Friday 5 July 2013

"It's life Jim... but not as we know it!!"

We have plenty of the alien Harlequin Ladybirds [Harmonia axyridis] Coccinelle asiatique around here...

This ladybird was brought in, originally, to control aphids in commercial greenhouses.
[it is also known as the Asian Harlequin]

Not as tricky as it seems with "velcro" feet!

The male is a "two-spot" variation of the Harlequin.

But it soon escaped and is increasing uncontrollably across Europe...
and at the same time apparently causing a massive decline in our native species.
Scientists say the alien is winning because its body fluid contains a parasite toxic to other insects.

There is a lot of information on the web about them... just look up Harlequin Ladybird!
So I'll not repeat it here... but Auntie Beeb had this article recently...


on some new research published in Nature

A selection of the colourways...
you will see that all the "multi-spot varieties have one thing in common...
the four central spots form an oval...
none of the native varieties do this.


It would appear, from the article, that the larvae and eggs are infected with a fungus...
to which they are immune...
but, if any other insect eats the larvae or eggs, they are infected with a fungus for which they have no natural immunity ...
Susan of Loire Valley Nature is shortly going to be publishing a deal more on this subject.

Two different colourways of the same pattern on a pair of  Harlequins.


All but the first two of these pictures were taken in Leeds, on a wall just outside our front door....
I have put a goodly selection up as it shows just how numerous and variable they are...
these had all dropped from the Sycamore above the wall.

Looking damaged on hatching... this Harlequin looks the closest to the colour of a human harlequin!!

Please note...
early reports spoke of the Harlequins causing the decline by eating all the native ladybird larvae...
ladybirds are carnivores... all ladybirds will eat others of any soft-bodied creature...
including their own larvae... if aphids are scarce...
and by soft-bodied... I include Man...
as anyone who was in North Norfolk in 1976 will testify.
The bites of a large number of hungry ladybirds hurt!!
The bite of one hungry ladybird hurts!!

There is a You-Tube video of them here...
and a report on the 2009 invasion in the Daily Wail here...

"Plague of ladybirds puts families to flight! Holidaymakers overrun by tens of millions of bugs."

But as the Wail says... despite the numbers, it was a good news story as both the invading species were the native 2-spot and 7-spot varieties...
giving a welcome boost to the declining populations.

Perhaps not the best picture...
but these are two colour versions of the Two-Spot Ladybird...
much smaller and a different leg colour.

Norfolk, Suffolk and the South Coast resorts get the worst attacks as they are closer to the continent...
but the 2009 invasion moved in a wave across the country from the East coast landing points!
The 1976 one must have done too....
as this blog entry states, it hit the Wirral...
but I was too busy nursing the bites to care about reading papers!!

5 comments:

Pollygarter said...

I remember the 1976 invasion hitting Birmingham - little varmints!

GaynorB said...

Well spotted!!

I don't recall either the 2009 or 1976 invasion.

Susan said...

At this stage my post is scheduled for 17 July, but you've covered the new research so I hardly need to publish :-) Terrific photos, and I will link back to your post so people can see the variations in pattern.

Tim said...

Susan, I haven't actually covered it...
just mentioned it and given links to a lay-English BBC version...
which may not be accurate...
I haven't the time to read the Nature article...
nor the need for an insomnia cure.

But...
where are all the bleeding things...
we are over run with aphids...
all I found on a plant the other day was three hoverfly [and one lacewing] larvae!!

And as for ANTZ!!!
Saw an ant carrying a large aphid up a clean stem of the nearest Artemisia.... instant squeeze of both... and then thought I ought to have photographed them first.

Tim said...

The Harlequins on the wall, Gaynor, were not really "well spotted"... the wall was crawling with the little buggers... and their offspring!!
Thanks.