Purple emperor cat

[Padfield]

Thanks, Felix.

I fear the worst for Constantine - it is surely far too late for him now. Here he is this afternoon, 18 days after I first found him:



SO, out of three wild pupae I have been following in the woods this year, I believe all failed to make it onto the wing. This is that white-letter hairstreak pupa now - the one that was being poked by shield bugs:



I presume this isn't a 'stone rolled away' moment, though there was a rather lovely female WLH sitting not 10m away a couple of days ago...


(Note she is heavy with eggs, so the cycle can begin all over again...)

It's interesting how the awful weather this spring and early summer (for that is what I chiefly blame for the emperors' demise, even if some parasite then took advantage of their weakened state) has affected the butterflies in this wood. Purple emperors have fared badly, with very low numbers being seen. Brimstones have done even worse - of several dozen eggs I saw laid in May, I believe not one even hatched into a caterpillar. But the first brood of Provençal short-tailed blue must have got in some pretty sneaky naughtiness, because despite their spring flight season being entirely washed out they are now, in their second brood, the commonest butterfly in the woods:



All the large fritillaries have done magnificently this year. I saw your post about high browns in the UK, Felix - well, this species has been on super form here this year...



... as has Niobe fritillary:



Guy

[Piers]

Dear goodness me, poked to death!
Not nice. Not nice at all.
Probably...

Good news on the Frits. The problem in this country (for the High Brown at least) seems to have been a decade of mild winters and cool damp springs, leading to massive mortality in the early larval stage. Although quite why (increased predation in mild winters? damp/mould/fungal? increased early vegitative growth meaning poor microclimate? lack of essential warmth in Spring? all of these??)

HBF seem to reach a critical minimum as well, from which they can not recover. Probably exacerbated because (unlike their close relatives) high Browns are very reluctant to pair with their siblings. Dirty old Dark Green don't care a jot whether their mate is their sister or brother, where as prudish little High Browns, while being morally commendable, are too picky for their own good.

Felix.

[geniculata]

hi guy and felix,

firstly guy i must commend you on your diligent obsevations, they have been a real insite to follow, even though it looks like a poor outcome for the emperors.
felix how would you speculate what possible benefits in evolutionary terms the high brown frits have in not being as incestuously promiscuous as dark greens when its quite clearly a plus for the dark greens?

gary.

[Piers]

Hi Gary,

In short: No idea!

But in all seriousness you have raised a very interesting point; why are High Browns so reluctant to pair with their siblings when closely related species (such as Dark Greens) will happily pair up with their own 'brothers and sisters'...?

It has long been known that in captivity High Brown Fritillaries are almost impossible to pair with other offspring from one female, but will pair quite happily and readily with an unrelated mate. Does this happen with any other (European) members of the genus?

It is easy to speculate how this propensity to avoid in-breeding would help ensure a genetically strong and healthy population, especially with a highly mobile species; but sadly in this country it could be to the butterfly's detriment when colonies become small and isolated. But, (and this is a big 'but') a lack of intolerance to inbreeding does not seem to do the Dark Green Fritillary (for example) any harm. Perhaps the Dark Green is a more mobile species anyway, in which case perhaps males are more given to wander in search of a mate making the pairing of siblings a far less likely occurrence?

Anyone care to speculate?

Felix.

[geniculata]

hi felix,

in my own experience i have found over the last decade in the hot the summers we've had, on more than one occasion, male dark greens several miles from the nearest colonys in the forest, in gardens in the middle of my home town new milton, so they definately do get up and travel.

gary

[Padfield]

Here's a mathematician's suggestion. If there existed in high brown fritillaries a low frquency recessive gene that was highly deleterious when expressed but advantageous when carried (as in sickle-cell anaemia in humans), a policy of outbreeding would maximise its chances of being useful.

We know that both high brown and Niobe fritillaries have considerable persistent genetic variation, expressed to a greater or lesser extent in different populations (for example, eris in Niobe and cleodoxa in high brown). If this is generally good, but if some of the reccessive forms are disadvantageous as homozygotes, you would have a pretty good reason for favouring outbreeding.

It's not really relevant, but I have to show off here this picture of high brown fritillaries mating - the female 'normal', the male cleodoxa:



Guy

[Padfield]

It might be worth adding that unlike high brown and Niobe, dark green fritillaries do not have persistent genetic variants. Its willingness to indulge in incestuous relationships would have as an obvious effect that any deleterious recessive genes would soon be eliminated.

Guy

[Piers]

I knew I could rely on you Guy, I don't care if it isn't the case; it just sounds so wonderfully plausible..!!

Fantastic cleodoxa as well, always very rare in this country, even when the butterfly was reletively common; and I very much doubt if they ever occur at all anymore. Not infrequent in Southern Europe or so I'm told...

Felix.

[JKT]

Not infrequent in Southern Europe or so I'm told...

Not uncommon in Northern Europe either...

[Padfield]

Constantine is gone. No sign of him/her at all, not on his/her leaf, nor in the leaf litter below the tree (I looked for a pupa there - bits of pupal material would have been too hard to see, and probably have blown away anyway).

BUT, there is what appears to be meconium on the underside of the leaf... Is it possible?



Guy

[Pete Eeles]

If this was a natural emergence, I'd be very surprised that the pupal case has disappeared (since it's lasted the last few weeks stuck to that leaf!) and that the meconium is splatted all over the leaf. I'd expect the pupal case still be there and no sign of meconium; this is normally found on the pupal case (if at all).

So - I'm stumped. And would like to think that Constantine emerged successfully, pumped his/her wings up and managed to fly off just as a bird went for him/her, resulting in "meconium backsplash" and a mouthfull of pupal case

Cheers,

- Pete

[Padfield]

Thanks Pete.

On re-examining the picture carefully, and comparing it with the leaf before, I notice that there is no meconium on it - it's all an illusion. That's my pink hand visible through holes in the leaf! Sorry to mislead! I only noticed the 'meconium' when I saw the photo and I had to rush into town for a meeting immediately after posting it.

So the pupa has simply gone, leaving nothing.

I very much doubt it was human agency, as there is no sign anyone else has been there (I always leave my footprints in the same places and avoid trashing vegetation, something very few others do!). I guess, therefore, a bird took it. Deer do pass that way, and a pupa might provide useful nutrition, but I would expect a deer to take some leaves at the same time.

Guy

[Cotswold Cockney]

I love a happy ending but, it was not to be for some reason for both pupae.

The absent pupa with no sign of where it's gone is a real puzzle. The reinforced area of silk where the pupa's cremaster was firmly embedded is clearly intact. Had a bird ripped it off the final segment or two of the pupa's abdomen would still be affixed to that silk pad ~ seen that before as they really are firmly embedded ~ or the silk pad and surrounding area of silk would show signs of disturbance. The silk does not appear to have been disturbed. I suspect careful removal and that would suggest human intervention.... pure speculation based on limited evidence available.

All very sad ... no happy ending at all ... a mystery.

Like to end on a brighter note... some sunshine in my Gloucestershire garden today ~ Peacocks basking in the sun on the garden table ~ Speckled Wood males vigorously 'fighting' in incessant flying circles most of the afternoon ~ they have been resident breeders in my small garden for twenty years ~ a couple of Holly Blues passing through and several whites... A Comma and Small Tortoiseshell ~ all observed without actually looking for them ~ just seen when working on one of my cars for a couple of hours. All nice to see.

[Lee Hurrell]

Better luck next year Guy, I know you'll be back looking for more in June 2011

Thanks for the updates though, even with the outcome you have it's been a fascinating read and I've learnt much I didn't know.

All the best,

Lee

[NickMorgan]

Guy,
I have only just come across this forum and I have been reading it with glee over the last couple of days. I particularly enjoyed this thread, but I was sad to read that you didn't get an emergence.
I have just returned from a family holiday to Menorca. I was delighted with the number of butterflies on the wing. One day a swallowtail swooped down in the garden of the villa we were staying in and laid an egg on some wild fennel. Five days later the yellow egg developed a brown band around it. The following day (the last of our holiday) it hatched. I called the caterpillar Barry and my family thought I was mad!
Having returned to the UK and read some more I now wish that I had spent some time checking other wild fennel plants for larger caterpillars! I hope that we return to Menorca one day.

[Padfield]

Thanks Nick - I'm glad you enjoyed the thread.

Nero, Julius, Augustus, Diocletian and Constantine lived out their lives discreetly in a remote corner of an obscure part of Switzerland, almost unnoticed by any creature there because of their brilliant camouflage, and yet they were briefly among the best known caterpillars in the world! Many people outside Britain, who never visit UK Butterflies, were aware of them through my online diary (http://www.guypadfield.com/butterflyyear.html) and I received quite a few e-mails about them. It was indeed a great shame Diocletian and Constantine perished (I don't know the fates of Nero, Julius or Augustus, though there is a possibility Julius and Constantine were one and the same emperor) but it was a privilege to be able to follow them and I will do the same next year (perhaps not giving whoever I find the same media coverage as I did this year!).

Name your caterpillars at your peril. You get all attached, and then it just hurts more.

Guy

[Lee Hurrell]

Oh dear.... (Cedric)

[Padfield]

Yes, I thought this thread was finished too, but there is an epilogue.

I nipped down to the woods today and with a certain wistful nostalgia revisited the place where I first found Nero, back in the spring. Just a few leaves away from where he/she spent such a happy childhood someone had left an egg...



I'd like to think Nero (whom I never saw after the last moult) was a girl and somewhere deep in her biology she remembered returning to that same leaf island morning after morning, after nights spent crawling around the sallow bush. That was where she had been safe and secure, under the watchful eye of the god with the Canon compact, and so that was where she laid her first egg.

Guy

[Pete Eeles]

Wow! Probably the best photo of an iris egg I've ever seen! if you could post it on the species-specific albums I'd appreciate it!

Cheers,

- Pete

[Padfield]

I shall do Pete! Every stage of the purple emperor is magnificent, isn't it - even the egg!

As you know, I'm off back to England on Tuesday so I can only hope there is a tiny caterpillar somewhere on the bush when I return ...

Guy