I have a couple of subspecies of Stapelia hirsuta, or starfish flowers, currently growing in my backyard. Different flowers attract pollinators in different ways. Moths are generally attracted to white, fragrant blossoms. Bees like a nice landing pad with nectar lines to guide them in. This flower attracts flies. It does this by emitting a foul odor, much like that of rotting flesh. This nauseating smell permeates the air within a five foot radius of the plant. It mimics the smell of rotting flesh so well that flies have deposited eggs in this flower. The picture on the right shows the larvae. Some are wriggling about, while others still seem to be encased. I doubt the larvae will survive as there is no real meat on which to feast on. Silly flies.
Update: Here's what it looked like the next day. The flower has wilted and the larvae are strewn about and dead.