Abstract: Tomato is rated the second most important horticultural crop after potato in most parts of the world. However, its cultivation is threatened by infestations of Tuta absoluta (Lepidoptera: Gelechiidae). The pest originated from South America and is now invading fields and greenhouse production sites in the world. Tuta absoluta was first officially reported in Kenya in March 2014 at Isiolo and has spread to all parts where tomato is grown. The pest has been nicknamed tomato ‗Al–s...
Abstract: Malaria is a strong selective force in the human genome, selecting genes for resistance to disease in human populations living in malaria endemic areas. Selection by malaria has generated genetic variations, providing evolutionary driving force mediating polymorphisms such as Glucose-6-Phosphate Dehydrogenase deficiency and sickle-cell anaemia. Genes encoding erythrocyte receptors of Plasmodium falciparum especially the sialoglycoproteins, glycophorins A, B and C, which are the mai...
The main purpose of this study was to establish the pathway(s) by which PEP from glucose catabolism is catabolised , the end products formed in the presence and absence of SHAM, the sub cellular localisation of some key enzymes involved in PEP catabolism and to partially characterise PEPCK in bloodstream T. congolense.
ABSTRACT Ticks pose a major challenge and economic burden to livestock rearing as they inflict physical injury and transmit diseases resulting in heavy losses of livestock. Their control has relied mainly on the use of synthetic acaricides which are expensive and hazardous to the environment and non-target organisms. Intensive use of these acaricides has also resulted in tick resistance. Plant extracts could provide a viable alternative to tick control and management strategies. Calpurnia...
Abstract: Cereal stemborers in Kenya include Busseola fusca, B. phaia, Sesamia calamistis, S. botanephaga, Eldana saccharina, Chilo orichalcociliellus, and Ch. partellus. The stemborers cause 50% yield losses in cereal crops including maize, sorghum, and sugarcane. Damage to the host plants results from the feeding and excavating of tunnels by the larvae. The different stemborer control options include pesticides, early planting, intercropping with non-cereals, and host plant resistance. ...
Abstract: The relationship between Pseudotheraptus wayi (cashew pest), Anacardium occidentale (cashew plant), and Oecophylla longinoda (natural enemy) is a trophic interaction that is very important in cashew nut production. However, the chemical ecology of the interaction, specifically between the cashew plant and natural enemy as well as the pest and natural enemy was little investigated. Based on the hypothesis that both interactions were mediated by chemical signals, the objective of thi...
Abstract: This work demonstrates how an integrated approach can be used for controlling Larger Grain Borer (Prostephanus truncatus) in maize (Zea mays L.) using solar disinfestation followed by hermetic storage in Purdue Improved Crop Storage (PICS) bags. PICS bags work by sealing grains in an airtight environment for long-term pest-free storage. In order to provide safe food with no inputs of chemical pesticides, the combination of solar disinfestation and the PICS bagging is likely to be a...
Table of Content List of Tables List of Schemes List of Figures Abstract Chapter One 1.1 General introduction 1.2 Malaria parasite 1.3 Malaria disease 1.4 Malaria vectors 1.5 Malaria control strategies 1.6 Significance of study 1.7 Hypothesis 1.8 Justification 1.9 Objectives of the Study Chapter Two: Literature Review 2.1 Uses of natural products in mosquito control 2.2 The Family Meliaceae 2.3 The Genius Turraea 2.4 Limonoids 2.5 Biosynthesis of limonoids Chapter Three: Experimental 3.1 G...
Abstract: Chilo partellus Swinhoe (Lepidoptera: Crambidae) is an exotic cereal stem borer that was accidentally introduced into Africa from South Eastern Asia early 20th century. It is now widespread in most of the lowland areas of the Eeastern and Southern parts of the African continent. The invasive stem borer C. partellus, has proved to be a highly competitive colonizer in many of the areas it has invaded in eastern and southern Africa, often becoming the most serious stem borer.
Abstract: In a previous study using three plant species (maize, sorghum and Napier grass), naïve gravid B fusca females significantly preferred sorghum and maize over Napier grass for oviposition a phenomenon, which was partly related to plant physical characteristics such as leaf surface texture and sheath toughness. The purpose of this study was therefore to determine the importance of plant chemical characteristics (volatiles as well as surface compounds) in host selection for ovipositio...
Abstract: The efficacy of Limburger cheese as an odour bait for sampling African malaria vectors was evaluated. Studies were done in Suba district, Western Kenya at Lwanda Nyamasare village and in a screen house set up at the Thomas Odhiambo campus of the International Center of Insect Physiology and Ecology (ICIPE). Preliminary investigations compared mosquitoes caught by a Counter Flow Geometry (CFG) trap baited with Limburger cheese, a standard centres for disease control (COC) light trap...
Abstract: Ticks are haematophagous ectoparasites capable of transmitting diseases to vertebrates and, therefore, constitute a threat to human, livestock and wildlife health. Though synthetic chemical acaricides have made a tremendous impact over the years in the control and management of the vector on livestock, ticks have developed resistance to most of them. In addition, the chemicals are toxic to non-target organisms. In some parts of Kenya, powdered parts of some plants, including those ...
Abstract: Maize lethal necrosis (MLN) disease caused by a dual infection of maize with Maize chlorotic mottle virus (MCMV) and any cereal potyvirus such as Sugarcane mosaic virus (SCMV), Maize dwarf mosaic virus (MDMV) or Wheat streak mosaic virus (WSMV) was first reported in Kenya in 2011 in Bomet County. This study was aimed at determining the presence and genetic variability of MCMV and SCMV in cereal crops,wild and domesticated grasses and the spatial distribution of alternative hosts in...
Abstract: Avocado is a horticultural crop of increasing economic importance in Kenya and around the world. Avocado production has been declining partly due to inadequate pollination. This decline in avocado pollination is currently linked to habitat fragmentation and climate change that negatively affects insect pollinators, especially in high altitude areas such as Taita Hills in coastal Kenya. However, there is scarcity of information on avocado flower visiting insects in Taita Hills. The ...
Abstract: Frankliniella schultzei Trybom is an important pest of ornamental and vegetable crops worldwide and a vector of Tospoviruses, which are plant viruses belonging to the family Bunyaviridae. It occurs as two color forms (dark and pale) which are morphologically very similar hence has been considered as one species. However, differences in vector competency and geographic spread has led to debate on whether they are one or separate species. Moreover, evidence is lacking on whether thes...