Sunday, August 5, 2012

Butterfly Eggs!

This afternoon, I saw a big black butterfly in a patch of fennel. It was fluttering more erratically than usual, flitting from plant to plant. It held still long enough for me to take the photo below, and to see the pattern on the underside of its wings. The top wing has two rows of yellow-orange spots (a little blurred by flapping). The bottom wing has two rows of orange spots separated by patches of powdery blue. It was a black swallowtail, Papilio polyxenes. Its behavior -- flitting from leaf to leaf, landing for a moment and bending its abdomen under -- told me that it was a female, and that she was laying eggs!
I stood still. She came close, landed, bent her abdomen to a leaf, and then flew away. When I looked very closely at the leaf, I saw this:
A black swallowtail butterfly egg! It's about the size of the tip of a ball-point pen. Those are my giant fingertips on the left. 

A month ago, I saw this caterpillar in the same fennel patch. It was in the final stage of growth for a black swallowtail caterpillar, and about to become a pupa.  Pupation takes them about two weeks. Adults emerge and live for a few weeks. It's possible that this caterpillar became the butterfly that I saw laying eggs today. 

Black swallowtails have time to complete two generations in northern locations like New York. Today's egg is likely to hatch and reach the pupal stage, enter diapause, spend the winter as a pupa, and emerge as a butterfly next spring.

That reminds me that summer is almost over. And that reminds me of these lines by Li Po.

The paired butterflies are already yellow with August
Over the grass in the West garden;
They hurt me. I grow older. 

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