Tuesday, November 23, 2010

Ladybird, ladybird, fly away home

Has anyone else had ladybirds setting up home in odd corners this autumn?

We've had a veritable plague. They started appearing early last month, when I took this photo: they were crawling around on the windows, wandering over ceilings, popping up in cupboards. I was initially delighted as I thought, aaahh, dear little ladybirds, looking for somewhere to stay for the winter.

Actually I had no idea they hibernated: but yes, apparently they like all sorts of different hibernating spots. And spots is the word: the number of spots on a ladybird's back determines where, and if, it will hibernate.

Seven-spots (the most common type) migrate; others mostly hibernate in hollow plant stems: but tree trunks, bushes and fence posts are other favoured spots. It's mainly two-spots which seek out our houses. And they all hibernate in big groups - it makes finding a mate easier in spring. If all goes well they can live two to three years, apparently. That's as long as our last pet hamster.

Sadly, though, there isn't a two-spot to be seen in my little cluster of snoozy ladybirds. That's because these are not our native ladybirds but the harlequins, the grey squirrels of the ladybird world. They're from America, but they're not nice cultured friendly amusing Americans: they're very large, very successful and very competitive Americans. In fact they have a simple strategy in elbowing out our native ladybirds, which tend not to like to make too much of a fuss (am I overdoing the anthropomorphism here?): they simply eat them out of house, home and aphid colonies.

This leaves me with a dilemma. Obviously the reason we gardeners like ladybirds is because they eat aphids - and a ladybird with a monster appetite sounds like a serious asset to a harassed vegetable gardener. But at what cost?

I am recording my little colony on the UK-wide Harlequin Ladybird Survey (http://www.harlequin-survey.org/) which is tracking the spread of this possibly-not-entirely-unwelcome alien across the country. We are definitely on the fringes of its spread - but it's definitely here and in some numbers.

But what do I do now? Kick this lot out of the corner of my dining room? Or live and let live? (this last does not apply to our local aphid colony next year, of course....)

6 comments:

Plant Mad Nige said...

When I brought our huge jade plant in for winter, last month, masses of hibernating ladybirds crawled out and I spent a lot of time tracking them down and putting them outside, hoping they'd quickly find somewhere else to spend their winter sleep. The closely packed, succulent leaves of the jade plant obviously suited them.

They were practically all 7-spot. I kept an eye open for harlequins, which we've seen here in the village, but glad to say, there were none on the jade plant. Had I found any, I'd have squashed them.

The problem with harlequin ladybirds, I believe, is that as well as eating aphids, they predate lots of other insect species which are either harmless or beneficial, so they are reducing biodiversity.

I don't think there's any harm in anthropomorphising, by the way, unless you begin to believe in your fantasies.

patientgardener said...

I noticed several of these in my office at work about a month ago, kept appearing every time I pulled the roller blind up or down. They seem to have disappeared now so I hope they have found somewhere better to hibernate

Esther Montgomery said...

I'd find this a dilemma. The grey squirrel parallel seems apt and I'd like to get rid of the harlequins somehow - but arranging for their death would be beyond what I could do.

Where do the seven spots migrate too? I thought the many who were crawling around my garden in the early autumn had decided to hibernate in my hollyhocks so I cut them down and left them in an unsightly pile. Was this pointless?

Esther

The Constant Gardener said...

Nigel: I always believe in my fantasies. And funnily enough there was a jade plant just underneath that bit of my dining room... hmm...

and PG rollerblinds don't sound like a very sensible choice at all. You'd have thought they would figure out a better place, wouldn't you?

Esther: I am completely with you. It is entirely beyond my moral compass to have to squash anything that looks like a ladybird (in fact I think this is a cunning defensive ploy by harlequin ladybirds, which may actually be large grey squirrels in disguise: see anthropomorphism comments above.)

The 7-spots migrate here from the continent according to Natural England (http://www.plantpress.com/wildlife/o209-ladybird7spot.php) so I'd imagine that's where they go back to. There are reports of swarms of migrating 7-spots invading places like Norfolk, too: http://news.bbc.co.uk/local/norfolk/hi/people_and_places/nature/newsid_8185000/8185894.stm

But some do hibernate: and so do lots of other types, especially in things like hollyhock stems, so your unsightly pile is far from pointless :D

La Petite Gallery said...

Growing up I was told that finding Ladybug was goodluck.

Happy Thanksgiving.
yvonne

The Constant Gardener said...

Yes I thought it was supposed to be good luck too, though I was always told to say to them when I was a kid:
'Ladybird, ladybird, fly away home
your house is on fire and your children are gone'
which I could never quite understand the point of and always thought was a bit unnecessarily unkind to ladybirds. It seems to be a universal rhyme though that all British children were taught at their mother's knee: anyone know exactly why?

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