Photo: Bobbi Meldahl
UPDATE: Since I published this post, I've received the following dainty sulphur reports: Barb Stigler reports one from Hamilton County on July 7. Jim Heflich found over a dozen in Lorain County on June 24, and one more in Summit County on June 30. John Pogacnik has encountered 34 of the butterflies this week in Lake County. This is certainly a good year for dainty sulphurs in Ohio!
One of our smallest irregularly occurring butterflies is the dainty sulphur, Nathalis iole. Bobbi Meldahl sent along the above photo, which she snapped this week at Dawes Arboretum in Licking County while conducting butterfly surveys. Bobbi found two, and reports that they are the first records of this southern species in 12 years of monitoring at Dawes.
Just yesterday, I wrote about a dainty sulphur that John Pogacnik and I saw along the Grand River in Lake County, and speculated that it might have been a county record, based on the map in the photo below. It was not. John wrote to say that one turned up at Headlands Dunes State Nature Preserve this spring, and there apparently is another Lake County record that precedes that. Another dainty sulphur turned up elsewhere in Lake County this week, and Pogacnik went on to find several others.
There isn't much to a dainty sulphur; these little wisps have a wingspan of only about an inch. They're incredibly easy to overlook, especially as their rapid darting flight is often low to the ground and they tend to perch on the ground.
I posted the account above in my last column; it is the dainty sulphur write-up from the Butterflies and Skippers of Ohio, which was published twenty years ago. A quote: "The dainty sulphur, the smallest of our pierids, is very rarely encountered in Ohio".
Things can change rapidly with insect populations, and that statement may soon no longer be accurate, if indeed it still is. Dainty sulphurs' core distribution is from Guatemala and southern Mexico to the southernmost U.S., such as Florida and south Texas.
Slight increases in mean average temperatures can apparently stimulate rapid shifts in distribution among flighted and highly mobile insects such as butterflies and dragonflies. We seem to be seeing an increase in migratory species of southern immigrants such as the dainty sulphur, and it's important to document their occurrence up here in the north, well beyond their normal range. Keep your eyes peeled.