Female Willow Emerald ovipositing by Harry Appleyard, Tattenhoe Valley Park 4 October 2016

Willow Emerald fascinating fact

The Willow Emerald was first found in Buckinghamshire by a member of the Society, Harry Appleyard. You can read more about Harry’s discovery here.

I have been reading a fascinating book Dragonfly by David Chandler and Steve Cham where they describe a stage in the dragonfly life cycle that is new to me:

What comes out of the egg?

Often a Dragonfly’s life cycle is simplified as egg—larva—adult—egg. This misses out one vital if short—lived stage — the prolarva.

The prolarva is what comes out of the egg. It can leap and squirm, and its job is to get to water, which is often where it finds itself on hatching anyway. But that isn’t always the case. The Willow Emerald Lester Lestes viridis damselfly is unusual among its near relatives in that it lays its eggs in twigs and branches over water. When things go well, its prolarvae simply fall into the water. When things don’t go well, however, the prolarvae find themselves on the ground and have to make their way to water. Prolarvae are not able to walk or swim, but they can have remarkable jumping abilities — one leap from the prolarva of the Japanese Relict Dragonfly Epiophlebia superstes can take it about 100 times further than its own length.

When it gets to water, a prolarva’s job is done. It moults and a very small true larva takes to the water. The prolarva may have survived for just seconds or perhaps an hour or two. Those of Aeschnophlebia longistigma, an Asian species, can make it to 14 hours.