Saw your comment about ants and Nepenthes. Sorry I don't have any
published literature to direct you to. I agree that the prey
specificity of Nepenthes is interesting. In my own observations N.
Mirabilis is an astounding ant catcher. It seems like other Neps. are
simply not very attractive to them when they can go after N. mirabilis
nectar.
Hope you find the info you need. I would be interested in seeing how your
research comes out.
Tom in Florida