I have never seen this phenomenon before where the facial skin remains after sloughing off the bodily skin. Usually a "tube" is left behind - excepting at pupation.
In the bottom left as you view, the skin is falling off as the caterpillar eats and today I found it, about the size of a white pin head, resting on a leaf.
The back to front lens is amazing!
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@fbailey@koalagardens@kali66@susie1205@joev
Raising insects is certainly fascinating and usually very informative. Today I found 2 more of these tiny left over face & head skins. All new to me, all adding to my sum of knowledge. The larvae are getting bigger now, don't "fit" the reversed lens even at its widest so it's closeups all the way.
The skin doesn't grow as ours does. It's wrinkly & stretchy & the caterpillar just eats until it's filled the skin, then sloughs it off & starts all over again. With Brimstones that's 4 times, the 5th time it becomes a pupa.
j
@gaylewood Thanks, Gayle. Sadly things are not going so well now. Of about 30 1st instar, I'm down to single figures I think.
Go back to last year:
24 eggs and NO surviving caterpillars.
I blamed the blasted Harlequin larvae which arrived on the unprotected little tree.
Brought caterbugs from the Meadow.
All disappeared.
Brought 10 home at 4th instar stage & put them inside.
Result - 10 butterbugs.
Back to present.
Of about 30-40 eggs, a similar number of 1st instar so brought about 30 inside and protected the tree with a heavy mesh, all I had at the time & better than nothing after I saw Blue Tit approach hungrily.
All went well 1st to 2nd instar, but 2nd to 3rd is very difficult for them & this is where I'm losing them. In theory they should just "walk out" of the existing skin, revealing the fresh wrinkled one underneath. This is not happening.
A few have made the transition but more have struggled and lost. Which makes me wonder how many were lost in the same way last year with Harlequin adding to the attrition.
Does anybody know? Has there been a controlled experiment to determine the truth? I understand that only 1 or 2 of a hundred eggs will eventually fly, enemies are many. It's so sad to see these tiny bodies struggle to free themselves. They manage to free their heads but the skin around their bodies is too tight & hasn't split.
What will happen at pupation???
Watch this space.
j
Raising insects is certainly fascinating and usually very informative. Today I found 2 more of these tiny left over face & head skins. All new to me, all adding to my sum of knowledge. The larvae are getting bigger now, don't "fit" the reversed lens even at its widest so it's closeups all the way.
The skin doesn't grow as ours does. It's wrinkly & stretchy & the caterpillar just eats until it's filled the skin, then sloughs it off & starts all over again. With Brimstones that's 4 times, the 5th time it becomes a pupa.
j
Go back to last year:
24 eggs and NO surviving caterpillars.
I blamed the blasted Harlequin larvae which arrived on the unprotected little tree.
Brought caterbugs from the Meadow.
All disappeared.
Brought 10 home at 4th instar stage & put them inside.
Result - 10 butterbugs.
Back to present.
Of about 30-40 eggs, a similar number of 1st instar so brought about 30 inside and protected the tree with a heavy mesh, all I had at the time & better than nothing after I saw Blue Tit approach hungrily.
All went well 1st to 2nd instar, but 2nd to 3rd is very difficult for them & this is where I'm losing them. In theory they should just "walk out" of the existing skin, revealing the fresh wrinkled one underneath. This is not happening.
A few have made the transition but more have struggled and lost. Which makes me wonder how many were lost in the same way last year with Harlequin adding to the attrition.
Does anybody know? Has there been a controlled experiment to determine the truth? I understand that only 1 or 2 of a hundred eggs will eventually fly, enemies are many. It's so sad to see these tiny bodies struggle to free themselves. They manage to free their heads but the skin around their bodies is too tight & hasn't split.
What will happen at pupation???
Watch this space.
j
j