The Perianth Tube narrows where the Perianth tube curves upwards. This allows Insects to Enter but Blocks their Exit. The Trichomes Wither when Pollen is released . The insects escape and Fly Away to another Aristolochia flower. This leads to Cross Pollination.
Pollen is contained in masses which are interconnected and called Pollinia .
The Stigma is usually located near the Pollinia but they are positioned so that self-fertilization is rare. Pollinia stick to pollinating insects who transfer them to the next orchid they visit. Ophrys probably have elaborate disguises which lure insects into mating with them. Their flowers resemble insect females. Males are attracted to them and try to mate with them.