so you know those orchids that emit scents that mimic insect pheromones to attract pollinators? well, these two species of orchid in southern France have different flowers that attract different species of bees and trick them into pollinating with different mechanisms, but it turns out that some bees mess up the system and go to both flowers! wtf. furthermore, the hybrids that they produce don't produce a scent in between the two parent flowers', but rather one that attracts a THIRD species of bee, so if they weren't sterile, the system would be a big evolutionary speciating mess.
Full article: http://news.bbc.co.uk/2/hi/science/nature/8632814.stm