Sunday, February 4, 2018

Weep!

We have entered the dangerous late winter period when hibernating Emperor larvae are most vulnerable to predation. I checked my six wild, unprotected larvae on Jan 16th and was delighted to find that all were again present and correct. No losses to mid-January - wow!

However, today I found that No 1 has vanished. I double-searched for him and shouldn't have missed him, had he moved. It's possible that he's moved and that I overlooked him, as he had previously moved twice after entering full hibernation. He moved a massive 1.5m between Nov 19th and Dec 3rd, and he then moved again between Dec 3rd and Jan 1st, just 15cm. Emperor larvae shouldn't move at all in hibernation, but are doing so increasingly during this era of mild winters (and January was, again, warmer than average in southern England) - one of my three captive larvae at home has moved four times this winter.

Also today, I found that larva No 9 has moved, 11cm, from bud to fork, between Jan 16th and Feb 4th (the temp reached 12C on Jan 28th and was around 10C on four other days in late Jan).  He has also shrunk a bit, which is a trifle worrying.

We need a proper spell of hard winter weather to drive the tit flocks out of the forests, and provide some protective frost and snow cover for hibernating larvae.  

Tuesday, January 2, 2018

Tomorrow Belongs To Me!

The dear little angel, below, some 9mm long, is spending five months in deepest meditation - contemplating terrorizing anything that moves in the midsummer tree tops, irrespective of size. If it's going to be male it will behave like an Uruk Hai orc; if female, a fire-breathing dragon. It seeks nothing short of world domination. Our task, as People of Purple Persuasion, is to help it realize that ambition...


The good news is that all six of the larvae I'm following through in the Savernake Forest area, Wilts, survived December (and November). This is a good omen, for truly great Purple Emperor years are born during winters of low predation (though I would have liked  a slightly bigger sample).  

And here's another, of the unusual all-brown colour form -



Wednesday, October 4, 2017

Apatura iris in N Norfolk

On Monday I visited the valley in heavily coniferised woodland on the National Trust's Sheringham Park estate, near Cromer, where a lone Purple Emperor was seen last year and other sightings were made this year.
  
Although the area occupied by sallows in those woods is relatively small the sallows themselves are of very high calibre. Most of the sallow trees I saw there are genuine Goat Willow Salix caprea, which iris strongly prefers. It is actually quite a rare tree, and one which may be in serious decline in the heartland of the Purple Empire (replaced by hybrids). 

The Sheringham sallows had copious amounts of the type of foliage the females most strongly favour for egg laying, and on which first instar larvae fare best - leaves which are mid-green in colour, have non-glossy surfaces, and are of medium thickness.  

Elsewhere in that landscape, on areas of Boulder Clay, the sallows are mainly hybrids, though hybrids leaning towards S. caprea. They look good, very good (and I've found over a thousand eggs and larvae in countless hours of searching).

My guess is that the butterfly is moderately well established on clay lands between Cromer and Holt, or even as far east as Fakenham. I think North Norfolk is nicely Purple, I can't wait to return...

The Purple Emperor is, of course, Norfolk's premier butterfly...

Sunday, October 1, 2017

Road proposed through the Purple Empire

Dear fellow subjects of HIM,

A new dual carriageway passing through the Purple Empire has been proposed by Highways England. Action is required now. Please respond to the consultation by October 16th!
Sussex BC have information:

I have also prepared a leaflet:


Thank you all


Wednesday, September 20, 2017

Bilateral Gynandromorph

Equally rare, if not even more so than the elusive iole, a recently eclosed A.ilia bilateral gynandromorph. I thought I would share some pictures for you all to see and enjoy. A fantastic and interesting beast.


Some interesting and unexpected findings. Firstly looking at the pupal case, the male opening is clustered to one side (section IX), while the female genital opening is still contiguios through section VIII.


Although generally considered to be equally split down the middle, when looking close up at the business end of the actual specimen, we see that the male does actually have a complete pair of claspers, but both of these are clustered on one side of the abdomen and I fail to find any sign of a female opening.


Looking close up at the vestigial front brushes (which can be used to sex non-sexually dimorphic Nymphalidae species), it is excellent to see the presence of the extra tarsal segment (with claw) on the female side.





Thursday, September 7, 2017

NORFOLK EMPERORS

FROM FRANCIS FARROW

Around mid-July there was some exciting news for Norfolk Naturalists with two sightings of Purple Emperor butterflies in Sheringham Park. These impressive butterflies have not been seen in Norfolk since they were resident in the early 1970s (apart from some recent infrequent sightings). Further to the Sheringham Park sightings a third sighting was made on Beeston Common, near Sheringham on 31st July. This site, which lies within a mile of the coast, is a mixture of habitats including heathland where the butterfly was seen.

Your dedicated website for the Purple Emperor states in its introduction ‘This is not an insect you will stumble upon, unless you are blessed with extraordinary luck.’ I believe I was extremely lucky as I literally stumbled upon a Purple Emperor on the ground.

This was a female, not the impressive iridescent purple male. The butterfly was on a path less than two metres ahead of me imbibing mineral salts from the soil. This was my first ever sighting and as I had missed out on an earlier Butterfly Conservation excursion to Fermyn Wood in Northamptonshire I was particularly happy to have found one on my local patch. Apart from moving around slightly while still imbibing the butterfly remained with its wings closed for about 20 minutes. Then there were a few tentative movements of its wings before finally the butterfly spread its wings, revealing its ‘eye-spots’, before taking off and ascending to around 10 metres after which, it glided some eight metres down to around three metres before flying off strongly to the south-west (the direction in which Sheringham Park lies). This last act was a great thrill – such an impressive insect.


One theory is that the recent Norfolk sightings are casual migrants, individuals from re-introduced Suffolk colonies that have done well in the last 10 years rather than deliberate releases of captive-bred stock.  Hopefully enough of these large and beautiful butterflies will arrive and start their own colonies in Norfolk woodlands.


Sunday, August 20, 2017

The 2017 Egg Lay

So you thought this was a good Purple Emperor season? Certainly, the Emperors were blessed with much fine weather, which might mean that activity levels were very high. 

However, that doesn't necessarily mean that actual adult numbers were unusually high. In fact, numbers of the Knepp Wildlands transect (established in 2014) were comparable to 2015, which seems to have been a  'reasonably good' year... Peak day counts in 2015 and 2017 were around 36 (36, on a single transect, you ask! Yes, 36, along a two hour route). 

I've been carrying out standardized counts of eggs and late summer / autumn larvae in and around Savernake Forest since 2009, by ground searching with a shepherd's crook. The methodology doesn't keep to the same route, but tracks new breeding grounds as they develop and abandons old ones as they degenerate, and involves 40 hours of searching annually. It is based on the assumption that the females lay the same percentage of eggs low down each year (there's no evidence either way).   

I am about two-thirds of the way through this year's monitoring, and think the final tally will be in the region of 26-28. That's an improvement on last year's nadir but is certainly not a bumper year - and iris does have bumper years. Here's the data -

          2009          141
          2010            59
          2011            21
          2012            22
          2013          190
          2014            24
          2015            20
          2016            17
          2017            ??

The only other person I know of who counts / monitors / surveys eggs &larvae is Brother Dennis (who likes to be known as The Setaceous Hebrew Character - being hirsute, Jewish and characterful. The original Setaceous Hebrew Character was, of course, the Baron de Worms, Heslop's great friend). 

Dennis is struggling to find any this year in 'Bucks Best Wood' - a privately owned wood which the enlightened owner manages with iris strongly in mind, and is choked with sallow.  

I am also struggling to find larvae at Knepp...

Any other information?