Comma (Early Stages)

[Vince Massimo]

Part 1 – The Comma egg and larva

This butterfly has an interesting life-cycle in that it has two forms which exhibit different behaviour. Upon emerging from their winter hibernation in March, the adult butterflies mate and eggs are laid. These give rise to a new generation which appears on the wing at the end of June to the beginning of July. The majority of the offspring have dark undersides and rusty orange upper sides and those individuals that survive the summer go on to hibernate in October without mating. The remainder (approximately 20%) have paler undersides and brighter golden upper sides and are known as the form hutchinsoni. These individuals breed and produce another generation which emerges at the end of August and beginning of September. The parents will die before winter but their dark offspring will go on to hibernate with the dark individuals that hatched in June.

Comma (dark form) - Chaldon, Surrey 19-March-2011

Comma (dark form) - Caterham, Surrey 4-Oct-2012

Comma (hutchinsoni) - Crawley, Sussex 28-July-2005

Comma (hutchinsoni) - Crawley, Sussex 1-July-2008

The principal trigger for the development of the hutchinsoni form is the day-length, but warm temperatures can also be a factor. It has been found that the majority of larvae that have completed their development before the summer solstice on 21st June (when the days are lengthening), will become the golden form. This strategy enables the butterfly to fit in another brood if there is a warm early spring which will therefore produce a higher proportion of breeding hutchinsoni adults.

The principal larval host plant is Common Nettle (Urtica dioica), but elm, hop and currant species are also used as well as some willows and occasionally hazel. Nettle plants growing in sheltered sunny positions, as well as dappled shade are preferred. Eggs are laid singly, mainly on the upper surface of a leaf, and usually on the tip or one edge. They are similar in appearance to those of the Red Admiral, although (in my experience) the latter species tends to lay more towards the centre of the leaf.

Comma egg-laying on Hop - Caterham, Surrey 27-July-2013

Comma ova on Hop - Caterham, Surrey 27-July-2013

Comma ovum on nettle - Crawley, Sussex 29-March-2011

Comma ovum - Crawley, Sussex 6-July-2017

Comma ova - Crawley, Sussex 12-Aug-2018

Comma ova - Crawley, Sussex 6-July-2017

Comma ova (2 hours before hatching) - Crawley, Sussex 9-July-2017

Eggs can hatch in as little as 5 or 6 days, but it usually takes 2-3 weeks. The emerging larva will immediately make its way to the underside of the leaf, where it begins to feed by chewing holes in the centre, before moving to the leaf edge. It will invariably maintain a curled position either when feeding or at rest. This behaviour is carried through until pupation.

Comma larvae (1st instar) on Hop - Caterham, Surrey 31-July-2013

Comma larva (1st instar) on Hop - Caterham, Surrey 31-July-2013

Comma larva 1st instar - Crawley, Sussex 14-Aug-2018

Comma larva (late 1st instar) - Caterham, Surrey 13-August-2012

Comma larva (late 1st instar) - Caterham, Surrey 13-August-2012

Comma larva 1st instar (pre-moult) - Nr. Amberley, Sussex 19-July-2017

Comma larva 2nd instar - Caterham, Surrey 16-August-2012

Comma larva 2nd instar - Crawley, Sussex 16-July-2017

Comma larva 2nd instar (pre-moult) - Crawley, Sussex 17-July-2017

Comma larva 3rd instar - Crawley, Sussex 17-July-2017

Comma larva 3rd instar - Crawley, Sussex 19-July-2017

Comma larva 3rd instar (pre-moult) - Crawley, Sussex 3-Aug-2021

Some authors state that larvae of the first brood have 5 instars while those of the second brood have 4 instars. However, Henwood (1997) shows that this is not so, with both broods going through 5 instars. In both broods the early instars remain largely dark with pale markings and spines. The bright colouration on the body and spines usually starts to develop towards the end of the penultimate instar.

Comma larva 4th instar - Caterham, Surrey 21-August-2012

Comma larva 4th instar - Caterham, Surrey 21-August-2012

Comma larva 4th instar - Crawley, Sussex 21-July-2017

Comma larva 4th instar - Crawley, Sussex 22-July-2017

Comma larva 4th instar (pre-moult) - Crawley, Sussex 25-July-2017

Comma larva 4th instar (pre-moult) - Crawley, Sussex 27-July-2017

In addition, some late-instar larvae can be quite pale, giving rise to correspondingly pale final instars, but the resultant adults will be of normal appearance.

Comma larva (4th instar) pale form - Caterham, Surrey 19-July-2013

Comma larva (early 5th instar) - Caterham, Surrey 26-August-2012

Comma larva (early 5th instar) - Caterham, Surrey 26-August-2012

During all stages of its development the larva is trying to camouflage itself by mimicking a bird dropping. This is partly through colouration but also by adopting various contorted shapes while it sits on the underside of a leaf.

Comma larva contortion - Caterham, Surrey 14-Sep-2012

Comma larva camouflage - Caterham, Surrey 30-August-2012

A mature final instar larva will reach a length of approximately 32mm.

Comma larva (pale form) 5th instar - Caterham, Surrey 24-July-2103

Comma larva 5th instar - Caterham, Surrey 19-Sept-2012

Comma larva (5th instar) - Caterham, Surrey 11-Aug-2013

Comma larva (5th instar) - Caterham, Surrey 11-Aug-2013

Comma larva 5th instar - Crawley, Sussex 27-July-2017

The larva is fully grown and ready to pupate after approximately 30 days. It usually remains on the host plant and suspends itself from a stem or the underside of a leaf in the “J” position. Pupation takes place within 24 hours.

Comma larva (preparing to pupate) - Caterham, Surrey 20-Sept-2012

Comma larva (nearing pupation) - Caterham, Surrey 22-Sept-2012

Comma larva (seconds from pupation) - Caterham, Surrey 22-Sept-2012

Comma larva (commencing pupation) - Caterham, Surrey 22-Sept-2012

Comma larva pupating - Caterham, Surrey 22-Sept-2012

Comma larva pupating - Caterham, Surrey 22-Sept-2012

Comma larva pupating - Caterham, Surrey 22-Sept-2012

Comma larva pupating - Caterham, Surrey 22-Sept-2012

Comma larva (completing pupation) - Caterham, Surrey 22-Sept-2012

Vince

[Vince Massimo]

Part 2 – The Comma pupa

The fresh pupa soon darkens, taking on the colours and appearance of a withered leaf, complete with small gleaming drops of dew.

Comma pupa (freshly emerged) - Caterham, Surrey 22-Sept-2012

Comma pupa (40 mins old) - Caterham, Surrey 22-Sept-2012

Comma pupa (3 hours old) - Caterham, Surrey 22-Sept-2012

Comma pupa (8 days old) - Caterham, Surrey 30-Sept-2012

There are many elements to the pupa which contribute to its appearance.

Comma pupa (lateral view) - Caterham, Surrey 29-Sept-2012

Comma pupa (lateral view) - Caterham, Surrey 29-Sept-2012

Comma pupa (ventral view) - Caterham, Surrey 29-Sept-2012

Comma pupa (dorsal view) - Caterham ,Surrey 29-Sept-2012

The different pupae exhibited various shades of brown colouration, with some being significantly darker than others. After approximately 20 days each pupa suddenly darkened further, masking the developing colouration of the wings within. However the orange/brown wing colours became more apparent in the few hours before emergence as the pupa pales noticeably and the abdominal segments become distended.

Comma pupa (8 days old) - Caterham, Surrey 30-Sept-2012

Comma pupa (22 hours before emergence) - Caterham, Surrey 3-Oct-2012

Comma pupa (30 mins before emergence) - Caterham, Surrey 4-Oct-2012

Comma pupa (pupal case splitting) - Caterham, Surrey 4-Oct-2012

Comma (emerging) - Caterham, Surrey 4-Oct-2012

Comma (emerging) - Caterham, Surrey 4-Oct-2012

Comma (emerging) - Caterham, Surrey 4-Oct-2012

Comma (emerging) - Caterham, Surrey 4-Oct-2012

Comma (expanding and drying wings) - Caterham, Surrey 4-Oct-2012

Comma (reared and released) - Caterham, Surrey 4-Oct-2012

Comma (reared and released) - Caterham, Surrey 4-Oct-2012

One of the emerging adults had a bleached patch on part of one hind wing, probably as a result of some pathological problem.

Comma (with wing defect) - Caterham, Surrey 4-Oct-2012

The butterfly gets it name from the comma-shaped white mark on the underside of the hind wing. Occasionally an aberrant form (ab. o-album) is encountered where the mark is closed.

Comma (ab. o-album) - Birling Gap, Sussex 22-Sept-2010

This report was produced by rearing 4 individuals from eggs laid on 5th and 17th August 2012. A fresh pupa was also found on 4th September. All were raised under cover, so development rates may have been affected. The pupal stages lasted between 12 and 20 days with emergences taking place between 22nd September and 4th October. All adults were released to their sites of origin or other appropriate locations when weather conditions permitted. Further images of eggs and larvae observed in the 2013 and 2017 seasons have now also been added.

Spring Comma - Crawley, Sussex 18-March-2009

Background Notes

The larvae developed as follows:

9th July 2017 - eggs hatched (1st instar larvae).
15th July 2017 - moulted to 2nd instar.
17th-18th July 2017 - moulted to 3rd instar.
20th-22nd July 2017 - moulted to 4th instar.
25th-27th July 2017 - moulted to 5th instar (then all except one larva were released).
5th August 2017 - remaining larva pupated.
15th August 2017 - adult emerged.


Reading References:

The Butterflies of Britain and Ireland (Thomas and Lewington 2014)
UK Butterflies Website

Vince

[Mark Colvin]

Hi Vince,

Inspiring work showing a side of entomology often overlooked ...

Good hunting.

Kind regards. Mark

[MikeOxon]

That's a magnificent piece of work, Vince, with many splendid and inspiring photos.

Mike

[David M]

Magnificent report. Thanks for sharing.

[Wurzel]

This is fantastic work Vince and should be published as I'd buy it!

Have a goodun

Wurzel

[Gibster]

Vince, this is simply superb stuff! Of all the many fantastic facets of this website I feel that your "early stages series" are easily the most educational and visually stunning pieces to be found. Thankyou for sharing, and I mean that sincerely.

Gibster.

[Vince Massimo]

Very many thanks for all your your enthusiastic and encouraging comments guys
Getting usable images of the larvae of this species was particularly challenging, so I was relieved to have completed the job in one season. The rest was relatively easy and mainly involved observing the timings of the development of the first few larvae in order that I would hopefully be ready to capture the critical stages of the ones that followed.
The Comma was a particularly interesting species to study and one which produced a lot of new information from my point of view.

I did say that this was to be the final report of the year, but there is one more project, which involves re-working the Brown Hairstreak report. This will be posted in the next few weeks and will hopefully assist any of you that are thinking of rescuing eggs and rearing this species next year.

Vince

[David M]

I did say that this was to be the final report of the year, but there is one more project which involves re-working the Brown Hairstreak report. This will be posted in the next few weeks and will hopefully assist any of you that are thinking of rescuing eggs and rearing this species next year.

That will be of particular interest, Vince. Thanks in advance.