Tuesday, 27 March 2007

Spot The Difference

As I walked round Bockhill farm today I noticed a group of Ladybirds on some low vegetation. The first two I found had seven spots but then I found two more that were, the invasive, Harlequin Ladybirds.
The common Seven-Spot Ladybird (Coccinella 7-punctata) is usually red, as above, but occasionally yellow. Its seven black spots are arranged three on each wing case or elytra and one at the back sitting across the two elytra.
The bright colours are a warning to predators that ladybirds have a bitter taste. If handled they exude orange liquid from their joints. This is actually a form of controlled bleeding which stains the hands and is very pungent. The smell is persistent for a long period. Like many other species of ladybird, this is the gardener's friend. Large numbers often migrate here from the continent in warm years.
Food Predatory: adults and larvae feed on aphids and play an essential role in keeping these down.

6 comments:

Annie said...

We might take a lesson from these, a lesson to mingle and learn from others who are a little different from us.

Tony Morris said...

Not really, when the larvae of one, Harlequin, will inevitably kill the young of the other!

tut-tut said...

Does this mean they are interbreeding??

Tony Morris said...

Hi tut-tut, no they won't do that. They weren't in a huddle until I put them together. Most insects have "naughty bits" like a lock and a key; wrong key won't undo the lock, that's why very similar moths or butterflies don't inter-breed, as far as I know.
The larvae of the Harlequin Ladybird are voracious beasts, when they run out of aphids the go on to other species of ladybirds. I believe in one are of Canada, where they were introduced, they have just about eliminated all the native species.

isabella said...

What is being done to stop the Harlequins? I don't want anyone harming my ladybirds - they bring luck, you know...
And I am still giggling at your mention of "naughty bits" ;-)

Tony Morris said...

I don't think it would be possible to control them now, as anything that would deplete their number would also kill off the native species. In some places they are still available as biological pest controllers, negleting the effect they have on things other than aphid pests. In the "mothing" world it is sometimes said that it is necessary to resort to the old soldier to identify a species, the old soldier being "private parts"!