Pearl-bordered Fritillary found dead on a sundew at Graffham Common!!!

Posted by Graeme Lyons , Saturday, 8 June 2013 17:32

I can hardly believe it but I have the dead specimen sitting on my desk in front of me. I went to Graffham Common with Rachael today to show her the heathland restoration we have been doing there. In the wet heath area I was looking for Marsh Clubmoss, I spotted one plant but then about 10 cm away my eye was drawn to a dead butterfly stuck to a Round-leaved Sundew leaf. It was a small fritillary. At this time of year it had to be one of the good ones. A quick call to Michael Blencowe to check it wasn't a wind up and I realised it had to be Pearl-bordered Fritillary. What the heck?! Where on Earth has this come from? What a strange way to find it too! Sadly, it's hard to imagine another one turning up. There are no violets on site as far as I know and neither are there ever likely to be with the soil types present. It's just likely to be a freak occurrence. But still. Where did it come from?!
I was hoping to find a few invertebrates associated with bare ground, early colonisers of the new habitat we have created but this was something else! Only four months ago this was a conifer plantation with a tiny proportion of relict wet and dry heath. It's hard to imagine how this butterfly could have made it to the spot prior to the felling. A very exciting find. I hope the sundew appreciated the meal.

Other highlights today included the saproxylic hoverfly Microdon analis, the longhorn Pachytodes cerambyciformis (both new to the site) plus another Diaperis boleti

4 Response to "Pearl-bordered Fritillary found dead on a sundew at Graffham Common!!!"

Rachel Bicker Says:

PBF: wrong place wrong time. GL: Right place, right time

Dan Hoare Says:

Hi Graeme, what a fantastic find! And a new species to add to the list of predators of PBF...
This is about 7.5km from the nearest site on the Cowdray Estate, and about 12km from the larger colonies near Arundel. Along with the Heyshott sightings and others on the Hampshire Downs this year I think this is good evidence of some longer-distance dispersal in recent years. We have probably underestimated their abilities! Unrecorded releases do cloud the issue for this species, but these seem very unlikely sites for that, and look more like wanderers. There could easily be undiscovered colonies out there. cheers Dan

Graeme Lyons Says:

Thanks for the comments. Great news Dan. What do you think were the triggers for dispersal in 2013. Weather? Success? Lack of resources? A desperate urge to be eaten by a plant?
Graeme

Dan Hoare Says:

My guess would be that the main dispersal happened in an earlier year - possibly even 2011, when they had a great season and prolonged hot weather. What we're seeingnow would be offspring of those, perhaps from Heyshott or another undiscovered colony. I'd be surprised if the weather this year or last was really suitable for much dispersal. But then I am often surprised by these things. Fantastic SWF pupa - never seen that myself!

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