Blue Butterfly Identification Tips
Blue butterflies are a subfamily (Polyommatinae) in the larger Lycaenidae family. They are among the most difficult butterfly species to identify.
| family Lycaenidae Johnson's Hairstreak Reakirt's Blue Silvery Blue Spring Azure Brown Elfin Purplish Copper Types of Butterflies |
The blue butterfly on the left shows a series of orange and dark spots on the bottom of the wing. You might be able to easily identify the butterfly starting with that bit of knowledge. However, a few different species of blue butterflies, such as the Lupine Blue, the Acmon Blue and the Pacific-dotted Blue, share that characteristic.
Complimenting an underside view, with a top view picture of any butterfly, helps in many instances where an underside view is insufficient for identification purposes. Fortunately, blue butterflies enjoy basking in the sun, and if you are patient around them, they eventually spread their wings for a nice picture.
The top view of this butterfly shows a similar orange and dark spotted pattern on the bottom of the wing. There is also a dark border around the top wings. Because physical characteristics of any particular butterfly species also differ somewhat from location to location, the darker border clue may or may not help with identification. My guess is that the butterfly in the photo is either an Acmon Blue or a Lupine Blue.
The point is that sometimes, even with a good view and/or some good pictures, without knowledge of the exact butterfly location, and maybe even a genetic test, identification is far from a certainty.
In spite of some identification difficulties with blue butterflies, it is not always a next to impossible task. The blue butterfly pictured on the left supports this position. You can see two orange spots, and on closer examination, a small tail at the end of the bottom orange spot.
This initial description might suggest that it is either an Easter-tailed blue or a Western-tailed blue. The Eastern-tailed is very common on the East Coast, however, there is also a population on the West Coast. The Western-tailed blue also has one, or maybe two orange and black spots on the underside of the wing, along with a tail. However, the orange spots often do not show through on the top side of the butterfly.
The picture on the left shows the top side of the butterfly with an orange spot at the bottom of the wing. This feature suggests that this is an Eastern-tailed blue butterfly.
The Silvery Blue and Spring Azure butterflies listed in the box, are two examples of blue butterflies without orange spots. Without careful examination and comparison of the patterns on the underside of their wings, they can be misidentified.
A good field guide to butterflies in your area along with some background knowledge covering identification clues, such as the presence or absence of spots, the number and color of spots and the presence or absence of a tail, will be enough to get you started on your own blue butterfly identification.
© 2007. Patricia A. Michaels