Digital Commons Network^™

Proximate Composition And In Vitro Protein Digestibility Of Extruded Aquafeeds Containing Acheta Domesticus And Hermetia Illucens Fractions, F. G. Irungu, C. M. Mutungi, A. K. Faraj, H. Affognon, S. Ekesi, D. Nakimbugwe, K. K.M. Fiaboe

All Peer-Reviewed Publications

Major protein sources for feed manufacture have become costly, and this has led to increased cost of products such as aquafeeds. This has dampening effect on fish production especially in developing countries, and has necessitated a search for alternative protein sources in processed feeds. The effects of extrusion on aquafeed blends containing fractions of adult cricket (Acheta domesticus) meal (ACM) or black soldier fly (Hermetia illucens) pre-pupae meal (BSFM) on proximate composition and in vitro protein digestibility were investigated. Extrusion resulted in higher contents of protein and nitrogen free extract, and lower contents of ether extract and crude fibre as …

Evaluation Of Onion (Allium Cepa) Germplasm Entries For Resistance To Onion Thrips, Thrips Tabaci (Lindeman) In Tanzania, Gabriel Michael Njau, Agnes M.S. Nyomora, Fekadu Fufa Dinssa, Jian Cheng Chang, P. Malini, S. Subramanian, R. Srinivasan

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Onion thrips, Thrips tabaci (Lindeman), is a prominent species infesting onion and tomato in the northern highlands of Tanzania. It causes considerable leaf damage by direct feeding and also transmits the Iris yellow spot virus (IYSV). Hence, one of the objectives of this study was to identify the most resistant onion entries against T. tabaci. One highly resistant (VI038552) and two resistant onion entries (VI038512 and AVON 1067) were identified against T. tabaci. Besides thrips resistance, the bulb size of VI038512 was also equivalent to one of the commercial varieties, Texas. The highly resistant VI038552 recorded the highest yield, followed …

Vector Potential Of Aedes (Stegomyia) Spp. Populations And Risk Of Dengue And Yellow Fever Virus Transmission In Three Kenyan Cities, Sheila Biloh Agha

All PhD Dissertations

Dengue (DENV) and Yellow fever (YFV) viruses are medically important flaviviruses that are transmitted by Aedes mosquito vectors of the subgenus Stegomyia especially Aedes aegypti and Aedes bromeliae, respectively, in East Africa.Urbanization has been identified as a major driver in the emergence of these diseases because of the permissive environment it creates promoting the convergence of susceptible human hosts and local vectors. However, while dengue outbreaks have mainly been reported in urban and semi-urban areas of East Africa, yellow fever outbreaks remain limited to the sylvatic cycle. Urban outbreaks may be facilitated by adaptation of the viruses to sylvatic vectors. …

Icipe Annual Report 2017, International Centre Of Insect Physiology And Ecology (Icipe)

icipe Annual Reports

No abstract provided.

Spatially Continuous Dataset At Local Scale Of Taita Hills In Kenya And Mount Kilimanjaro In Tanzania, Sizah Mwalusepo, Estomih S. Massawe, Tino Johansson

All Peer-Reviewed Publications

Climate change is a global concern, requiring local scale spatially continuous dataset and modeling of meteorological variables. This dataset article provided the interpolated temperature, rainfall and relative humidity dataset at local scale along Taita Hills and Mount Kilimanjaro altitudinal gradients in Kenya and Tanzania, respectively. The temperature and relative humidity were recorded hourly using automatic onset THHOBO data loggers and rainfall was recorded daily using GENERALR wireless rain gauges. Thin plate spline (TPS) was used to interpolate, with the degree of data smoothing determined by minimizing the generalized cross validation. The dataset provide information on the status of the current …

H3abionet, A Sustainable Pan-African Bioinformatics Network For Human Heredity And Health In Africa, Nicola J. Mulder, Ezekiel Adebiyi, Raouf Alami, Alia Benkahla, James Brandful, Seydou Doumbia, Dean Everett, Faisal M. Fadlelmola, Fatima Gaboun, Simani Gaseitsiwe, Hassan Ghazal, Scott Hazelhurst, Winston Hide, Azeddine Ibrahimi, Yasmina Jaufeerally Fakim, C. Victor Jongeneel, Fourie Joubert, Samar Kassim, Jonathan Kayondo, Judit Kumuthini, Sylvester Lyantagaye, Julie Makani, Ahmed Mansour Alzohairy, Daniel Masiga, Ahmed Moussa, Oyekanmi Nash, Odile Ouwe Missi Oukem-Boyer, Ellis Owusu-Dabo

All Peer-Reviewed Publications

The application of genomics technologies to medicine and biomedical research is increasing in popularity, made possible by new high-throughput genotyping and sequencing technologies and improved data analysis capabilities. Some of the greatest genetic diversity among humans, animals, plants, and microbiota occurs in Africa, yet genomic research outputs from the continent are limited. The Human Heredity and Health in Africa (H3Africa) initiative was established to drive the development of genomic research for human health in Africa, and through recognition of the critical role of bioinformatics in this process, spurred the establishment of H3ABioNet, a pan-African bioinformatics network for H3Africa. The limitations …

Icipe Annual Report 2016, International Centre Of Insect Physiology And Ecology (Icipe)

icipe Annual Reports

No abstract provided.

Application Of Environmental Dna (Edna) In The Detection And Quantification Of Anopheles Mosquito Larvae In Artificial Aquatic Habitats, Joel Odero

All Master’s Theses

Background Environmental DNA (eDNA) analysis is an emerging tool in ecological monitoring of aquatic habitats. When applied correctly, it can overcome the limitations of traditional aquatic sampling methods. This current study develops and validates a protocol for using eDNA analysis to detect and quantify mosquito larvae in laboratory and controlled field setting. Methods Species-specific PCR primers were designed from An. gambiae s.l and An. funestus, and qPCR primers for An. gambiae s.l using mitochondrial cyt b gene and validated on 1:10 and 1:100 dilutions of gDNA from both species. In the laboratory eDNA testing, An. gambiae s.s mosquito larvae (1 …

Predicting The Impact Of Temperature Change On The Future Distribution Of Maize Stem Borers And Their Natural Enemies Along East African Mountain Gradients Using Phenology Models, Sizah Mwalusepo, Henri E.Z. Tonnang, Estomih S. Massawe, Gerphas O. Okuku, Nancy Khadioli, Tino Johansson, Paul André Calatayud, Bruno Pierre Le Ru

All Peer-Reviewed Publications

Lepidopteran stem borers are among the most important pests of maize in East Africa. The objective of the present study was to predict the impact of temperature change on the distribution and abundance of the crambid Chilo partellus, the noctuid Busseola fusca, and their larval parasitoids Cotesia flavipes and Cotesia sesamiae at local scale along Kilimanjaro and Taita Hills gradients in Tanzania and Kenya, respectively. Temperature-dependent phenology models of pests and parasitoids were used in a geographic information system for mapping. The three risk indices namely establishment, generation, and activity indices were computed using current temperature data record from local …

Larval Habitat Discrimination By The African Malaria Vector Anopheles Gambiae Sensu Lato: Observations From Standardized Experiments And Field Studies, Herrera-Varela Manuela

All PhD Dissertations

Current malaria vector control strategies in Africa target indoor resting and biting mosquitoes and rely heavily on a small number of insecticides. These interventions have lead to the selection of insecticide resistance, behavioural adaptations of the vectors and leave naturally exophilic species nearly untouched. Gravid Anopheles gambiae s.l. female searching for an oviposition site would be a novel target for vector control. However, little is known about the oviposition-site selection behaviour (criteria) of this mosquito. The major aim of the presented research was to investigate if gravid An. gambiae s.l make informed choices when selecting an oviposition site and to …

Modelling The Impact Of Climate Change On The Maize Stem Borer Communities And Their Main Natural Enemies Along Altitudinal Gradients In East Africa, Sizah Mwalusepo

All PhD Dissertations

Maize is one of the most important staple foods in East Africa. In spite of its importance, maize production in the region faces increased risk of being attacked by maize stem borers due to climate changes. This thesis aims at modelling the impact of climate change on the distribution and abundance of two maize stem borers crambid Chilo partellus (Swinhoe), noctuid Busseola fusca (Fuller), and two of their main natural enemies, Cotesia flavipes and Cotesia sesamiae Cameron at local scale along Mount Kilimanjaro and the Taita Hills transects in Tanzania and Kenya, respectively. Mathematical models for the impact of the …

Agro-Ecosystems' Resilience To Damage: Determination Of Index Of Susceptibility To Climate Change In Mount Kilimanjaro, Tanzania., Shirima Kelvine

All Master’s Theses

This paper assesses maize-coffee-banana agro-ecosystems' resilience to damage as well as computing the social-ecological vulnerability index to climate change on the southern slope of Mount Kilimanjaro in Tanzania. The study focused on identifying agronomic practices and assessing their impacts on agro-ecosystems' resilience; examine the socio-economic status of the farmers in the region and its impacts on agro-ecosystems; and examine the agro-ecosystems' natural resilience and assess social-ecological vulnerability index to the impacts of climate change. About 400 households was covered in this household survey with response rate of 97% where by farmers were asked on their farming practices and systems, key …

Responses To Pyrethroids In Heavy Metal Tolerant Anopheles Gambiae Vector Of Malaria, Fauzia Khagai Musasia

All Master’s Theses

Anopheles gambiae mosquito, the principle Afro-tropical vector of malaria, has been documented in habitats with heavy metals in excess of natural loads. The mosquito has also displayed resistance to most conventional insecticides, and potential to resist challenges by heavy metals. Investigations were conducted in strains of An. gambiae ss, in which tolerance to cadmium and lead heavy metals were established. This study was undertaken to determine any putative relationship between tolerance to (cadmium and lead) heavy metals, and resistance to pyrethroid insecticide in An. gambiae. Tolerance to cadmium and lead heavy metals was developed in larval stages and this development …

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 …

Effect Of Temperature And Relative Humidity On The Development And Fecundity Of Chilo Partellus (Swinhoe) (Lepidoptera: Crambidae), A. Tamiru, E. Getu, B. Jembere, T. Bruce

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The spotted stemborer, Chilo partellus (Swinhoe) (Lepidoptera: Crambidae), is one of the most important insect pests attacking maize and sorghum in Ethiopia. Recent studies have indicated that the pest is spreading to new locations where it was not reported before. In the current study, laboratory investigations were carried out to determine the combined effect of different levels of relative humidity and temperature regimes on the development and fecundity of C. partellus, as these physical factors are known to play an important role in the life cycle of insects and adaptability to local climate. Developmental time, longevity, potential fecundity and realized …

Bioecology Of The Mango Mealybug,Rastrococcus Iceryoides Green (Hemiptera: Pseudococcidae) And Its Associated Natural Enemies In Kenya And Tanzania, Chrysantus Mbi Tanga

All PhD Dissertations

Rastrococcus iceryoides Green (Hemiptera: Pseudococcidae), an alien invasive mealybug pest of Asian origin was first detected in Tanzania in 1989. This pest rapidly spread by the mid-1990s and was soon present in Coastal Kenya and Northern Malawi, where it has been regarded and remains a major pest of mango. Because of its novelty status, there was no information on its biology, ecology and its natural enemies that could aid development of management efforts. This study, therefore, was initiated to establish the bioecology of R. iceryoides and its natural enemies in Kenya and Tanzania, and to explore for efficient co-evolved natural …

Potential Of Oecophylla Longinoda (Hymenoptera: Formicidae) For Management Of Helopeltis Spp. (Hemiptera: Miridae) And Pseudotheraptus Wayi (Hemiptera: Coreidae) In Cashew In Tanzania, Moses Iwatasia Olotu

All PhD Dissertations

Cashew, Anacardium occidentale Linnaeus, is an economically important cash crop for more than 300,000 rural households in Tanzania. Its production is, however, severely constrained by infestation by sap-sucking insects such as Helopeltis anacardii Miller, H. Schoutedeni Reuter and Pseudotheraptus wayi Brown. The African weaver ant (AWA), Oecophylla longinoda Latreille, is an effective biocontrol agent of hemipteran pests in coconuts in Tanzania; but its efficacy for the control of sap-sucking insects, especially Helopeltis spp. and P. wayi, has not been investigated so far in cashew crops in Tanzania. Field trials were carried out at the Coast region of Tanzania to evaluate …

Biodiversity Assessment Of Tetranychid Mites In Kenya And The Conservation Hotspots Of Tanzania, Faith Jebet Toroitich

All PhD Dissertations

The aims of this study were to develop a detailed record of the tetranychid mites of Kenya and Tanzania, to assess the diversity of tetranychid mites in the east African biodiversity hotspots and to determine female characters that can be used to identify the species of the economically important Tetranychus species found in these countries. The genetic diversity of the most abundant Tetranychus species (Tetranychus evansi Baker & Pritchard) was also assessed. The Tetranychidae (Acari) contain some of the most important pest species of phytophagous mites worldwide. Out of the almost 1,300 species in this family, 256 species are known …

Ecology: A Prerequisite For Malaria Elimination And Eradication, Heather M. Ferguson, Anna Dornhaus, Arlyne Beeche, Christian Borgemeister, Michael Gottlieb, Mir S. Mulla, John E. Gimnig, Durland Fish, Gerry F. Killeen

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Existing front-line vector control measures, such as insecticide-treated nets and residual sprays, cannot break the transmission cycle of Plasmodium falciparum in the most intensely endemic parts of Africa and the Pacific. The goal of malaria eradication will require urgent strategic investment into understanding the ecology and evolution of the mosquito vectors that transmit malaria. Priority areas will include understanding aspects of the mosquito life cycle beyond the blood feeding processes which directly mediate malaria transmission. Global commitment to malaria eradication necessitates a corresponding longterm commitment to vector ecology.

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

All Peer-Reviewed Publications

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 …

Relative Attractiveness Of Anopheles Gambiae Mosquitoes To Synthetic Oduor Blends And Human Emanations, Evelyn Adhiambo Olanga

All Master’s Theses

Mosquito host seeking behaviour is mediated by chemical, physical and visual cues. Identification of chemical and physical cues utilized by mosquitoes in host location can lead to the development of novel vector management strategies. This research set out to identify synthetic odour blends that simulate human body emanations that can be used to develop mass trapping devices for vector management. The relative attractiveness of human body emanations and synthetic odour blends as attractants of Anopheles gambiae mosquitoes was investigated under semi-field conditions at the International Centre for Insect Physiology and Ecology (ICIPE) Mbita Point, western Kenya. The effect of heat …

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. …

Field Guide To The Stemborer Larvae Of Maize, Sorghum And Sugarcane In Eastern And Southern Africa, W. A. Overholt, K. V. N. Maes, F. R. Goebel

icipe Manuals

Introduction

Lepidopteran stemborers are generally considered to be the most important group of insect pests that attack maize, sorghum and sugarcane in many areas of the world. In eastern and southern Africa, there are several important species. Correct identification of the stemborers occurring in an area is the first step towards developing an appropriate pest management strategy.

The objective of this publication is to provide agricultural scientists and extension workers with a simple, user-friendly taxonomic key to allow the rapid identification of larvae of the major stemborer species found in maize, sorghum and sugarcane in eastern and southern Africa. Fact …

Comparative Development And Population Growth Of An Exotic Stemborer, Chilo Partellus (Swinhoe), And An Ecologically Similar Congener, C. Orichalcociliellus (Strand) (Lepidoptera: Crambidae), Jacob C. Mbapila, William A. Overholt, Hosea Y. Kayumbo

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Studies were conducted to determine the effect of temperature and diet on the development of Chilo partellus (Swinhoe) and Chilo orichalcociliellus (Strand) (Lepidoptera: Crambidae). Developmental times of C. partellus and C. orichalcociliellus for the egg, larval and egg-adult life stages were inversely related to temperature. The larval developmental period of C. orichalcociliellus reared on artificial diet was longer than the developmental period on natural diet. Chilo partellus had a higher intrinsic rate of natural increase than C. orichalcociliellus at all diet/temperature combinations except natural diet at 31°C. © 2002 ICIPE.

Comparative Evaluation Of Cotesia Flavipes And C. Sesamiae (Hymenoptera: Braconidae) For The Management Of Chilo Partellus (Lepidoptera: Pyralidae) In Kenya, M. N. Sallam, W. A. Overholt, E. Kairu

All Peer-Reviewed Publications

Cotesia flavipes Cameron, a gregarious larval endoparasitoid native to the Indo-Australian region, was imported from Pakistan and released in Kenya in 1993 for management of the exotic stemborer, Chilo partellus (Swinhoe). Recent reports confirmed the successful establishment of the parasitoid in three locations in Kenya and in northern Tanzania. Functional response studies on this parasitoid and an indigenous congener, Cotesia sesamiae (Cameron), indicated that C. flavipes had a higher searching ability and attacked more larvae when Chilo partellus was the host. When a native stemborer, Sesamia calamistis Hampson, was the host, there was no significant difference between numbers attacked by …

Responses Of Common Bean (Phaseolus Vulgaris L.) Cultivars To Beanflies (Diptera: Acromyzidae), John Huria Nderitu

All PhD Dissertations

The population patterns and behaviour of the immature stages and the adults of two species of Ophiomyia, namely Opbiomyia spencerella Greathead and Ophiomyia phaseoli Tryon on seven selected cultivars of common beans (Phaseolus vulgaris L.) were studied under field conditions with a view to determining the esistance/susceptibility of the cultivars to infestation of beanfly. The method adopted for evaluating resistance/ susceptibility of the cultivars involved exposing growing bean plants to natural beanfly populations in the field and recording the number of leaf punctures, eggs, larvae, pupae/puparia, and percent infested plants, percent plant mortality and damage scores of representative sample for …

Responses Of Common Bean (Phaseolus Vulgaris L.) Cultivars To Bean Flies (Diptera: Agromyzidae), John Huria Nderitu

All PhD Dissertations

uniform. beanfly infestation of sufficient level to which the cultivars were subjected during the growing period. However, natural populations of beanfly on beans planted in a• single planting in the late part of the cropping season or the beginning of noncropping season was sufficient to cause observable damage symptoms, which could be reliably used as parameters for resistance. successive plantings of bean cultivars in the middle part of cropping season could also produce a beanfly population sufficiently high for screening purposes. Under moderate field infestation, determination of percent plant mortality due to Q. spencerella, stem damage scores due to o. …

Attempts On The Synthesis Of The Pheromone Component Lineatin, Serry Francis Rwehikiza

All PhD Dissertations

poorly achieved. Direct alkylation on the alkenal V with 8-methallylmagnesium chloride followed by oxidative cleavage of 2,5,5-trimethylocta-l,7-diene-4-ol (VIlI) and methylenation via a Wittig reaction gave an improved yield of the alkylated product, 4,4-dimethyl-5-(2-methyl-2-propenyl)oxacyclopentan-2-one (IX). This compound and its precursors showed a strong tendency to cyclize and it was therefore difficult to prepare aketene precursor. Blocking the c 4-0H of compound VIII before oxidising the C-C double bonds was considered as one way of reducing this cyclization tendency. However, protection of the c 4-oH of VIII as a methyl ether followed by ozonolysis under reductive conditions (CH2cl 2/DMS) gave unexpectedly the …

The Influence Of Salinity On Larval Development And Population Dynamics Of Anopheles Merus Dönitz (Diptera: Culicidae), F. W. Mosha, C. M. Mutero

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Variations in density of adults of Anopheles merus Dön. in Jimbo Village on the Kenya Coast were found to be correlated both with rainfall and with salinity at their breeding sites. Densities started to increase at the beginning of the rains when several breeding sites were formed. This was followed by a decline in numbers resulting mainly from the decrease in salinity in the semi-permanent breeding sites. A second rise occurred after the end of the rains, corresponding with an increase in salinity in the semi-permanent breeding sites due to evaporation. Peak density coincided with salinities of 30–50% sea water …

An Economic Analysis Of Damages And Other Losses By Ticks And Tick Borne Disease Particulary In Relation To East Coast Fever (Ecf), Francis Mwega Mwaura

All Master’s Theses

Ticks and Tick-borne diseases are a major impediment to the developrrent of the livestock sector in Kenya. They cause significant production losses through mortality, impair productivity of surviving anirrals, and discourage the genetic improvement of cattle in the high potential areas. Of the tick-borne diseases, ECF is the most important. No vaccine or drug has been adopted for widespread field use against the disease, and its control relies on the application of acaricides on animals to control the tick population.Indigenous cattle in endemic areas have developed partial .immunity to the main tick-borne diseases. It is the genetically improved cattle that …