The mango tree is one the important sources of income in the rural economy of Senegal. However, mango producers in Ziguinchor are facing fruit fly infestations leading to important losses in income. The aim of this study is to measure the impact of the losses encountered by mango farmers in Ziguinchor over three years 2012, 2013, and 2014 and conduct an econometric study to examine household characteristics associated with high level of losses. At the household level, the total yearly losses on average from fruit fly infestations represent 17.09 % of the average total household income in Ziguinchor (Casamance). The losses associated with variability of production are much smaller than losses from decreases of average yield. Furthermore, the results show that the number of hectares, level production, and use of Keitt varieties are three factors statistically significant, with a significant positive influence on losses from infestation. The use of fruit fly control technologies does not appear to significantly reduce losses. / Master of Science / Mango production is an important activity in Senegal such as in the south part of the country, in Ziguinchor (Casamance). And this activity hurled Senegal to the second largest exporter among West African countries in European market place. However, mango production is threatening by fruit fly pests and are responsible for a considerable loss in production. The aim of this paper is to evaluate the losses faced by mango producers in the south of Senegal by calculating the average losses and losses from a variation of the mango production for three years. Furthermore, characterize the different variable that are principally responsible for producer losses. A survey has been run in Ziguinchor. The results that farmer losses can reach up to 17.09% of annual total income per year. The different variables that impact the most losses are the number of plants, the production and the Keitt variety mango. Keywords: Mango production, Fruit fly infestation, Mean yield decrease loss, Producer risk loss