Strange Symbiosis: The Fig and the Wasp

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It sounds like a rumor on the elementary school playground: figs have digested wasps in them! Except that unlike most grade school legends, this one is actually true. This week The Atlantic shared a fascinating excerpt from the science blog Oscillator, which explains the symbiotic relationship between certain fig trees and the wasps that pollinate them.

Figs are technically inverted flowers that store their pollen inside the fruits. In order to pollinate the female fruits, the trees have developed a specialized relationship with a type of wasp which burrows inside figs to lay its eggs. After hatching, the baby wasps mate and the males, who are born sharp-toothed but wingless, chew holes through the fig's skin for the winged females' escape. Parenting duties fulfilled, the males die.

The females, pregnant and loaded with pollen, fly to other fig trees and crawl into the fruits to lay their eggs, beginning the cycle anew. The catch? Female figs don't have receptacles for wasp eggs, but the wasps are tricked into climbing in anyway.

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 now-flightless wasp is trapped inside the ripening fruit, where it is digested by special enzymes within the fig. According to fossil records, this process has been going on virtually unchanged for the past 34 million years. What a weird and wonderful symbiotic relationship!

More on figs and wasps:

Everything You Never Wanted to Know About Figs - The Atlantic
Edible Symbiosis - Oscillator
How fig trees are pollinated - Figweb.org
World's Oldest Fig Wasp Discovered - Live Science

Had you ever heard of this? Does it change how you feel about figs?

Related: How to Select and Store Figs

(Image: Emily Ho)

(Originally published September 14, 2010)

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