Last night I happened to glance up to the top of the window in my study, and noticed something strange. There was a small heap of ladybirds clustered together in one corner of the window frame, looking as though they were huddling together for warmth. A quick headcount revealed at least a dozen, perhaps more, all apparently asleep. Slightly further along the frame I spotted another bundle, and then a couple more by themselves in another corner.
I called Dave in to look and he said 'oh, how sweet, they're over-wintering. Leave them be.' But I wasn't convinced. It's not quite bodysnatchers, but there's something slightly sinister about insects in those numbers, and besides, I had visions of them waking up in spring, breeding like fury, and us arriving back one day to find millions of the little blighters. I do hate killing things, though, so I prepared to 'leave them be'.
Until a few minutes later when Dave poked his head back round the door and said, "Um, slight problem. They're Harlequins." He'd been on the net and found some information, and apparently Harlequins are the only sort that deliberately move indoors to hibernate over winter. A quick check through a magnifying glass and we were certain - they were definitely Harlequins.
For those of you who don't know (which included me until last year) Harlequin Ladybirds are an invasive species. They're much bigger than any of our native varieties and they're forcing the smaller types out. For some reason they had a bumper year this year and apparently some people have hundreds or even thousands of them clinging in bunches to south-facing internal walls and windows. Ours was only a small-scale plague. Even so, we took a deep breath and got the vacuum cleaner out. I still don't like killing things, but Harlequins are classed as a pest and I was even more concerned about them breeding next spring and filling the whole place. So we're officially Ladybird Murderers, but hopefully it was in a good cause.