Highlights: Southern Cloudywing, Aphrodite Fritillary, Hayhurst’s Scallopwing, Common Sootywing
Late July into early August marks the zenith of butterfly diversity in the mid-Atlantic, a confluence of lots of grass skippers, the greater fritillaries, and some midsummer univoltine specialties like Bog Copper and Northern Metalmark. That drives the sightings on iNaturalist to about 60 each in MD and PA this week and 70 in VA, which gets to factor in such southern specialties as Diana Fritillary, Lace-winged Roadside Skipper and Gemmed Satyr. And that’s even after discounting from the iNat photo maw such misidentified univoltine spring butterflies as Juvenal’s Duskywing and Indian Skipper and a Summer Azure masquerading as a New Zealand Lesser Grass Blue. Pennsylvania also had an Australian Double-banded Crow (in reality a Spicebush Swallowtail) and West Virginia had a Sri Lankan Common Grass-dart. It’s a great time to be out in the field — abundant nectar, high diversity, and vacation time!
Sachems are everywhere again, and compounding the already fraught skipper ID issues with male and female forms and various states of wear. All the expected grass skippers are flying, including good numbers this year of Northern Broken-dash and the year’s first good numbers of Crossline Skippers. Zabulon Skipper is beginning a run at a final summer brood. Joining the skipper-fest this week were new broods of both Hayhurst’s Scallopwing and Common Sootywing. Southern Cloudywing appeared in some numbers, too. The Cape May NJ count tallied a pretty awesome 32 Dion Skippers.
Bog and American Coppers were both flying well this week (see Lydia Fravel’s photo below, where between the Fravels and Tom Stock and me we had more than 30 freshly minted Americans nectaring on clover and their favorite diminutive nectar source, Poorjoe). Summer Azure is slowly beginning to build again. Gray and White M Hairstreaks are the primary hairstreaks about just now, with Satyrium hairstreaks about done for (a few Hickory Hairstreak and Banded Hairstreak reports trickling in still) and Red-banded Hairstreak beginning to show up again after being between flights. Juniper (Olive) Hairstreak (which of course is actually an elfin) is having a really terrific flight just now.
Eastern Giant Swallowtails were noted from several locations this week, and yet another fresh emergence of Zebra Swallowtails with the longest tails of the season!
The greater fritillaries are on the main stage for the Nymphalidae, with good sightings of Aphrodite Fritillary this week among the many Great Spangled Fritillaries. Meadow Fritillary is also flying well. It’s the time of year when just about any nymphalid could show up, from anglewings and cloaks (Mourning Cloak, Eastern Comma, and Question Mark were all tallied this week), to emperors (both Tawny and Hackberry Emperor are on the wing), to checkerspots (Baltimore and Silvery) and crescents (mostly Pearl Crescent, but be on the looking for the second flight of the poorly known P. cocyta-group toward the mountains). American Lady numbers really ticked up this week, but Painted Lady has been very hard to come by this year — which lends credence to my suspicion that most Painted Ladies in the mid-Atlantic have their origins in classroom butterfly rearing projects, which were mostly on hold in this pandemic summer. Common Buckeye and Variegated Fritillaries are both gaining ground for strong late-summer flights. And there are plenty of Monarchs to go around.
Finally Cloudless Sulphurs are being flagged across the region, although not yet in the numbers we generally expect. Sleepy Orange is out in numbers.
Food for Thought: Does it make a difference whether the extinct Xerces Blue was a full species in its own right or a subspecies of the still-extant Silvery Blue? DNA analysis of museum specimens of Xerces Blue seem to have confirmed that Xerces was its own species, earning it the dubious distinction of being the first North American butterfly to be rendered extinct by human activity. See the full story in the New York Times or Science News.
Notable Nectar: While not native to our area, Tall Verbena (Verbena bonariensis, native to South America) is a true butterfly magnet wherever it’s planted. At the butterfly garden in Anne Arundel (MD) County’s Glendening Nature Preserve this week it was pulling in Fiery Skipper, Southern Cloudying, Sleepy Orange, hairstreaks and azures, and the occasional swallowtail and Monarch. As well as this avid Sachem.
Prognostications: Atlantis Fritillary is almost certainly flying amongst the Aphrodites and Great Spangleds in the mountains (there was a report from late June in WV), and the blue female Dianas will show up this week or next to join the males already on the wing. Ocola Skippers (there were reports from the south this week) will begin to filter in through the rest of our area, and we should see our first Long-tailed Skippers of the year soon.
Share your observations and questions about regional butterflies here as a comment or, if you’re in Maryland or DC, on MDLepsOdes, the Google Group for field observations of leps and odonates.