Description: A Thesis Presented to the Faculty of Science of the University of Neuchatel for the degree of Doctor of Philosophy
Abstract: Biometric studies coupled with physiological investigations have made it possible to propose a scheme of post-embryonic development and polymorphism in Macrotermes michaellseni. ...(continue from the attached PDF)
Abstract: The control of Amblyomma variegatum and other economically important ticks, like Rhipicephalus appendicu/atus, has relied mainly on the use of acaricides worldwide. However, due to the drawbacks of chemical control, future tick control will have to move more in the direction of integrated approaches emphasizing more regular use of environmentally-friendly non-chemical methods, such as tick parasitoids. lxodiphagus hookeri, one of the seven species of tick parasitoids known, occurs ...
Abstract: Tsetse flies use olfaction in search for food, mates and larviposition sites. Olfactory proteins [(odorant binding proteins (OBPs), pheromone binding proteins (PBPs), chemosensory protein (CSPs), odorant degrading enzymes (ODEs) and odorant receptors (Ors)], located within the antennae, play key role in this process. In this work, presence of olfactory proteins was investigated by constructing and sequencing cDNA libraries from Glossina pallidipes Austen, antennae; Glossina palpali...
Abstract: Midgut trypanolysin from Glossina morsitans morsitans was isolated by a combination of an anion-exchange and gel permeation chromatography. The trypanolysin activity was recovered in the bound fraction. The native molecular weight of trypanolysin was determined -669kDa. Analysis oftrypanolysin by SDS-PAGE recovered a single sub-unit ofMr-14kDa. The induction of trypanolysin activity by bloodmeal increased gradually reaching a peak at 72-120 h after the bloodmeal, and then decreased...
Abstract: Laboratory investigations were carried out to assess phytophagy and its effects on the biology of phlebotomine sandflies and their capacity to transmit Leishmania parasites. Preliminary trials to determine the optimum working standards in terms of anthrone concentration, exposure period and duration, effect of sandfly species and/or sex and effects of diets on the feeding rate, led to the choice of 1.25% as the concentration (w /v) of anthrone reagent to detect the presence of suga...
Abstract: We have chosen the urine innurioglobulin M (IgM) as system to study glycoprotein biosynthesis and carbohydrate processing. Secreted IgM heavy chain (m) has five glycoasylation sites which location and structures have been determined. chain variable region (VH) ia involved in antigen binding, while the constant region (CH) is responsible for the effect or functions in which the carbohydrate plays an important role.
Abstract: A comparative study of the ecology of mosquito vectors of malaria was carried out in the Parkerra irrigation scheme and the Loboi swamp in Baringo districy, Kenya. The swamp was found to be more productive than the irrigation scheme both in terms of species diversity and the relative abundance of individual mosquito species.
Abstract: The oviposition behaviour of Maruca testul ali s on host plant (cowpea), non-host plant s (cotton and sunhemp), and artificial substrates (filter , butter, crepe, and aluminium foil papers) was observed in laboratory and field. These studies were carried out with the aim of gathe ring data on oviposition behaviour patterns e s pecia l ly on how the ovipositing female inter acts with host pla nts, non- host plants as well as potential artificial oviposition substrates. It was also i...
INTRODUCTION 1.1 Pheromones and related compounds It has long been known that animals communicate with each other. The communication becomes more important the more social the animal is. Even in microorganisms and plants communication seems important. For example, "biological communication" as broadly defined, 1 involves the release of one or more stimuli by an individual of a species to induce a reaction to the receiver and the benefit of such a reaction may be to the emitter, the receiver o...
Abstract: This study was conducted to assess the possibility of immunising rabbits against Rhipicephalus appendicuatu Neumann, the vector for East Coast fever and Corridor disease, the most important tick-borne diseases in East and Central Africa. The antigens whose efficacy in the control of this vector were assessed included commercially available insect moulting hormone, beta-ecdysone and tick haemolymph components. However, since antibodies play a major role in the acquisition of tick re...
Abstract: Trypanosomiasis continues to be a serious problem in sub-Saharan Africa. The inadequacies of existing control strategies necessitate the development of alternative control measures. In most cases, the causative agents of African trypanosomiasis, Trypanosoma spp., require an obligatory passage through the tsetse, Glossina spp (Diptera; Glossinidae ), vector. This developmental step of the parasite leads to vector-parasite interactions, especially within the midgut. Among the vector ...
Abstract: The overall goal was to contribute to crop-productivity by developing sustainable pest management and the objective was to select and identify an efficacious local B. thuringiensis isolate active against the selected stem borers, C. partellus, E.saccharina, B. fusca and S. calamistis.Various isolates of B. thuringiensis were isolated from soils and dead insects collected from different places in Kenya. They were screened against various stem borers including C. partellus, E. saccha...
Abstract: Tsetse flies are the biological vectorsof human and animal trypanosomiasisand hence representant medical and veterinary importance. The sense of smell plays a significant role in tsetse and its ecological interaction, such as finding blood meal source, resting, and larvicidal sitesand for mating. Tsetse olfactory behaviour can be exploited for their management;however, olfactory studies in tsetse flies are still fragmentary. Here in my PhD thesis, usingscanning electron microscopy,...
Abstract: Background:Vector-borne pathogens (VBP) present a seriousthreat to both animal and humanhealth globally due to their zoonotic potential.‘One Health’ epidemio-surveillance systems that integrate human, animal, and arthropod vector facetsof VBP transmission enhance detection and can give rise to informed effective multi-sectoral vector-borne disease control options. The most important vectors are ticks and mosquitoes, which have a cosmopolitan distribution due to their ecological...