Larvae predation

Checked all 37 hibernating larvae today, Sun 31st. Regret that 4 had vanished without trace, presumably eaten, and another had shrivelled up and died - this one looked poorly on my previous visit, Sun 17th. So 5 were lost in late Jan, which is disappointing as none had been lost since about Christmas when Percy Bysshe Shelley vanished.

There is a mortality hot spot along the Roman Road. My guess is that there's a flock of tits regularly using that area. The remedy is simple, next time I'm taking Flea with me, my cat. All tits must be crunched.

Of the 4 presumed predated, 3 were by buds and were yellow-green in colour, and the other was on a scar and grey in colour. The latter is (was) one of those photoed by Brother Neil in early Jan - the 3rd larva illustrated in the blog for Jan 13th.

These new losses include Christina Rossetti and Philip Larkin, renowned for being the first poet to use the F word in verse. This is most distressing.

So far, I have lost 9 hibernating larvae to assumed predation, 6 of them in the Roman Road area. I've lost 2 from scars, 7 from buds. A distinct little seat pad is all that remains. And one of my captive larvae has withered up and died. This was an odd larva that never changed into autumn colours.

I now have 32 left. Those by buds are greening up. Please remember them in your prayers.

Matthew.

Bred Specimens emerge early

Hello Dennis

I have always felt that the micro climate of a bred species will encourage faster development.

When we checked the national history museum collection for ‘local’ specimens it was quite apparent that many of the bred pinned specimens from across the country had considerably earlier dates (within the flight period) to those that had simply been captured and then had a pin stuck in them.

This was one of our arguments for why the individual seen in West Norfolk in the 2004 on the 26^th July was the genuine article!

Liz

I believe I've told you about the last 3 years in Switzerland, when, each year, one of my larvae in captivity [out of about 20] developed rapidly, pupated and produced an imagine in sept/oct; astoundingly, this happened last year in the UK[but not in any of the previous years in the UK, 2003-2008] , when 2 out 4 larvae did this, although the development was slower than in Switzerland and the larvae perished [in november!] before pupating.

Of course, my conditions are slightly warmer than in nature because my sallow is sleeved in a net, so the wind chill factor is reduced, but not that much, surely? The sallows are always outside.

Anyway, the best comments I have had on this were from Giles Carron [sadly deceased] in 2000.

I think it makes very interestiung reading, and I want to share it with you

Dennis

Giles comments

Hi Dennis,

I would agree with Giles' comments. I think it is easy to under-estimate the degree of 'forcing' caused by retention of your larvae in sleeves. If Brown Hairstreak caterpillars are sleeved outdoors, even when kept in shady conditions, emergence times are approximately 2-3 weeks early. Larval growth rate in betulae is slow - it can be much more rapid (pro-rata considering ultimate size) in iris, and the degree of potential 'forcing' of the latter is probably greater. I've little doubt that the odd wild cat will grow super-fast (and usually perish), but these are the individuals that might assist an evolutionary switch to bivoltinism in the dim and distant future, should climatic and other conditions ever allow it. I'm sure that sleeving will encourage a much higher incidence of super-growth than is ever seen in the wild.

Best Wishes, Neil

All 37 present today. No losses so far this year, though 1 is rather shrunken and 2 others look unwell.

28 are by buds, 5 in scars / lesions, 2 in forks and 2 where green wood meets old brown wood (like WLH eggs). Dennis, these figures differ to what I guessed the other day.

23 are in heavy winter shade, receiving hardly any direct winter sun (or none). 7 receive some early morning winter sun. 6 are in dappled situations and 1 gets some afternoon sun. None is remotely in full sun. Those on sunny sprays are on the dark side of the twig.

22 are yellow-green in colour. 7 are grey. 3 are yellow-brown. 2 are yellow-green-brown. 2 are green. 1 is yellow-grey-green.

Crucially, they match the stem they are on, not the colour of ,y buid they're lined up against. Neil: my nice chestnut brown ones have changed colour! Yes, even in deep sleep they can change colour.

24 are 1-10cm from the spray tip, 7 are 11-20cm from tip, 2 are 21-30cm from tip, 3 are •5m from tip and 1 is 2m from tip.

First we sleep the winter
Then we dance the spring



Matthew

Just a reminder that there are a number of resources available for download on the website, including the collection of 2009 reports, Purple Again.

These are mostly .pdf documents, and can be found on the home page here:

www.thepurpleempire.com

eXtremeButterflying

An Extraordinary General Meeting of Extreme Butterflying took place on Sunday January 10^th 2010 in a Wiltshire wood, with 5” of lying snow, a maximum temperature of 0C, frequent snow flurries, and depressingly bad light.

Mr Hulme was in the chair. Mr Oates was 3m up in a sallow tree. Attendees wore ladies’ tights.

The minutes of the previous meeting were smoked. There were no matters arising.

The sole agenda item was to find and photograph hibernating larvae of Apatura iris, especially those capable of producing specimens of ab. iole.

Doings had to be restricted to the part of the wood adjacent to the main road, the side roads and lanes being utterly impassable. An attempt to drive to the prime iris area was thwarted by glacial conditions, the car spun into something nasty that had escaped from Antarctica and Mr Oates was forced to dig his vehicle out of a snow drift, obtaining some fine pupae of Smerinthus ocellata in the process.

Twelve iris larvae were observed, one of which was new to science. This was accidentally found by Mr Oates, whilst teasing down a branch already known to hold a larva. He had nearly squashed it. Had he done so, his life would have been forfeit.

Mr Hulme obtained some fine photographs, primarily of the uncommon grey colour form adopted by larvae hibernating on scars or lesions in bark, or in forks.

Only two specimens were photographed of the commonest colour form, the yellow-green form that predominates when larvae position themselves by sallow buds, the most frequent location chosen for hibernation. The rare brown colour form was not observed, due to the intervening presence of a large ice sheet.

At this point, darkness descended, torches were lit, and the police arrived, alerted by phone calls concerning men behaving oddly in a public place. The meeting then adjourned to the local constabulary. Mr Hulme is helping Wiltshire police with their inquiries. Mr Oates is missing: his last words were, ‘I’m just going out, I might be some time.’

Another Extraordinary General Meeting will be called.