Wednesday 7 March 2012

Heath Potter Wasp and Weevil Hunting Wasp

I just remembered I've a few things from the summer that I never got around to putting on here and seeing as I'm feeling a bit under the weather today, it would be a good time to rectify this.

I've always been fascinated by insects, there are just so many out there waiting to be noticed. They are so easily overlooked but can be very rewarding given a closer look. Some are incredibly beautiful (well I think so) and some pretty gruesome, most being both of these things at the same time!

Until last June I'd never seen a Potter Wasp or one of their pots but had always wanted to, so when I heard from Dave L that there were some not that far away on the edge of Dartmoor I went over there to see them. They are very picky about the weather, they like it good and sunny, so I only managed to see them on two occasions due to the very changeable summer weather we had. Fortunately though John Walters a naturalist who is studying the wasps was on site both times and was able to show us the location of some pots which had just been built and I was able to see the wasps bringing in prey items. I also saw the female wasps collecting mud from their favoured 'quarry' though I wasn't lucky enough to see a pot actually being built. Dave lives much nearer to the site and was able to visit almost daily for about a fortnight I think. He saw several pots being built and got some superb video footage of it which I was able to watch later. To see more about these fascinating wasps take a look at John's website.

Here's John in action. You can just see him crouched behind the bush left of centre.
He watches the wasp fly over from the 'quarry' area and marks where he loses site of it with a piece of white paper. He then searches that spot for the beginnings of a nest and if there isn't any sign of one hides in that spot and does the same thing again. Sometimes it takes several stages as the wasps can build their nest hundreds of metres from where they collect the mud.

Female Potter Wasp (Eumenes coarctatus)

Here she is, mining. Look at that impossibly narrow waist!

She collects a ball of mud, rolling it between her front legs... so.

 Finished pot

This pot has been filled with paralysed caterpillars ( I think Dave counted over 30 into one pot) and sealed up.

This pot has been built with mud from two different 'quarry sites'

 Wasp at the nest

Incoming with a caterpillar.
 My camera wasn't quite up to the challenge of catching these very quick insects in flight. Here's how it should be done...

© Dave Land 2011
 Camera envy or what!?

On a hot and sunny day in July ( yes, there was at least one!) I was looking for butterflies along the beaches below Beer Head/Hooken Cliffs when I noticed another wasp I haven't seen before. They were very active in the hot weather and very obvious in flight as they looked massive! They aren't though, it's just that they are flying carrying a weevil that's bigger than they are!  They were Cerceris arenaria also known as the Weevil Hunting Wasp, for obvious reasons.

In the eroded cliff face the remains of last years nests were visible as collections of  empty weevil exoskeletons, all very macabre.

Weevil Hunting Wasp

Here's one flying in complete with paralysed weevil undercarriage!
I don't know how they can fly carrying that! ...In fact they were often having a lot of trouble and crash landing to take a breather before struggling on with their massive cargo.

It's a very tight squeeze to get into the burrow...Poor weevil. What a way to go!

This weevil wasn't fully paralysed and struggled as it was being dragged into a burrow, the wasp lost its grip and the weevil fell to the ground. It soon stopped moving as the venom took effect though. Interestingly the wasp didn't come back for it and no other wasp picked it up. They like 'em live and kicking! Horrible!

A video of  fore mentioned life or death struggle. Or more accurately, death or death struggle for the doomed weevil. 


Skev said...

Fascinating stuff Karen - more things I now want to see!

kirstallcreatures said...

Wow fascinating, great series of pics Karen

Mark said...

Wow. The natural world is full of astonishing surprises!

Karen Woolley said...

Thanks for the comments.. much appreciated.

I'm really looking forward to the warmer days to come, when the creepy crawlies will be out in force :-)

Josh Marshall said...

Incredible, really interesting Karen

Karen Woolley said...

Thanks Josh, I'm looking forward to discovering more wasps this this space! :-)