I was out with friends feeding the ducks in the grounds of the University of York on Tuesday (23 October 2007). We were admiring a beautiful bird sculpture carved out of a dead tree when Cath suddenly pointed and said ‘Look at these lovely ladybirds!’ I took one look and my heart sank: harlequin ladybirds (Harmonia axyridis), the most invasive ladybirds on the planet! And they’d reached my doorstep …
Harlequin ladybirds are from Asia. They were first sighted in Britain in 2004, and have been making their way across the country ever since (see annual spread maps). They threaten to wipe out all our native ladybird species. In August I heard they’d been spotted in my home town, York. Now I’d seen them too.
I collected up as many of them as I could (7), and took them home. There I took photos that I sent to the National Harlequin Ladybird Survey, along with data about what I had seen and where.
I’ve now heard back from Dr Helen Roy of the survey. This is what she said:
“Thank you very much for your ladybird photo. You have correctly identified a harlequin, Harmonia axyridis. This is a valuable record for our survey.
At the moment ladybirds are forming aggregations in preparation for winter – which they spend in a dormant state. This is why they are so conspicuous at the moment. Harlequin ladybirds characteristically spend winter in buildings and are particularly attracted to light coloured stone at this time of year. We think this relates to their behaviour in their native range (Asia) where they head for rocky mountains to overwinter.
In the spring the ladybirds will start to emerge and again this is a time when we see lots but not as many as in the autumn because quite a few will die over the winter time.
It would be great if you could record all your future observations on-line – www.harlequin-survey.org
You may like to know that we now have confirmed records of the harlequin from many sites across southern England, East Anglia and the Midlands. Further north there are a large number of records from Derbyshire and Cheshire and a few from Staffordshire, Humberside, Lancashire, Yorkshire and county Durham. The harlequin has now also reached Wales, with records from Glamorgan, Monmouthshire, Pembrokeshire and Carmarthenshire.
If you would like to download a colour ladybird identification sheet from the Harlequin Ladybird Survey, go to: www.harlequin-survey.org/downloads/Ladybird%20descriptions_Info%20pack_NEW_v.5.pdf
The trouble with identifying harlequins is that they come in so many different colour patterns – over 100! (The ones I saw were the succinea form.) But the main thing that stands out is that they are big, and look unlike the ‘normal’ ladybirds you’re used to seeing. If in doubt, contact the harlequin ladybird survey people!
The question is, what to do about them? This is Dr Helen Roy of the UK Ladybird Survey again:
‘This a problem without an easy effective solution so far. However, the following websites may give some ideas:
We do not recommend killing any ladybirds and although this is partly because of the risk of native species being misidentified as harlequins, also any that are killed will unfortunately make very little difference to the population.
Unfortunately there is currently no effective control method that will only target harlequins. However, research is being done to try and develop one (possibly using a pheromone that only attracts this species).’
So, there we have it. Only time will tell what will happen to our native ladybirds …
Find out more about my subsequent encounters with Harlequin ladybirds here.