What I Learned Today

I haven’t ever eaten a fresh fig. Friends tell me they’re quite tasty, especially here where you can get locally grown ones. Figs with wasps inside? Maybe not so much.

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!

[From Christina Agapakis, via The Atlantic’s Daily Dish, via Hacker News, via my officemate Ben.]

There is also a PBS special, called “The Queen of Trees”, that includes actual footage of this process (!). Here’s a preview:

These are tiny wasps, only 2 mm long. So their contribution to your protein intake would be minimal. Further, it seems that not all figs use this method of reproduction; some (those most often cultivated in the U.S.) instead use parthenocapy. This is the process of producing fruit without fertilization, which is handy if the plant has been imported without a fertilizing partner (or wasp), or if the desired result is a seedless fruit. New plants can be created “vegetatively” (e.g., putting a stem in water and having it sprout, or grafting one plant onto another). Clever, clever!