Wasps Help Fig Trees Have Sex Over Long Distances

Photo via Aluka

Life has never been too easy for the African wasp Certosolen arabicus--having a lifespan of two days, after all, doesn't afford them much 'me' time. But, if there is one thing that makes their 48 hours of life worth living, it would their intimate relationship with the fig tree Ficus sycomorus. In fact, the two are inseparable, and quite literally. Sure, there may be 'plenty of trees in the forest', so to speak, but the wasp only eats the fig's nectar--and in turn, the wasp is the only thing capable of pollinating the fig tree. For ages, the unlikely partnership has carried on unfettered. But deforestation in the region means less fig trees, more sparsely distributed--so researchers tested to see if the love-affair between the wasp and fig could survive the challenges of a long-distance relationship."Don't tell me it's not worth tryin' for..."
In an environment full of pollinator promiscuity, the symbiotic relationship between the wasp and fig compel a loyalty uncommon in the natural world--their life-cycles so inexorably intertwined. The fig tree, which serves as a nest for the wasp eggs, only opens its pollen-rich male flowers once the wasps are born. That same tree will wait two weeks to open its female flowers, to avoid being self-pollinated since the wasps only live a couple of days.

So, the young wasps sip from the male flower's small reserve of nectar, picking up pollen on the way, and head out to find their next meal at another fig tree's more nectarous female flower. Once there, they eat, pollinate, mate, lay eggs, and finally, die. Just like that.

"You can't tell me it's not worth dyin' for..."
But, because of deforestation, researchers worried that the fig trees would eventually become too few, too isolated for the little wasps to get to them in their brief lives--thereby effectively breaking the reproduction capability of the wasp and fig.

In order to find out just how far the wasps were able to travel from a male flowering tree to a female flowering tree, scientists collected seeds from 79 different fig trees across Namibia to perform a DNA test on each--essentially a tree paternity test.

"You know it's true..."
What researchers found was quite surprising. While some trees may be closer to one another, the wasps still preferred to travel impressive distances to find a female fig flower. The paternity tests found that, on average, the wasps traveled a whopping 88.6 miles to pollinate--and that's in a single evening, mind you. In fact, scientists found at least one tree was pollinated with the DNA of another that was 150 miles away.

How can that be? Well, according to biologist Fernanda Reinach, the wasps are assumed to be riding the wind for incredible distances, flying towards fig trees when they smell the nectar of a blossoming female flower.

"Everything I do, I do it for you."
The results of this research are reassuring to scientists who feared that fig trees isolated by great distances as a result of deforestation would gradually be lost. Because, as it turns out, the wasp and fig are quite accustomed to their long-distance relationship--and they're not about to let a few miles get in the way of a beautiful thing.

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