Ian, a resident of Bridge has sent in a picture of a ladybird he spotted (haha) on an orange he purchased recently.What actually drew his attention was that there appeared to be more spots than normal. As it turns out, Ian has captured evidence of one of the most concerning issues in British insect study.
The picture is of a Harlequin Ladybird, so called because varieties of the same species can appear in several different colour forms. Another name is the Asian Ladybird, which gives a clue as to its origins.
The Harlequins were imported into America in 1916 as a method of ‘bio’ aphid control, but they quickly expanded their numbers and are now quite literally taking over the world, driving out, out competing, and killing off all other native species of ladybird wherever they go. They are now the most common ladybird in the United States and are rapidly taking over Canada. The species has been classed as a domestic pest there because it overwinters in large numbers in houses, leaving an unpleasant smell, and also as an agricultural pest, because it damages certain crops and spoils the taste of grapes for wine making. The Harlequin will also bite humans, and though not generally serious, some people have proven to be allergic to the bite.
In Britain, having only arrived here in 2004, they have become more and more prevalent in the south and are moving north rapidly.
Harlequins are not easy to identify because they appear in a variety of forms, and there are several native UK species which can appear similar. The number of spots and main colour is not always a guide. However as a general rule, the Harlequin always has: a larger size, a distinct M or W just behind the head, a more domed shape, and reddish brown legs.
Interestingly, the variety shown in Ian’s picture is apparently typical of California, a large exporter of oranges, so it is possible that the ladybird came all the way to Bridge with oranges from that state.