Mid-Atlantic Butterfly Field Almanac for the week of May 8, 2021

Giant Swallowtail from Green Ridge State Forest along Fifteen Mile Creek Road [2021 May 02, photo by Walt Gould]

The persistent rain over much of the region this week kept butterfly observations somewhat down, but with a couple of new FOYs including some nice rarities. I spent the week in wet Garrett Co MD in the extreme western part of the state, and all I had for my butterflying efforts were variations on the duskywing model — Juvenal’s, Sleepy, and Dreamy. But the botanizing, herping, and birding more than made up for it; just didn’t provide much fodder for this blog!

Other folks had better luck; the week’s lists on iNat included 37 species for MD (but a number of species haven’t been entered, so I know the list would be at least 42), 45 for Virginia (after discounting two Zabulon Skippers misidentified as Hobomoks), and 30 in PA.

The week started off well for a number of us who visited Green Ridge State Forest last weekend; Giant Swallowtail and Common Roadside-skipper were the clear highlights, although more than a dozen Juniper Hairstreaks at one site, multiple Cobweb Skippers, and the FOY Northern Cloudywings of the year were also terrific finds. Silvery Blues are ending up their flight in Green Ridge and looking pretty tattered. Giant Swallowtail was also reported from VA.

Also at Green Ridge, fresh Appalachian Tiger Swallowtails are beginning to fly as the Eastern Tiger Swallowtail first brood is winding down. Tons of Palamedes Swallowtails are currently about in the Great Dismal Swamp (NC/VA).

Good candidate for Appalachian Tiger Swallowtail, Papilio appalachiensis. Note the light lemony color, broad blue submarginal band on the HW, and nearly continuous submarginal band on the FW. Mid-MD is a hybrid zone area for Appalachian x Eastern Tigers and the specimens run the gamut in terms of diagnostic characters. [2021 May 02, Green Ridge State Forest, photo by REB]

Other skippers of note this week include FOY sightings of Zabulon (males only at this point), Peck’s, and Fiery (in VA). One report came through of Pepper and Salt Skipper (also VA). A Long Dash showed up in VA’s iNat rolls, and it may well be but I can’t really tell from the photo.

Red-banded Hairstreaks emerged with a vengeance across the region; there are also a few White M Hairstreaks still in flight. In many areas, Eastern Tailed-blues are already winding down from their first brood.

Satyrids are beginnning to fly including Gemmed Satyr, Carolina Satyr and Southern Pearly-eye (in the Great Dismal Swamp). Red-spotted Purple is also on the wing.

More botanical butterflies: Many nymphalids are quite picky when it comes to the plants they will oviposit on; Baltimore Checkerspot in MD, for example, is only known to oviposit on turtlehead, Chelone glabra. What then to make of these terrific photos of checkerspot caterpillars on lousewort, Pedicularis? Again, like many nymphalids, late instars may wander rather widely and feed on otherwise unlikely host plants, and there is turtlehead in the same creek valley where these caterpillars were photographed on lousewort, so it’s possible that they wandered (en masse) over to the lousewort when they outstripped their food supply on turtlehead. Possible, but I suspect rather unlikely.

Baltimore Checkerspot caterpillars, Euphydryas phaeton phaeton, on an unusual host plant, Peducularis canadensis (Canadian lousewort) in Green Ridge State Forest [2021 May 02, photo by Merry Stinson on Facebook]

In other parts of its range, Baltimore Checkerspots feed on plantain (New England) and on false foxglove (Ozarks). Until recently, plantain and turtlehead were in separate plant families, but (and the checkerspots say “I told you so”) recently turtlehead was determined to actually be part of the plantain family, too. Similarly, the Orobanchaceae, or broomrape family, is sometimes lumped into the plantain family or at least closely related. False foxglove is one of the hemiparasitic members of the Orobanchaceae; so too, it happens, is lousewort.

Given the multiple caterpillars here, and the likely distance to the nearest turtlehead, I strongly suspect these were result of a female ovipositing on Pedicularis. It’s good to think that Maryland’s Baltimore Checkerspot might have a wider host plant range than just turtlehead, and possible even a wider habitat spectrum: In the Ozarks, Baltimore Checkerspots (the subspecies there is ozarkae; the mid-Atlantic’s is phaeton) favor the mesic glades and hillsides where one finds false foxglove rather than the wet meadows and marshes where Maryland’s checkerspots hang out.

Also interesting to note that I’ve never seen Baltimore Checkerspot flying in Green Ridge State Forest, so the numbers must be quite low and the population pretty restricted.

Prognostications: Hobomok Skippers will join Zabulons (look for the dark veins across the orange expanse of the dorsal HW; it’s clear in Zabulon). Second brood of Summer Azure will be on the wing, and we should be seeing the first of the Appalachian Azures. Northern Crescents of the cocyta-group should be flying shortly as well. The large numbers of late-instar Silvery Checkerspots suggest that we’ll have adults on the wing in a week or 10 days. Viceroy and both Emperors will be out as well.

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.

This entry was posted in almanac, Forecasts, general butterfly news, sightings, taxonomy. Bookmark the permalink.

1 Response to Mid-Atlantic Butterfly Field Almanac for the week of May 8, 2021

  1. Rebecca Samawicz says:

    On Tuesday, May 4, we were up on top of Freezeland Rd in Linden, VA and went a way down a way into the G. Richard Thompson WMA. I was surprised to see swallowtails, thinking they would be out later in year. Seems every year it’s damp and drizzly up there when trilliums & other Spring ephemerals are out, so have not seen so many butterflies it here. So happy to learn from your log that there’s more than one brood per year. Thanks.
    Snd love article on butterflies as great botanists. Or could we say gourmands 😹

    Keep up your great reporting! Thanks so much,
    REBECCA F SAMAWICZ

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