Hi Durban,
Very interesting nep you have there!! Usually pitchers will secrete nectars to attract insects... But now since you discover your pitcher produce salty deposits, it's sort of make sense to me...
Anyone remember seeing Wildlife documentary/when trekking in the forest on how insects (especially butterflies) congregate in large numbers in one spot "licking" mineral salts from the ground ?? I think some animals also behaved to same way... Might this
N. mirabilis "found" another way to attract it's intented prey?? Hmm....
Very interesting indeed...
BTW, welcome to PP and looking forward to see your pics on your collection, thanks.