The colors of summer...

...one of our most graceful and beautiful summer butterflies, the Eastern Tiger Swallowtail, will continue to fly in our town for a little longer this year spreading her summer colors and tricking me into thinking the warm, sunny days of summer will never end, but today is Labor Day, the unofficial end of summer, and by the end of September, our pretty yellow and black butterfly will have vanished from sight, taking summer and all its colors along with her...

Female Eastern Tiger Swallowtail (Papilio glaucus)

...with bright yellow wings the same color as the flower she's nectaring from, this female Eastern Tiger Swallowtail is a picture of summer. I'll miss her this winter when all is grey...

Male and female Eastern Tiger Swallowtails have yellow wings with black tiger stripes. They also have blue and orange scales on their wings, but females have significantly more blue scaling (as shown above) than males who have only four small blue circles on their hindwing ("Butterflies of Ohio," by Jaret C. Daniels). Females also have a dimorphic dark form..

Dark-form females are mostly black with markings that mimic toxic and foul-tasting Pipevine Swallowtails. Mimicry provides protection from predators.

The blue scaling on dark-form females is prominent...

...and you can often see a "tiger stripe" showing through the black.

The abdomen on dark-form female Eastern Tiger Swallowtails is solid black on top with small yellow and black stripes underneath. This plain abdomen is an easy way to distinguish female dark-form Tiger Swallowtails from Pipevine Swallowtails (the butterfly they are mimicking), because the Pipevines have a blue abdomen with spots (click here for an earlier post on a Pipevine Swallowtail to see its abdomen and read about its toxicity).

The abdomen on yellow females and males is yellow with black stripes.

Click here for an earlier post on Eastern Tiger Swallowtail butterflies with information on butterfly wings and scales. I photographed these little ladies on 7/16/10 at Shawnee State Park in eastern Ohio.

Have a Happy Labor Day!