Bug FAQMexican Yellow
Eurema mexicana · Order: Lepidoptera · Family: Pieridae
The Mexican yellow has a wingspan of about 32 to 57 mm and its upper wings are pale yellow with a black border that forms a “dog-face” pattern; the hindwing has a small black edge.
Source: Wikipedia
How to recognize it
The upperside is pale yellow with a black submarginal border that looks like a dog or wolf face, and the hindwing has a small black outer margin.
Source: Wikipedia
Size
Wingspan ranges from 1 ¼ to 2 ¼ inches (32 to 57 mm).
Source: Wikipedia
What it eats
Caterpillars feed on several acacias and related plants, including New Mexican locust, fern acacia, prairie acacia and Diphysa robinoides.
Source: Wikipedia
Life cycle
The species produces three to four broods each year. Larvae are green with a creamy or yellow stripe along the back and a yellow stripe on the side.
Source: Wikipedia
When you see it
Adults may be seen almost year-round in Arizona and Texas, and from April to November in New Mexico. They sometimes wander northward in late summer, rarely reaching Canada.
Source: Wikipedia
Lookalikes
Similar species include Boisduval's yellow and Salome yellow. Boisduval's yellow is smaller, brighter yellow, with a weaker dog-face pattern and less black on the upper side; its hindwing is less sharply pointed.
Source: Wikipedia
Where it is found in the US
Recorded in 17 of 51 states and DC. Most records: Arizona, Texas, New Mexico, Oklahoma, Colorado, Kansas, California, Minnesota.
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
Questions people ask
What do the caterpillars look like?
The larvae are green with a creamy or yellow stripe down the middle of the back and a yellow stripe along each side.
Source: Wikipedia
What plants do the caterpillars eat?
They feed on New Mexican locust, fern acacia, prairie acacia and Diphysa robinoides.
Source: Wikipedia
How can I tell Mexican yellow apart from similar butterflies?
Look for the pale yellow upper wings with a black “dog-face” border and a small black edge on the hindwing; Boisduval's yellow is smaller, brighter, and has a weaker pattern.
Source: Wikipedia
Same family (Pieridae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Eurema_mexicana
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.