Pete Eeles

[Pete Eeles]

Pamber Forest

I couldn't resist returning to Pamber for an hour late this afternoon and found another 7 White Admiral larvae, including a pair on the same sprig of Honeysuckle. I'm not sure if the eggs were laid on the same leaf originally (I could only see the remnants of one egg shell) but am trying to figure out what happens to the 2nd larva when the leaf tip is already occupied, since that's where they set up home. Perhaps moving to another leaf is the answer! The larvae are at different stages, so most likely the offspring of 2 separate females, since eggs are laid singly. The youngest larva not only built a platform out of silk and frass, but had also decorated itself in the stuff! It also builds a "latrine" on the leaf, presumably to deter any predators. This (and other phenomena) are beautifully explained in the paper "The larva of the White Admiral butterfly, Limenitis camilla (Linnaeus, 1764) - a master builder" (Entomologist's Gazette, Volume 56, Issue 4, page 225-236). I hope to do a precis over the winter using my photos (and those from other contributors) to exemplify the points being made in the paper.

Cheers,

- Pete

[Padfield]

Brilliant stuff, Pete. I'm interested to see the variation in ssp. scotica. As I'm sure you know, the species is very variable in the Alps, even on the same mountain, but I had always thought the UK populations were more homogeneous.

Interesting too to see the white admiral larvae. It's a pity you've lost the pair on the same leaf - maybe I'll learn how camilla cats get on together tomorrow morning. I imagine the presence of a second caterpillar is evident (to a caterpillar) long before they meet, simply because of the silky tracks they leave. At the very least, the build-up of silk and frass on the leaf side of the tip extension should enable junior to avoid a direct confrontation.

Guy

[Pete Eeles]

Pamber update

I think I've been to Pamber 3 days in a row now, and have now mapped out the White Admiral population that I'll be following through the winter and into next year. I'd show a map, but this would give away where I've placed markers so will omit that (for now, at least!) given that undesirables read these forums In total, there are 7 separate locations, hosting 22 larvae and 3 eggs as of this morning, giving a population of 25 in total, which seems a nice round-ish number. I know I could increase this (I found 5 more larvae today without even looking) but will leave it at those I've already found.

So - some photos. Guy's photos of a leaf hosting more than one larva are far-superior to mine since the platform that the 2nd larva has formed, at the side of the leaf, has collapsed, so not a brilliant image, but does confirm the behaviour. The egg that I'm monitoring on a separate leaf (that already contains a larva) has yet to hatch. I'll have to catch up with this in a week or so, since I fly out to Brazil (for work) tomorrow night (I'd much rather be in a Hampshire wood!). The first blurry photo sets out the scene on the lower 3 leaves.

Location 3c - 2 larvae, larva + unhatched egg, larva

Location 3c - 1st instar larva on the side of a leaf containing a 2nd instar larva

Some other shots (read the captions for info):

Location 2a - wins a prize for the most beautifully-decorated

Location 5 - the most advanced 2nd instar with a wonderfully-constructed latrine

Location 5 - larva + marker

Location 6 - the intricate pattern of feeding damage

And, finally, I came across a final instar larva that was still alive, with the cocoons of parasites all over it. Poor thing.

Location 4a - final instar parasitised larva

Location 4a - final instar parasitised larva

Cheers,

- Pete

[Pete Eeles]

Scottish Specialties

Another trip to Scotland and a chance to visit both Glasdrum Wood and some of the Glens on the way back to Glasgow, including Glen Kinglas, where I found a Scotch Argus larva by torch a while back. Glasdrum was superb, where Scotch Argus ssp. caledonia were putting on a great show - I must have seen between 50 and 60 in total. However, Glen Kinglas was just amazing with literally hundreds of Scotch Argus making this a sight to remember. Every footstep would result in 3 or 4 Scotch Argus taking to the air - certainly a memory not to be forgotten! There must have been thousands in the area. The Scotch Argus were also taking minerals from the footpath I followed, which I wasn't expecting to see. Plenty of both males and females were seen, although I failed to find a mating pair.

At Glasdrum, a few other specialties were also seen, notably Green-veined White ssp. thomsoni and Speckled Wood ssp. oblita, which were in remarkably good nick, possibly representing a 3rd brood in both cases. A few Dark Green Fritillary were also bombing about. But the highlight was re-discovering 5 Chequered Skipper larvae that I've been following through at Glasdrum - and it was a pleasure to show these to Alan, the transect walker, who I met at Glasdrum on a previous occasion. A full report of the Chequered Skipper study will be published in due course (including plenty of photos!).

Scotch Argus ssp. caledonia - male

Scotch Argus ssp. caledonia - male (showing the sheen of a newly-emerged adult)

Scotch Argus ssp. caledonia - male underside

Scotch Argus ssp. caledonia - female

Scotch Argus ssp. caledonia - female underside

Green-veined White ssp. thomsoni - female

Speckled Wood ssp. oblita - female

Chequered Skipper - larva

Cheers,

- Pete

[Pete Eeles]

Back to Pamber

A quick trip back to Pamber Forest to monitor the White Admiral larvae I'm following. Unfortunately, several have disappeared, although I did find 3 more just 5 feet from another pair I'm following. It had been raining in the morning, and I caught a larva drenched at the base of a leaf. I also found a larva whose latrine seems to have been flushed down its "pier" which must be great for repelling boarders!

Many larvae are preparing to change skin, with a few 3rd instar larvae around - the instar in which they will overwinter in a hibernaculum made from a dried honeysuckle leaf. The larger larvae seemed to prefer resting at the base of the leaf, facing the leaf tip, rather than remaining on their pier.

I managed to find one larva that seemed to be preparing its hibernaculum. It's at the bottom of the leaf in the first shot below, and I've also included a closeup showing the silk strands that attach the leaf to the branch.

And finally, one larva playing peek-a-boo

Cheers,

- Pete

[David M]

Fascinating images, Pete.

You are starting to give Guy Padfield some serious competition!

[Pete Eeles]

Let's face it - he needs it Although I consider this a joint project between a number of collaborators.

Cheers,

- Pete

[Pete Eeles]

Holly Blue on the Rise!

It looks as if Holly Blue is going to hit one of its cyclic "peaks" this year, if my own counts of ova are anything to go by. I average 5 ova / larva on a small patch of Ivy at the back of my house each year. This year - no less than 14 ova! More of an observation, than a report. Keep yer eyes peeled

Cheers,

- Pete

[David M]

I shall keep an eye out for ova this next few weeks, Pete.

I agree that there seems to be a decent number of agriolus about right now. I expect them to 'crash' in 2016 as a consequence!

[Pete Eeles]

Holly Blue Bonanza!

The Holly Blue ova at home have all hatched, with the larvae attaching themselves to the same (or nearby) bud, making them quite easy to find, once you know what you're looking for.

But the biggest surprise was finding a full-grown final instar larva at the local park, while out walking the dogs. Eggs have clearly been laid over a protracted period and this is further evidence that this species is having a great year!

As Matthew Oates says in his book, watching immature stages is a great way for keen butterfliers to get through the winter (and inclement periods of weather!).

Cheers,

- Pete

[Pete Eeles]

Pamber in the Rain

An enjoyable hour spent in the company of Andy Bolton, catching up on the White Admiral larvae I'm following. At least 50% seem to have created (and moved into) their hibernaculum in which they will overwinter, which are surprisingly varied - ranging from complete leaves through to, what would appear to be, the basal portion of a Honeysuckle leaf that has been folded (using silk) in which the larva rests. Whether the latter is actually a hibernaculum or not remains to be seen. As ever, the inclement weather made for some great photographic opportunities

White Admiral larva living life in a raindrop

Head down in a Honeysuckle leaf

A "traditional" hibernaculum, with backside of larva just visible!

Cheers,

- Pete

[Padfield]

Very interesting. There's no doubt that hibernaculum activity is going on there - but it's very early by Swiss standrds. I got back from the UK last night and did a quick check in the woods before bed. All the cats were sitting out on their piers exactly as before I left. There was no sign at all of leaf-cutting or other hibernaculum preparation.

Guy

[Pete Eeles]

Very interesting. There's no doubt that hibernaculum activity is going on there - but it's very early by Swiss standrds.

We seem to have inherited your weather I'll be keeping an eye on the remaining larvae, but look forward to your reports on the Swiss camilla.

Cheers,

- Pete

[Pete Eeles]

There was no sign at all of leaf-cutting or other hibernaculum preparation.

Hi Guy - is "leaf-cutting" a phenomenon you've seen and/or read about? I'd be interested to know more since I'm seeing quite a few examples of leaves appearing to be "cut"! Are there any references you'd recommend? (asking here for the benefit of this wonderful community!).

Cheers,

- Pete

[bugboy]

Very interesting. I've not been able to check my ones since the 22nd, I'm planning on going to check on them tomorrow afternoon so I'll give an update on them in the next day or two. If they are all still alive they should all be 3rd instar by now.

[Padfield]

There was no sign at all of leaf-cutting or other hibernaculum preparation.

Hi Guy - is "leaf-cutting" a phenomenon you've seen and/or read about? I'd be interested to know more since I'm seeing quite a few examples of leaves appearing to be "cut"! Are there any references you'd recommend? (asking here for the benefit of this wonderful community!).

Let me quote from the Swiss Bible, http://shop.fo-publishing.ch/index.php/ ... ume-1.html, (my bold):

"La chenille hiverne au deuxième stade; elle mesure de 3 à 4 mm et se confectionne une loge (hibernarium): elle découpe un bout de feuille à la base du limbe et le plie en tissant quelques fils sur le dessus; en fanant, la feuille tendre s'enroule souvent d'elle même et la chenille ferme les bords au moyen d'un fil en zig-zag."

This is entirely consistent with my experience.

Guy

[David M]

There was no sign at all of leaf-cutting or other hibernaculum preparation.

Hi Guy - is "leaf-cutting" a phenomenon you've seen and/or read about? I'd be interested to know more since I'm seeing quite a few examples of leaves appearing to be "cut"! Are there any references you'd recommend? (asking here for the benefit of this wonderful community!).

Let me quote from the Swiss Bible (my bold):

"La chenille hiverne au deuxième stade; elle mesure de 3 à 4 mm et se confectionne une loge (hibernarium): elle découpe un bout de feuille à la base du limbe et le plie en tissant quelques fils sur le dessus; en fanant, la feuille tendre s'enroule souvent d'elle même et la chenille ferme les bords au moyen d'un fil en zig-zag."

This is entirely consistent with my experience.

Guy

Knowing the French language proves useful occasionally on here!!!

I wonder if the same 'rules' apply in the UK?

[Pete Eeles]

I think my French O level will help here more than Google translate But my observation is that this is more "ou" than "et", in that it is an either / or situation - either the larva "cuts" the leaf, or the larva leaves the leaf (!) intact but folds / silks any excess, by attaching it to the main body of the leaf. Not sure of this makes sense, but it seems to me that a variety of hibernacula types exist and they are quite, quite different from one another.

Cheers,

- Pete

[Padfield]

It looks as if you, me, Bugboy and anyone else who is following camilla cats into the winter are at the cutting edge of Lepidopterological research then!!

When I say, 'my experience...', I am in fact referring to last winter only, as that was the first winter I watched hibernaculum construction and followed the cats through to the spring. Some hibernacula were messy, others extremely neat, but all followed very much the same general design, and notch cuts near the base were pretty much universal. They typically used the small pair of leaves Inside the terminal leaves of a spray and these did not always require cutting at the apical end of the leaf. A typical hibernaculum was about 1 cm long. Caterpillars used them as retreats or bolt-holes while the autumnal weather was still clement, before retiring definitively for the winter when the leaves withered and the cold arrived.

Guy

[Pete Eeles]

Thanks Guy - excellent input. I'm going to be keeping a real close eye on the hibernacula construction in that case! Unfortunately, it was too wet today to determine whether the leaves I was observing had been "silked" onto the stem (indicating a hibernaculum) or not; all were pretty much under water! But there do seem to be at least 2 construction types to me; one where the leaf is cut above the apex, and one where it is not (and is "folded/silked" onto the main leaf body).

A comparative set of observations between the UK and Switzerland will also make fascinating reading in the fullness of time

[EDIT] And a prize surely awaits the first member that is able to photography a camilla larva deliberately nipping away at the leaf base, and determining whether the silking happens before or after this event!

Cheers,

- Pete