A delightful lunch conversation about fruits introduced me to what may be my new favorite symbiotic relationship! Figs are not actually fruits but a mass of inverted flowers and seeds that are pollinated by a species of tiny symbiotic wasps. The male fig flower is the only place where the female wasp can lay her eggs, at the bottom of a narrow opening in the fruit that she shimmies her way through. The baby wasps mature inside the fig into males that have sharp teeth but no wings and females ready to fly. They mate, the males chew through the special fig pollen holders and drop them down to the females, chew holes in the skin of the fig to let the females out, and then die. The females, armed with the pollen, fly off in search of new male figs to lay her eggs in. In the process some of the female wasps land on female figs that don’t have the special egg receptacle but trick the female into shimmying inside. As the female wasp slides through the narrow passage in the fig her wings are ripped off (egg laying is a one-way mission) and while she is unsuccessful in laying her eggs, she successfully pollinates the female flower. The female flower then ripens into the fig that you can get at the supermarket, digesting the trapped wasp inside with specialized enzymes! For the females that managed to lay their eggs the life cycle continues with a new brood of tiny wasps ready to mate and pollinate.
There is a whole PBS special about figs that I really want to watch now, here are some clips from youtube:
Thanks to Mara for teaching me about the wonders of figs!
UPDATE: Oooh ooh also check out this great post about mutualism and active vs. passive pollination of figs over at Observations of a Nerd!