Mediterranean fruit fly (medfly) Ceratitis capitata (Diptera, Tephritidae) occurrence data

<i>Ceratitis capitata</i> occurrence data were obtained from the Global Biodiversity Information Facility (GBIF: www.gbif.org), Royal Museum for Central Africa, and published literature (Szyniszewska and Tatem 2014). Records dated pre-1950 were excluded, assuming that older records may be more prone to digitisation errors, due to potentially less accurate data collection techniques. Moreover, older records might represent occurrences in habitats that changed over time. Thus, we are focusing on more recent data points. Records representing <i>C. capitata</i> detections only, and those that fell well outside the known climatic niche and no evidence of <i>C. capitata</i> overwintering and establishment were considered outliers and thus excluded from the analysis. Data were reviewed for clear outliers with incorrectly typed coordinates and those that evidently showed country or administrative units’ centroids. The identified outliers were removed from the dataset. The GBIF data contained a large number of occurrence points from areas in northern latitudes well outside the known distribution area of <i>C. capitata</i>. We removed obvious outliers from countries where <i>C. capitata</i> is listed as absent according to EPPO and CABI Pest Distribution Compendia. For the remaining outliers located in northern locations of countries where the distribution is believed to be limited to southern areas, we consulted in-country experts to indicate which records may indicate true overwintering generations and which represent seasonal <i>C. capitata</i> trapping with no evidence of overwintering potential. Several bellwether sites remained, notably in Spain, France, Italy, Austria and Romania.