Ceraunus Blue (University of Arizona Pollinator Field Guide)

Ceraunus Blue

Hemiargus ceraunus

Who am I? ²

~pssst, over here~
Hey you! My name is Ceraunus blue! Or if we want to be more scientific, I am Hemiargus ceraunus. We are actually the second largest member of Lycaenidae butterflies, which are typically very small butterflies. My relative, Brephidium exilis / exile, is one of the smallest butterflies in the world! There is debate on who is the smallest, haha. Reports from Florida usually advise to refrain from collecting these butterflies because they are confused with a more rare and endangered butterfly, the Miami blue (Cyclargus thomasi bethunbakeri). Although we are abundant, we are small so it might be hard to spot us... but! If you take the time to look closely I am sure you will find us ~wink~.

Quick facts ²

Common name: Ceraunus blue

Scientific name:Hemiargus ceraunus (Fabricius 1793)

Family: Lycaenidae - Polyommatinae

Characteristics:

Wingspan: 3/4 - 1 1/8 inches (2 - 3 cm)
Sexually dimorphic
Upperside of males are blue with narrow, dark border
Upperside of females are brown with some blue at wing bases
Undersides are grey: dark grey bars with white bands, black spots with white outlines
Hindwing (underside) has a prominent black spot with an orange rim

Host plant: Prefers woody legumes such as the partridge pea (Cassia brachiata), mesquite (Prosopis species), and rosary pea (Abrus precatorius)

Nectar plant: Feeds on a variety of flowers

Distribution: Southern United States to South America, sometimes strays north

Flight times: Produces multiple broods a year; can be present year-round in warmer regions, but otherwise they will be most abundant during the warmer months. See seasonality: https://www.inaturalist.org/taxa/69940-Hemiargus-ceraunus

Where can you find me on campus? ²

Since Ceraunus blue are small butterflies they may be difficult to spot, but they also do not have known preferences for any particular flower. So far, they have been spotted at the Old Main fountain and near the Nugent building. Ceraunus blue, like other Lycaenidae, often require a close eye. They are likely present in other areas if you are willing to take the time to stand in certain areas around campus!