Monday, 25 April 2016

Comma, Life Cycle

 Female Commas normally lay there ovum [eggs] on the edge of Nettle leaves and are fairly easy to find but, can be mistaken for a Red Admiral's ovum,  [who also lay their ovum on Nettle leaves and, sometimes on the edge of the leaf] as both are very much alike. The contents of the ovum are green when first laid. Then after about 8 days the contents turn a light greenish yellow and eventually you can see the tiny larva through the skin/membrane of the ovum at least 24 hours before the larva emerges, as the membrane/skin of the ovum is transparent. There are 2 broods.
Comma ovum after about 8 eight days, now a light
greenish yellow in colour
Comma ovum after 12 days, the tiny larva  is quite visible
through the transparent membrane/skin of the ovum
This stage can last anywhere between about 12-21 days depending on the weather conditions, hot, cold etc.

On the 13th day, this particular larva emerged, [the time scale for emerging larva does vary].

A newly emerged 1st instar larva
Once the larva have emerged they make their way to the back of the Nettle leaf, where they eat and rest-up,  right up to the stage of the 3rd instar larva.

2nd instar Comma larva on the back of a Nettle leaf
Once they reach the 4th and 5th instar larva they become more exposed.

Final instar Comma larva
The larval stage lasts about 3 weeks, [but does vary in both broods] and there are 5 instars  [4 moults] with the 1st brood in the Spring, and 4 instars [3 moults] with the 2nd brood in the summer. When the final instar larva is ready to pupate it will find a suitable stem, twig etc and, make a Cremaster which it will attach itself to with a number of tiny hooks at the bottom of it's abdomen, hanging up-side down.
 Final instar Comma larva ready for pupation
This particular stage lasted 10 days, but the weather was extremely warm for this particular pupa, and the period of pupation can last longer.

Comma pupa, the butterfly emerged after 10 days, but this does vary
When the butterfly eventually emerges it can take a couple of hours before he/she to completely dry out and, be able to fly.

The 1st brood are most likely to produce the Aberration Hutchinsoni which normally emerge late June, early July.
Comma, female ab. Hutchinsoni
 Comma showing the upper side of it' wings
Comma showing the undersides of it's wings

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