Summer Azure

The summer azure butterfly, Celestrina neglecta. Click to enlarge. Note the handsome black and white striped antennae. 

Summer azure butterflies are all over Brooklyn's flowers right now. The place is teeming with them. But they are small and often overlooked. Their wingspan is about an inch, so the one pictured above is just half an inch tall. They are white underneath and usually hold their wings closed over their backs. It is easy to mistake them for flower petals when they perch on blossoms. The upper surface of the wings is powdery blue.

Summer azures are in the butterfly family Lycaenidae, famously studied by Vladimir Nabokov and commonly called "blues." Although I stood for an hour with my shutter poised, these little ones were too busy to linger with their wings open so I did not get a single shot of the blue surface.

Like many other members of their butterfly family, summer azures spend their catterpillarhood in the company of helpful ants. The ants protect them by driving off hostile insects. The caterpillars in return produce a sweet substance from a nectary organ (on their backs) that the ants eat. It's rather like humans keeping cows for milk, except it's ants and caterpillars.

Adult summer azures eat flower nectar. In this photo you can see the butterfly's long proboscis probing the flower blossom. 

Here is a poem I like that has a blue butterfly in it. 

Butterfly Laughter, by Katherine Mansfield

In the middle of our porridge plates

There was a blue butterfly painted

And each morning we tried who should reach the 

butterfly first.

Then the Grandmother said: "Do not eat the poor 

butterfly."

That made us laugh.

Always she said it and always it started us laughing.

It seemed such a sweet little joke. 

I was certain that one fine morning 

The butterfly would fly out of our plates, 

Laughing the teeniest laugh in the world, 

And perch on the Grandmother's lap.

The false head hypothesis

The gray hairstreak butterfly, Strymon melinus.

This butterfly often perches upside down. It has tiny tails on its hind wings; when the butterfly is perched it occasionally rubs those wings against each other causing the tails to move. The black spot in the orange area is called an eyespot.

Upside down orientation, eyespot, and moving tails create the illusion of a butterfly's head!

Take another look. If you were a bird intent on eating that butterfly you might take a bite of the false head and be left with a mouthful of tails, wondering what happened, as the butterfly flew off in a totally unexpected direction.

(But some scientists think that birds preferentially attack butterflies from behind and the purpose of the false head is to deflect attacks toward the real head where the butterfly can see them coming.)

Confusing!

There is more information about urban insects in my book, A Field Guide to Urban Wildlife of North America, which will be published by Stackpole Books in spring 2011.