Sunday, May 24, 2015

Final Instar

Iris larvae have now entered their final instar, in the wild in Wiltshire.  This is bang on time, and despite yet another poor May.  
Here's No 4, photographed today.  Incidentally, he's the only spring larva I've recorded on a narrow-leaved sallow - 

And here's an in situ photo of No 7, who has just changed skin (on May 23rd).  The cast skin is just visible, below his tail end - 

My other wild larvae have entered the 5th and final instar and wandered off up tree, which is rather inconsiderate of them, but normal.  Two are visible through binoculars.  They become increasingly mobile and sun loving in early summer.

At this stage it looks as though the Purple Emperor season will be on time, but the insect can get stuck for ages (4 weeks) in the pupal stage during poor Junes - and we may be due a poor June... .  Also, the two larvae shown here have ten days of feeding before they can start to pupate.

Watch this space...


dennis said...

well, I don't believe my 7 in captivity will be out in one month: they are not as big as Matthew's in the wild

Matthew Oates said...

You may may be right. They haven't grown this last week (Sun 'May' 31st).