The arrival of the Normans is often quoted as the last successful invasion of England. In human terms it may be but in plant and animal terms we are under constant invasion from abroad. One of the latest and most successful of these alien invaders is an Asian ladybird, the Harlequin Ladybird (Harmonia axyridis), which first arrived in South-East England in 2004. By the autumn of 2007 hundreds and even thousands of individuals had been recorded as far apart as Durham, the Lizard and West Wales. In 2006 on the Isle of Wight people had to get their vacuum cleaners out to hoover them up as large quantities of these invaders swarmed in.
Like many Ladybird species it is highly variable in appearance. Described as the most invasive ladybird on earth it was introduced on purpose to the USA in 1916 as a means of biologically controlling pest insects. At first it failed to become established but in the 1980s it suddenly spread rapidly and can now be found right across the whole of North America.
Deliberate introductions were also made across mainland Europe and although it was not purposely introduced here it arrived in England in 2004, Wales in either 2005 or 2006, and Scotland and Ireland in 2007. It is a pest species insofar as it is a threat to native biodiversity, a human nuisance, and a pest of grape growing and the and wine industries.
Ladybird recording schemes have existed for a few decades across England but they are becoming of even greater importance as the spread of this invader is tracked. Databases held by the Biological Records Centre can be seen at www.searchnbn.net . The Harlequin survey has its own website at http://www.harlequin-survey.org/
On a more frivolous note – it’s a shame that the Harlequin doesn’t look like this – we might be able to distinguish it better!
I assume the last pic is the female of the species? :-)
ReplyDeleteI remember when I lived in the USA, and one year in the early nineties there was a ladybird plague. The little blighters were everywhere. I remember a white interior wall in my house looking as though it had recently ben re- wallpapered in orange polka dots
My Mum used to like Ladybirds until one year, around the 1970s, she got covered in a swarm of them as she walked through Childwall Woods in Liverpool. It put her off them for life.
ReplyDeleteHey, just wondered if knew who this picture belongs to? I'd very much like to ask for permission to borrow it :)
ReplyDeleteI regret I don't know whose picture this is. When Io do I acknowledge it. When I don't I tend to assume it's in the public domain but I can't guarantee that.
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