Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

History of Europe --- letters [correspondence] --- biography [general genre] --- Gogh, van, Vincent --- Gogh, van, Theo --- anno 1800-1899

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

alcoholism --- drinking vessels --- wine --- beer [beverage] --- Hoogsteder, John --- Hoogsteder, Willem Jan

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Twenty million Ethiopians depend on Enset (Ensete ventricosum (Welw.) Cheesman). Enset can survive the periods of drought, which are common in Ethiopia, by storing water in its pseu-dostem and thus form a stable food source. Enset bacterial wilt (EBW) affects the production of Enset and can even lead to a production loss of 100%. EBW is a bacterial wilting disease, caused by Xanthomonas campestris pv. musacearum (Xcm). How EBW spreads between dif-ferent Enset plants and farms still remains an issue of debate. According to local farmers, a leafhopper (Tettigoniella medleri Young) which is abundantly present in the region could be a vector for Xcm. Experiments and observations were conducted between elevations of 1417 m and 2998 m in the Chencha catchment, located in the Southern nations, nationalities and people’s region, Ethiopia. Two thousand fifty-seven leafhoppers were counted and their feeding spots on the plant written down during visual observations. Five thousand, three hundred ninety-seven leaf-hoppers were caught with yellow sticky traps. Ninety-five famers were questioned about in-sects in their Enset fields. Information received from these surveys was used to determine the ecological niche of this leafhopper. Between 1417 m and 2100 m, leafhoppers are present in 100% of the investigated farms. Between 2100 m and 2411 m, their numbers decline with ris-ing elevation. Leafhoppers are present in most (64,3%) but not all farms. Between 2411 m and 2641 m leafhoppers are still present, but It is hypothesised that their numbers are too low to have a visible impact in EBW distribution. Between 2641 m and 2998 m leafhoppers, are pre-sent in 0% of the farms. These differences in leafhopper abundance can be caused by multiple factors. A major factor is temperature. Temperature decreases with an increasing elevation. Decreasing temperature causes the overall decrease in leafhopper abundance. Until an elevation of 2641 m where it is too cold for the leafhopper to survive. But also other factors such as cultivation of other crops in lower areas can play a role. A study by both Broeckhoven (2018) and Vantyghem (2018), which was conducted during the same period, mapped EBW distribution. By comparing the disease distribution of EBW with the distribution of leafhoppers, a statistical significant relation between symptomatic farms and leafhopper presence was found. To test if leafhoppers could carry Xcm, DNA-analyses were performed on leafhoppers which had fed on a symptomatic Enset. During these analyses no Xcm was present in the leafhoppers. The negative result can however be a consequence of the small number of samples on which the analyses were conducted. Thus, so far no causal relation has been confirmed. Other gram-negative bacteria, such as Erwina and Pseudomo-nas, have been detected. Together with the leafhopper also other insects which use Enset fields as their habitat were studied. Forty-six different species were caught. Forty-four were identified up to order. Twenty-one of these could be identified to genus or species. Two known vectors for plant pathogen are Psychoda cinereal (Diptera: Psychodidae) and Acanthocephala sp. (Hemiptera: Coreidae). These pathogens are all fungi however, while EBW is caused by bacteria. Furthermore, unlike leafhoppers, farmers never mentioned a link between these insects and EBW.