Udea vacunalis

Distinguished from other Udea species by the complete absence of forewing markings and the pure white, nearly unmarked hindwings. The partial black dotted line on the hindwing margin and terminal row of dots at the fringe base are key features. Similar species such as Udea rubigalis (Celery Leaftier Moth) show more pronounced patterning on forewings.

Forewings pale yellowish white, lacking any markings. Hindwings pure white and immaculate, with a dotted exterior black line that is only partially continued. Terminal row of dots present at the base of white fringes on hindwings. Overall appearance is notably plain compared to many congeners.

Specific habitat associations are not documented. Based on known California records, likely occurs in varied terrestrial environments where host plants of related Udea species are present.

Endemic to North America; recorded only from California, USA. No additional state or provincial records documented.

Adults active July to August. Single-brooded, with flight period corresponding to mid-summer.

Nocturnal, as is typical for the family. Adults attracted to light sources.

• Udea rubigalisCelery Leaftier Moth has more distinctly marked forewings with visible pattern elements, whereas U. vacunalis forewings are completely unmarked; U. rubigalis also has broader distribution across North America and is known agricultural pest
• Other Udea speciesMost congeners exhibit some degree of forewing patterning (lines, spots, or shading); U. vacunalis is unusually plain among the genus

• Crambidae
• Spilomelinae
• California endemic
• pale moth
• summer flight
• poorly known

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life
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