Abstract: Pests and diseases have continued to hamper productivity of the horticultural inductry round the globe. The Kenyan citrus industry is no exemption with a huge decline on its perfomance over the last decade. Although faced with numerous challenges including low productivity, inadequate capacity to buy farm inputs, lack of improved crop varieties, insect pests and diseases are cited to be the most appalling attribute to the decline in citrus productivity. Key among them are the Afric...
Abstract: The spread of the dwarf honeybee, Apis florea, in Sudan along the river Nile in a linear fashion provides a good model for studying the population dynamics and genetic effects of an invasion by a honeybee species. We use microsatellite DNA analyses to assess the population structure of both invasive A. florea and native Apis mellifera along the river Nile. The invasive A. florea had significantly higher population densities than the wild, native A. mellifera. Nevertheless, we found...
Abstract: Huanglongbing (HLB) is a serious disease of Citrus sp. worldwide. in Africa and the Mascarene islands, a similar disease is known as African citrus greening (AcG) and is associated with the bacterium Candidatus Liberibacter africanus (Laf). in recent years, Candidatus Liberibacter asiaticus (Las) associated with the severe HLB has been reported in ethiopia. thus, we aimed to identify the Liberibacter species affecting citrus, the associated vectors in Eastern Africa and their ecolo...
Abstract: Oviposition site selection by gravid female insects is an important determinant inspecies distribution, abundance, and population dynamics. Females may assess thesuitability of a potential oviposition substrate by using cues from conspecific orheterospecific individuals already present. Here, we assessed whether the presenceof conspecific or heterospecific larvae and parasites influenced oviposition decisionsby the stable fly,Stomoxys calcitrans(Linneaus). Using dual and multiple-c...
Abstract: Black soldierfly frass fertilizer (BSFFF) is increasingly gaining momentum worldwide asorganic fertilizer. However, research on its performance on crop production remains largelyunknown. Here, we evaluate the comparative performance of BSFFF and commercialorganic fertilizer (SAFI) on maize (H513) production. Both fertilizers were applied at the ratesof 0, 2.5, 5, and 7.5 t ha-1, and 0, 30, 60, and 100 kg nitrogen (N) ha-1. Mineral fertilizer (urea)was also applied at 0, 30, 60 and ...
Abstract: Abstract:This study was conducted in the scope of developing a sustainable effective approach againstsubterranean termite pests using entomopathogenic and endophytic fungus-based biopesticides.Termites,Odontotermesspp. workers, were tested for their susceptibility to 15 entomopathogenicfungal isolates through the direct spraying of conidia suspensions at 1×108conidia/mL. In general,all the isolates screened were pathogenic, with 100% mortality 4–7 days post-inoculation. However,...
Abstract: The stem borer Busseola fusca (Fuller) (Lepidoptera: Noctuidae) is an important pest of maize and sorghum in sub-Saharan Africa. This insect has oligophagous feeding habits, feeding mostly on maize and sorghum with a narrow range of wild Poaceous plant species. We hypothesised that first instar B. fusca larvae, the critical stage for successful establishment on a host plant, can establish and then grow on a particular plant as a result of induction of a complement of digestive enzy...
Abstract: Insects such as the Mediterranean field cricket, Gryllus bimaculatus and the Desert locust, Schistocerca gregaria, are emerging as potential sources of human food and feed for livestock. High nutritive value and efficient feed conversion make them attractive for commercial production as novel livestock, but these properties strongly vary with the insects´ diet. Current mass-rearing protocols are based on fresh, non-storable feed materials. This requires constant supply and makes t...
Abstract: Aggregation of the bean flower thrips, Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), has been observed on cowpea, Vigna unguiculata (L.) Walp. To understand the mechanism underpinning this behavior, we studied the responses of M. sjostedti to headspace volatiles from conspecifics in a four-arm olfactometer. Both male and female M. sjostedti were attracted to male, but not to female odor. Gas chromatography/mass spectrometry (GC/MS) analyses revealed the presence of t...
Abstract: Fall armyworm (FAW), one of the most important pests of maize in Latin America, suddenly appeared in Africa in 2016 and spread rapidly. Estimates of crop losses due to FAW are essential in order to compare the impact of these losses with the cost of controlling FAW and advise appropriate technology dissemination and policy. In this study, therefore, crop losses due to FAW in 2017 and 2018 were estimated in all the maize production areas of Kenya. Data were collected during June and...
Abstract: Bactrocera dorsalis (Hendel) is an important pest of fruit-bearing plants in many countries worldwide. In Africa, this pest has spread rapidly and has become widely established since the first invasion report in 2003. Wolbachia is a vertically transmitted endosymbiont that can significantly influence aspects of the biology and, in particular, the reproduction of its host. In this study, we screened B. dorsalis specimens collected from several locations in Africa between 2005 and 20...
Abstract: Methanolic extracts of liana of Caesalpinia welwitschiana and leaves of C. bonduc were found to possess moderate antifeedant and ovicidal activities against Tuta absoluta. Bioassay-guided isolation of constituents from the most active fraction of C. welwitschiana led to the identification of four known compounds [isobonducellin 1a and bonducellin 1 b, intricatinol 2, (-)-epigallocatechin-3-O-gallate 4] and one new constituent [welwitschianic acid 3]. The most active fraction of C...
Abstract: Edible insects are increasingly being considered as sustainable alternatives to fish and soybean meals in animal feed because of their high nutritional quality and environmental benefits. However, successful introduction of a new product to the market depends on the target user’s acceptance. Thus, evaluating the potential demand of insect-based feeds would provide relevant information for policy development. The present study assessed farmers’knowledge on edible insects as feed...
Abstract: Nowadays, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is becoming a serious insect pest of chickpea in Ethiopia and its management has faced considerable challenges, to improve yields in many crops, in most parts of the world. This experiment was initiated with the objective to evaluate the effectiveness of Azadirachta indica and Milletia ferruginea extracts for the management of H. armigera in chickpea from July to December during 2017 and 2018 cropping season under fie...
Abstract: The use of black soldier fly frass fertilizer (BSFFF) is being promoted globally. However,information on nitrogen (N) fertilizer equivalence (NFE) value and synchrony of N mineralization forcrop production remains largely unknown. Comparative studies between BSFFF and commercialorganic fertilizer (SAFI) were undertaken under field conditions to determine synchrony of N releasefor maize uptake. The BSFFF, SAFI, and urea fertilizers were applied at the rates of 0, 30, 60,and 100 kg N...