Saturday, July 26, 2025

Dark Swallowtail in the Garden

Eastern Tiger Swallowtail on Bergamot
Female, Dark Morph (Papilio glaucus)

The commoner yellow form of the Eastern Tiger Swallowtail is a frequent visitor to the garden at this time of the year. I always enjoy seeing them, but the appearance of this dark morph female in the bergamot a few days ago was something to crow about. 

All dark morphs of the species are female. They are examples of Batesian mimicry, a phenomenon in which members of a harmless species evolve to resemble another species which is toxic or unpalatable. The lady mimics the poisonous Pipevine Swallowtail butterfly, thus gaining a measure of protection from predators. 

1 comment:

Kate said...

I'll be looking more closely, now, at what appear to be black moths as I walk down the road. There is wild bergamot in bloom!