Spring Azure

Spring azures are one of our earliest butterflies and can be seen as early as mid-March in Kentucky. Photo credit: Peter Pearsall/U.S. Fish and Wildlife Service, public domain

The spring azure (Celastrina ladon) is a common butterfly that can be found throughout much of the eastern U.S. It is one of the earliest butterflies to appear each year in our region. In Kentucky, spring azures can start flying as early as mid-March. Further south, they may start flying slightly earlier. While further north, it might be mid-April before they start flying.

Spring azures can range in size from approximately the size of a nickel to approximately the size of a half dollar. (Most of the ones I see are much closer to size of a nickel or quarter than the half dollar size.) The upper surfaces of their wings are a beautiful dusty blue to sky blue color, sometimes with various dark markings. However, the underside of their wings is a pale, almost greyish, color with various dark markings. They can be very easy to overlook, not only because they are small, but also because they tend to rest with their wings closed which allows them to blend in remarkably well with a variety of surroundings.

The adult butterflies only live a few days and will drink nectar from a variety of different spring flowers. The females lay their eggs on the flower buds of several native plants including flowering dogwoods, New Jersey tea, and blackberry. Once the caterpillars emerge from their eggs, they will eat the plant’s flowers and fruit. Depending on where you live, you may have one or two generations of spring azures each year. The last generation will overwinter as a chrysalis before emerging as an adult the following spring to start the process over again.

Although the upper surfaces of a spring azure’s wings are a beautiful blue, the undersides are a pale, almost grey, color with dark markings that blend in incredibly well with a variety of different surroundings. Photo credit: Mike Boone, cc-by-sa 2.5

Although spring azures are common butterflies, there is still much we have to learn about them. One of the biggest questions is whether the spring azures represent a single species with locally variable coloration patterns and host plants or whether they represent a complex of species that look very similar. The taxonomic debate and research surrounding this basic question is ongoing, showing once again that just because something is common or can be found in our yards, doesn’t mean that we know everything there is to know about that species. However, regardless of whether the spring azures are a single species or multiple species, their appearance is a welcome sign that spring has begun.


This article was part of Shannon’s original Kentucky Pollinators and Backyard Wildlife blog which evolved into the blog for Backyard Ecology.


Backyard Ecology: Exploring Nature in Your Backyard
Nature isn’t just “out there.” It’s all around us, including right outside our doors. Hi, my name is Shannon Trimboli, and I am the host of Backyard Ecology. I live in southcentral Kentucky and am a wildlife biologist, educator, author, beekeeper, and owner of a nursery specializing in plants for pollinators and wildlife conservation. I invite you to join me as we ignite our curiosity and natural wonder, explore our yards and communities, and improve our local pollinator and wildlife habitat. Learn more or subscribe to my email list at www.backyardecology.net.

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