Illegal alien – Galena, Illinois – October 2008
When we were in Chicago last year, we drove out to Galena for the weekend and stopped at the Chestnut Mountain Resort on the banks of the Mississippi River. While I was waiting for Nick, I snapped this little guy, and I was surprised to find he wasn't the only ladybird around. When we got to our rented house, we found literally swarms of them, hurling themselves against the fly screens and crawling around the rooms. I had never seen anything like it in my life.
Turns out this is an Asiatic or Harlequin ladybird (Harmonia axyridis), introduced from Asia into the US at various times from the early 1900s to the 1980s to control plant pests including aphids and scale insects. So far so good. What wasn't on the label was the fact that these insects are voracious feeders and have swept across the US, quickly becoming by far the most common ladybird species. Their increase in numbers has proved to be a catastrophe for native North American ladybirds as Harlequins consume their prey. The Harlequin ladybird is also partial to overwintering inside houses in huge numbers and have come to be regarded as an unwelcome annual invasion on par with wasps. Their defecations, and nasty habit of secreting some of their own foul-smelling blood when threatened, can destroy upholstery, curtains and wallpaper. The Harlequin ladybird now roams across not only its native Asia and North America, but also the UK, France, Belgium, Germany, Holland, Poland and Scandanavia with numbers soaring annually. They are now the dominant ladybird species in the UK and have even arrived in South Africa.
This is part of a series of non-food photographs that will be published every Saturday on CookSister. Click here for a full list of photographs previously featured.