Flat blue and metallic blue butterflies – male or female?

There is more blue on a butterfly’s wings … does that mean it is a male or a female?

In the United States: In general, if the butterfly has a flat blue color, such as in Black Swallowtail butterflies, they are females.
Female and male Black Swallowtail
Black Swallowtail butterflies Left: female Right: male
In general, if the butterfly has a metallic blue color, such as in Pipevine Swallowtail butterflies, they are males.
Comparisons must be done WITHIN the species. Flat blue:Females of some butterfly species, such as the Tiger, have a good bit of blue on their hind wings. Males have very little blue.  In the photo of Eastern Tiger Swallowtail butterflis below, the male is on the left and the female is on the right.

Females of other species, such as the Palamedes, have very little blue on their hindwings. Males have less or none.

The blue dots on the hindwings of a female Palamedes Swallowtail butterfly
The blue dots on the hindwings of a female Palamedes Swallowtail butterfly

Spicebush females are much like Tiger females. There is a good bit of blue on their hindwings. Most male Spicebush Swallowtail butterflies are more green than blue.

 

Female Spicebush Swallowtail on the left and male Spicebush Swallowtail on the right
Female Spicebush Swallowtail on the left and male Spicebush Swallowtail on the right

 

Metallic blue:

Pipevine Swallowtail butterflies: female on the left and male on the right. The male has metallic blue hindwings. Females have metallic black hindwings.
Pipevine Swallowtail butterflies: female on the left and male on the right. The male has metallic blue hindwings. Females have metallic black hindwings.

Pipevine Swallowtail males have a large patch of brilliant metallic blue on their hind wings. Female Pipevine Swallowtail butterflies have very little actual blue. Their hind wings are more of a metallic shiny black color.

Male Great Purple Hairstreak

Great Purple Hairstreak butterflies; males have more metallic blue and females have less metallic blue.

Many of the Hairstreak species are the same; males have more blue.

Remember – compare WITHIN the same species, not from species to species.

(Metallic blue isn’t color on the wings; it’s a refraction of light in a different manner than most blue colors. It’s an interesting online study. We encourage you to look up information about the blue that is in butterflies like the Blue Morpho and Pipevine butterflies!)