Abstract: Glossina brevipalpis is a vector of trypanosomes that cause Animal African Trypanosomiasis. Chemoreception in tsetse flies is critical for identifying larvipositioning sites, hosts and mates. Odorant binding proteins (OBPs) are thought to mediate insect chemoreception by shuttling odours to receptors on olfactory sensory neurons. Little is known about the roles of OBPs in tsetse fly chemoreception. The genome of G. brevipalpis has been sequenced and 28 OBPs identified. This study a...
Abstract: Phytopathogenic fungi and bacteria cause enormous crop yield losses worldwide. Over the years, management of plant pathogens has primarily relied on the use of synthetic chemical antimicrobials and development of disease resistant varieties. Exploration for biologically active compounds from plants with an aim of discovery and development of novel and eco-friendly biopesticides to combat current and emerging phytopathogens has received increased interest in the recent past. This st...
Abstract: Maize is a staple food crop in Kenya with about 90% of the rural households depending on it. However, the grain is vulnerable to degradation by mycotoxin producing fungi in the field and during storage. Mycotoxins produced by these fungi cause significant economic losses and deleterious health effects to humans and animals. Strategies such as storage of maize in hermetic bags have been developed to reduce post-harvest grain losses due to pest attack, fungal growth and mycotoxin con...
Abstract: In this study, carried out in Nguruman, southwestern Kenya, 10 bee species were identified as eggplant pollinators. Their foraging behaviour was shown to be affected by the prevailing ambient temperature and not time of the day or the number of flowers per square meter in the eggplant fields. Only 2 bee species, Xylocopa caffra and Narnia sp., visited the eggplant blossoms at a great frequency. Their pollinator effectiveness was determined in two eggplant cultivars (the Black Beaut...
Abstract: For centuries, maize producers in sub-Saharan Africa have been plagued by post-harvest losses from insect infestation and mould infections, with small-scale producers representing the most vulnerable populations. Participatory on-farm trials were conducted to assess the effectiveness of triple layer hermetic (PICS™) bags for storage of maize in small-scale farmers’ stores in rural villages in Makueni County,Kenya. PICS bags are three-layer hermetic bag-system that forms a barri...
Abstract: African coffee white stem borer, Monochamus leuconotus (Pascoe), Cerambycidae, is a major insect pest of coffee that causes yield losses as high as 25%. However, studying biology of Cerambycids is difficult due to the nature of their life cycle, which is mostly spent in the wood. This study aimed at developing and describing a rearing method of M. leuconotus using original artificial diet and its life history in the laboratory. The bioecology information generated will be useful in...
Abstract: Tsetse flies (Glossina sp) are the vector of African trypanosomes, the causative agents of sleeping sickness in man and Nagana in cattle. The insect is strictly hematophagous, taking in significantly high quantities of water during bloodmeals that present a considerable osmotic challenge. This necessitates machinery for eliminating excess water. One potential candidate is a group of membrane channel proteins called aquaporins (AQPs) that are responsible for the movement of water ac...
Abstract: By 2015, target 8 of the United Nations Millennium Development Goal number six aimed to have halted and began to reverse the incidence of malaria and other major diseases. One of the strategies through which this target was expected to be achieved is to increase the proportion of the population in malaria risk areas who use effective malaria prevention and treatment measures. Malaria is one of the most common vector-borne diseases widespread in tropical and subtropical regions, inc...
Abstract: Several studies have shown that Rhipicephalus appendiculatus from geographically isolated areas differ in their susceptibilities to Theileria parva, the haemoprotozoan causative agent of East Coast Fever. In Kenya, R appendiculatus from Muguga have been reported to be less susceptible to T. parva infection than those from Rusinga Islands. As the same tick species from different areas shows variation in vector competence, it was considered to be of epidemiological interest to determ...
Abstract: Smallholder subsistence farming is important in the production of food crops for basic livelihoods and income generation in rural areas. However, yields have remained low due to high disease, weed and pest incidences. Currently, crop pests and diseases are largely controlled by use of chemicals, which have adverse effects on the environment and nontarget organisms. There is need for new methods that are environmentally safe to supplement existing control strategies in order to enha...
Abstract: The adsorption of heavy metal ions (Cd2+), Cu2+), Pb2+) and Zn2+) by untreated water hyacinth Eichhornia crassipes obtained from Lake Victoria, Kenya was investigated under batch mode. A The effects of sample part, particle size, contact time, solution pH, and temperature, shaking speed, adsorbent dosage and initial metal ion concentration of aqueous solutions were investigated. The roots showed highest ability for the uptake of heavy metals (Cu, Zn, Cd and Pb) from aqueous solutio...
Abstract: Survey was carried out during 2004 main cropping season to investigate the abundance and distribution of stemborers, with emphasis on C. partellus in central and eastern Ethiopia. Three species of stemborers, Chilo partellus (Swinhoe), Busseola fusca (Fuller) and Sesamia calamistis (Hampson) were recorded. C. partellus was dominant and widely distributed species recorded in 96 % of the surveyed sites. On the other hand, B. fusca was mainly recorded in highland areas while S. calami...
Abstract: In Africa, intercropping of some legumes with cereal crops has been found to cause remarkable reduction of Striga infestation and improved production of cereal crop. Desmodium uncinatum controls Striga infestation in intercrop with cereals through an allelopathic mechanism, which involves post-germination growth inhibitors exuded from the roots. Allelopathy is a natural and environmentally friendly technique, which has a potential to be a new approach for weed control. A standardiz...
Abstract: The variation of the mannose-binding protein (MBP) gene and the role of lectins during infection in mosquitoes were investigated using genomic DNA approach based on sequencing of the gene and the levels of its expression determined using semi-quantitative Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) approach. Using shotgun cloning ~trategy, sequences were determined from cloned PCR products obtained from genomic DNA of An.gambiae, s.s, An. arabiensis and An. funestus an...
Abstract: Insect pollination sustains the biodiversity of 90% of wild plants, and 75% of crop species for food and nutritional security. Chemical pesticides used to manage arthropod pests constitute a key driver to the unprecedented declines of insect pollinators worldwide. Hence, biopesticides based on entomopathogenic fungi (EPF) are being promoted as safer alternatives. The effects of EPF on insect pollinators have not been investigated in detail for the application in pollinator-resource...