Web/Nest structure or Eggsac?

Hi Francis, thank you for your reply to my comment. I have been researching a little further, into this interesting topic because what I wrote (in my comment) was based on my memory of something I had looked at some years ago. The Banana Skipper larvae, at least in my area, tend to appear on banana leaves in the months of October and November. Since that is rather a long time to wait, I looked back through some old stuff I have from the years 2014 to 2017 and I found some photos which show that my comment was probably wrong, but if you look at them, you will surely see some similarity to you spotting. Of course, I have no way of sending you my pictures on Project Noah. So, I will send you an email with 6 pics. attached. I hope that's O.K. with you.

Hi Francis, Could this possibly be some kind of leaf roller caterpillar which has pupated on the banana leaf having, for some unknown reason, failed to cut a section of leaf to wrap itself? I am thinking of a banana skipper larva. The only way I can think of finding out is to look for a rolled up section of leaf and gently unroll it. If you see something similar to your photos inside, then you will have the answer. Your spotting is very interesting and I am going to be on the lookout for a banana leaf-roller to open it and have a look.