South Jersey Butterfly B/Log

Brian Johnson’s recent night-time shot of a Henry’s elfin with green highlights inspired some reading into a spring-season butterfly mystery that has surfaced now and again on our Sightings Log for several years.  

The mystery revolves around two questions:

1. What plants are the primary hosts for Henry’s elfin on NJ’s Coastal Plain?
2. How frequent (and identifiable) are “greenish” Henry’s elfins here?

If either question interests you, the next few weeks are the ideal time to try to help find an answer.  Henry’s fly in South Jersey from mid/late March to early/mid-May. 

Harry Pavulaan first described a greenish form of Henry’s in The Maryland Entomologist in 1998 and named it as a new subspecies, Incisalia henrici viridissima. He credits Samuel Gifford for discovering the form while doing field work on North Carolina’s Outer Banks from 1974 to 1980. In a report of Gifford’s work on several hairstreaks, Gifford & Opler wrote, “Individuals of the Hatteras population [of Henry’s] had a greenish cast ventrally and might eventually be described as a separate subspecies.”  

Pavulaan took up the gauntlet.  He examined Gifford’s specimens and dozens of other museum specimens from the East Coast to study the differences.  He finally sorted them  into five phenotypes:  (1) all-brown “nominotypical” Henry’s; (2) viridissima greenish-types; (3) intermediates between all-brown and greenish-types; and (4, 5) two southern subspecies found only from southern South Carolina into Florida.  

Then he created a map of their distribution of the eastern range of Henry’s from Florida to Maine. Viridissima and intermediates appear from the Outer Banks northward to northern Virginia, the panhandle of West Virginia, southern Maryland, the Delmarva peninsula, and Cape May County, NJ.  

To see that map and to learn many other details, including Pavulaan’s meticulous description of the field marks of greenish Henry’s and his careful discussion of host plants, you can go to the full article linked at the end of this post.    

In the meantime, here’s a quick summary of the key points most relevant for South Jersey butterflyers:

– On Pavulaan’s 1998 map at least, Cape May County, seems to be the northern limit of the area he calls the “blend zone,” where three of his five types can be found:  all-brown individuals (the majority), intermediates, and viridissima individuals.  (From central New Jersey north to New England all the Henry’s specimens Pavulaan examined were the all-brown type.) 

– The frequency of viridissima and intermediates may be related to differences in soils and host plants.  Redbud, Cercis canadensis, is the primary host inland, where all-brown individuals dominate. Hollies, including yaupon, Ilex vomitoria, and American holly, Ilex opaca, seem the most likely hosts on the Outer Banks and probably elsewhere in the sandy soils where viridissima and intermediates may be found.  

– The greenish cast Pavulaan describes can be subtle, short-lived, and dependent on the lighting, even in “pure form” viridissima individuals.  It is best seen on fresh, living butterflies in full sunlight.  He writes, “Optimally, one should examine specimens under natural sunlight to view the full effect of the green characters in combination” and notes that some observers thought the butterflies they netted in the field looked greener than they appeared in the lab later after collection.

The original article is in black-and-white, but a photo of a plate of two viridissima collected on Bodie Island, NC, in 1991 was later added as a supplement. [4-12-23: The link below seems to hang up for some readers. If you’d like to see it and can’t, email me and I’ll send you the pdf directly.]

Color plate of 1991 specimens from Bodie Island, NC

Pavulaan speculated about a possible connection between host plant differences and color-form variations:    

“I believe the greenish characters found in I. h. viridissima are an early-stage evolutionary adaptation to the evergreen holly forest habitat in the mid-Atlantic coastal region…. lndividuals with strong greenish coloration might gain protective advantage by blending imperceptibly against a background of green holly leaves in early spring. Inland populations, which have a predominantly brown venter and feed primarily on redbud (Cercis canadensis), do not stand to gain from such coloration against the stark leafless dark brown branches of their early-spring forest habitat. Theoretically, the green characters in holly-feeding populations [of Henry’s] may have been selected over time, providing an effective measure of camouflage.”

Just last week, twenty-five years after his original work, Pavulaan restated and updated his sense of this subspecies in an interesting exchange with Rick Borchelt on the mdlepsodes google discussion group (a group well worth joining for many reasons). You can read that here:

mdlepsodes on greenish Henry’s elfins

One point that might tweak the interest of South Jersey readers is not discussed in the 1998 article (or in the mdlepsodes exchange).  This is the apparent frequency of viridissima and intermediates in Cape May County that is evident in Pavulaan’s data.  Go to page 13 of Pavulaan’s article and check out the percentages.  He examined 54 specimens of Henry’s from Cape May and found 9 (17%) were viridissima and 13 (24.5%) were intermediates.  Those are higher percentages for those two forms in Cape May County than any other county north of the Outer Banks except Anne Arundel County, MD.  

I scrolled backward for logged photos of greenish Henry’s to accompany this write-up and found myself often unsure.  Just as collectors were frustrated when the green they saw in the field did not match the netted specimen, photographers may find it difficult to capture the green with their cameras.  A few Aprils ago, my wife Jesse and I studied a Henry’s through our bins from a dozen feet away and simultaneously said something like, “Look at the green!”  I stepped forward and snapped the shutter moments later.  The photograph below might seem unconvincing, I know.  All I can say is “You had to be there!”

That Mannheim Avenue Henry’s  and perhaps others in the photos above might qualify only as “intermediates” in the Pavulaan system, but if so, the blend zone extends northward beyond Cape May County. Could the entire Outer Coastal Plain of NJ be a blend zone of three types: all-brown, intermediates, and viridissima?   

Can we record pure viridissima here?  Have we already? The three photographed Henry’s below strike me as our best evidence (so far) that we have.  Note that the first two come from well north of the Cape May County line.  Jack Miller included in his report that McNamara WMA (just south of the CMY line) “produces the greenish [Henry’s] on the Cape.”    

Redbud seems an uncommon or rare plant throughout most of the NJ Coastal Plain (outside backyards and other cultivated situations).  We have at least four species of hollies here, however: American holly, inkberry, winterberry holly, and smooth winterberry holly.  The first two are especially widespread and numerous.  Do Henry’s use hollies as their host plants in our area?  Pavulaan’s article and his recent comments suggest yes.  But our log could use more proof.  The single photograph I could find of ovipositing Henry’s is one of our most recent reports, from Scott McConnell at Whitesboro just last week.

Scott wasn’t thinking about ovipositing when he took this shot because, like me, he finds it hard to believe elfin caterpillars can possibly chew on the tough, tough leaves of American holly.   But after studying his photo sequence, he reports that his Henry’s kept its abdomen pressed to the leaf for 20+ seconds.   

So, here’s the two-pronged challenge for any South Jersey butterflyers interested:

1. Can we determine and document which plants are Henry’s primary hosts here? Photographs of any form of Henry’s – brown, greenish, or intermediate – ovipositing on any plant would be significant and exciting to have.
2. How many greenish Henry’s – viridissima or intermediate – can we document this spring?  How common are they?

If you see ovipositing by Henry’s or any green Henry’s, please report them to our log.

My too-quick backtrack through the log probably missed photos or reports that would help answer one or the other of those questions.  If you remember such a report or submitted a relevant photo or report yourself, please send me an email. I could use them in an update of this post.

Other corrections and comments are also welcome, of course.  

Keep exploring, everyone, and posting your sightings when you can.

Jack Connor

April 10, 2023

Harry Pavulaan, “A New Subspecies of Incisalia henrici from The Outer Banks of North Carolina” (1998)

Thanks to Kathy Horn’s sharp eyes and quick-thinking camera work, we have added a new species to our South Jersey Butterfly Project’s all-time list, the southern broken-dash, Wallengrenia otho.

Our log is in its 15th year, so new species — butterflies that no one has previously reported anywhere in New Jersey’s southern eight counties — do not come often. Until last year we had added no new species at all to our all-time list after June 2017, when Beth Polvino found and photographed a great purple hairstreak in her garden. Now, though, we’ve added two in the last nine months. Jack Miller won us our 108th species with his superb find of a eufala skipper at Rea Farm, Cape May Point, last November and Kathy has documented our 109th with her find this week.

Polvino’s great purple hairstreak and Miller’s eufala seemed to come out of nowhere. Both are species generally found only hundreds of miles south of NJ. The southern broken-dash, by contrast, breeds in Delaware and Maryland and has been teasing us for the last six years — since Harvey Tomlinson photographed the butterfly below:

You can see several similarities in the two photographs aboved: both individuals show an reddish overall ground color (different than the darker brown of northern broken-dash), two-toned wing fringes (gray on FW, buff on HW) and another, more subtle field mark to be detailed below.

Two other possible southern broken-dashes were found in the summer of 2016. Will Kerling photographed this individual in Estell Manor, Atlantic County, just three days after Harvey photo’d his:

And a few days after that Dolores Amesbury found this individual in her garden in Cape May Court House:

Despite this flurry, we did not add the species to our log’s “official” all-time list. One problem was there were no previous records of southern broken-dash for the state of New Jersey; another was that both SBD and NBD are variable and the differences between them are subtle. We had some other reasons for caution also. If you are interested in those and the history of the taxonomic split between SBD and NBD, see this post from August 2016:

Southern Broken Dash: A Species To Look For?

In the years since 2016 we have had a few “might-have-been” SBDs, but none apparently as convincing as Kathy’s individual this week. Here’s her superb dorsal shot of her 7-20-22 butterfly:

The South Jersey observers who have studied Kathy’s photographs so far agree that this is a southern broken-dash — and at least a couple of us are now re-studying those old photos from 2016. We also have support from three esteemed friends of the Project whose credibility adds much weight to the ID. David Wright replied to a request for his take with “I think [Horn’s] photos are Southern Broken-Dash,” and he added, “I think the 2016 photos are good too. They align with what Kathy has documented this week.” Jim Springer replied, “The evidence for calling [those butterflies] SBDs — especially Kathy’s individual — is pretty compelling to me.”

Wade Wander sent us the longest comment (shortened here), “I must admit to being somewhat skeptical when I saw the ventral view photo taken by Harvey a few years ago. Although it was obviously reddish and certainly resembled a SBD, I wanted to see more photos of different individuals including the upper surface…

“But having seen these additional photos I am convinced that SBDs are present in south Jersey. And this should not be surprising as many of us have witnessed the northward expansion of many species of birds, moths, odonates, and, most notably, Wawas. Take for example the Dot-lined White Moth (Artace cribrarius). This primarily southern species first appeared at my moth lights in Sussex County in 2017. I have seen it annually since and in increasing numbers. In fact, I have found cocoons, so it is now a resident species. The Carolina Mantis has also rapidly expanded south to north and is now found at least as far north as central Jersey….

“So, is SBD resident? If its host grass is present. then why not now, and if not now, then certainly soon.

“And surely Whirlabout is on-deck.”

How To Find Our Next Southern Broken-Dash In South Jersey:

If you are inspired to track down a SBD yourself, the first thing to recognize is that separating it from northern broken-dash is no easy task. Even in states to the south where both species can be found regularly observers differ on the best ways to distinguish them, and most seem to agree it is often a judgment call.

Second, you need to take sharp, well-lit, close-up photographs of any possible SBD that you encounter.

Third, know that most field guides and on-line sources illustrate “text-book” and fresh individuals that we are unlikely to see here until we have a breeding population. (All four of the individuals in the photos above are somewhat worn. If they or future SBDs are all strays from Maryland or Delaware, wing wear is to be expected.)

Fourth, recognize that no single field mark seems completely reliable. To document our next southern broken-dash you will need to find most of the field marks below.

1. Overall reddish ground color (noted by all field guides).
2. Two-toned wing fringes — one gray, one buff (noted by Cech & Tudor in their Butterflies Of The East Coast and by a couple of other sources). Tomlinson’s and Amesbury’s shots and Horn’s ventral shot all show this feature.
3. A yellowish rectangular spot trailing the stigma on males (noted in Kaufman’s Butterflies of North America, by David Wright and James Monroe in their Butterflies of Pennsylvania, and elsewhere.) Kerling’s photograph and Horn’s dorsal shot both show this.
4. A leading edge of the forewing (the costal area) on males that is brighter and more orange than the same area on male NBDs (illustrated in Cech & Tudor and in Wright & Monroe). Kerling’s photograph shows this, and it also seems present in Horn’s shot. Neither is “text-book” bright, however.
5. A pattern of dots in the hindwing underside that suggest a 3 because two of the dots project inward (as illustrated in Glassberg’s Swift Guide To Butterflies and in the Kaufman field guide). Amesbury’s photo and Tomlinson’s photo show this most clearly above. In Horn’s ventral shots this feature is suggested by only one dot, perhaps because wing wear has shortened the leading edge of the other dot.

When To Search For Our Log’s Next SBD?

Now! All four butterflies above were found in July.

Good luck to all explorers. Keep chasing, photographing, reporting, and enjoying the butterflies of South Jersey.

Jack Connor

July 26, 2022

Our two local anglewings, the eastern comma and the question mark, show many similarities besides their physical resemblance:

• They share a mostly-overlapping range with each other, south from Maine to Florida and west to the Dakotas, and are the most widespread and southernmost members of the genus Polygonia in eastern North America.  (The four other Polygonia of the East – gray comma, hoary comma, satyr comma, and green comma – are generally limited to northern woodlands).    

• Their caterpillars feed on a similar mix of host plants, including elms and nettles.

• Both species occur here in two, clearly-distinct broods – one brood in early summer and, weeks later, a second in late summer/early fall.  

• Many individuals of both species of that second brood over-winter as adults in South Jersey (unlike all but two or three others of our 90+ species), and both species regularly fly in late-winter and early-spring, usually weeks ahead of all but the mourning cloak, their fellow Nymphalid.

• As adults, both species feed frequently on sap, dung, and rotten fruit, and neither one nectars regularly on flowers.

• Both species also migrate southward in fall and some individuals, at least, seem to migrate north in spring.  The question mark has occasionally erupted northward from southern states in huge migratory flights, most recently in May 2012.

• Both their populations also ebb and flow obviously from year to year – numerous and hard-to-miss some years, tougher-to-find in other years.

And that leads to our ecology puzzle:  Are their two populations also in sync with each other?  In other words, do their many similarities lead to similar records of ups and downs, so that they share the same good years and bad years?  Or, do  they differ in their ecologies so much that one can boom while the other busts, and vice-versa?   

I called upon my junior-high spreadsheet skills to see how our log’s numbers might answer those questions.

A Note About Numbers:

The Reeves’ system that powers our log enables us to measure and compare abundance and yearly fluctuations in two different ways – by total reports for a species in a given year or by total individuals counted in all reports of that species for the year.  Each method has its pluses and minuses, but in this case the question mark irruption of 2012 distorts our individuals’ totals significantly.  Observers estimated a total of 5000+ individuals on the peak day of the flight, May 4.  That was more question marks reported in one day than we have ever recorded for the species in any other full year.  To avoid that distortion problem and to keep things simple, I am using total records as the comparison measures for the three graphs below.  

The question mark has long been considered the more numerous of the two species in our area. Arthur Shapiro made this point in his Butterflies of the Delaware  Valley in 1966, and Gochfeld & Burger came to the same conclusion in their Butterflies Of New Jersey in 1997 (citing sources going back to the late 1800s).  Our log records confirm that the question mark continues to be more common.  Over our log’s first ten full years, 2009-2018, we compiled an average of about 220 reports/year and 845 individuals totaled/year for the question mark.  The comma’s numbers were lower on both counts: 124 reports/year and 295 individuals totaled/year.  

Two Trend Lines:

The trend lines in the first two graphs below of all reports suggest that the comma seems to be increasing in South Jersey while the question mark seems to be declining.  I am uncertain whether these trends are meaningful.  Both trends are modest, and they might be temporary – part of a longer cycle, where a species increases or decreases for five or ten years and then returns to its former numbers.     

Booms & Busts:

But what about those booms and busts? Are commas and question marks so similar that they share good years and bad years in parallel? 

To make comparisons easier, the bars in the next graph indicate each species’ numbers vs. its own 10-year average (calculated for 2009-2018) as the standard.  The 100 line = 100% of that 10-year average.

“Good” & “Bad” Years

Each species has had five “good” (= above average) years and eight “bad” (below average).  The question mark’s five have been 2010, 2011, 2012 (its best year by far), 2017, and 2019.  The comma’s above-average years have been 2014, 2016, 2017, 2018, and 2019, a string of five good years in six and followed by 2020 with a count right at 100% of the 10-year average.  

In Sync? 

One hint that their similar ecologies lead them to struggle at the same time are the three years when both had numbers well below their averages – 2009, 2015, and last year, 2021.   They also have shared two or three “good” years – 2017 and 2019, and 2011, when the comma reached its average while the question mark totaled 120% of its average.  

Or Not?

The story grows more complicated when we look at the five years of 2010, 2012, 2014, 2016, and 2018, when one species boomed while the other busted.  The years 2012 and 2014 seem the clearest examples of mismatched booms and busts:  in the question mark’s best year of 2012 the comma had its second-worst (of our log’s thirteen); in the question mark’s second-worst year in 2014, the comma had numbers well above its average.  

One key to these mismatches might be differences in their host plants.  Most texts list elms, nettles, and hops for both anglewings, but their specific preferences seem to differ. Our log has many reports of question mark using hackberry as a host, for example, but I don’t see that as a listed host for eastern comma, and I can’t seem to remember log reports or photos of comma using hackberry.  If you have photos or remember them doing so, can you please send me a note?

Another possible difference involves stinging nettle (Urtica diocia). That plant is often listed as a host for eastern commas but not, it seems, for question marks. Anyone with a photo or a memory of a question mark ovipositing on stinging nettle or their caterpillars using it? 

Butterfly gardeners, please let us know which plants the anglewings have used in your yard. You may know more about the host plants for these two species in South Jersey than anyone!

Your Thoughts?

I will stop here and invite comments from anyone with other thoughts about these numbers.  I see several complications we could explore, along with questions about host plants: 

Is thirteen years of logging too short a period to draw lines of population trends?  Does that question mark boom year of 2012 distort its record for all our log’s thirteen years so far?  As many of us have become better butterflyers over the years, with more experience and better field guides, do we now separate more commas from question marks than we used to?  (If so, that could create an apparent rise of the first and decline of the second.)  Are the ecologies of the two species actually so different – despite their many apparent similarities – that comparing them is like comparing apples and oranges and so finding parallels or contrasts is self-delusion?  And so on.  

I am also reminded of a line I saw recently in Doug Tallamy’s The Nature Of Oaks: “Ecology is not rocket science,” a friend once observed, “It’s much more complicated than that!”

Our blog’s comments tool had to be disabled as it was plagued by spam.  Thoughts, questions, or complaints can be emailed to me nacotejackATgmailDOTcom and I will post below.  Thanks for reading!

jc 

[PS: The anglewing in Jeanine Apgar’s photo at the top of this post is an eastern comma.]

[May 2 Update: Governor Murphy re-opened the state parks today. Leaving the note below for future reference.]

South Jersey Butterflyers & Friends,

As everyone knows, we are living through a disorienting and frightening time.  Decisions that were so simple two months ago have become problematic.  Even “Where should I go walking today?” has become a complicated question.

Governor Murphy’s Executive Order on April 7 closing all state and county parks has also created a problem for us as moderators of the South Jersey Butterfly Sightings Log.  We want to encourage everyone to get out and search for butterflies — walking outdoors in safe areas is good for any naturalist’s mental and physical health (obviously), and your reports create valuable data. We believe, however, that allowing reports from restricted areas could be seen as disrespect for the Governor’s measures.  

Whether or not it was the right choice to close the parks, the Executive Order came as one component of a much larger and crucially important effort to save lives by flattening the curve of the pandemic.  

Out of respect for that decision and in general support of any attempt to protect NJ residents from the virus, we are encouraging people to stay away from closed areas. 

We are also announcing here that the log will not be posting reports from those closed areas.

Questions, comments, and suggestions are welcome, of course.

Stay safe and keep exploring — when and where you can!

Jack Miller
Jack Connor

Co-Moderators

South Jersey Butterfly Project

Update: Emile DeVito, Manager of Science & Stewardship for the New Jersey Conservation Foundation, has kindly responded to our email about this desicion with a reminder about New Jersey WMAs and NJCF Preserves.  He has also sent a helpful map of Michael Huber Preserve which is linked below.  

He writes, “Southern NJ has so many NJ Div F&W WMAs and they are ALL still open. Please encourage folks to use those areas with proper safeguards until other areas open up. Also, all NJCF Preserves in southern NJ are open except Franklin Parker Preserve. Explore especially Michael Huber Preserve!”

The map is here: NJCF Michael Huber Preserve Trail Map