Bug FAQDainty Sulphur
Nathalis iole · Order: Lepidoptera · Family: Pieridae
Also called: Dwarf Yellow
The dainty sulphur is the smallest North American pierid and lives in many open areas, often flying low to the ground. Males have a distinctive oval scent patch on each hindwing, and the wings show yellow uppersides with black tips and bars. It produces several generations a year, and the underside colour changes with the season, yellowish in summer, greenish-gray in winter.
Source: Wikipedia
How to recognize it
The forewings are long and pointed, yellow on top with a black tip, and both fore- and hindwings have black bars along the edges. Males carry an oval androconial spot in each hindwing bar. The underside colour varies: summer butterflies have yellowish hindwings, winter ones have greenish-gray hindwings.
Source: Wikipedia
Size
It is the smallest pierid species found in North America.
Source: Wikipedia
Where it lives
It usually flies very close to the ground.
Source: Wikipedia
What it eats
Females lay single lemon-yellow or orange-yellow eggs on young leaves of the host plant. The caterpillars are quite variable in appearance.
Source: Wikipedia
Life cycle
It has several broods each year. When days are short during the larval stage, the chrysalis forms a winter form that yields a butterfly with three times more dark scales.
Source: Wikipedia
When you see it
Summer individuals show yellowish hindwings underneath, while winter individuals show greenish-gray hindwings.
Source: Wikipedia
Where it comes from
The dainty sulphur (Nathalis iole) is a North American butterfly in the Pieridae family.
Source: Wikipedia
Lookalikes
Similar species include the barred yellow and the little yellow, both of which are larger and lack the same wing patterns.
Source: Wikipedia
Where it is found in the US
Recorded in 38 of 51 states and DC. Most records: Texas, Arizona, Florida, California, Oklahoma, New Mexico, Colorado, Arkansas.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Same family (Pieridae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Nathalis_iole
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.