Encounters with an alien: a European perspective

The harlequin ladybird, Harmonia axyridis, was introduced into continental Europe in the 1980s as a classical biological agent of scale insects and aphids. It was never intentionally introduced into Britain, but arrived in the southeastern county of Essex in 2004. The spread of this non-native species across Britain has been spectacular; approximately 100 km per year. The harlequin ladybird is particularly abundant in the southeast of England, but there are many records from central and northern England, Wales and also a few records from Scotland, as far north as Orkney. The UK Ladybird Survey has been monitoring H. axyridis since it arrived in Britain through an online public participation survey: www.ladybird-survey.org. The survey has received more than 30,000 records of this species, and particularly notable are the very large numbers of the beetle which are commonly reported in the autumn each year, when this species enters buildings to locate suitable overwintering sites. The autumn of 2009 is no exception; the survey received approximately 800 records a week during October. The pattern of rapid spread and high abundance of H. axyridis has also been documented across northern and central Europe. Harmonia axyridis has been recorded as established in (order relates to approximate time of establishment): France (first report), Germany, Belgium, Netherlands, Switzerland, Luxembourg, England, Czech Republic, Italy, Austria, Denmark, Norway, Poland, Wales, Liechtenstein, Scotland, Hungary, Slovakia and Bulgaria (last report). Interestingly this species is not so successful in southern European countries.