The barred sulphur, Eurema daira, is a butterfly of many looks, gray at times, more yellow at others. But it's still fairly easy to identify.
It's a common butterfly throughout Florida, found in all 67 counties, and throughout the southeastern United States, particularly along the Atlantic and Gulf coastal plains. You'll find the barred sulphur fluttering about fields, scrubs, roadsides, ditches and open pine woodlands.
In the world of butterflies, barred sulphurs fall on the smaller side, with a wingspan that goes between an inch and a quarter to nearly an inch and three quarters, give or take. The edge of the wings might have an yellowish tinge.
In flight, it looks white. But if you get a glimpse of one when it lights, you might see peppery steel gray or a brighter yellow, depending on the time of the year and the sex of the particular butterfly you're looking at. Generally, barred sulphurs are smaller and duller in the summer wet season, larger and brighter come winter's dry. Males have more distinct black markings on the leading edge of their forewings than the females. They also are less yellow in winter than females. The peppery look — more like salt and pepper — is a constant regardless of the season or sex.
Host plants include members of the pea family, including joint vetches. Adults will nectar on a wide variety of flowers, including vetches and the ubiquitous Spanish needles. They're active, or in flight, throughout the year in Florida, and in most of the southern parts of their range, producing three or more generations a year. When they stray north, they're limited to late summer and early fall.
Although their primary range is the Southeast, there's a population in the Southwest, including parts of Arizona, and they will wander as far north as Washington, D.C., and even South Dakota. The southward limits of the barred sulphur's range extends through Mexico, the Caribbean, Central America and South America to Argentina.
Overall, barred sulphurs are considered weak flyers. Males spend their time patrolling for receptive females. Fertilized females will deposit their eggs singly on mature leaves of one of its host plants. The eggs are white-yellow; the larvae, or caterpillars are green, with a white or yellow stripe along the side. Adults who overwinter pause in reproducing.
Note: If you're going to do any research on the barred sulphur, remember Eurema daira. Oddly if you Google barred sulphur butterfly, chances are you're going to get a ton of hits for the orange-barred sulphur butterfly. However, if you Google Eurema daira, you'll get this guy, the barred sulphur butterfly. Apparently, it gets overshadowed by the more spectacularly colored orange, at least on the internet. Weird but true.
The barred sulphur is a member of Pieridae, the family of white and sulphur butterflies. Other common names include barred yellow. Note: barred yellow is also used as the common name for two species of moth.