The ‘Harlequin’
a large ladybird which has recently arrived in the UK.
The Harlequin ladybird was deliberately introduced into America and has recently been discovered in the UK. In both places it is harming the native species.
Ladybugs or Ladybirds are useful in the garden since they and their young eat greenfly. They are so useful that a large species, the ‘Harlequin’ Harmonia axyridis, originally found only in Asia, was introduced into North America in 1988 to help with pest control. This introduction was extremely successful, so much so that it is now the most common species of ladybird in America.
In September 2004 the ‘Harlequin’ was found in England, and alarm bells have started ringing in the bug world. The problem is that the ‘Harlequin’ is such an efficient predator that it easily out-competes all our native species. Worse still, it will actually eat other ladybirds when the supply of greenfly runs low.
If you would like to get involved with ladybird surveys in the UK there is a very good website to get you started. Or if you would just like to be able to identify the ‘Harlequin’ there is a special site for that too, and you can also see what the Natural History Museum in London has to say about the invasion.
There are many examples of introduced species becoming a problem themselves. The list is a long one, but the introduction of the cane toad to Australia should act as a cautionary tale. When any species is let loose in a new environment there is always an element of risk. It is very difficult to predict what will happen when natural enemies are absent. The ‘Harlequin’ is very good at controlling garden pests, the problem is that it also ‘controls’ the useful insects. It has eclipsed the other 450 or so species of ladybugs in America, and looks likely to do the same to our 46 ladybird species in the UK.
If you want to encourage ladybirds in your garden there are many commercial sites where you can buy ‘houses’ to help them overwinter.
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