Vespa velutina or Yellow-legged hornet is native to India, Indochina, Indonesia and southern China, where the nigrithorax subspecies is present. In Europe, following its introduction into France near the city of Bordeaux, the species started to spread in many neighbouring countries. In France, the species has quickly colonized much of the country in few years. Then Vespa velutina entered the north of Spain in 2010 and quickly colonized the three provinces of the Basque territory and then reached Galicia; recently Vespa velutina passed the Pyrenees in Catalonia and reached Majorca Island. The species is also spreading in Portugal. A first colonization of Belgium appears not to have led to the formation of viable populations, while recently some nests were found in Germany and Great Britain. Other areas of introduction are South Korea where Vespa velutina is present since 2003 and Japan since 2012.

In Italy the first animals were captured in 2012 in Liguria, near the cities of Ventimiglia and Loano. In 2013 the first nests were discovered, five in western Liguria and two in the province of Cuneo in Piedmont.

In the following years the species increased quickly its range: the area occupied by the species in Liguria was approximately 205 km² in 2013, it increased to 346 km² in 2014 and reached 930 km² in 2015, with an annual estimated linear expansion rate of about 18.3 km/year. The western part of Liguria, especially from Ventimiglia to Arma di Taggia, is colonized with a massive presence of colonial nests. However, nests have also been found up to Imperia and animals up to Alassio and Albenga, indicating a continued spread of the species.

Adults were found also in Piedmont near the towns of Vicoforte Mondovì, Borgo San Dalmazzo, Caraglio, Mondovi and Rivoli. A nest was discovered in Monasterolo Casotto too. However the observations of the species in Piedmont are occasional and it seems that the species has not yet settled there permanently. However, these reports do not rule out the possibility of colonization in the coming years. A recent observation of the species come from the municipality of Bergantino in Veneto region, several kilometers away from Liguria and Piedmont regions.