Spread of Rhagoletis completa in Switzerland
In Switzerland, Rhagoletis completa (Diptera: Tephritidae – EU Annexes) was first found in Ticino at the beginning of the 1990s. For approximately 15 years, R. completa remained confined in the Southern part of the country, but in 2005 it started to spread towards the North, crossing the Alps. Recent studies have showed that R. completa is now present in all regions of Switzerland. Considering the low importance of walnut (Juglans regia) cultivation in Switzerland, R. completa is no longer a notifiable pest and no compulsory control measures are taken against it. However, phytosanitary measures concerning the production of young plants are currently being discussed. It is thought that the spread of R. completa across Switzerland is a consequence of climate change. It has been observed that the surface of the cold area prevailing at the Alp summits is diminishing and no longer acts as a natural barrier to stop the spread of invasive animals and plants.
The situation of Rhagoletis completa in Switzerland can be described as follows: Present, first found in the 1990s in Ticino, now widespread.
Sources
Press release from Agroscope, Wädenswil, Switzerland (2010-10-12)
La mouche des brous du noyer : un ravageur américain sur tout le territoire suisse pour cause de changement climatique. http://www.admin.ch/aktuell/00089/index.html?lang=fr&msg-id=35537&print_style=yes