Project: Alert network and evaluation of population levels of the olive fly Activity: Health and Sanitation Product: Plant health Geographic data: Madrid, España Start date: May 2011 End date: April 2012 The main objective of the network known as "Dacus," which Tragsatec has collaborated on since 1990, is to provide information about the population of the primary pest to olive trees, (Bactrocera oleae, Gmell), in order to determine the optimal time for treatment. It provides weekly information on the airborne population levels, female fertility, larval population inside olives and level of damage caused to the fruit. At the same time, it provides information on crop phenology, pest biology, crop forecasting and climatic conditions in the control areas established in Spain's main olive-growing areas. Characteristics of the Alert Network and Surveillance: -26 provinces -Field surveillance: from June 15 to November 15 -Over 95 field technicians -Over 950 monitoring stations -95 automatic agrometeorological stations -Over 1,500,000 hectares of olive trees monitored Knowledge of these field and laboratory data allows a determination of the convenience and optimal timing for treatments and study of their effectiveness. Thanks to this network, application of pesticides was significantly reduced, thus reducing the environmental impact and working towards obtaining high quality virgin olive oils from healthy olives.