In the U.S., the first attempts to introduce the beetle took place as far back as 1916. Repeated efforts were not successful. In the early 1980s, aphids were causing significant problems for growers of pecan trees, so the United States Department of Agriculture again attempted to bring the insect into the country-this time in the southeastern United States, using beetles brought from their native region in northeastern Asia. After a period of time, USDA scientists concluded that their attempts had been unsuccessful. However, a population of beetles was observed near New Orleans, Louisiana around 1988, though this may have been an accidental introduction event independent of the original, planned efforts. In the following years, the beetle quickly spread to other states, being occasionally observed in the Midwest within about 5-7 years, and becoming common in the region by about 2000. The species was also established in the northwest by 1991, and the northeast by 1994, in the former case quite possibly involving additional introductions, rather than reaching there from the southeast.
In Europe, the beetle has been first seen in Belgium in 2001. It spread fast and has begun penetrating western Germany (2002), northern France (2004) and the UK (2004). It has now had confirmed sightings from the South East to the Midlands. This is of particular concern as this species has the potential to jeopardise the native species due to it being a very effective aphid predator. When this food source becomes scarce, it will eat ladybird eggs and larvae, and butterfly/moth eggs and caterpillars.
The first harlequin ladybird to be found in Jersey, Channel Islands was located in St Catherines Woods in February 2007. It is presumed that it was blown over from the French coast.
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