18 research outputs found

    Thermal Tolerance of the Coffee Berry Borer Hypothenemus hampei: Predictions of Climate Change Impact on a Tropical Insect Pest

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    Coffee is predicted to be severely affected by climate change. We determined the thermal tolerance of the coffee berry borer , Hypothenemus hampei, the most devastating pest of coffee worldwide, and make inferences on the possible effects of climate change using climatic data from Colombia, Kenya, Tanzania, and Ethiopia. For this, the effect of eight temperature regimes (15, 20, 23, 25, 27, 30, 33 and 35°C) on the bionomics of H. hampei was studied. Successful egg to adult development occurred between 20–30°C. Using linear regression and a modified Logan model, the lower and upper thresholds for development were estimated at 14.9 and 32°C, respectively. In Kenya and Colombia, the number of pest generations per year was considerably and positively correlated with the warming tolerance. Analysing 32 years of climatic data from Jimma (Ethiopia) revealed that before 1984 it was too cold for H. hampei to complete even one generation per year, but thereafter, because of rising temperatures in the area, 1–2 generations per year/coffee season could be completed. Calculated data on warming tolerance and thermal safety margins of H. hampei for the three East African locations showed considerably high variability compared to the Colombian site. The model indicates that for every 1°C rise in thermal optimum (Topt.), the maximum intrinsic rate of increase (rmax) will increase by an average of 8.5%. The effects of climate change on the further range of H. hampei distribution and possible adaption strategies are discussed. Abstracts in Spanish and French are provided as supplementary material Abstract S1 and Abstract S2

    Fruit flies infesting Arabica coffee in Tepi, Southwestern Ethiopia

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    No Abstract. Ethiopian Journala of Biological Science Vol. 4 (2) 2005: pp.207-21

    Assessment of quantitative and qualitative losses of stored grains due to insect infestation in Ethiopia

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    Published online: 15 Sept 2020This study was designed to determine the quantitative and qualitative losses of stored grains that arise from insect infestation in three districts of southwestern Ethiopia. One district was selected from each zone based on the production potential of the target crops (maize, sorghum, wheat and fababean). A total of 240 farmers’ stores from all districts were randomly selected. The grain samples used in the present study were stored for 5 different time periods, ranging from 1 to 5 months and from the same farmers’ stores, to determine grain weight loss, insect damage, and nutritional losses. Grain damage showed significant differences over the storage periods across the study districts. A similar trend was observed for weight loss for each of the grains in all districts. The moisture content of the grains decreased along the storage duration. Crude protein and crude fat contents significantly decreased as the storage duration increased in all traditional storage types. Furthermore, the crude fibre and ash contents of the different grain types significantly increased as the storage duration increased in all storage types. These results demonstrated that traditional storage structures have a substantial effect on quantitative and qualitative losses of stored grains. This finding has great implications for food security and hidden nutritional deficits in society. Thus, there is a need to develop and disseminate storage technologies that minimize losses and that are affordable for small farm holders

    Bottom-up and top-down drivers of herbivory on Arabica coffee along an environmental and management gradient

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    While sustainable agriculture relies on natural pest control, we lack insights into the relative importance of bottom-up and top-down factors on pest levels, especially along broad environmental and management gradients. To this aim, we focused on bottom-up and top-down control of herbivore damage in sixty sites in the centre of origin of Arabica coffee in southwestern Ethiopia, where coffee grows along a management gradient ranging from little or no management in the natural forest to commercial plantations. More specifically, we examined how canopy cover, percentage of surrounding forest and management intensity affected caffeine and chlorogenic acid concentration (bottom-up process) and attack of dummy caterpillars by ants and birds (top-down process), and how these in turn affected pest levels. Caffeine and chlorogenic acid concentrations were negatively related to canopy cover, while ant attack rate was positively related to canopy cover. Both ant and bird attack rate increased with the percentage of surrounding forest. Yet, secondary chemistry and caterpillar attack rates were unrelated to herbivory, and herbivory was only directly and positively affected by management intensity. Our study highlights that canopy cover can have contrasting effects on plant defence and predation, and that changes in bottom-up and top-down factors do – unlike often assumed – not necessarily translate into reduced pest levels. Instead, direct effects of management on pest levels may be more important than bottom-up or top-down mediated effects

    A Coffee Berry Borer (Coleoptera: Curculionidae: Scolytinae) Bibliography

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    Native to Africa, the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae), has gradually invaded most coffee-growing areas worldwide. Adult females colonize the coffee berry and oviposit within galleries in the coffee seeds. Larvae and adults consume the seeds, resulting in drastic reductions in yields and quality, negatively affecting the income of approximately 20 million coffee-growing families (~100 million people) in ~80 countries, with losses surpassing more than $500 million annually (Vega et al. 2015). It has become evident that the coffee berry borer scientific community could greatly benefit from having access to a bibliography of the literature related to the insect. Such an information source would allow scientists to find out what research areas have been explored throughout the many coffee berry borer-infested countries after more than 100 years of research on the topic. It could also help to direct lead future research efforts into novel areas, and away from topics and ideas that have been thoroughly investigated in the past
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