Butterfly: Wingspan: 1 - 1½ inches (3 - 3.8 cm). The underside of the hindwing is pale brown with a postmedian band of dark brown oval spots rather than dashes. The blue tail-spot is typically not topped with orange, although sometimes there may be some red scales. There is typically one tail on each hindwing; sometimes there is an additional very short tail.
ID Tip: A band of white-ringed oval black spots on closed wing surface separates this from other hairstreaks. There is no orange or very slight orange on the blue spot near the tail.
Egg: Flattened disc. Creamy, tinged with pink later turning pale green. Laid singly or in very small groups at the base of saplings near specific ant colonies. Eggs are the overwintering stage.
Caterpillar: Dark brown with dark band and a series of pale dashes or lighter brown with more extensive pale dashes. Late stage caterpillars eat at night and are tended by ants, which recieve sugary secretions from a nectary on the caterpillars back end.
Chrysalis: Tan or chestnut speckled with dark brown. May occur within ant-built shelters, in ant tunnels, in nearby dead leaves, or attached to the host tree's base.
Edwards' Hairstreaks have one brood, flying once a year in early summer. The flight typically coincides with the blooming of Butterfly Milkweed, a favorite nectar source. Other nectar sources are also used, but Butterfly Milkweed is a magnet. Both sexes avidly nectar and often sit together on the same flower head. Males perch on low vegetation (or even the ground) to establish territories and to look for females; they are very noticeable when they dart out to investigate anything that flies.
Females deposit eggs in bark crevices on sapling trees. In Alabama, tree height has been documented to range from 10 feet to 12 inches, with most topping out at 2 feet or less. Placement is low on the tree trunk, sometimes at ground level. Several eggs may be placed in one spot, where they remain throughout the fall and winter. In spring, caterpillars hatch and eat young leaves. At third instar, larvae develop a honey gland (sometimes called a Newcomer’s organ) that secretes a sugary substance extremely attractive to ants. A species of wood ant (Formica integra) discovers the caterpillars and defends them against predators in order to protect their food source. The ants build a detritus structure known as a byre at the foot of the caterpillars’ host tree. During the day, caterpillars rest/hide within the byre. Under cover of darkness, they journey up the tree to eat. Ants precede them and sweep the area for predators. At dawn, the caterpillars, along with attendant ants, crawl back down the tree to the shelter. Chrysalides are formed within the byre, in ant tunnels within or under the byre, in nearby dead leaves, or are attached to the host tree's base. Since Edwards’ Hairstreak pupae also contain Hinton’s glands, ants continue to vigorously defend them. Upon emergence, adult hairstreaks crawl out of subterranean chambers if their chrysalides were formed within the ants’ tunnels.
Edwards’ Hairstreaks’ close resemblance to other hairstreaks in their genus (satyrium) and their short flight time makes them easy to overlook and misidentify. Prior to 2020, Edwards’ Hairstreaks were known from only two sites in Alabama. In late May of that year, an Edwards' was identified in a photograph from the Shoal Creek Ranger District of the Talladega National Forest. In the three weeks that followed, there were 40 records. In 2021, a photo of Clasping Milkweed taken in the Talladega Ranger District of the Talladega National Forest also contained three Edwards’ Hairstreaks, and an even larger colony was discovered. Thirty-two individuals were recorded in one day. During late spring/early summer, small hairstreaks should be carefully examined to determine their identity--particularly near Alabama's eastern border where Edwards' occur.
A dot on the county map indicates that there is at least one documented record of the species within that county. In some cases, a species may be common throughout the county, in others it may be found in only a specific habitat. The High Count information shows the highest numbers recorded for this species as well as when and where they occurred.
The sightings bar graphs depict the timing of flight(s) within each of three geographic regions. Place your cursor on a bar within the graph to see the number of individuals recorded during that period.
The abundance calendar displays the total number of individuals recorded within each week of the month. Both the graphs and the calendar are on based data collection that began in 2000.
The records analyzed here are only a beginning. As more data is collected, these maps and graphs will paint a more accurate picture of distribution and abundance in Alabama. Submit your sightings to firstname.lastname@example.org.
Sightings in the following counties: Clay, Cleburne, DeKalb
View county names by moving the mouse over a county or view a map with county names
Open thickets and scrubs, roadsides, utility easements, and trails that are located in or near oak woodlands. Edwards' Hairstreak habitat is almost always fire-maintained. The presence of Formica ants (Formica spp.) is probably a requirement.
Oaks that include Black Jack Oak (Quercus marilandica) and Turkey Oak (Q. laevis) are used in North Carolina. Scrub Oak (Q. ilicifolia) and Black Oak (Q. velutina) are listed in other areas.
Black Oak (Quercus velutina) has been documented in the Talladega National Forest (Shoak Creek and Talladega Ranger Districts) in Alabama. It is possible that other oaks are also used.
Formica integra ants have been identified as the attendant ant species.
Edwards' Hairstreaks often nectar of Butterfly Milkweed. They have also been observed nectaring on other milkweeds, several composites, and even Oakleaf Hydrangea.
For more information about these plants, please visit the Alabama Plant Atlas using the links above.
If Edwards' Hairstreaks are in the area, they will be attracted to flowering plants like Butterfly Milkweed (Asclepias tuberosa) and Common New Jersey Tea (Ceonanthus americanus), nectar-rich plants that bloom during the butterflies' flight period.
Including oaks in the landscape is beneficial to many butterfly species, including Edwards' Hairstreaks.
Click on individual photos to view a larger version that includes photo credits, county, and date.
Photos with comments are indicated by a small, tan dot on the bottom right.