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Creature Feature #5 When is a Fly not a Fly...??

When it is a dragonfly? True, but that is not the insect (or insects) in question today. Instead, let’s look at the amazing Owlfly (Ululodes macleayanus)! Unlike true flies (order Diptera), these insects have two pairs of wings, in fact they differ from flies in a number of ways. Check out the really long, clubbed antennae. At rest, they often drop the wings and point the abdomen skywards to resemble a small twig. I've never seen a fly do that.

Here is a close-up of these weird and wonderful eyes.

The Owlfly gets it’s a name from its extremely large eyes. Remarkably, the eyes are not just large, but each

one is divided into two parts. I tried to find out why this is the case, and the information is highly technical, but seems to boil down to the fact that one part is exclusively sensitive to UV and the other part can detect a wider spectrum. This aids them in capturing moving prey when in flight.

I found this Owlfly by setting up a UV light on the lower balcony of my treehouse, El Fenix, at Finca Bellavista Community, in Costa Rica's Southern Zone. I was looking for moths, but it is always interesting to see the awesome variety of night life in the rainforest.

Owlflies are pretty cool as adults, but the larvae are even more interesting. They are ambush predators with an impressive set of pincers. Called "ugly ducklings" by some, I think they are just very well-camouflaged hunters. They sit and wait in leaf litter or on a tree branch for prey to come by, which they grab with the pincers.

This photo is by Gianfranco Gomez, co-owner/operator (with his wife Tracie) of The Night Tour. Don't miss their amazing trips when you are in Drake Bay!

by Fiona A. Reid

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