Abstract: Oviposition decisions are a prominent example of behaviour directly affecting the fitness, abundance, distribution, and population dynamics of holometabolous insects. Due to eggs being immobile and adult insects often not practicing biparental and/or maternal care, gravid females, when ovipositing, should select substrate(s) that maximise fitness of their offspring. Studies have revealed that this selection is influenced by biotic (intra and interspecific competition, parasitism, l...
Abstract: The ant Pachycondyla analis (formerly Megaponera foetens, commonly known as the Matabele ant) is a widespread ponerine in sub-Saharan Africa. It feeds solely on termites of economic importance belonging to the sub-family Macrotermitinae. These termites are captured during organised raids on their nests and galleries. Previous studies mostly concentrated on certain aspects of the raiding behaviour and trail laying pheromones in this species. Thus the detailed raiding behaviour and c...
Abstract: Tomato is one of the most important vegetable crops grown in Ethiopia. Its production is constrained by arthropod pests and diseases. Fruit borer (Helicoverpa armigera), Whiteflies (Bemisia tabaci), Aphids (Aphis spp), leafminer (Tuta absoluta), Serpentine leafminer (Liriomyza sp), Thrips sp and two spotted spidemites (Tetranchus urticae Koch) are the major economic pests recorded in the study area. The research was initiated to evaluate the potential of intercropping and plant ext...
Abstract: Potato is an important tuberous vegetable crop in Ethiopia. It is production is constrained by arthropod pests, nutrient depletion of soil and diseases. Among the arthropod pests, two-spotted spider mite (TSSM) is one of the major pests affecting potato production in eastern Hararghe, Ethiopia. To tackle this problem, the survey was undertaken to assess the status of TSSM on the irrigated potato. The data were collected from ninety-six potato producers from October to March in Hara...
Abstract: Cotton flea beetle, Podagrica puncticollis Weise is among the most chronic and economically damaging insect pests of cotton in Northwestern Ethiopia. Although this beetle is known to cause significant crop losses, the ecological aspects and management of this insect pest have not been adequately assessed and documented. Thus, five studies were conducted in the area. The first study was conducted in Metema district to assess the cotton growers’ perception and knowledge of cotton f...
Abstract: The study was conducted in Plant Protection Laboratory and greenhouse (GH) at Haramaya University under 25±2 oC, 70±5% RH and 30±2 oC, 60±5% RH, respectively, during 2016. The objectives were to: 1) evaluate the efficacy of some pesticides on Tetranychus urticae in the laboratory and greenhouse; and 2) evaluate the performance of TSSM to six plants under GH conditions. The efficacy of five pesticides, viz. Amitraz, Profenofos, Chlorantrniliprole + λ-cyhalothrin, and Profenofos...
Abstract: In sub-Saharan Africa, three fruit dlies: Ceratitis cosyra (Walker, C. fasciventris (Bezzi) and C. capitata (Wiedemann) (Diptera: Tephritidae) are important pests of commercial fruits. C. cosyra and C. fasciventris affect.....(continue from the attached PDF)
Abstract: The study was conducted in western Kenya, a prime banana growing area during the period of May 1996 to February 1999. The objectives were to control the banana weevil and parasitic nematodes with neem materials, thereby reducing yield losses and contributing to sustainable banana production. The repellent, antifeedant, ovipositional deterrent, and growth inhibitory effects of powdered neem seed (NSP), kernel (NKP), cake (NC) and neem oil (NO) on Cosmopolites sordidus and its popula...
Abstract: Infestation by insect pests and infection of disease causing pathogens are among the major biotic constraints hindering production, profitability and contribution of citrus to economic development. The African citrus triozid (ACT), Trioza erytreae (Del Guerico) (Hemiptera: Triozidae) and the Asian citrus psyllid (ACP) Diaphorina citri (Kuwayama) (Hemiptera: Liviidae), known vectors of Candidatus Liberibacter spp. pathogens, causal agents of the incurable and deadly citrus greening ...
Abstract: The research described in this thesis focused on the characterization of some of the factors that influence disease assessment, development and expression of resistance in wheat cultivars to septoria tritici blotch. Earliness appeared to have a strong effect and tallness a small effect on disease severity (DS). A regression equation derived was used to correct the DS in the entries. Another method that gave good disease assessment was to group the cultivars according to their earli...
Abstract: The Lepidopteran stemborer Chilo partellus is a key constraint to cereal production in most resource-poor farming systems as it causes damage to the crop, accruing up to 80%. When plants are damaged by herbivorous insects, they produce herbivore-induced plant volatiles (HIPVs) which can act as repellants for these insect pests and as attractants for organisms antagonistic to these pests (parasitic wasps and predators). Plants can also produce signals that warn other plants of impen...
Abstract: Lepidopteran stem borers are among field insect pests responsible for the low maize production in sub-Saharan Africa. In Kenya, Chilo partellus Swinhoe (Pyralidae), Busseola fusca Fuller (Noctuidae) and Sesamia calamistis Hampson (Noctuidae) constitute the major proportion of stemborer community. Concerted efforts to reduce stemborer populations in maize fields have been emphasized without a good understanding of potential losses associated with damage by respective stemborer speci...
Abstract: This study was undertaken to establish the effect of temperature on the development and survival of B. fusca, S. calamistis and C. partellus and their larval parasitoids The stem borers and the larval parasitoids were reared at 200C, 250C, 280C and 300C and their development time, survival, fecundity and longevity were recorded. These parameters were subjected to analysis of variance (ANOVA) in General Linear Model (GLM). Results showed that development of stem borer larvae varied ...
Abstract: The two initial objectives of this research project were (1) to obtain a detailed chemical description of secretions from the accessory reproductive glands CARGs) of the male desert locust, . Schistocerca gregaria Forskal, and (.2 ) to identify the chemical nature of the spermatophore and seminal fluids in order to obtain a better understanding of the roles of individ~al ARG secretions in their formation. The secretions of the 16 pairs of ARGs were subjected to disc gel electrophor...
Abstract: The ectoparasitic mite Varroa destructor is one of the parasiteglobally reported affecting honeybee healthand causing high colony losses.Of notable importance is the associationof the mite with viruses and their transmission to honeybees which causesgreatharm to bees. Kenyan beekeepers have reportedthat bee populationshave been ondecline in recent years and therefore the need for research to establish whether Varroa destructoris negativelyaffectinghoneybee survival and development....