Hi Rudi and Keith !
Many thanks for your messages. I was not with my friends in Maluku last July. So, it's a little bit difficult for me to answer your questions. It's better that I forward the questions to those who were in Halmahera and Seram.
a) night collects :
on the webpage only three pictures for the night collect. I'll ask Gérard if he has more pictures.
b) The caterpillar. Keith is right. Looking at the Matsuda's page on Ornithoptera larvae (p. 241), it's obvious that the pictured caterpillar is not
O. croesus. I believe that it's not
Atrophaneura polydorus (see the attached picture of
A. polydorus larva). I'm sorry : when editing the post about this entomoexpedition, I did not check everything (I checked for butterflies but forgot to check the caterpillars), trusting my friends who were there. I have to determine this larva !
Best wishes