Summer Azure
Celastrina neglecta
Photo: Mary Jane Krotzer
Blue Ridge Audubon Society Beaver Lake Bird Sanctuary
1056 Merrimon Ave, Asheville
Can you spot the bright, blue wings of the Summer Azure butterfly along the Beaver Lake trail?
With Support From
The Carmody-Peterson Family
Meet the Butterfly
The iridescent blue Summer Azure, and its close cousin, the Spring Azure, are among the smallest butterflies found in the United States.
The word “azure” refers to the bright, blue color of a clear sky on a sunny day.
Summer Azures have a wingspan of 0.91 to 1.41 inches (2.3-2.9 cm).
Photo: Jules Stringer
In comparison, the Eastern Tiger Swallowtail (one of NC’s largest) has an average wingspan of 4.5 inches.
Photo: Sharon Mammoser
Mistaken Identity
Summer and Spring Azures are often confused, but there is growing consensus that they are different species within the genus Celastrina, rather than a subspecies of the Spring Azure (Celastrina ladon) as previously believed.
How can you tell the difference between Spring Azures and Summer Azures? Read on to find out.
Male or Female?
Females are distinguished from males by the width of the black borders on their open (dorsal) wings. Females have much wider borders than males.
With their wings closed (ventral view), both sexes look pale grayish-blue or chalky white with an array of black spots.
In either case, they are styling with their giant black eyes and white-tipped black-and-white striped antennae perfectly coordinated with their black-and-white striped legs.
Life Cycle Timing
Spring Azures only emerge in the spring when their favorite host plant, the dogwood tree, is blooming, but Summer Azures may fly in spring, summer or fall.
Egg: 3-6 days
Caterpillar: 12-25 days
Chrysalis (if not overwintering): 7-19 days
Adult: 3 days-few weeks
Eggs
Summer Azure mothers carefully lay an egg in a host plant’s new flower bud, where the caterpillar will be well camouflaged in open flowers as it eats. Most other butterflies lay their eggs on leaves or stems.
The surface of the off-white/blue-green egg has detailed patterns that create a lacy effect.
Caterpillars
Summer Azure caterpillars are very small and have the appearance of a backbone! It may be green, yellow-green, creamy white or pinkish red along the length of their bodies.
Ants: Caterpillars’ Best Friends, Paid Bodyguards, or Slaves?
Like most members of the Lycaenidae (gossamer-winged) family of butterflies, Summer Azure caterpillars feed on the flowers and fruits of their host plant and secrete sweet “honeydew” from special glands.
Some ants like honeydew so much, they care for the caterpillars rather than eat them. To stimulate the caterpillar to release more honeydew, the ants may stroke (“milk”) them with their antennae!
Since both organisms are benefiting, the relationship is called mutualistic symbiosis. In exchange for the sweet reward, the ants provide the caterpillars with protection. They may swarm, bite, or even eat threatening predators or parasitoids.
You be the judge: are the ants the caterpillars’ best friends, paid bodyguards working for food, or slave labor?
Azures even have a fabric named after them. “Celestrina” (spelled with an “e” instead of an “a”) is a dainty silk taffeta fabric with a pale beige and dusty blue color, sometimes with a hint of lavender, said to evoke the beauty and grace of azure butterflies.
Thank You
Many people and organizations made this Butterfly Trail possible. See the full list.
For the Tiger Swallowtail Butterfly, we’d like to give a special thanks to:
UNCA NEMA lab for their research and illustration support
Dr. Matt Bertone, Department of Entomology and Plant Pathology, NC State University for taking photos of their butterfly specimens for the freestanding wings
Asheville Chamber of Commerce for hosting the station
Amy Landers at Landers Creative for webpage design
Jill Jacobs at Spriggly’s Beescaping for interpretive sign design
And these incredible photographers:
Photo: David DeHetre, CC BY 2.0, via Wikimedia Commons
