My Aristolochia is going crazy with flowers. Since they looked very similar to the pitchers of N. lowii (even though N. aristolochioides is named after this genus) I decided to half one. This brought me to this set of conclusions.
But first a brief discription of the flower. The flower has a large landing pad that is normally perpindicular to the ground. it protudes slightly out at the opening to the flower which insects must crawl inside to pollinate the flower. Short, semi-stiff white downward pointing hairs line this passage as if to prevent escape. Since it has been raining for a couple days some water entered the bulbous chasm this passage leads too. Several small crawling and flying insects were seen floating in this (all were dead). The hairs line every inch of this chasm also and all face the bottom of it. Once the insect has struggled through this it must reach the downward pointing stigma, stamens, etc. But reight before this is the "prize". Dark brown dectar glands secrete a sticky nectar just below the stigma, etc. The area around the stigma is slightly glabrous (waxy). Two small flying insects (gnats?) were seen glued to this nectar.
With this information at hand I see no reason to believe that it would be a major jump for the plants to become carnivorous. They are acually quite amazing with a semi-leaf (rounded pressed against the stem) where ever a flower grows from the stem. I beleve these plants may catch insects on purpose, other wise what would be the purpose of the downward pointing hairs and bulbous bottom? I do not beleve they are true carnivores but further tests may prove them to be capturing insects or perhaps the circumstances surrounding my plant my be unique. I will of course keep studying this plant.