On our recent trip to Jamaica we learned this about the Duppy Fly Trap:

Duppy Fly Trap is the local name of a plant (Aristolochia Grandiaflora) which is an insect-trapping flower. The plant does not eat the insect but use it as a means of propagation. The plant gives off an unpleasant odor which attracts flies and small insects. After being trapped inside the flower and fully covered with pollen grains, they are allowed to escape, so that when attracted into another “Duppy Fly Trap”, the powder is rubbed off and fertilization takes place.

Taken from www.visitjamaica.com