The Lyside Sulphur is a medium-sized, pale whitish to yellow butterfly that sometimes appears in spectacular migratory swarms in Texas, with millions moving northward in fall. Its plain, nearly unmarkered wings make it one of the simplest-looking sulphurs. It is associated with guayacan and other subtropical shrubs in its year-round range in southern Texas and Mexico.
Best time to see a Lyside Sulphur
The best time to see a Lyside Sulphur is April–September, when about 61% of U.S. sightings happen, based on 5,642 research-grade iNaturalist observations.
Not certain it is a Lyside Sulphur? What bug is this? walks through what to check first and the lookalikes that catch people out.
Recent Lyside Sulphur sightings near you
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