Pete Eeles

[Pete Eeles]

Another interesting question is this: "is a White Admiral larva able to get through to its 3rd (overwintering) instar using a single leaf, or not?". My last photo above would suggest that, on occasion, this is absolutely the case!

Cheers,

- Pete

[Padfield]

As a parting shot before bed - the repeated references to overwintering in 3rd instar intrigue me and this is also something to check up on. The Swiss Bible says white admirals overwinter in the second instar and I took this for granted when I watched them last year. I thought I observed the transitions to third, fourth and fifh instars this spring. It could be a difference between the UK and Switzerland - or I might have seen what I expected to see rather than what was really there.

Guy

[Pete Eeles]

Thanks Guy - interesting! According to Frohawk (the British bible, as far as I'm concerned!) the larvae overwinter in 3rd instar, and this does seem to correlate with my own observations in the south of England. Below are 3 larvae, all from Pamber Forest. If you look at the spines (or lack thereof) and the facial mask then there are, in my opinion, clear differences. I'll need to dig deeper in terms of size differences, but the overwintering larvae seem to be significantly larger than 1st instar larvae, so much so, that I'd expect there to be an intermediate instar Having said that, I wouldn't rule out the overwintering in either 2nd or 3rd instar and this should be investigated. The first call to action is to distinguish 2nd and 3rd instar larvae! The " face mask" does appear to be different from my own observations and Frohawk seems to concur (thanks Fred!).

1st instar larva - no spines - 6th August

2nd instar larva - prominent spines and black face mask - 6th August

3rd instar larva - prominent spines and brown face mask - 20th August

Cheers,

- Pete

[Pete Eeles]

Pamber Update

The 29 White Admiral ova and larvae that I've been following through are now down to a mere 10, although I expect such losses to be quite normal, since the larvae are now exclusively in their 3rd instar and are extremely lucky to have made it this far! It's fascinating watching each larva build its hibernaculum. The process starts with the larva "silking" the leaf onto the stem so that, when the leaf withers, it does not fall away from the branch; this seems to be the only consistency in the process! Some larvae seem to simply fold an entire leaf so that there is a compartment within which it can overwinter. The majority (based on my own observations, those of Guy, and many authors) seem to cut the leaf into 2, so that only the basal half remains, and which is silked together to form a compact compartment. I'm not yet sure if the leaf is folded and then cut, or cut and then folded, or both! Watch this space!

White Admiral 3rd instar larva

White Admiral 3rd instar larva

Larva inside folded leaf

Larva inside folded and cut leaf

Larva inside folded and cut leaf (closeup)

Cheers,

- Pete

[Padfield]

I'm not yet sure if the leaf is folded and then cut, or cut and then folded, or both! Watch this space!

If I had only visited this cat on 2nd Sep, as well as 1st and 3rd, I might have had a more complete answer to your question (in one instance, anyway) ...



I think they cut first, even if not always so beautifully and symmetrically as this one did.

Guy

[Pete Eeles]

Thanks Guy - I thought that was the case too (and you have some incredible images of sights I've yet to see!) until I saw this chap (whose leaf seems untouched):

Unfortunately, I won't get to revisit for a couple of weeks but shall certainly report back!

Cheers,

- Pete

[Pete Eeles]

Update

It's been a while since I last posted, largely due to work and family holiday, so here's an update. First off, the White Admiral saga On balance, I think there are 3 (at least) different forms of White Admiral hibernacula. Each of these should be given a nice, crisp, characterisation, but I'm not sure what that would be! Anyway, based on my own observations and those of Guy and Wolfgang Wagner, here we go. In all cases, the larva "silks" the leaf onto the stem so that it does not fall from the stem when it dies ...

Cut and seal
In this form, the larva deliberately cuts the leaf so that the half furthest from the stem falls away, leaving quite a small space in which to overwinter. Guy has some great shots of the leaf being cut, and Wolfgang an entire sequence of this behaviour here: http://www.pyrgus.de/Limenitis_camilla.html. The end result is shown below, including (in this case) the complete sealing of the leaf:

Seal and let wither
The second form is where the larva seals (quite neatly) the leaf, aligning most of the edges of the leaf. However, the leaf is not cut, but simply allowed to wither.

Fold
The final form is the simplest of all; just fold the leaf (which is often the leaf on which the egg was laid).

Of course, there is much more analysis to do, but I find this different behaviour really interesting and may help with the monitoring of the overwintering larvae.

Cheers,

- Pete

[Pete Eeles]

P.S. I also have a new toy, so expect more of this kind of thing over the winter

Cheers,

- Pete

[Padfield]

Nice toy! Amazing picture.

I too have found what seem to be alternative hibernaculum designs but when I can't see the occupant within it's difficult to be certain if that's really what they are. Plenty of cats are still siting out on their poo-sticks, as if playing dare with the cold weather that must come. What an incredible life these tiny creatures live.

Guy

[David M]

P.S. I also have a new toy, so expect more of this kind of thing over the winter

I shall certainly look forward to that, Pete.

What is this new toy precisely?

[Pete Eeles]

Hi David - it's a Canon MP-E 65mm macro lens, that gives up to x 5 magnification (most macro lenses go to x 1). I had one years ago and didn't get on with it, but feel like I now know how to use it, having played around with extension tubes for quite some time to get past the x 1 limitation!

I've come to the (inevitable) conclusion that the best photos for super-macro photography will be a series of stacked images that are then brought together in the final composition, such as the one I posted, which is composed from 6 separate images. Anyway, a Canon MP-E lens came up on eBay for a stupidly-cheap price (at least £150 lower than it could have sold at if auctioned rather than "Buy it Now") and it's as good as new. Here are some areas I need to become expert at:

1. Moving the camera (or subject) in the desired increments for stacking - normal focusing rails are way to coarse and just don't work. I'm currently changing the focus point using the lens, which is clearly not correct since (in this lens) this changes the magnification too. I'm currently looking into the use of a micrometer to move the subject, which is the same technique when applied to the camera in the Cognisys Stackshot product (not cheap!) that automatically captures images by moving the camera (on a rail) in defined steps using a stepper motor. It does look the bee's knees

2. Stacking the images. I think I have this sussed to a large degree, and purchased the Zerene Stacker software specifically for this. Again, this wasn't cheap.

Cheers,

- Pete

[David M]

Looks like money well spent already, Pete. Those are superb close up shots and given your interest in early stages I'm sure you'll get plenty of use out of your new 'toy' over the next few months/years.

[Pete Eeles]

Observing the small stuff

A few Holly Blue larvae are still present on the ivy at the back of my house - the culmination of a superb year for them.

Holly Blue larva

And I've also been playing with my new lens - some shots below. A whole new world has opened up for me

High Brown Fritillary

Brown Hairstreak (redone!)

Black Hairstreak

Black Hairstreak

Cheers,

- Pete

[Wurzel]

Wow, the structure of the ova is amazing, I'm surprised I haven't seen architects 'getting inspiration' from those

Have a goodun

Wurzel

[David M]

Wow! I think we're all in for a real treat with the results from your new acquisition, Pete.

[Pete Eeles]

And Finally ...

I've managed to make a couple of trips to Glasdrum Wood over the last month where I'm monitoring some Chequered Skipper larvae so this is a wrap-up for 2015. I also took the opportunity to take some scenic shots yesterday to give a sense of the locality; classic Chequered Skipper habitat at the edge of a loch, in this case, Loch Creran which also happens to be a Marine Protected Area.

Glasdrum Wood is at the base of the hill on the left

Location of the car park for Glasdrum Wood

The contrast between June (when Chequered Skipper are flying) and November (now) is quite something, with all of the greens being replaced with browns and yellows.

Glasdrum Wood in June

Glasdrum Wood in November

The Purple Moor-grass, the Chequered Skipper larval food plant, has completely died back, producing a sight that wouldn't look out of place in a hay meadow. Unsurprisingly, the larvae will be a light brown when they re-emerge in the spring and bask on the dead grass leaves before, without feeding further, pupating.

Back in October I spent some time photographing the hibernacula that I could find. In both of these shown below, there is a fully-grown Chequered Skipper larva, nicely wrapped up in silk. Every hibernaculum I found was constructed using two or more leaves, and I've tried to highlight them in the 2nd of each pair of shots below.

I cannot now wait for early spring, when I hope to revisit in search of basking larvae in the Scottish sun

Cheers,

- Pete

[David M]

Lovely sequence that, Pete. It's quite striking to see how the glory of early summer descends into the austerity of late autumn. It's quite a contrast!

Good luck with your early stage hunting next year.

[Wurzel]

Interesting to put the name of the site into a visual context. I'd love to visit it one day...but it will probably be a fair few years yet

Have a goodun

Wurzel

[Neil Hulme]

Fascinating report and yet not so much as a glimpse of the beast. With so many good shots of adult butterflies so widely available these days, I must admit to finding reports of this nature much more interesting.
BWs, Neil

[Pete Eeles]

Thanks David, Wurzel, Neil. I must admit that my interests have evolved over the years - taking photos of adult butterflies just isn't enough any more. Fortunately, Mother Nature is very giving, and I find this kind of study fascinating in itself.

I'll be giving a talk in March at a joint Dorset BC / DWT event - "From Photography to Ecology" which will explain this transition in detail - I just need to figure out what to talk about

Cheers,

- Pete