Common Blue (Early Stages)

[Vince Massimo]

I have been looking around for a new project following the conclusion of my Brown Hairstreak early-stages odyssey, but have so far failed spectacularly to attract even a female Large White to the garden. Then, on 1st August, I saw a small dark butterfly on the front lawn of my garden in Caterham, Surrey, which turned out to be a female Common Blue, looking to lay eggs. Sure enough she found a Black Medick plant and popped a bright egg on the upper surface of a leaf. The plant was immediately taken into care, but the leaflet supporting the egg became blighted by a leaf-miner which made it very un-photogenic. The egg, however, remained undisturbed and hatched 10 days later on 11th August.

The larva, at one day old, is approximately 1mm in length and soon found a healthy adjoining leaflet to inhabit.

Common Blue larva at 1 day old (1mm in length) 12-August-2011

Having munched through its eggshell it then scraped its second meal from the surface of the top leaflet.

Common Blue larva 12-August-2011

In the time it took me to re-position the leaf for another series of images, the larva attracted the attention of a type of mite.

Common Blue larva 12-August-2011

Hopefully the mite poses no danger to the larva, otherwise this may be my last entry on this topic. However, whilst on this subject, I would steer you towards a beautiful image of a Common Blue larva having just emerged from its egg, posted by James Weightman
https://ukbutterflies.co.uk/album_photo.php?id=9646

Vince

[MikeOxon]

Hopefully the mite poses no danger to the larva

It does make you think about the nature of life when you look down at the lower reaches of the food-chain.

Mike

[Vince Massimo]

Hopefully the mite poses no danger to the larva.........

So far, so good. He seems to have battled through, although I was concerned for a while. The only observation I have made so far (which differs from the books) is that the larva has been feeding on the upper surface of the leaflet rather than the underside.

Common Blue larva (3-day old first instar) 14-August-2011

Apart from now calling it a "he", I have resisted all thoughts of naming him after any famous historical worriors.
More photos after the first moult.

Vince

[Mark Senior]

" Historical worriors " ???

Is that a mis-spelling of historical warriors or a malopropism for hysterical worriers

[Vince Massimo]

" Historical worriors " ???

Is that a mis-spelling of historical warriors or a malopropism for hysterical worriers

Ha! . Well spotted Mark! Historical Worriors seems to cover it very well, so I'm leaving it in

Cheers,
Vince

[MikeOxon]

Historical Worriors seems to cover it very well

I think it is how I must have been feeling when I wrote the rather gloomy statement before! Pleased to hear all is going well and looking forward to the moult.

Mike

[Vince Massimo]

I expect some of you have been "worried" about the progress of the larva (now labelled W1)..................well so was I, because the day after posting the last report, W1 went missing. I was hoping that it had just changed leaves and had reverted to normal behaviour by staying on the underside of the leaf. However after 13 days I could find no trace, so feared the worse. Then, this morning I saw some typical feeding damage on a leaf and checked the underside and found him . The feeding damage was quite extensive and I don't know how I managed to miss it.

He is now 17 days old and looks to have moulted into his second-instar. Length has increased to 3mm, but I do not expect W1 to complete his development this year. This generation of the Common Blue will usually over-winter as a third instar larva amongst a clump of vegetation.

Typical feeding damage caused by Common Blue larva 28-August-2011

Common Blue larva (17-day old second-instar) 28-August-2011

Expect further updates as things hopefully progress.

Vince

[Vince Massimo]

Just a quick update...........The larva is now 21 days old and has now darkened and coloured-up since the last photo. I assume that the previous pale colouration was due to a recent moult. It is still in its second instar and is now feeding on top of the leaf again. The photo also shows what appear to be minute eggs on the surface of the leaf and I have also seen several of the mites that investigated the larva in its early days. They still continue to take an interest, but I have ceased to be concerned about this behaviour.

Common Blue larva (21-days old) 1-Sept-2011

More news after the next moult.

Vince

[Susie]

Wow, Vince, I am loving your reports. This is fascinating and the images first class!

[David M]

I'm starting to feel a sentimental affinity for them!

[Vince Massimo]

Common Blue larva developing at this time of the year will typically overwinter in clumps of vegetation at third instar stage and given the recent spell of hot weather I would have expected it to still be active. However I have not seen it anywhere since 14th September which is when I took the last photos. At that time it was still only about 5mm long and I noticed an odd feature on the front right quarter when I enlarged the images. It was a cylindrical swelling which looked as if there was a parasitic larva under the skin. This feature did not exist on the left side.

Common Blue larva third instar (with swelling on right side) 14-Sept-2011

Common Blue larva third instar (left side) 14-Sept-2011

I have to say that this is pure speculation on my part and I don't even know whether they are prone to such attacks.

Cheers,
Vince

[Vince Massimo]

He's back

It's been over five and a half months since I last saw the larva and it looks like it has just emerged from hibernation. This seems to be its first meal, since there is no other evidence of feeding damage on the plant. It is feeding on top of a leaf and is approximately the same size as when last seen on 14th September 2011.

Common Blue larva (third instar) emerged from hibernation 4-April-2012

The strange cylindrical swelling is still there on the front right quarter, but it seems to come and go. Any further significant news will be posted.

Vince

[Vince Massimo]

Here is the final installment in this story.

To summarise the progress so far:

* The egg was laid on 1st August 2011.
* The larva hatched on 11th August 2011.
* On 12th August the larva was investigated by a type of mite and I my initial concerns turned out to be unfounded.
* Larva entered hibernation on approximately 15th September 2011 and re-awakened on 4th April 2012............

Then, on 24th May 2012, it stopped feeding and became restless. This signaled that it was ready to pupate.

Common Blue larva (final instar) 24-May-2012

Within a day it began to construct a fragile structure around itself on the surface of the ground. This comprised a loose cell of silken strands, leaf fragments and soil. It then positioned itself horizontally under the roof this structure. Pupation took place on 27th or 28th May, resulting in a pale green pupa which was just visible through small gaps in the side of the shelter.

Common Blue pupal cell 29-May-2012

Common Blue pupal cell 29-May-2012

The pupa was smaller than I was expecting, having a length of just 11mm. It went through a wide range of colour changes in the days prior to emergence, starting off pale green, then fading to white and yellow, partially darkening to brown, before turning blue/black.

Common Blue pupa (freshly formed) 3-June-2012

Common Blue pupa (6 days before emergence) 8-June-2012

Common Blue pupa (4 days before emergence) 10-June-2012

Common Blue pupa (3 days before emergence) 11-June-2012

Common Blue pupa (2 days before emergence) 12-June-2012

Common Blue pupa (1 day before emergence) 13-June-2012

The use of flash accentuated the blueness of the wing case. It actually appeared blue/black to the naked eye in natural daylight.

The dorsal view revealed a number of interesting features, particularly in the abdominal area. There appears to be a slight deformity in the pupal case here in that two of the segments are triangular rather than curved. This is best seen in the final image in the following sequence. The developing abdomen does not appear straight either.

Common Blue pupa (still attached to the top of the pupal cell) 29-May-2012

Common Blue pupa (11 days before emergence) 3-June-2012

Common Blue pupa (3 days before emergence) 11-June-2012

Common Blue pupa (2 days before emergence) 12-June-2012

Common Blue pupa (1 day before emergence) 13-June-2012

The pupal stage lasted approximately 18 days and the emerging male was healthy, albeit slightly undersized. Rather than releasing him in my garden (where the egg was laid), I took him to my local Common Blue hot-spot to give him a better chance of finding a mate.

Common Blue male (upon release)

Reading References:

The Butterflies of Britain and Ireland (Thomas and Lewington 2010)
UK Butterflies Website

Vince

[dilettante]

Great report, with a happy ending! Thanks for showing us this fascinating sequence.

[Vince Massimo]

Thanks dilettante

Just to raise an additional point, I note that there has been much comment on the colour of the Common Blue females this year. Certainly, in my case, the blue ones have outnumbered the brown ones. One individual was particularly striking.

Common Blue female - Chaldon, Surrey 2-June-2012

Compare this with a brown female and a normal male.

Common Blue female - Chaldon, Surrey 2-June-2012

Common Blue male - Woldingham, Surrey 1-June-2012

There was also another male with slightly unusual spotting on the underside of the forewing

Common Blue male (wing spot variation) - Addington, Surrey 30-May-2012

It will be interesting to see what the next brood will produce.

Vince

[Susie]

I've enjoyed re-reading this thread, it's so informative and a credit to you Vince and also to this site.

[Pete Eeles]

Fred Frohawk would have been proud of Vince for sure (and he took 24 years to rear every British species through!). And you've got all this to look forward to

Cheers,

- Pete

[Cotswold Cockney]

A very fine effort Vince. Well done.

A delight to read for this enthusiast for Butterfly Life History studies.

Searching lowly plants like Medick and Bird's Foot Trefoil can be very productive for the Butterfly breeder. I once found a Common Blue ovum, a half grown Green Hairstreak Larva and a Dingy skipper ovum all on the same small Trefoil plant.

[Vince Massimo]

Thanks for the comments Susie, Pete and CC. I'm glad this topic is still generating interest

Fred Frohawk would have been proud of Vince for sure (and he took 24 years to rear every British species through!).

This made me smile . Seeing my name and Frohawk in the same sentence is a bit of a stretch, but I appreciate the sentiment. Just to add that Frohawk's position is safe. For the purposes of making "Early Stages" as accessible as possible I will continue to concentrate mainly on the common species (with the occasional "Special Project").

Cheers,

Vince

[Goldie M]

Hi! Vince, I've just read your account of the Common Blue and funnily enough on Tuesday of this week I came across a lovely Female CB, I couldn't believe my eyes at first she was so Blue I thought it was a Male so I'm putting a shot of her in my Dairy.
together with a Peacock I found unusual and also I think Pupa, Of What! i haven't a clue. Thanks again for all the work you've put into your report Ill have to read it a few times more before I'm sure it sinks in Goldie