Sunday, August 31, 2014

Woe, and thrice Woe!

My first full search for larvae in / around Savernake took place yesterday, accompanied by Ian Shale.  In 4hrs 30 mins searching we found signs of three larvae, only - egg case bases and 1st instar larval feeding leaves + silk seat pads, two of them with 2nd instar feeding leaves too.  But no attendant larvae.  Presumably, these had perished.

The tiny egg case bases can last for weeks - last year I found one in early November.  But the larva eats the bulk of the egg, leaving just the glued-on base behind, like this:-


The larval feeding leaves + seat pads are quite salient by late August, hence why I prefer to look for 2nd or 3rd instar larvae, rather than eggs.  They look like this:-


This is a dismal tally, given that we searched much of the traditional main breeding area.  Last year the same trees produced nearly 50 larvae!  Part of the problem was that frog-hopper nymphs had devastated much of the foliage, and iris females avoid such trees.  Also, the early spring had led to the development of coarse, thick and dark leaves, which are generally avoided.  I realise why I saw just a lone female in that part of the forest this flight season.

The hunt is now on to find where the females laid their eggs...

Watch this space, but at present the prospects for 2015 look distinctly bleak!

Friday, August 29, 2014

Swiss Update

In answer to Dennis, below, it's difficult to give a useful comparison because I have only searched on readily accessible sallows, in places I can easily check on my daily dog-walk. Of 12 eggs originally found, the tally is: 10 hatched (the remaining two are dead), 3 cats gone awol, 1 cat known dead and 6 still in the pink of health (3 1st instar and 3 2nd instar, as of today). I subsequently found another second instar cat, so I am presently keeping tab on 7 cats in total. They are (as photographed this morning):

Brahmā:

Sarasvatī:

Varuṇa

Indra

Trijaṭā

Vibhīṣaṇa

Sītā

Poor old Rāma was eaten by something a couple of days ago - so he's the one I know is dead:

The egg that I found eaten on August 10th is still intact on its leaf, nearly three weeks later:
(Aug 10th)

(today, 29th August)

Et voilà! It remains to be seen how many of these I will be able to follow into hibernation!

Guy


Thursday, August 28, 2014

larvae

It does not get better in Bucks/Oxon: so far, just 5 found in 7 hours intensive searching in five woods.
Guy: how is it in Switzerland?
It will be interesting to hear how Matthew gets on in Savernake.

Purple Battles from 2014 season

Hi all, have put together a selection of shots of Emperors battling over this past 2014 summer season. All taken at the Bookham Common Hill Farm territory. Best wishes - Rob Hill
 
 
A selection of males sparring...
 
 
   
  
 
 
 
A male pursuing a female (the pair slowly moved around the territory canopy for over 15 minutes).  

 
 
Male active in the canopy late in season

 
 
Male chasing a dragonfly.
 
 
 
 








 

Thursday, August 21, 2014

Mixing Up The Medicine

Shocking video of Neil Hulme mixing up his shrimp paste bait bucket.  Fermyn Woods, 8th July 2014.  Not for the faint-hearted.

'I love the smell of shrimp paste on the forest rides in the morning.  It smells of Victory!'

video

Tuesday, August 19, 2014

Purple Emperor Butterfly at Chedworth Roman Villa

Not sure if Matthew spotted this but Female photographed not far from his home in the Cotswolds on 30 July at the site of an old roman villa - National Trust property by all accounts see
http://carolinegillwildlife.blogspot.co.uk/2014/08/purple-emperor-butterfly-at-chedworth.html
Kind Regards
Mark

Monday, August 18, 2014

Honorary Butterfly

By the powers invested in me I hereby declare the Bee-eater an honorary butterfly, and am entering it for Butterfly of the Year 2014.  It is almost as amazing as the Purple Emperor, almost.  It is good to have an insectiverous butterfly.

Here's two of the eight or so currently breeding on the Isle of Wight (photo by courtesy of Andy Butler, IOW naturalist and Servant of the Glanville Fritillary) -


Friday, August 15, 2014

very low numbers of larvae?

I agree with Matthew so far. It may turn out to be a very poor season for larvae.
I spent 90 minutes today looking for larvae on Salix caprea trees in a good iris wood in Bucks. Normally, in an average season, I would expect to find about 4 larvae in that time: I found none. I didn't even see any leaves with the characteristic eating pattern, but without larvae, indicating that a predator had got there before me. This points towards a low egg lay, possibly due to a below average number of females.

Off with his head

My firstborn, Brahmā, shed his skin in the rain this morning and entered 2nd instar. His skin is visible as a gelatinous mess at his tail and his old head capsule is on the leaf beside him:


Brahmā is a wild caterpillar, living at about 1000m in the Alps. He hatched on 3rd August and passed his first instar almost entirely in the cold and rain - but this does not seem to have delayed this transition. I think 13 days for first instar is normal.

Later in the day he coloured up:



Guy

Sunday, August 10, 2014

Closing Time...

My last sighting of Apatura iris this year should prove to be the old male seen patrolling one of the favoured territories along the summit of Three Oak Hill Drive in Savernake Forest yesterday, Sat August 9th.  I had thought that the butterfly would last a little longer than that in Savernake, given that adults didn't start to emerge there until June 30th but the strong winds of the tail-end of Hurricane Bertha should end the season.  Gales knock this butterfly right out.

The general impression is that this has been an 'average' season at most sites, though distinctly below average at some and perhaps a little above average in one or two places, notably in Fermyn Woods which is in a dimension of its own. 

At Savernake, the real test will come when I finish my systematic search for eggs and larvae, which I have done annually since 2009.  My guess is that the 'egg lay' there is right down, to something like 30-40 - i.e. extremely low.

 

Egg through a straw

Of a dozen iris eggs I have found this summer, five have hatched, three are heads-up, ready to hatch in the next couple of days, and one has been sucked dry by some predator:


Notice the small hole in one of the transparent panels. That must be where something stuck its proboscis in and drank the contents. Yesterday, this egg looked like this:


Clearly, either the contents is liquid at this stage or the predator injected some digestive fluid to liquify it.

Guy

Wednesday, August 6, 2014

Brownie Badge

Butterfly badgemeister Paul Fosterjohn has been at it again, this time producing a highly versatile piece which will complement your lapel on all occasions from the casual to the most formal. The Brown Hairstreak pin-badge is set to become a family heirloom and might one day appear on the Antiques Roadshow.

The limited edition run of only 25 will mean that many people can't have it. Details of the badge and how to get hold of it can be found on our sister website at http://betulae.blogspot.co.uk/2014/08/b ... adges.html Profits go to Warwickshire and West Midlands branches of BC. Wear it well.

Monday, August 4, 2014

The world through a raindrop

A one-day-old purple emperor caterpillar in a raindrop:


Guy

Sunday, August 3, 2014

Little emperors

Here in Switzerland it rained almost non-stop throughout July and carried on in the same vein into August, breaking all-time records for precipitation and lack of sun. Despite that, Mrs Iris somehow managed to lay some eggs and I have been keeping an eye on five, on my daily dog-walk. Two of these hatched today and by great good fortune I happened to be there when the second one stuck her head out:


Apologies for picture quality - my compact struggles in poor light.





She then began eating her eggshell:




I say 'she' but I have no idea what sex she really is. I'm naming this season's caterpillars after gods and other beings from Hindu myth, so the first one to emerge was Brahmā and this one is Brahmā's consort, Sarasvatī. I found Brahmā earlier in the day, just as he finished consuming his Golden Egg:



Guy







Battling Onward...


Managed to see five males in three of the main territories along Three Oak Hills Drive during a two hour visit to Savernake Forest this afternoon.  This included a vista of three (two were busy clashing and chasing, whilst another sneaked in from the back to occupy the favoured bough).  Also, lone and very inactive males in two other favoured territories.

Spotting iris males this late in the season is very difficult.  They only visit the primary territories, from about 1pm, and can be extremely inactive there if no other males are around (or if there's little other aerial biodiversity to stimulate them into action).  They only utilise very small areas. 

In Savernake, there are one or two territories which are utilised only late on in the season.  One of these was occupied today.  Conversely, they stop using The Column glade towards the season's end (none seen there today). 

I've no idea what's happened to the Savernake females this year.  I've scarcely seen any, and none for three weeks.  It's a bit like the ent wives in the Lord of the Rings - they seem to have gone missing.  I'm anticipating a very low egg lay here... .

There should be one or two males around in Savernake next weekend, though the weather is set to turn bad which could end the season quickly (gales and cold nights knock them out).

For the record, I have now seen iris (in one or more of its life stages) in the wild for 63 consecutive months.  That's obsessive...

Still seen in August in Upper Thames

Mick Campbell visited our best viewing territory.....the high point of Little Wood, Oxon......on the 28th, 30th July, and  on 1st August. I accompanied him on the 30th. Two males, one worn, were seen, very active and clashing high in the air, on the 28th. On the other two days, two were again seen, but not quite so active.
As in Sussex, it has been an average season here in Berks/Bucks/Oxon. It started a little earlier than usual, but has not burned out early as we imagined it might have. Highlights were a female nectaring on Buddleia in a Chinnor garden for several hours [!], and the sighting of a mating pair in Bernwood at quite a low level. Again, several new localities were found, extending the known range.