Abstract: Citrus is considered one of the most important fruit crops globally due to its contribution to food and nutritional security. However, the production of citrus has recently been in decline due to many biological, environmental, and socio-economic constraints. Amongst the biological ones,pests and diseases play a major role in threatening citrus quantity and quality. The most damaging disease in Kenya, is the African citrus greening disease (ACGD) or Huanglongbing (HLB) which is tra...
Abstract: Background: Anopheles gambiae larvae traditionally thrive in non-polluted environments. We previously documented the presence of the larvae in heavy metal polluted urban aquatic environments and the associated biological cost. The goal of this study was to unravel the molecular dynamics involved in the adaptation of the mosquitoes to the heavy metals. Methods: Total RNA was extracted from third instar larvae of both cadmium treated populations and untreated control populations. The...
Abstract: The parasitoid lifestyle represents one of the most diversified life history strategies on earth. There are however very few studies on the variables associated with intraspecific diversity of parasitoid insects, especially regarding the relationship with spatial, biotic and abiotic ecological factors. Cotesia sesamiae is a Sub-Saharan stenophagous parasitic wasp that parasitizes several African stemborer species with variable developmental success. The different host-specialized p...
Abstract: Understanding the ability of parasitoid insects to succeed in new host populations is a relevant question forbiological control and adaptive mechanisms.Cotesia typhaeis an African parasitoid specialized on the mothSesamiae nonagrioides, also called the Mediterranean corn borer. Two Kenyan strains ofC. typhaediffer in theirvirulence against a new host population from France. We explored behavioral and physiological hypothesesabout this differentiation.Cotesiagenus belongs to a group...
Abstract: This paper explores the economic implications of fall armyworm (FAW) and its management strategies by exploiting exogenous variation in FAW exposure amongst households in southern Ethiopia. We find that FAW exposure affects maize yield and sales negatively, but not consumption. Furthermore, we find evidence of crowding in and intensification of insecticide use in response to FAW exposure. We also find suggestive evidence that existing extension service arrangements lack the capacit...
Abstract: Although the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae) is the most destructive insect pest of coffee worldwide, there is much to learn about its thermal biology. This study aimed to develop temperature-based models for H. hampei development and to provide the thermal requirements of immature stages in the laboratory. Using a new observation method, larval development and survival were monitored daily on fresh Arabica coffee seeds, und...
Abstract: Efforts to recycle organic waste using black soldier fly (BSF) larvae into high-quality alternative proteinbingredients in animal feeds and organic fertilizers have gained momentum worldwide. However, there is limited information on waste manipulation to increase nutrient retention for enhanced larval perfor mance and frass fertilizer quality. In the present study, brewer’s spent grain with a carbon to nitrogen (C/ N) ratio of 11 (control) was amended with sawdust to obtain subst...
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...