, Ring T. Cardé, Anandasankar Ray Jun 2011

Ultra-Prolonged Activation Of Co2-Sensing Neurons Disorients Mosquitoes, Stephanie Lynn Turner, Nan Li, Tom Guda, John Githure, Ring T. Cardé, Anandasankar Ray

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Carbon dioxide (CO2) present in exhaled air is the most important sensory cue for female blood-feeding mosquitoes, causing activation of long-distance host-seeking flight, navigation towards the vertebrate host 1 and, in the case of Aedes aegypti, increased sensitivity to skin odours2. The CO2 detection machinery is therefore an ideal target to disrupt host seeking. Here we use electrophysiological assays to identify a volatile odorant that causes an unusual, ultra-prolonged activation of CO2-detecting neurons in three major disease-transmitting mosquitoes: Anopheles gambiae, Culex quinquefasciatus and A. aegypti. Importantly, ultra-prolonged activation of these neurons severely compromises their ability subsequently to detect CO2 for …

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Wide-Scale Application Of Bti/Bs Biolarvicide In Different Aquatic Habitat Types In Urban And Peri-Urban Malindi, Kenya, Joseph M. Mwangangi, Samuel C. Kahindi, Lydiah W. Kibe, Joseph G. Nzovu, Peter Luethy, John I. Githure, Charles M. Mbogo Jun 2011

Wide-Scale Application Of Bti/Bs Biolarvicide In Different Aquatic Habitat Types In Urban And Peri-Urban Malindi, Kenya, Joseph M. Mwangangi, Samuel C. Kahindi, Lydiah W. Kibe, Joseph G. Nzovu, Peter Luethy, John I. Githure, Charles M. Mbogo

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Larval control is a major component in mosquito control programs. This study evaluated the wide-scale application of Bti/Bs biolarvicide (Bacillus thuringiensis var. israelensis [Bti] and Bacillus sphaericus [Bs]) in different aquatic habitats in urban and peri-urban Malindi, Kenya. This study was done from June 2006 to December 2007. The urban and peri-urban area of Malindi town was mapped and categorized in grid cells of 1 km2. A total of 16 1-km2 cells were selected based on presence Community Based Organization dealing with malaria control within the cells. Each of the 16 1-km2 cells was thoroughly searched for the presence of …

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Phylogenetics, Species Boundaries And Timing Of Resource Tracking In A Highly Specialized Group Of Seed Beetles (Coleoptera: Chrysomelidae: Bruchinae), Gael J. Kergoat, Bruno P. Le Ru, Gwenaelle Genson, Corinne Cruaud, Arnaud Couloux, Alex Delobel Jun 2011

Phylogenetics, Species Boundaries And Timing Of Resource Tracking In A Highly Specialized Group Of Seed Beetles (Coleoptera: Chrysomelidae: Bruchinae), Gael J. Kergoat, Bruno P. Le Ru, Gwenaelle Genson, Corinne Cruaud, Arnaud Couloux, Alex Delobel

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Though for a long time it was hypothesized that the extraordinary diversity of phytophagous insects was better explained by a synchronous pattern of co-diversification with plants, the results of recent studies have led to question this theory, suggesting that the diversification of insects occurred well after that of their hosts. In this study we address this issue by investigating the timing of diversification of a highly specialized group of seed beetles, which mostly feeds on legume plants from the tribe Indigofereae. To that purpose, a total of 130 specimens were sequenced for six genes and analyzed under a Bayesian phylogenetic …

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Study On Weight Loss And Moisture Regain Of Silk Cocoon Shells And Degummed Fibers From African Wild Silkmoths, Addis Teshome, S. K. Raina, F. Vollrath, J. M. Kabaru, J. Onyari, E. K. Nguku Jun 2011

Study On Weight Loss And Moisture Regain Of Silk Cocoon Shells And Degummed Fibers From African Wild Silkmoths, Addis Teshome, S. K. Raina, F. Vollrath, J. M. Kabaru, J. Onyari, E. K. Nguku

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A study was conducted to determine weight loss and moisture regain properties of silk cocoon shells, shell layers and degummed fibers of the four African wild silkmoths Anaphe panda, Argema mimosae, Epiphora bauhiniae and Gonometa postica and compare with the industry standard mulberry silkmoth, Bombyx mori. No. significant difference was observed between the moisture regain of the wild silk fibers after degumming. However, there were significant differences in weight loss and moisture regain between cocoon shells as well as shell layers. E. bauhiniae had the lowest weight loss and moisture regain of 23.19 and 5.64%, respectively while G. postica had …

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Plasmodium Falciparum Transmission And Aridity: A Kenyan Experience From The Dry Lands Of Baringo And Its Implications For Anopheles Arabiensis Control, Albert O. Mala, Lucy W. Irungu, Josephat I. Shililu, Ephantus J. Muturi, Charles M. Mbogo, Joseph K. Njagi, Wolfgang R. Mukabana, John I. Githure May 2011

Plasmodium Falciparum Transmission And Aridity: A Kenyan Experience From The Dry Lands Of Baringo And Its Implications For Anopheles Arabiensis Control, Albert O. Mala, Lucy W. Irungu, Josephat I. Shililu, Ephantus J. Muturi, Charles M. Mbogo, Joseph K. Njagi, Wolfgang R. Mukabana, John I. Githure

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Background: The ecology of malaria vectors particularly in semi-arid areas of Africa is poorly understood. Accurate knowledge on this subject will boost current efforts to reduce the burden of malaria in sub-Saharan Africa. The objective of this study was to describe the dynamics of malaria transmission in two model semi-arid sites (Kamarimar and Tirion) in Baringo in Kenya. Methods: Adult mosquitoes were collected indoors by pyrethrum spray collections (PSC) and outdoors by Centers for Disease Control (CDC) light traps and identified to species by morphological characteristics. Sibling species of Anopheles gambiae complex were further characterized by rDNA. PCR and enzyme-linked …

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Reliance On Trial And Error Signal Derivation By Portia Africana, An Araneophagic Jumping Spider From East Africa, Robert R. Jackson, Ximena J. Nelson May 2011

Reliance On Trial And Error Signal Derivation By Portia Africana, An Araneophagic Jumping Spider From East Africa, Robert R. Jackson, Ximena J. Nelson

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All species from the jumping spider (Salticidae) genus Portia appear to be predators that specialize at preying on other spiders by invading webs and, through aggressive mimicry, gaining dynamic fine control over the resident spider's behavior. From previous research, there is evidence that P. fimbriata, P. labiata and P. schultzi derive signals by trial and error. Here, we demonstrate that P. africana is another species that uses a trial and error, or generate and test, algorithm when deriving the aggressive-mimicry signals that will be appropriate in different predator-prey encounters. We discuss the implications of these new findings and the findings …

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Duration Analysis Of Technology Adoption Effects Of Dissemination Pathways: A Case Of 'Push-Pull' Technology For Control Of Striga Weeds And Stemborers In Western Kenya, A. W. Murage, G. Obare, J. Chianu, D. M. Amudavi, J. Pickett, Z. R. Khan May 2011

Duration Analysis Of Technology Adoption Effects Of Dissemination Pathways: A Case Of 'Push-Pull' Technology For Control Of Striga Weeds And Stemborers In Western Kenya, A. W. Murage, G. Obare, J. Chianu, D. M. Amudavi, J. Pickett, Z. R. Khan

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Since its introduction, the 'push-pull' technology (PPT) has been promoted as an innovative approach for addressing yield losses caused by Striga weeds and stemborer infestations on farmers' maize fields in western Kenya. The technology has been disseminated through different pathways each of which might have different uptake enhancement capabilities. This study was concerned with how different dissemination pathways impacted on farmers' time to adoption while controlling the effects of selected socio-economic and regional factors. This assessment was necessary in order to recommend which dissemination pathway or combination of pathways that could provide an effective dissemination strategy that speed up adoption, …

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Effects Of Prey-Spider Odour On Intraspecific Interactions Of Araneophagic Jumping Spiders, Fiona R. Cross, Robert R. Jackson May 2011

Effects Of Prey-Spider Odour On Intraspecific Interactions Of Araneophagic Jumping Spiders, Fiona R. Cross, Robert R. Jackson

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An important prediction from game theory is that the value of a resource will influence the level to which an animal is willing to escalate during conflict with conspecific rivals. Here we use this prediction as the rationale for experiments aimed at determining whether escalation decisions made by predators are influenced by the presence of preferred prey. The predators we use are adult individuals of Portia fimbriata, a jumping-spider (Salticidae) species from Queensland (Australia). P. fimbriata is known to prefer other salticid species as prey and can detect the odour of Jacksonoides queenslandicus, this being an especially common salticid species …

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A Longitudinal Study On Anopheles Mosquito Larval Abundance In Distinct Geographical And Environmental Settings In Western Kenya, Susan S. Imbahale, Krijn P. Paaijmans, Wolfgang R. Mukabana, Ron Van Lammeren, Andrew K. Githeko, Willem Takken Apr 2011

A Longitudinal Study On Anopheles Mosquito Larval Abundance In Distinct Geographical And Environmental Settings In Western Kenya, Susan S. Imbahale, Krijn P. Paaijmans, Wolfgang R. Mukabana, Ron Van Lammeren, Andrew K. Githeko, Willem Takken

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Background: As the ecology of mosquito larvae can be complex there is need to develop a rational framework for undertaking larval ecological studies. Local environmental characteristics, such as altitude, climate and land use, can significantly impact on phenology and population dynamics of mosquito larvae, and indirectly affect the dynamics of mosquito-borne diseases. The aim of this study was to assess the feasibility of implementing an integrated approach to larval source management under the distinct ecological settings. Methods. The study was conducted in two highland villages and one village, at a lower altitude, in the Lake Victoria basin, where malaria is …

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Tracking The Feeding Patterns Of Tsetse Flies (Glossina Genus) By Analysis Of Bloodmeals Using Mitochondrial Cytochromes Genes, Catherine N. Muturi, Johnson O. Ouma, Imna I. Malele, Raphael M. Ngure, Jane J. Rutto, Klaus M. Mithöfer, John Enyaru, Daniel K. Masiga Mar 2011

Tracking The Feeding Patterns Of Tsetse Flies (Glossina Genus) By Analysis Of Bloodmeals Using Mitochondrial Cytochromes Genes, Catherine N. Muturi, Johnson O. Ouma, Imna I. Malele, Raphael M. Ngure, Jane J. Rutto, Klaus M. Mithöfer, John Enyaru, Daniel K. Masiga

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Tsetse flies are notoriously difficult to observe in nature, particularly when populations densities are low. It is therefore difficult to observe them on their hosts in nature; hence their vertebrate species can very often only be determined indirectly by analysis of their gut contents. This knowledge is a critical component of the information on which control tactics can be developed. The objective of this study was to determine the sources of tsetse bloodmeals, hence investigate their feeding preferences. We used mitochondrial cytochrome c oxidase 1 (COI) and cytochrome b (cytb) gene sequences for identification of tsetse fly blood meals, in …

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Dry Season Ecology Of Anopheles Gambiae Complex Mosquitoes At Larval Habitats In Two Traditionally Semi-Arid Villages In Baringo, Kenya, Albert O. Mala, Lucy W. Irungu, Josephat I. Shililu, Ephantus J. Muturi, Charles C. Mbogo, Joseph K. Njagi, John I. Githure Mar 2011

Dry Season Ecology Of Anopheles Gambiae Complex Mosquitoes At Larval Habitats In Two Traditionally Semi-Arid Villages In Baringo, Kenya, Albert O. Mala, Lucy W. Irungu, Josephat I. Shililu, Ephantus J. Muturi, Charles C. Mbogo, Joseph K. Njagi, John I. Githure

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Background: Pre-adult stages of malaria vectors in semi-arid areas are confronted with highly variable and challenging climatic conditions. The objective of this study was to determine which larval habitat types are most productive in terms of larval densities in the dry and wet seasons within semi-arid environments, and how vector species productivity is partitioned over time. Methods: Larval habitats were mapped and larvae sampled longitudinally using standard dipping techniques. Larvae were identified to species level morphologically using taxonomic keys and to sub-species by polymerase chain reaction (PCR) methods. Physical characteristics of larval habitats, including water depth, turbidity, and presence of …

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Improvement Of A Synthetic Lure For Anopheles Gambiae Using Compounds Produced By Human Skin Microbiota, Niels O. Verhulst, Phoebe A. Mbadi, Gabriella Bukovinszkiné Kiss, Wolfgang R. Mukabana, Joop J.A. Van Loon, Willem Takken, Renate C. Smallegange Feb 2011

Improvement Of A Synthetic Lure For Anopheles Gambiae Using Compounds Produced By Human Skin Microbiota, Niels O. Verhulst, Phoebe A. Mbadi, Gabriella Bukovinszkiné Kiss, Wolfgang R. Mukabana, Joop J.A. Van Loon, Willem Takken, Renate C. Smallegange

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Background. Anopheles gambiae sensu stricto is considered to be highly anthropophilic and volatiles of human origin provide essential cues during its host-seeking behaviour. A synthetic blend of three human-derived volatiles, ammonia, lactic acid and tetradecanoic acid, attracts A. gambiae. In addition, volatiles produced by human skin bacteria are attractive to this mosquito species. The purpose of the current study was to test the effect of ten compounds present in the headspace of human bacteria on the host-seeking process of A. gambiae. The effect of each of the ten compounds on the attractiveness of a basic blend of ammonia, lactic and …

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Detection Of Phytoplasma By Loop-Mediated Isothermal Amplification Of Dna (Lamp), E. Obura, D. Masiga, F. Wachira, B. Gurja, Z. R. Khan Feb 2011

Detection Of Phytoplasma By Loop-Mediated Isothermal Amplification Of Dna (Lamp), E. Obura, D. Masiga, F. Wachira, B. Gurja, Z. R. Khan

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Napier stunt phytoplasma (16SrXI and 16SrIII) in eastern Africa is a serious threat to the expansion of Napier grass (Pennisetum purpureum) farming in the region, where it is widely cultivated as fodder in zero grazing livestock systems. The grass has high potential for bio-fuel production, and has been adopted by farmers as a countermeasure to cereal stem borer Lepidoptera, since it attracts and traps the insect. Diagnosis of stunt phytoplasma have been largely by nested polymerase chain reaction (nPCR) targeting the 16S rRNA gene. However, the method is laborious, costly and technically demanding. This investigation has developed a simpler but …

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Effect Of Infection By Metarhizium Anisopliae (Hypocreales: Clavicipitaceae) On The Feeding And Oviposition Of The Pea Leafminer Liriomyza Huidobrensis (Diptera: Agromyzidae) On Different Host Plants, L. N. Migiro, N. K. Maniania, A. Chabi-Olaye, A. Wanjoya, J. Vandenberg Feb 2011

Effect Of Infection By Metarhizium Anisopliae (Hypocreales: Clavicipitaceae) On The Feeding And Oviposition Of The Pea Leafminer Liriomyza Huidobrensis (Diptera: Agromyzidae) On Different Host Plants, L. N. Migiro, N. K. Maniania, A. Chabi-Olaye, A. Wanjoya, J. Vandenberg

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The effect of fungal infection by Metarhizium anisopliae on feeding and oviposition of adult Liriomyza huidobrensis was examined on three host plants, faba bean (Vicia faba), French bean (Phaseolus vuklgaris) and snow pea (Pisum sativum) in the laboratory. Flies were contaminated with dry conidia and allowed to feed and oviposit on the different host plants. Mortality in L. huidobrensis varied between 14% and 20% in the controls and between 77% and 100% in fungal treatments 120h post-infection for the three host plants. L. huidobrensis made more punctures (47.3-52.6cm-2) in the control than in the fungal treatments (23.1-26.9cm-2) for the three …

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Diversity Of Agromyzidae And Associated Hymenopteran Parasitoid Species In The Afrotropical Region: Implications For Biological Control, Robert Musundire, Adenirin Chabi-Olaye, Bernhard Löhr, Kerstin Krüger Feb 2011

Diversity Of Agromyzidae And Associated Hymenopteran Parasitoid Species In The Afrotropical Region: Implications For Biological Control, Robert Musundire, Adenirin Chabi-Olaye, Bernhard Löhr, Kerstin Krüger

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Agromyzidae (Diptera) is a family with many species of economic importance on agricultural plants. However, many species are attacked by hymenopteran parasitoids which are known to be habitat rather than species specific. In the Afrotropical region, information about agromyzid and parasitoid diversity in different habitats is scattered in literature. Our aim was to assemble this dispersed information and discuss future needs of biological control efforts against invasive agromyzids in the Afrotropics. From published information, 581 agromyzid records comprising 302 species from 20 genera were recorded from 48 plant families. Parasitoids (90 records) were associated only with 20 agromyzid species belonging …

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Spider Cognition, Robert R. Jackson, Fiona R. Cross Jan 2011

Spider Cognition, Robert R. Jackson, Fiona R. Cross

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Spiders, having minute brains, were once considered simple, instinct-driven automatons, but research on spider biology is revealing increasing evidence of their cognitive abilities. In this review, we discuss the complex, flexible behaviour of spiders, especially salticids, and highlight how sometimes the cognitive character of spider behaviour closely parallels that of much bigger animals. This includes the use of selective attention (both visual and olfactory) and the use of planned detours. The implications of these findings, and how they relate to bigger issues traditionally associated with big-brain animals, such as 'representation' and 'mind', are discussed. Also discussed are issues relating to …

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Sex Pheromone Composition And Reproductive Isolation In Two Busseola Species (Lepidoptera: Noctuidae) In Kenya, A. E. Félix, P. A. Calatayud, B. Le Ru, J. F. Silvain, B. Frérot Jan 2011

Sex Pheromone Composition And Reproductive Isolation In Two Busseola Species (Lepidoptera: Noctuidae) In Kenya, A. E. Félix, P. A. Calatayud, B. Le Ru, J. F. Silvain, B. Frérot

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Closely related species provide an interesting and useful model to understand mate communication diversification. Pre-mating isolation is the result of selection processes and is achieved by utilization of different sex pheromones, but also by different ecological and life traits such as geographic distribution, host-plant specialization and allochrony of sexual behavior. Here, we report sex pheromone identifications and pre-mating isolation of two closely related species of stemborers: Busseola segeta and the yet undescribed Busseola nov. sp., developing on different host-plants and in different geographical locations in Kenya. GC-MS analyses showed that the two species produced the same pheromone components, but in …

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Isolation, Phylogeny And Evolution Of The Symrk Gene In The Legume Genus Lupinus L., Frédéric Mahé, Dragomira Markova, Rémy Pasquet, Marie Thérèse Misset, Abdelkader Aïnouche Jan 2011

Isolation, Phylogeny And Evolution Of The Symrk Gene In The Legume Genus Lupinus L., Frédéric Mahé, Dragomira Markova, Rémy Pasquet, Marie Thérèse Misset, Abdelkader Aïnouche

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SymRK is one of the key genes involved in initial steps of legume symbiotic association with fungi (mycorrhization) and nitrogen-fixing bacteria (nodulation). A large portion of the sequence encoding the extracellular domain of SYMRK was obtained for 38 lupine accessions and 2 outgroups in order to characterize this region, to evaluate its phylogenetic utility, and to examine whether its molecular evolutionary pattern is correlated with rhizobial diversity and specificity in Lupinus. The data suggested that, in Lupinus, SymRK is a single copy gene that shows good phylogenetic potential. Accordingly, SymRK provided additional support to previous molecular phylogenies, and shed additional …

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The Flight Activity Of Prostephanus Truncatus (Horn) (Coleoptera: Bostrichidae) And Teretrius Nigrescens Lewis (Coleoptera: Histeridae) In Kenya, Bonaventure Aman Omondi, Nanqing Jiang, Johnnie Van Den Berg, Fritz Schulthess Jan 2011

The Flight Activity Of Prostephanus Truncatus (Horn) (Coleoptera: Bostrichidae) And Teretrius Nigrescens Lewis (Coleoptera: Histeridae) In Kenya, Bonaventure Aman Omondi, Nanqing Jiang, Johnnie Van Den Berg, Fritz Schulthess

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The invasive storage pest, the larger grain borer (LGB) Prostephanus truncatus (Horn), was introduced into the maize-deficit, semi-arid areas of the eastern region in Kenya in the early 1980s. In spite of containment efforts and the introduction of the predator Teretrius nigrescens Lewis from Mexico, LGB has spread to the main maize production zone in western Kenya during the past five years. The present work presents results from a 28-month monitoring effort of LGB and its predator, using pheromone traps at five locations along an east-west transect across Kenya. LGB occurred in all regions with highest trap catches in the …

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Phylogeographic Structure Of Teretrius Nigrescens (Coleoptera: Histeridae) Predator Of The Invasive Post Harvest Pest Prostephanus Truncatus (Coleoptera: Bostrichidae)., B. A. Omondi, J. Van Den Berg, D. Masiga, F. Schulthess Jan 2011

Phylogeographic Structure Of Teretrius Nigrescens (Coleoptera: Histeridae) Predator Of The Invasive Post Harvest Pest Prostephanus Truncatus (Coleoptera: Bostrichidae)., B. A. Omondi, J. Van Den Berg, D. Masiga, F. Schulthess

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The invasive larger grain borer Prostephanus truncatus (Horn) is the most important pest of farm-stored maize in Africa. It was introduced into the continent from Mesoamerica in the late 1970s and by 2008 had spread to at least 18 countries. Classical biological control using two populations of the predator Teretrius nigrescens Lewis achieved long-term and cost effective control in warm-humid areas, but not in cool and hot-dry zones. The present study investigated the phylogenetic relationships between geographical populations of the predator. Ten populations of T. nigrescens were studied using randomly amplified polymorphic DNA polymerase chain reaction (RAPD-PCR), sequence analysis of …

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Oviposition Preferences Of The African Wild Silkmoth, Gonometa Postica Walker (Lepidoptera: Lasiocampidae) On Different Substrates, Ken O. Fening, Esther N. Kioko, Jones M. Mueke, Suresh K. Raina Jan 2011

Oviposition Preferences Of The African Wild Silkmoth, Gonometa Postica Walker (Lepidoptera: Lasiocampidae) On Different Substrates, Ken O. Fening, Esther N. Kioko, Jones M. Mueke, Suresh K. Raina

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Gonometa postica Walker (Lepidoptera: Lasiocampidae) is currently being utilised for commercial wild silk production in Eastern Kenya. The oviposition preferences of female G. postica on four substrates in a net-sleeved cage was studied in the laboratory in the long and short rainy seasons in 2007 for two generations, i. e. early (late March to April) and late flights (late September to October) of the moth. The first generation moths laid the highest number of eggs on net sleeves followed by plastic pot, twigs and wooden plank, whereas the second generation moths preferred wooden plank and net sleeves over the plastic …

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Parasitism Of Lepidopterous Stem Borers In Cultivated And Natural Habitats, Duna Madu Mailafiya, Bruno Pierre Le Ru, Eunice Waitherero Kairu, Stéphane Dupas, Paul-André Calatayud Jan 2011

Parasitism Of Lepidopterous Stem Borers In Cultivated And Natural Habitats, Duna Madu Mailafiya, Bruno Pierre Le Ru, Eunice Waitherero Kairu, Stéphane Dupas, Paul-André Calatayud

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Plant infestation, stem borer density, parasitism, and parasitoid abundance were assessed during two years in two host plants, Zea mays (L.) (Cyperales: Poaceae) and Sorghum bicolor (L.) (Cyperales: Poaceae), in cultivated habitats. The four major host plants (Cyperus spp., Panicum spp., Pennisetum spp., and Sorghum spp.) found in natural habitats were also assessed, and both the cultivated and natural habitat species occurred in four agroecological zones in Kenya. Across habitats, plant infestation (23.2%), stem borer density (2.2 per plant), and larval parasitism (15.0%) were highest in maize in cultivated habitats. Pupal parasitism was not higher than 4.7% in both habitats, …

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Construction Of A Ssr-Based Genetic Map And Identification Of Qtl For Domestication Traits Using Recombinant Inbred Lines From A Cross Between Wild And Cultivated Cowpea (V. Unguiculata (L.) Walp.), Mebeaselassie Andargie, Remy S. Pasquet, Bhavani S. Gowda, Geoffrey M. Muluvi, Michael P. Timko Jan 2011

Construction Of A Ssr-Based Genetic Map And Identification Of Qtl For Domestication Traits Using Recombinant Inbred Lines From A Cross Between Wild And Cultivated Cowpea (V. Unguiculata (L.) Walp.), Mebeaselassie Andargie, Remy S. Pasquet, Bhavani S. Gowda, Geoffrey M. Muluvi, Michael P. Timko

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Cowpea (Vigna unguiculata (L.) Walp.) is a grain legume commonly grown and consumed in many parts of the tropics and subtropics. A genetic linkage map was constructed using simple sequence repeat (SSR) markers and a recombinant inbred (RI) population of159 individuals derived from a cross between the breeding line 524B, a California Blackeye, and 219-01, a perennial wild cowpea from Kenya. Out of 912 primer combinations predicted to amplify SSRs in cowpea, 639 reliably produced amplification products in PCR assays and 202 (31.6%) were polymorphic between the two parents. These polymorphic SSRs were used to construct a genetic map consisting …

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Dissemination Of Entomopathogenic Fungi Using Busseola Fusca Male As Vector, Nguya K. Maniania, Elizabeth Ouna, Peter Ahuya, Brigitte Frérot, Anne Emmanuelle Félix, Bruno Le Ru, Paul André Calatayud Jan 2011

Dissemination Of Entomopathogenic Fungi Using Busseola Fusca Male As Vector, Nguya K. Maniania, Elizabeth Ouna, Peter Ahuya, Brigitte Frérot, Anne Emmanuelle Félix, Bruno Le Ru, Paul André Calatayud

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The stem borer, Busseola fusca (Fuller), is an important pest of maize Zea mays L. and sorghum Sorghum bicolor (L.) in eastern and southern Africa. To control this pest, biological control methods including the use of entomopathogenic fungi are being considered. The pathogenicity of one isolate of Metarhizium anisopliae (Metsch.) Sorok. and one isolate of Beauveria bassiana Bals. (Vuill.) were first tested on different developmental stages of B. fusca including eggs, neonate, 2nd and 3rd-instar larvae. Both fungal isolates were pathogenic to all the stages tested. However, differences in mortality were observed among larvae that hatched from treated egg masses. …

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Flexibility In The Foraging Strategies Of Spiders, Ximena J. Nelson, Robert R. Jackson Jan 2011

Flexibility In The Foraging Strategies Of Spiders, Ximena J. Nelson, Robert R. Jackson

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Although many spiders build prey-capture webs, spider foraging strategies include species that, instead of building webs, deploy silk in other ways for prey capture. Additionally, there are species that capture prey, either by ambush or by active pursuit, without making notable use of silk in the process. There are striking examples of predatory specialisation from spiders, particularly among the Salticidae, suggesting that assumptions about adaptive trade-offs, in which the small nervous systems of spiders might constrain their cognitive or sensory abilities, need to be carefully evaluated. Predatory versatility, whereby an individual spider adopts a conditional strategy with which it classifies …

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Repellent Activity Of Catmint, Nepeta Cataria, And Iridoid Nepetalactone Isomers Against Afro-Tropical Mosquitoes, Ixodid Ticks And Red Poultry Mites, Michael A. Birkett, Ahmed Hassanali, Solveig Hoglund, Jan Pettersson, John A. Pickett Jan 2011

Repellent Activity Of Catmint, Nepeta Cataria, And Iridoid Nepetalactone Isomers Against Afro-Tropical Mosquitoes, Ixodid Ticks And Red Poultry Mites, Michael A. Birkett, Ahmed Hassanali, Solveig Hoglund, Jan Pettersson, John A. Pickett

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The repellent activity of the essential oil of the catmint plant, Nepeta cataria (Lamiaceae), and the main iridoid compounds (4aS,7S,7aR) and (4aS,7S,7aS)-nepetalactone, was assessed against (i) major Afro-tropical pathogen vector mosquitoes, i.e. The malaria mosquito, Anopheles gambiae s.s. and the Southern house mosquito, Culex quinquefasciatus, using a World Health Organisation (WHO)-approved topical application bioassay (ii) the brown ear tick, Rhipicephalus appendiculatus, using a climbing repellency assay, and (iii) the red poultry mite, Dermanyssus gallinae, using field trapping experiments. Gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS) analysis of two N. cataria chemotypes (A and B) used in the repellency assays …

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Interpopulation Variation In Kairomone Use By Cyrba Algerina, An Araneophagic Jumping Spider From Portugal, Ana M. Cerveira, Robert R. Jackson Jan 2011

Interpopulation Variation In Kairomone Use By Cyrba Algerina, An Araneophagic Jumping Spider From Portugal, Ana M. Cerveira, Robert R. Jackson

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Geographic variation in a predator's reliance on kairomones from prey was investigated. The predator studied, Cyrbaalgerina, is an araneophagic (spider-eating) jumping spider (Salticidae) and the prey were oecobiid spiders (Oecobiidae). There were two study sites (Sintra and Tavira), both in Portugal. Oecobiusmachadoi was a common oecobiid in Sintra, but no oecobiids were found in Tavira. Staged encounters showed that oecobiid-specific prey-capture behaviour was adopted by the C. algerina in Sintra but not in Tavira. In experiments using a Y-shaped olfactometer, significantly more Sintra C. algerina individuals chose the side with oecobiid odour instead of the blank side when the odour …

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Control Of Cuticle Sclerotization In Two Species Of Tsetse Fly Larvae (Diptera: Glossinidae), David L. Whitehead Dec 2010

Control Of Cuticle Sclerotization In Two Species Of Tsetse Fly Larvae (Diptera: Glossinidae), David L. Whitehead

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The presence of ecdysteroids during the larval life cycle and in the abdomens and ovaries of pregnant tsetse flies was established using radioimmunoassay. The hormone titre rises on day 9 of the larval life cycle 2-3 days after the hardening of the polypneustic lobes, mouthparts, phragma and anus. How initiation of tanning of the cuticle of the polypneustic lobes and later the puparium of tsetse fly is regulated is discussed as these events are separated in time by several days. It would seem to be unlikely that the pyrokinin neuropeptide, which is responsible for initiating the events that lead up …

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Systematics And Molecular Phylogeny Of Two African Stem Borer Genera, Sciomesa Tams & Bowden And Carelis Bowden (Lepidoptera: Noctuidae), P. Moyal, B. Le Ru, D. Conlong, D. Cugala, B. Defabachew, T. Matama-Kauma, B. Pallangyo, J. Van Den Berg Dec 2010

Systematics And Molecular Phylogeny Of Two African Stem Borer Genera, Sciomesa Tams & Bowden And Carelis Bowden (Lepidoptera: Noctuidae), P. Moyal, B. Le Ru, D. Conlong, D. Cugala, B. Defabachew, T. Matama-Kauma, B. Pallangyo, J. Van Den Berg

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Currently, the systematics of the African noctuid stem borers of the subtribe Sesamiina, which include major pests of cereals, is confused. In addition, their ecology is poorly known, as are the factors influencing their evolution. In this paper, we address these shortcomings for two genera of the Sesamiina, Sciomesa Tams & Bowden and Carelis Bowden. Mixed Bayesian phylogenetic analysis, which included their host plants and two mitochondrial genes, showed the genus Sciomesa to be polyphyletic. Two new genera were created, Pirateolea and Feraxinia. The genus Carelis proved to be paraphyletic and was subdivided into two sub-genera. The genera Sciomesa, Carelis …

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