Last week I was out training group leaders how to do the fabulous OPAL Air Survey . We were at the University of York campus, looking at lichens on trees, when we spotted masses of Harlequin Ladybirds, their larvae, and some pupae. Here's a photo of one of the common colour forms:
These ladybirds are bigger than our native ladybirds (according to the UK Ladybird Survey website we have 46 native species!). They were introduced to North America from Eastern Asia in the 1980s to control aphids, and quickly spread across the continent. The Harlequins first appeared in England in 2004 and have been moving northwards since then. This year is the first time I've seen them in York, so I went onto the Harlequin Ladybird Survey website to record my sighting. This website has masses of information about these ladybirds, including photographs that can help to distinguish them from native ladybird species.
The website also gave information about why we should be concerned about this species - they can outcompete native ladybirds because they are more effective aphid predators, and have been known to eat the larvae of other ladybirds. I told my friend I'd seen some, and she said "Yeah me too, I squashed 5 on the allotment today! Did you squash the ones you saw?". I told her I hadn't squashed them as I didn't see the point - they are so widely distributed now. Plus, I didn't want to advocate squashing "strange looking ladybirds" - there is a risk that people might confuse some of our rarer ladybirds with the Harlequins.
Have you seen Harlequin Ladybirds in your area this year?