At the moment.... mostly about moths

Wednesday, 29 July 2009

Harlequin Ladybird (not)

The Harelquin Ladybird is an invasive alien species that arrived in the UK a few years ago. It's of particular concern because it is highly competitive with native species for prey (e.g aphids) and is also known to regard native ladybird species as prey so will consume them directly. I first saw this species in our garden in 2006. By 2007 the numbers were up and last year we were inundated. I didn't make systematic counts, but there must easily have been 100 larvae at any one time. It seemed that the Harlequin had taken over our garden. This year though... I've seen 1 or 2 and no more and they were only adults, i haven't seen any larvae, not as yet anyway. Not only that but there are plenty of 7 spots around, and I've seen orange, 10 spot and 22 spot. So what's happened? Is it just our garden, or is this more widespread? And why? The only reason I can think of is maybe the cold weather over the winter - did that kill 'em all off? Maybe something else is eating them. I don't know. Anybody else seen this? Or are they just as common as last year?

6 comments:

IanG said...

Hi Jerry, oddly enough I included the Harlequin in my blog because it's very common in Derby...or at least it was a few weeks ago?. I regularly visit a local area which usually has a large concentration of Harlequin and other native Ladybirds but when I was there earlier this week the numbers had diminished quite drastically. I know there are people who sell Ladybirds to gardners for pest control so there's a possibility that someone has been 'harvesting' them and the area in question is adjoining some large allotments but the population had gone from hundreds to tens in a matter of weeks...very strange??.

JerryL said...

Ian - I've never heard of ladybird harvesting, if it means people aren't using pesticides, maybe it makes sense, I'm not sure though! It certainly hasn't happened in our garden - none in the first place.

BillyBBee said...

愛情不是慈善事業,不能隨便施捨。.........................

午餐 said...

每次看完你的文章,總是回味許久,要經常發表喔。.........................

消化 said...

失意人前,勿談得意事;得意人前,勿談失意事。..................................................

春天來嚕 said...

thx u very much, i learn a lot