The big story this week was not so much new species as huge numbers. In particular, Silvery Checkerspot seems to be having a banner summer flight, with reports of high numbers in appropriate habitat from throughout the region. A conservative 100 were on the Rudbeckia flowers at the visitor center of Patuxent Wildlife Research Refuge North Tract last Saturday, with hundreds if not thousands more along the roadsides on Rudbeckia and fleabane. Also in high numbers early in the day basking (if not baking) on the asphalt road leading out to Bailey’s Bridge at Patuxent were Red-spotted Purples; I did a quick scout there soon after the Tract opened for the morning and had 43 just on that portion of the wildlife drive. Small numbers of Zebra Swallowtails and Sleepy Oranges were also on the Refuge.
Also reaching peak numbers across the area are Eastern Tiger Swallowtails; the single buttonbush near the butterfly house at Brookside Gardens in Wheaton had more than 50 on it at one time one late afternoon this week. In this location, the percentage of dark-morph females is quite high. The Verbena bonariensis stands near the lower entrance are always good skipper watching; mostly this week they were Sachems and Silver-spotted Skippers. To the west, Northern Metalmarks are still being seen in good flights visiting woodland sunflower along roads on the eastern side of Green Ridge State Forest, wherever the host plant round-leaved ragwort is found (it’s a shale specialist).
We’re still not seeing much of an influx of southern migratory skippers this year. A few more Fiery Skippers have been seen but nothing to suggest a strong northward push. An early Clouded Skipper was observed last weekend at the National Arboretum; Hayhurst’s Scallopwing and Common Sootywing are also both flying in the butterfly garden there – look for them low to the ground, zipping in and out of the (purposefully) weedy borders. Red-banded Hairstreak, uncommon this year, was on the Clethra in Fern Valley.
Hayhurst’s were also at Eastern Neck NWR over the weekend.
Monarchs were flying in good numbers this week in the milkweed field opposite the temporary visitor center at Blackwater National Wildlife Refuge, where the common milkweed is pretty bloomed out but monarda and perennial sunflowers are kicking in. The field also had huge numbers of Black Swallowtails, as well as a few Sleepy Oranges and Cloudless Sulphurs. In general, in contrast with recent reports from northern VA, milkweed, swamp milkweed, and dogbane stands are all quite lush on DelMarVa, and several less common species of milkweed were also observed in good shape there last weekend. Dogbane and yard zinnias in Worcester Co. were swarmed with Spicebush Swallowtail and a few Zebra Swallowtails; much less activity for some reason in similar habitat in Dorchester Co.
Another personal foray (my third) to the Nelson Road location for King’s Hairstreak proved futile, although a second verified sighting was made there last week. The consolation prize for the drive down for me and Tom Stock was a fresh Dion Skipper along New Bridge Road, although other skippers were hard to come by (even the normally abundant Broad-winged Skipper) in this location this year. Nectar is pretty scarce there. Nevertheless, one observer had six Great Purple Hairstreaks at that location last week. Summer flights of Little Wood Satyr were observed at both Nelson Road and New Bridge.
Best sighting of the week undoubtedly goes to Billy Weber, our PA colleague, who watched a Palamedes Swallowtail making a quick pass at street plantings in Ocean City. Palamedes are very occasionally seen in Worcester Co., especially on strong winds from the south.
On our Nelson Road excursion, Tom and I had a brief but intriguing look at a very large white pierid beating its way down the canal-side path. Our first thought was the accidental Great Southern White, but we never got a definitive enough look to rule out a very paleCloudless Sulphur (it was that large) or other species. It is, after all, the right time of year for unexpected Dixie visitors. Zebra Heliconians are beginning to pop up throughout South Carolina, and Ocola Skipper was noted at the arboretum in Raleigh NC Monday.
OF NOTE: The Loudon Wildlife Conservancy NABA Count is August 3. The Count Circle stretches from White’s Ferry in the east to the Appalachian Trail and the Blue Ridge Center in the west and south to Lincoln. Locations include butterfly gardens, sanctuaries, roadside wildflower areas, and parks. Past counts have accrued 2,000 butterflies of 50 species. Registration Required: Sign up online at http://www.loudounwildlife.org/Butterfly_Count.htm or contact Nicole Hamilton at firstname.lastname@example.org. Groups will meet at different locations at different times. Sector leaders will contact group participants with directions and meet up times/places. Some groups are meeting at 8 AM and others will meet at 9 AM or later. All experience levels and ages welcome. Rain Date: August 4
Follow mid-Atlantic butterfly sightings at https://leplog.wordpress.com and on Google Groups at MDLepsOdes.