Alabama Butterfly Atlas

Originally a northern species, Clouded Sulphurs moved south in the early 1900’s as western-based Orange Sulphurs moved east.  In the resulting mix, Cloudeds took a back seat to Orange Sulphurs.  Clouded Sulphurs fly in Alabama but are far less common than Orange Sulphurs.  They are not expected to occur in the Coastal Region.

The two species are closely related: their life stages look identical, and behavior is indistinguishable.  However, female sulphurs can choose appropriate mates because they are able to detect ultraviolet patterns that differ in the two species.  Orange Sulphur upper wing surfaces reflect UV light, while Clouded Sulphur wings absorb it.  Even so, hybrids reportedly occur.

Clouded and Orange Sulphurs often fly in the same habitats, creating a potential identification nightmare. Both species produce white form ('alba') females, and these cannot be distinguished in the field. Clouded Sulphurs are lemon or greenish yellow on ventral and dorsal wings. They do not show orange or egg-yolk yellow above.  Orange Sulphurs have some orange or gold on their upper surface, although there is less in spring-flying individuals. Unfortunately, neither species sits with open wings, so the all-important field mark must be glimpsed in flight. In Alabama, a definitive identification of Clouded Sulphur cannot be made without a look at the dorsal wings.

*The Alabama Butterfly Atlas requires photographic documentation of Clouded Sulphur sightings. Keep in mind that the dorsal (top side) surface must show. Even an out-of-focus in-flight picture will suffice!