A Tiny Dragonfly Makes Record-Breaking Flights around the Globe

(The Washington Post) -

Imagine being just an inch and a half long and flapping your wings all the way across the ocean.

According to a new study, the itty bitty dragonfly Pantalaflavescens could take longer flights than any other known insect, putting it in the ballpark of larger migratory animals such as birds and whales.

The estimated 4,400 miles or more traveled by members of this tiny species smashes the previous record for insect migration of 2,500 miles, held by monarch butterflies.

The study, published Wednesday in PLOS ONE, couldn’t rely on GPS trackers to figure out flight durations for the little bugs – they couldn’t support the weight of such devices.

Instead, researchers looked at their genes. The reason Pantalaflavescens were suspected to be such prolific fliers is that they can be found all over the globe. For this study, researchers looked at the genes of Pantala collected in Texas, eastern Canada, Japan, Korea, India and South America.

“This is the first time anyone has looked at genes to see how far these insects have traveled,” senior author Jessica Ware, an assistant professor of biology at Rutgers, said in a statement. “If North American Pantala only bred with North American Pantala, and Japanese Pantala only bred with Japanese Pantala, we would expect to see that in genetic results that differed from each other. Because we don’t see that, it suggests the mixing of genes across vast geographic expanses.”

In other words, the insects are more similar from continent to continent than scientists would expect, should they mostly stick to their own regions. They must be doing a lot of long-distance flying assuming they really are as frequent fliers as their genes would suggest.

It seems that Pantala is well-suited for long-haul flights, with wings designed for gliding on the wind for much of the trip, especially if they can get caught up in strong hurricane winds.

But believe it or not, crossing an ocean when you’re the size of a paper clip – even if you’ve evolved to do just that – isn’t exactly a walk in the park: Ware says the trip is “kind of suicide mission.” It’s good for the survival of the species, because the insects have to move from place to place to make sure they have fresh water to lay eggs in no matter what the season. But many individuals will die during the trek.