Padfield

[Padfield]

Hi Benjamin. To be honest, I'm not 100% about the instars. Pete's book says 3rd instar is up to 7mm. I estimated some of my '3rd instar' at 8mm but of course it's difficult to tell just by eye, especially at night. Once they're into 4th instar they grow very fast, and I think anything that looks about 1cm or more must be 4th instar. Again, according to the book, 4th instar grows up to 16mm long. I've only known two pupae, both in Switzerland. One I found as a prepupa, preparing for transition near the end of a low twig. The other was a caterpillar I had found wandering across a stony river bed miles from any elm. I moved it to an elm tree, which it quickly shot up before pupating at the top.

Guy

[Padfield]

A series of white-letter hairstreak cats from tonight. You can see a common pattern in three of them - they sit underneath a leaf, eating a hole into it. Where the caterpillar is a little back from the hole it is probably because it moved between my finding it and getting the camera ready and focused.











That last one was the biggest - pretty well full grown, at about 1.5 cm long.

Then I saw one with an attendant that I first took to be some kind of predator:



I have witnessed a white-letter hairstreak pupa being devoured by forest bugs in Switzerland and as it was difficult tonight to see what the creature was, I reached up and nudged it away. In seconds it was back. It looks like an ant in my pictures and I'd like to think this is what it is - a friendly ant doing what ants do with Lycaenids:



Any thoughts on this would be welcome. I recall seeing ants running around white-letter hairstreak elms in Switzerland and think I photographed it, but can't quickly locate my records. I think this cat is freshly moulted. The silk on the right might be where he attached himself to the leaf during ecdysis and the beige thing is his old skin. It doesn't look exactly like previous examples of this I've photographed so I might be wrong.

In more cat action, the first orange tip cats were out of the egg in the garden this morning:





Guy

[Padfield]

In answer to my own question, white-letter hairstreaks do indeed have a dorsal nectar organ on their 7th abdominal segment, and ants are attracted to it:

http://www.filming-varwild.com/a-w-album.html

Guy

[Neil Hulme]

Hi Guy

I was about to answer your question, which you have now answered yourself. Yes, a black ant doing what it should!

Turtle Doves and Nightingales are happily an almost daily experience for me, as I'm doing so much guiding work at the Knepp Wildland. Knepp transports me back to my youth through its sadly now-rare soundscape. Last year we had 28 singing Nightingales (UK decline 92% in 48 years) and 23 purring Turtle Doves (UK decline 98% in 48 years; 82% in the last 10 years) and numerous Cuckoos sounding off.

Do consider visiting Knepp next spring. It has the most amazing camping and glamping facilities and provides a now almost unique UK wildlife experience. I'd be happy to give you a free tour.

For other fans of the Nightingale's awesome performance: https://www.youtube.com/watch?v=DSNeK0S43rQ

BWs, Neil

[Padfield]

Hi Neil. Thank you for the confirmation, and for the offer to show me around Knepp. I may well take you up on it one day, though my preferred camping style is about as far from glamping as you can get: just a bivvy bag, with a Jack Russell stuffed inside to keep me warm.

What a remarkable recording: a bird and a nation, each defending its territory in the only way it knows how.

Guy

[David M]

Absolutely fascinating WLH information (and images), Guy. Do the larvae generally feed at night and rest during the day? There are several healthy elms on my estate and although I inspected the feeding damage many times this time last year I never found any larvae.

[Wurzel]

Cracking set of behaviour shots Guy What service does the Ant complete for the nectar payment - or is it to placate the Ant?

Have a goodun and stay safe

Wurzel

[Padfield]

My impression, David, is that they do feed predominantly at night. I say that because at night I frequently find them sitting by holes in the leaf or at nibbled edges, guzzling away, while in the day they usually seem to be resting in leaf folds or sitting beneath entire leaves. The behaviour is a little different here from in Switzerland, perhaps due to the species of elm. There, I find them on wych elm, when the cats are easy to spot in the daytime on the undersides of the broad leaves - again, frequently entire. In my local meadow here, they feed on Siberian elms, with much smaller leaves. In the day they are really quite difficult to find.

My understanding, Wurzel, is that in return for their fix, the ants protect the cats. Not out of kindness, of course - but to keep the supply going. If you're a fat, tasty grub, it's quite useful to have ants patrolling your branch and looking out for you.

Guy

[Wurzel]

Ah that would explain it; the Ants are the 'muscle', the Henchmen on protection duty

Have a goodun and stay safe

Wurzel

[Padfield]

That's about the size of it, Wurzel! Some cats feed on poisonous plants. Others get on the right side of the local mafia. All good strategies for staying alive in a dangerous world.

I just had time to photograph my fattest cat tonight before Minnie saw a fox or a muntjac and was 200m away on the other side of the meadow in a heartbeat. So I had to leave the elms and bring her back under control! She wears a glowy collar at night and it's quite funny to see it shooting through the darkness, if a little alarming. Jack Russells chase by sight and when they've latched onto something it doesn't matter how much you scream and shout - they can't hear you because all the brain processing power is being used up in the optical department. So you have to watch for a natural pause, when they can hear again, and then hope they respond. Minnie did. Good girl.

Here's the fat cat:



It has been full length for a while, so I imagine it is literally getting fatter now.

Guy

[Padfield]

The same fat cat today, showing why white-letter hairstreak cats are so hard to find if you don't know how to look!





I deliberately didn't use flash, so as to keep as close as possible to natural colours.

He will be thinking about pupation very soon.

Guy

[Wurzel]

The mimicry really is amazing, with those darker diagonal stripes resembling the veins of a leaf - stunning

Have a goodun and stay safe

Wurzel

[Matsukaze]

I just had time to photograph my fattest cat tonight before Minnie saw a fox or a muntjac and was 200m away on the other side of the meadow in a heartbeat. So I had to leave the elms and bring her back under control! She wears a glowy collar at night and it's quite funny to see it shooting through the darkness, if a little alarming.

Given your area's UFO history I expect to be hearing garbled accounts of this for years to come.

[Padfield]

Isn't it fantastic, Wurzel?

I'd be interested to know what any low-flying aliens make of the strange, violet lights in the elm trees every night too, Matsukaze! I'm a little surprised I haven't had a neighbourhood watch squad sent out to see what I'm doing ...

More ant action tonight. It's the same caterpillar as before, I think, as evidenced by the black dots on the side, though it was several branches away from where I saw this last. Unfortunately the rain and wind made it very difficult to photograph naturally, and holding a light, a camera and the branch was not easy. I couldn't get the right distance for the flash. These are the best I could do:







(the pink background is my hand)

Maybe it's the same ant as well as the same caterpillar. True love in the meadow.

Guy

[Matsukaze]

What kind of torch are you using to seek out the caterpillars, Guy? Is it picking up any non-target species? I look at a lot of elm leaves but find less and less WLH larvae, partly as I have been focused more on looking for the larvae of Cosmia moths on them, which give away their presence by living in spinnings.

I reckon there's a chance your ant might be the fairly scarce, arboreal Lasius brunneus, though whether they can be identified from photos I do not know.

[Benjamin]

Maybe it's the same ant as well as the same caterpillar. True love in the meadow.

He was eating heart shapes into the leaves a few posts back.....

Great shots of the camouflaged cats - with all the different instars taken into account I think WLH cats take it to another level.

[David M]

Superb images, Guy, and thanks for the heads-up earlier regarding WLH larval feeding behaviour.

Nice to know Minnie's as active as ever, even if certain activities aren't necessarily welcome!

[Padfield]

Hi Matsukaze. I use a UVA penlight, and yes, it does pick up other things, including other larvae and spiders. There are lots of moth larvae on the elms around Woodbridge, often living in folded, silked leaves.

Thanks David. I'm definitely seeing a bit of a pattern here: feeding at night and resting by day. It's flexible, though. They also rest at night, especially while laid up for ecdysis, obviously, and maybe eat during the day - I haven't really proved this yet.

Thanks Benjamin. And speaking of romantic antics - or should I call it stalking on the stalks - the same cat had quite probably the same attendant last night:





I saw and photographed plenty more cats, including these ...







... and this one, the only one not out feeding:



In the morning, a male orange tip sat peacefully on a blown dandelion while Minnie had her own fun in the background:







Guy

[Wurzel]

Cracking image OT image Guy - I wish I had that one in my collection They do seem to investigate white things and I've seen them 'buzzing' Dandelion clocks before but never landing on them .

Have a goodun and stay safe

Wurzel

[Padfield]

Thanks Wurzel. It's a strange place to sit, but I've seen quite a few species settling on dandelion clocks.

The usual May 2021 day today: occasional promises of sun but mostly cloud and a little rain. In the evening I went out for my w-album fix, quickly finding plenty. By this time last year I had long seen the last of them as they headed towards a June emergence. Here are another three piccies:


(Spot the shredded leaves all around)


(This one was still 7-8 mm long - perhaps freshly 4th instar? It still has a hint of brown/pink)


(Different leaf, different branch, but probably the same cat and ant. I hope he's getting some feeding in and not just enjoying the tickle)

I made a rather poor attempt at filming the ant, so I could share what is going on. It was night, of course, and I was using my iPhone for light. What made it a little easier - and is quite unusual - is that the caterpillar was on the upperside of the leaf.

https://www.youtube.com/watch?v=lBwI0o0 ... uyPadfield[/video]

If that doesn't open, the direct YouTube link is here:

https://www.youtube.com/watch?v=lBwI0o0 ... uyPadfield

Guy