Brown Argus and Small Tortoiseshell

[kielder]

I have been reading an article in June's issue of BBC Wildlife Magazine. In case people don't know about this issue, thought I would share the article with you:

"Over the past 30 years, the brown argus butterfly has expanded its UK range northwards in repsonse to a warming climate. New research has now revealed that, in doing so, it appears to have given some of its enemies the slip.

Rosa Menendez and colleagues from Lancaster University have discovered that brown argus caterpillars in newly-colonised regions of northern England suffer significantly less from parasitoid wasps than their southern counterparts. The ecologists speculate that the northern wasps are not spotting the new arrivals because they are accustomed to targeting the larvae of more established species, such as the common blue."

But while some butterflies seem to be benefitting from milder season, others are losing out. Butterfly Conservation recently announced that the small tortoiseshell has mysteriously declined in south-east England by 80% since 1990. Some experts believe this is due to the northward spread of the parasitoid fly Sturmia bella , species more common in Southern Europe. Sturmia lays its eggs on nettle leaves - the caterpillars accidentally eat the eggs, Sturmia larvae hatch and develop inside their hosts, killing them before they can pupate"!

Dan Eatherley BBC Wildlife Magazine

Does anyone else read this by the way?

[ChrisJB]

I'm a bit of a cheapskate and usually have a 'free read' of BBC Wildlife on the shelves of WHS. If there are an abundance of decent articles then I'll buy it.
Certainly in my neck of the woods, the small tortoiseshell has seriously declined. When I was a kid it was the commonest species by a country mile.
As for the brown argus, I have never seen them up north, though have seen plenty of northern brown argus around lovely ol' Silverdale.

Regards, Chris

[Ukwildlifeo]

I read that. Was an interesting story. The parasites wont be far behind though I reckon, and the small tortoiseshell will adapt or move further north hopefully

BBC wildlife isn't a bad read. I by it before a long journey if I can, so get most issues

[Swallowtail]

Disappearance baffles scientists - Butterfly Conservation

Butterfly Conservation are working with Oxford University to see if they can find out more about the parasite. Numbers are definately down.

[aeshna5]

Originally Posted by Swallowtail

Disappearance baffles scientists - Butterfly Conservation

Butterfly Conservation are working with Oxford University to see if they can find out more about the parasite. Numbers are definately down.

Numbers of Small Tortoiseshells are more than down here, they've effectively disappeared. To me this is even more serious than the once abundant House Sparrow decline, yet the ST gets a fraction of the publicity, despite it being a colourful, well known species!

[ron1863]

Small Tortoiseshells have not moved up here in any numbers, only seen the odd one this year

[Wild-Woman]

I've not seen one Small Tort in N Kent so far this year-which is indeed a worry. If it is due to the parasitoid, let's hope there's a parasitoid that will parasitise the parasitoid...if you see what I'm getting at. That way the original parasitoid may be held in check and the Small Torts could recover.

[aeshna5]

Originally Posted by Wild-Woman

I've not seen one Small Tort in N Kent so far this year-which is indeed a worry. If it is due to the parasitoid, let's hope there's a parasitoid that will parasitise the parasitoid...if you see what I'm getting at. That way the original parasitoid may be held in check and the Small Torts could recover.

I did see 1 in North Kent today close to Elmley Prison. I also saw a fresh looking one yesterday over a nettle patch in my local country park, that was a real joy to see an old friend again!

[Wild-Woman]

When I think back to my childhood, the Small Tortoiseshell and the 'Cabbage White' as it was called then, were abundant in gardens. Considering I lived on the outskirts of SE London, in an urban area, it really does show how numbers of these lovely butterflies have plummeted.
We raised the caterpillars in sweet jars and waited until the chrysalis was produced. I can remember doing this at school too. Now you would be lucky to find the caterpillar of the ST here.
The whites were seen largely as a 'pest' but even they are low in numbers compared to the dozens I can recall fighting over the vegetable patch.

[aeshna5]

Originally Posted by Wild-Woman

When I think back to my childhood, the Small Tortoiseshell and the 'Cabbage White' as it was called then, were abundant in gardens. Considering I lived on the outskirts of SE London, in an urban area, it really does show how numbers of these lovely butterflies have plummeted.
We raised the caterpillars in sweet jars and waited until the chrysalis was produced. I can remember doing this at school too. Now you would be lucky to find the caterpillar of the ST here.
The whites were seen largely as a 'pest' but even they are low in numbers compared to the dozens I can recall fighting over the vegetable patch.

I was a London kid too + yes Small Tortoiseshells + the whites were in numbers in all the gardens.

Have seen many Small + GV Whites recently, but very few Large Whites. What is going on here?