Dichotomous Key to the Blues of Washington State
David Droppers introduced us to his key to identifying the many blue butterflies at the March 2, 2011 meeting. Now the key is available for downloading.
He updated it in December 2019. This version includes a few hairstreaks that were not included in the last version that may be confused with certain species of blues. It also better accounts for the vast variation of Boisduval’s blue, and provides better paths to its correct identification.