Sunday, 21 October 2012

What is it? #5 revealed

photo: Wendy Denton
This is the most invasive ladybird on Earth and it's called a harlequin ladybird, harmonia axyridis. Where you right? 

It arrived in Britain in 2004, possibly on some flowers or vegetables that were brought in to the country from Europe or Canada. It is a real danger to our native ladybird as it's a very good predator and can travel further distances than our native ladybirds, allowing it to find more food and easily out compete them. Harlequin ladybirds also eat a greater range of food, so if there are few aphids about they will eat other prey, including ladybird eggs, larvae and pupae!
Like all ladybirds, the harlequin ladybird undergoes complete metamorphosis and goes through an egg, larval, pupal and adult stage.Scarily a single female can lay over 1000 eggs! The most common ladybird in Britain is the seven spot ladybird but the two spot ladybird has declined by nearly half since the arrival of the harlequins.

So how can you tell the difference? Well, harlequin ladybirds are larger and more round than our natives.The most common forms in Britain are orange with 15-21 spots or black with 2 or 4 orange/red spots and their legs are almost always brown. If your ladybird is less than 5mm then it is unlikely to be a harlequin.
Here's a selection of harlequin ladybirds that were found on one site in London. you can see that the markings do vary quite a lot and it can be difficult to distinguish from a native ladybird. For more help and to log your sightings go to the Harlequin Ladybird survey site -

If you'd like to print out a guide to the most prominent ladybirds in the UK to help you go ladybird spotting you can find a good one here.

So, finally, here's a little quiz for you. See if you can work out if the ladybirds in the pictures below are native or harlequins. Good luck!

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