What can butterflies and moths teach us about conserving nature on a warming planet?

Dr. Callum Macgregor in the field.

View this interesting presentation by Callum Macgregor from the University of Hull as he discusses what we know and suspect about the impact of climate change on butterflies and moths. Callum’s talk was part of the Thomas C Emmel seminar series on Expanding Horizons in Leidoptera Research at the Florida Museum’s McGuire Center for Lepidoptera and Biodiversity, March 30, 2021.

Much of the discussion centers around whether univoltine or multi-voltine butterfly species are more likely to adapt to a warming climate, and what tradeoffs may be made by butterflies that adapt to global warming by advancing their phenology in the spring (i.e., emerging earlier). The issue, Macgregor suggests, is not straightforward.

Much of his work is also captured in this open-access article in Nature Communications (2019). His subsequent work on the UK’s Speckled Wood published in PeerJ (2021) focuses on morphological changes in response to climate change by this widespread British butterfly.

Posted in climate change, conservation, European butterflies, general butterfly news | Leave a comment

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.

Posted in almanac, Forecasts, general butterfly news, sightings, taxonomy | 1 Comment

Butterflies Make the Best Botanists

A Gray Comma from Garrett Co MD [2012 July 10, photo by Rick Cheicante]

The go-to place in Maryland for Gray Comma — normally a butterfly of the Northwoods — is along Big Run in Garrett Co., following Big Run Road from New Germany Road down to Big Run State Park proper. The best sites are the dozen or so state forest campsites before you get to the park; especially on Monday mornings when the weekend campers depart the Gray Commas descend on the campsites and fire rings for spilled beer, rotting fruit, and (one suspects) somewhat less savory things left behind.

Gray Comma is also known from other places in western MD, certainly, primarily in Allegany and Garrett Counties. But not with the regularity one finds it along Big Run.

As far as we know, the host plant for caterpillars of Gray Comma in the mid-Atlantic is Appalachian Gooseberry, Ribes rotundifolia. Which presents a bit of a problem, since documented records of Appalachian Gooseberries exist only for Allegany Co., and certainly not along Big Run in Garrett. There are sparse records in the scientific literature of Gray Commas using rhododendron and other gooseberries, but the heavy favorite is rotundifolia.

But I’ve long harbored a suspicion that there is Appalachian Gooseberry along Big Run as well, a population sufficient to support pretty good numbers of Gray Comma some years. So I spent some time this week botanzing Big Run while the persistent clouds and showers kept butterflies out of sight.

And sure enough, there is Appalachian Gooseberry along Big Run — rather a lot of it, actually — and since it’s in bloom now it can confidently be identified. Or at least I *think* I’ve correctly identified it. It’s got a striking pinkish-purple calyx tube, with stamens that extend quite far out from the petals, the leaves are the rounded shape that give Appalachian Gooseberry its Latin species name, and it lacks the spines and prickles that we associate with other native (and introduced) gooseberries.

When it’s out of flower and not in fruit, the small bush is rather nondescript and could be passed off as a viburnum or chokeberry or ninebark or even a scraggly hawthorn if one doesn’t look too closely at the leaf arrangement and smooth stems. But that doesn’t fool the commas. They really do make excellent botanical sleuths.

Posted in conservation, evolution, general butterfly news | 1 Comment

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

Harvester puddling in Green Ridge State Forest MD [2021 April 27, photo by Lydia Fravel]

April ended on a blustery, gale-ridden note, and the first week of May looks to be unsettled and mostly wet. But for those who watch the fortunes of butterflies in the field, this rain is only an inconvenience to us but of critical importance to butterflies. Too much — especially combined with cool or cold weather — is generally bad for caterpillars, and particularly for those that feed or shelter at ground level in grass clumps or debris at the base of food plants. Adults can be knocked back a little too, but they’re more resilient and go into almost a refrigerated torpor to wait out the wet. But too little rain — and we’ve had rather a dry spell here in the mid-Atlantic — and nectar production is down, moisture to free ions for males is scarce and puddling opportunities rare, and eggs and young larvae are subject to dessication. So count your blessings for sunshine today and tomorrow and expect the rains to bring new species for Mother’s Day weekend.

But for now there hasn’t been a lot to report from the field over past week. Virginia iNaturalists reported 41 species on the wing (well, 39 if you discount the report of California Tortoiseshell that iNat ID’s from a poor photo of a Pearl Crescent; and the Common Buckeye photographed on a madly blooming lantana with an Ocola Skipper on a nearby flower — clearly fudged on the date). The tally did include last week’s prognosticated Red-spotted Purples, and additional Cloudless Sulphurs (which appear to be on track, weather permitting, for an early season in the mid-Atlantic).

Maryland racked up 37 species, including the first regional report of Harvester for the season from Green Ridge State Forest. Other notables included Cobweb Skipper (multiples of those were also reported from Green Ridge this past week, and singletons elsewhere), and White M Hairstreak.

Pennsylvania’s 26 iNat observations included a Blue Morpho from what looks like a painting or piece of fabric, so let’s call this 25. Meadow Fritillaries were part of the observations, as was West Virginia White.

Hairstreaks, blues, and elfins in general were an interesting group this week. The first solid reports of Red-banded Hairstreaks in any numbers were registered, but it appears this first flight will be a late, extended one or on the small side. Ditto for Gray Hairstreak, which is likewise being reported across the region but in very small numbers. Harry Pavulaan has commented on the local listservs about the poor showing of azures generally this season, although early Appalachian Azures were noted in Shenandoah NP. More Great Purple Hairstreaks were recorded this week as well.

In addition to the Cobweb Skippers noted earlier, Horace’s Duskywings have begun to tick up, joining the Wild Indigo Duskywings and Juvenal’s Duskwings already in numbers across the region, and Sleepy and Dreamy Duskywings in the mountains.

Among the late-flying spring univoltine species for which a few reports still straggled in are Falcate Orangetips and Olympia Marbles; see them now or wait until next year!

Eastern Tailed-blues doing their best to populate ruderal habitats for the next flight in June [Parris Glendening Nature Preserve, Anne Arundel Co MD, 2021 April 25, photo by REB]

A dynamic ruderal duo: Not to be picking collegiate sides, but meadows in the mid-Atlantic are sporting lots of Gator colors this week, with good flights of Eastern Tailed-blues (blue) and Pearl Crescents (orange). Both are typical of what we know as ruderal (from the Latin ruderalis, rubble) habitats: weedy, often disturbed habitats in full sun, where the host plants clover (for the ETBs) and field asters (for the crescents) abound. This habitat preference will be a good clue for those of us out hunting the “other” crescent — notionally Northern Crescents of the cocyta-group, which favor damp streamsides, palustrine meadows, and shady woods margins bordering grassland. Once the habitat starts to succeed into shrubs and trees, ruderal species decline and finally wink out. Other ruderal specialists include Checkered Whites, American Copper (good numbers reported this week), Sachem (reported again this week), and Common Checkered-skipper (good numbers for this one also noted this week).

Prognostications: The next week or two should yield for us Common Sootywing and Common Roadside-skippers, as well as the first Zabulon and Hobomok Skippers of the season. Look for Giant Swallowtail to round out the list of expected swallowtail species, and for the first of the Appalachian Swallowtails (which in Maryland at least often fly in the relative lull between flights of Eastern Tiger Swallowtail).

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.

Posted in almanac, Forecasts, general butterfly news, sightings | Leave a comment

Mid-Atlantic Lep Almanac for the week of April 24, 2021

Brown Elfin, Callophrys augustinus [2021 April 23, Anne Arundel Co MD, photo by REB]

We have a couple of lulls in butterfly activity that are normal every year, not brought on by scorching heat or a sudden cold snap or a week of soggy rain. This is one such lull, the transition between the univoltine spring species (or the first brood of multivoltine species) and the butterflies of summer, which here in the mid-Atlantic is with us beginning in the middle of May. So this is the time to be out looking for the spring specialists — elfins, azures (only Summer Azure is multi-brooded for us), the spring duskywings (Sleepy and Dreamy), and the early whites — Falcate Orangetips, West Virginia White, Olympia Marble. They won’t last much longer. Tempus fugit, just like butterflies do.

Eastern Pine Elfins and Brown Elfins are still flying well; Henry’s had a rather disappointing flight and is mostly over and done with. Despite a teaser of a very early Frosted Elfin, no further sightings have come in. We’re between azure broods now, at least in the non-mountain regions; the next up will be second brood Summer Azure any day now and the late spring specialist Appalachian Azures. Eastern Tailed-blues emerged with a vengeance this week; I saw well over a hundred on a walk through MD’s Patuxent Research Refuge in Anne Arundel Co yesterday.

The balance in the sex ratio of Falcate Orangetips has shifted in most places to overwhelmingly female; males are out a good week or 10 days before females, but females linger into May for us. Olympia Marbles are still in flight.

It’s been a rather disappointing season so far for nymphalids other than cloaks and anglewings; we have a few scattered reports in the region this week of Red Admiral, and both Painted and American Ladies. Best chance for American Ladies just now is probably in the tents the caterpillars make on pussytoes (Antennaria spp.). Pearl Crescent is either off to a slow start or a poor flight. And there have been a few sightings of Monarchs but many more sightings of eggs on freshly emergent milkweed from stealthy female Monarchs that escaped notice.

Horace’s Duskywing sightings are starting to trickle in, unlike last year when they outnumbered Juvenal’s by a wide margin in their spring flight. Juvenal’s (almost all males in most places still) are common to abundant this season. Wild Indigo Duskywing sightings are up this week. Aside from these duskywings and a few reports of Common Checkered-skipper, skipper season has yet to kick off; although Silver-spotted Skipper reports came in from a number of locations this week.

Eastern Tiger Swallowtail numbers are building, and the first reports of dark morph females made the rolls this week. This is the time, of course, to observe wing pollination of native azaleas by swallowtails, as neatly documented by NC State U biologist Jane Epps and explained in this blog by Jim McCormac. The constant “fanning” of wings by swallowtails is more than an attempt to keep them balanced; it’s an important aspect of pollination, where the large wings bridge the wide gap between the azalea’s stamens and pistils and its nectar source — in ways that other pollinators can’t.

A Palamedes Swallowtail pollinating native pinxter azalea by fanning furiously with its wings while it probes deep into the flower for nectar with its proboscis. A bee going into the throat of the azalea would miss the stamens and pistil entirely, and fail to pollinate the plant. [image courtesy North Carolina Audubon, photo by Will Stuart]

Prognostications: Given the mild winter, it could be a good year for Checkered White, which would be showing up about this time. Once this chilly week is behind us and we pick up again with the steamy hot days of mid-Atlantic spring, we will be seeing FOY Red-spotted Purples. The cold delayed blackberry bloom a bit (back in the Ozarks where I grew up we’d refer to these late spring cold snaps as “blackberry winter”) and thus the cloudywings; they’re still due out shortly. Pepper and Salt Skippers should be out; they’ve been reported to our north.

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.

Posted in almanac, Forecasts, general butterfly news, sightings | Leave a comment

The Dope on Duskywings (Juvenal’s vs Horace’s)

We’ve seen a lot of interest the last couple of days about how to tell apart our two common, large spreadwing skippers. By this, I mean the two named for Roman poets: Juvenal’s and Horace’s Duskywings, Erynnis juvenalis and Erynnis horatius, both of which are flying in April and May. We get a lot of pictures of these two, dark, quarter-sized skippers every year about this time. Both feed as caterpillars on oak, both nectar as adults on spring blossoms (blueberry, dandelion, cresses), and both look to the normal eye almost identical from above.

They both have a “bracelet” of 3 large white spots on their forewing “wrists” — this bracelet differentiates them from their cousins Dreamy and Sleepy Duskywings. They also both have another prominent white spot (the “costal spot”) about halfway between the “bracelet” and the base of the forewing, which distinguishes them from the otherwise similar Wild Indigo Duskywing. And they’re both rather strongly patterned in gray, brown, and black above, darker in males than in females. And for most of us, impossible to separate based on dorsal views alone. Pictures of just the upperside don’t help us get too far toward an ID.

Underneath, it’s a different story. Juvenal’s (male and female) have two large pale spots on the underside of the hindwing; these two large spots are absent on Horace’s. Problem is, neither duskywing usually shows its underside — you have to watch for a split-second when they raise their wings (very seldom; this is what gives this group the name spread-wing skippers), or see them balancing on a tall flower and showing their undersides as they move around the blossom.

Or net them and examine them in hand. If you do the latter, you’ll notice one other diagnostic character that separates the males — Juvenal’s Duskywings have long, white hair-like scales scattered over the forewings that Horace’s lacks. After the end of May or so, the situation is much clearer — Juvenal’s has only one brood a year, in the spring, while Horace’s flies again in midsummer.

Note the two large pale spots near the leading edge of the ventral hindwing in this male Juvenal’s Duskywing.
These white hairlike scales scattered over the forewing of male Juvenal’s Duskywing differentiate it in hand (or with XCU macro shots) from Horace’s.

[No butterflies were harmed in this examination 😉]

Posted in Identification tips | 5 Comments

Mid-Atlantic Lep Almanac for the week of April 17, 2021

Great Purple Hairstreak from Wicomico Co MD [2021 April 11, photo by Daniel Taylor]. An early date for this species on Maryland Biodiversity Project.

Almost everything one would expect to be flying now is, including some that are on the early side. All the expected swallowtails, for example, are on the lists this week — Zebra, Black, Pipevine, Spicebush, Eastern Tiger. Early still for Appalachian Tiger and Palamedes.

There’s a lull in nymphalids — a few American Snout reports but nothing like in previous years, emergence of the first Pearl Crescents. Because we don’t know much about the taxonomy of other Phyciodes species (like the cocyta-group, notionally Northern Crescent) in the mid-Atlantic, lep observers can add much to our understanding of this potential species complex by closely examining the males (which have a much larger orange, unpatterned field on their dorsal hind wings) to see if the underside of the antennal club is orange or black. Many crescents of all kinds have orange tips to the antenna; cocyta-group males have the entire underside of the scape orange. Take careful note of the habitat — open field, woods margin, wet meadows — and flight behavior. All can be useful information to better understand the increasingly complex crescent situation.

Also in the nymphalid tribe were FOY reports of Meadow Fritillary and continuing Variegated Fritillary.

Azures have had a bad season so far, it appears. The early brood of Summer Azure lasted but a short time (rain and cold weather, I’m guessing), and Spring Azures were hard to come by. There have been reports on iNat and elsewhere of Holly Azure, but largely without definitive photo support. We’re a ways still from Appalachian Azures. But other hairstreaks are on the wing; it’s been a good spring so far for Juniper and White-M Hairstreaks in particular. Also flying are Gray and Red-banded Hairstreaks, and the season’s first Great Purple Hairstreak. Silvery Blue reports from the mountains also arrived this week.

Elfins are likewise experiencing a rather disappointing flight. Frosted Elfin is out early on the MD Eastern Shore. But Henry’s and Eastern Pine, while being seen, are at nowhere near their usual populations, and Brown Elfin has not yet been reported. Rounding out the lycaenids are FOY American Coppers.

Early Monarchs were reported as well, hunting out the fresh emerging shoots of milkweed. These may be northward migrations of progeny that overwintered in Mexico, I suppose, but more likely to be from the populations that overwinter in the Gulf States, I suspect.

We’re seeing the big flush of skippers now, which will be rivaled only by the late summer clouds of Sachems and the like. No additional Sachem sightings save the one a week ago, but added this week to the skipper fauna on the wing now are Horace’s, Appalachian Grizzled Skipper, Wild Indigo Duskywing, and Common Checkered-Skipper. Great time to hone your skills on differentiating Horace’s from Juvenal’s, and Dreamy from Sleepy.

While we have no satyrids on the wing in northern parts of the mid-Atlantic, Gemmed Satyrs are flying in VA. And appear to be inching northwards. They occur at roughly the same latitude as central MD in OH where they are flying now.

It’s been a good season for Falcate Orangetips, which are at their peak this week. A few more Olympia Marble reports trickled in, along with a lot of Cabbage (Small) Whites. Regular but modest numbers of Orange and Clouded Sulphurs; no Sleepy Oranges.

Prognostications: Silver-spotted Skipper in the next week or so. Early emergence of Little Wood Satyrs. West Virginia Whites — I think they are already in flight but just haven’t been reported. Cloudless Sulphur by first of May. Northern Cloudywing on early blackberry and dewberry blooms.

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.

Posted in almanac, Forecasts, general butterfly news | Leave a comment

Mid-Atlantic Lep Almanac for the week of April 10, 2021

Tom Feild’s shot of an Olympia Marble this past week in Green Ridge SF [2021 April 6]. Note the rosy flush at the base of the wings, indicating a fresh specimen that emerged recently.

Often when a season is delayed or slow, everything that’s been piling up seems to emerge at once. That’s at least what it seemed like this week as many butterflies showed their FOY colors.

Olympia Marbles are in fact flying in Green Ridge State Forest, and in numerous spots not normally considered “the” places to see them. This bodes well for the continuing recovery of this very isolated population, which unlike its much more common midwestern praire and open woodland siblings, seems to be restricted to shale barrens. We’re still awaiting word of FOY West Virginia Whites in our area, which are already on the wing in New England.

Sulphurs are not doing very well, so far. Scattered sightings of Sleepy Orange came in again this week, but rather sparse reports for either Clouded or Orange Sulphurs.

Elfins are presenting an interesting situation this season. Generally, Henry’s Elfin is the common species through the mid-Atlantic, but this year they have been hard to come by. Eastern Pine Elfin is being more widely reported, with Brown Elfin yet to be noted. Among other notable FOYs in the hairstreak tribe are Red-banded and Gray; White M Hairstreak continues to be reported rather widely. The season’s first Eastern Tailed-blues made lists in VA and NJ, and a number of American Coppers were sighted.

Azures generally seem to be having a poor to moderate flight, with Spring Azure being reported sparingly across the region (Summer Azure has been on the wing for a couple of weeks already, as has Northern Azure). NJ observers report Holly Azure and Blueberry Azure.

Nymphalids recently reported on the wing for the first time this season include Painted Lady (which joins American Lady) and Red Admiral. Pearl Crescents popped in VA.

Interesting skippers include first reports of Juvenal’s Duskywing and Horace’s Duskywing, although online photos seldom provide definitive ID characteristics of the underside of the hindwing, which offer the clearest and most reliable diagnostic characters of large pale spots (present on Juvenal’s, absent on Horace’s). A probable early (but not outrageously so) Sachem report came in from central MD; the photo might or might not be a Sachem but the observer is well trusted and had good looks at the skipper before shooting the photo.

This is a good time to remind all of our field folks that definitive ID from photographs almost always requires clear dorsal and ventral shots for skippers and azures. iNaturalist is replete with presumptive “Spring Azures” that show only some version of the underside of the butterfly; I get great joy is asking each contributor how they differentiated their pics from Summer Azure, Holly Azure, or any others in the complex. I seldom get a response. Same when I question dorsal only photos of Juvenal’s/Horace’s.

No new reports on the swallowtail front, but the early arrival of Zebra Swallowtails didn’t portend a large flight. Modest numbers across the region.

Mourning Cloak ovipositing on hackberry, caught in the act by Kathy Litzinger in her back yard in Ellicott City (I think!). [2021 April 4]

Prognostications: This week, given good weather, we should see Brown Elfins — Harry Pavulaan reminded me this week that Browns also use mountain laurel as a host plant, in addition to blueberries, so it’s worth checking out habitat one might ordinarily discount. Cobweb Skipper is probably flying now. We are overdue for American Snout (which is often one of our first butterflies of the season). Compton Tortoiseshell is always a (rare) possibility this time of year in the western panhandle of MD and in PA. Silvery Blues are probably also flying in Green Ridge SF, where it appears to be restricted there to Carolina vetch — it uses others Vicia species in other parts of its range.

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.

Posted in almanac, Forecasts, general butterfly news, sightings | 3 Comments

When Summer Comes Before Spring

Almost every year, LepLog readers have been fortunate to get a lesson in the complex Azure complex from one of the resident experts on azure classification, Harry Pavulaan. With his colleague David Wright, Harry helped re-jigger the entire spring lineup of these iconic lycaenid butterflies, and we have a new contribution to the many excellent pieces he’s written for LepLog. This one originated as a post on the Google Group MDLepsOdes.

Part of a mixed puddle party of azures and Silvery Blues in Green Ridge State Forest, March 2016

>> Harry writes:

The common name for Celastrina neglecta – “Summer Azure” – can rightfully be considered a misnomer.  But why was it called “Summer Azure” in the first place? 

Background:

Historically, it was believed that the Spring Azure (C. ladon) and Summer Azure (C. neglecta) were just different broods of the same species.  W.H. Edwards first described C. neglecta as a species, realizing it was different from C. ladon, which he re-described as Celastrina violacea.  [Thus, we now have the synonym C. ladon (=violacea)]  Edwards conducted several years of rearing trials and later changing his mind and believed his “C. violacea” and neglecta were just spring and summer broods of the same insect.  His rearing experiments had one major flaw, which David Wright and I learned the hard way back in the 1980’s: ANY univoltine Azure raised indoors from egg or first instar caterpillar, through to the chrysalis will produce a FALSE second generation later that same season.  So, Edwards was confused by his own rearing.  His false second-generation Spring Azures produced adults that looked superficially like the Summer Azure.  [He also considered the Appalachian Azure (now known as C. neglectamajor) part of a multi-brooded Azure.  Wrong again.]  Many have continued to follow Edwards to this day. 

So here is why “Summer Azure” is a misnomer.  Back as recently as the 1980’s, Dave Wright and I, through many rearing trials, learned that the Spring Azure (C. ladon) does NOT produce the Summer Azure.  The main difference is that Spring Azure males have a wing scale structure that is unique among all Azures (except the Sooty Azure, C. nigra).  This wing scale structure breeds through 100% of the time to the next generation, and so on.  However, up until the early 80’s, the Spring Azure was very common in the eastern U.S., using Flowering Dogwood as its primary host.  I remember finding Spring Azures in huge puddle parties at places along the Potomac River and at McKee-Beshers WMA.  The Summer Azure was primarily a multi-brooded Summer insect that first emerged in May and did not produce an earlier full spring brood except for occasional individuals emerging in winter or in March.  In New England, there was no spring brood of the Summer Azure at all and early July was the first time one would see Summer Azures annually.  Nobody ever before seemed to notice that winter individuals in the Washington D.C. region had a different wing scale structure from the Spring Azure.  We all thought that they were all C. ladon!  Once David Wright did some microscopic analysis of the wings in the 1980’s, we suddenly realized that there were TWO Spring Azures in our region: univoltine ladon with the unique wing scale structure and multivoltine neglecta with “normal” Celastrina wing scales.

The Spring Azure went into rapid decline with the demise of Flowering Dogwood starting about 1990.  It appears that, being highly adaptable, the Summer Azure moved in to replace the Spring Azure in its springtime niche.  Since that time, the Summer Azure has produced a full spring brood in this region and is now our common “spring” Azure.  The original Spring Azure (C. ladon) is now quite rare in the Piedmont region.  Spring Azures are still fairly numerous in places like Green Ridge where the caterpillars feed on Black Cherry flower buds, flowers and fruits, rather than Flowering Dogwood.  Similarly, Spring Azures have adapted to using American Holly on the western shore side of the Chesapeake Bay.  But in both places, it flies with the Summer Azure’s spring brood.

Uppersides (males only) of six mid-Atlantic spring-occurring azure species [Courtesy Harry Pavulaan, 2016]

Key:

Top Row: (left) C. ladon, Spring Azure; (right) C. lucia, Northern Azure

Middle Row: (left) spring form C. neglecta; (right) C. serotina, Cherry Gall Azure

Bottom Row (left) C.  idella, Holly Azure; (right) C. neglectamajor, Appalachian Azure


So, the confusion over which species flies earlier, Spring or Summer Azure, is easily explained by referencing historical treatment of Azures in most all of our field guides until a few years ago.  Some of the more recent state guides have an accurate description of Azure relationships: Pennsylvania, Indiana, North Carolina (online).  Older guides will tell you that Spring Azure flies first, then later comes the Summer Azure (and, erroneously, they’re both broods of “C. ladon”).  This is now an outdated view based on flawed information dating back to Mr. Edwards.  Now we know that the Summer Azure produces a full earlier flight than the Spring Azure.  The Summer Azure is actually a year-long Azure.  I have documented them from February to November but there have been reports in Dec. and Jan. by others.  Most years, they peak in late March, but a few years ago, they flew in large numbers here in Leesburg, VA. throughout the month of March, then finished their flight around April 1, only to reappear during the second annual brood in May.  One single Spring Azure was documented in early April that year.

I hope this clears up why people are confused over why Spring Azure is not the first Azure on the wing.  Rick is correct that many naturalist sites have not caught up with science, and the Azure complex is outdated in many past guides, and some groups (in particular NABA) use their own approach which, frankly, puzzles me. 

Harry Pavulaan

P.S. – I will write up a short paper on the above topic with detailed images sometime this year.  Hopefully I can get it published by Banisteria by next winter.  Banisteria is now free, open-access, online, and better since you don’t have to be a subscriber to read issues.


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New Forecast, New Name: Introducing the Mid-Atlantic Lep Almanac

Welcome to a new season of butterfly sightings, but I’m going to make some changes in the full-up forecasts I’ve done in previous seasons. When I first started this weekly update, I tried to make it a recap of pretty much anything you’d be likely to run into if you were in the field that week. Folks, that got to be exhausting!

These days you can get a good sense of the common things by following butterflies on iNaturalist (or on the Maryland Biodiversity Project website, which now also brings in iNat sightings). On iNat just select butterflies, plus your local region or state, and set the filter for the last week or so — like magic you will get a list of all the butterfly sightings that have been contributed. On MBP it’s even easier; just click on “Only Recent Photos” and it will show the same sort of selection, only you get more than butterflies, and that to me is a good thing.

Here on LepLog, I’ll concentrate only on recent “Hot Seens” — sightings of recent rare or unusual (or at an unusual time or location) butterflies in the mid-Atlantic region. More like a Rare Bird Alert for butterflies. It’ll be shorter and more focused, but also will take a lot less time to put together for me. I frankly thought about ending the weekly report altogether because it was getting to be such a time-consuming chore, but this compromise I hope will keep my loyal readers engaged and me somewhat more sane. And I’ll probably engage in a little prognostication and rumination as well from time to time. Like this week’s soapbox about azures.

So, without further ado … The weekly Forecast has metamorphosed into the first Mid-Atlantic Lep Almanac, for the week of April 3, 2021.

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The 2021 season is off to a fast start, although it might be slowed down a bit by the end of the week’s heavy rain (snow in Garrett Co!) and frigid blast.

At least two species of azures are out already, the more or less ubiquitous Summer Azure and Northern Azure, which was found on the higher elevation ridges in Green Ridge State Forest last week.

The first elfin sighting (Henry’s) was sent in from the Eastern Shore and multiples from VA. With redbud coming into bloom in the Piedmont, this species should start showing up more widely across the mid-Atlantic.

Other early lycaenids included multiple sightings of Juniper Hairstreak (fun fact: also technically an elfin) and of White-M Hairstreak. Gray Hairstreaks were on the wing in VA.

Both Eastern Tiger and Zebra Swallowtails were on the wing last week. A confirmed Pipevine Swallowtail account came in from the Shenandoahs, as did another of Black Swallowtail from VA.

Whites that have emerged already include Falcate Orangetips (males only so far, which come out and haunt the open woodlands for females as they emerge) and Cabbage (Small) White. So far, no Olympia Marbles have been reported. Sleepy Oranges are out exceptionally early this year. A solo Orange Sulphur is the only other pierid to make an appearance so far this season.

Skipper season is off to a good start too, with both Dreamy and Sleepy Duskwings observed basking in Green Ridge State Forest. Juvenal’s Duskywing appears to be flying in VA.

In addition to cloaks and anglewings reported throughout the region, the nymphalids were represented by Variegated Fritillary sightings in VA.

Soapbox of the Week: Pay no attention to those scads of Spring Azure sightings for our area on iNaturalist this week. I can say with pretty good assurance that most if not all are Summer Azure spring brood, which in our area emerges two weeks or more earlier than Spring Azure. Watch LepLog for a good explanation coming shortly from noted azure expert Harry Pavulaan.

Juniper (aka Olive) Hairstreak, Callophrys gryneus. Attentive readers will note that Callophrys is the same genus that our elfins fall into; yes, Juniper Hairstreak is actually an elfin. Note the use of spade tip (aka “butterfly”) forceps for handling butterflies without damaging their wings or rubbing off too many scales.

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.

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