Sunday, 27 December 2015

Speckled Wood , ovum to final instar caterpillar

This article depicts the life stages of the Speckled Wood's ovum, larva and pupa which overwinters as a pupa. The ovum [egg] was laid on the 6th September in a very shaded area, with very little or no sun. Some eggs when first laid seem tohave a green sheen to it but, this could quite easily be caused by light refraction and the eggs are infact white. The ovum are also not quite round in shape. The tiny larva hatched after 13 days, and on emerging the tiny larva consume the empty eggshell. There were 3 moults [the final moult, 3rd to 4th instar transition took 6 days, after each moult the larva eat the discarded skin] and therefore 4 instars. When the 4th instar reached the length of about 25mm, pupation took place. The larval stage lasted 73-74 days, [ten and a half weeks] preparing for pupation on the 70th day,  [the larval stage can last as little as three and a half weeks in the summer] and finally started to pupate on December 1st, day 74.

Freshly laid Speckled Wood ovum 
A closer view of a Speckled Wood ovum
The tiny larva is about to emerge
The tiny white larva on hatching
Now 4 days old, and 4mm in length
2nd instar larva, 24 hours since moulting

2nd instar larva pre-moult
3rd instar larva having just moulted
4th instar Speckled Wood larva 16 days before pupation took place.  

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