South Jersey Butterfly B/Log

Celastrina idella photo by Dave Amadio, Salem WMA April 4, 2011

Yes, our second “spring azure” species is now on-the-wing.  Holly azures  make a tricky ID, but their emergence means checking out those little blue butterflies at our feet has suddenly become a lot more fun!

We had an unusually early record for holly azure on 3/19/11 (Lizard Tail Swamp, W. Kerling), but early to mid-April is when we can generally expect first emergences, especially north of  Cape May County.  Dave Amadio’s find of a holly  on April 4th in Salem County probably announces  the start of their primary flight period.

Separating idella (holly) from lucia (blueberry azure) by sight involves factoring in several variables. And it also  seems we also have to keep in mind that not all free-flying individuals can be certainly named.

One key seems to be the “cleaner” and brighter underside on idella vs. lucia.  The dark spots are smaller and seem to stand out more sharply from the ground color of the underwing.

The majority of C. lucia individuals (74%) are the “marginata” form with a dusky ground color below and dark markings, especially on the trailing edges (the margins) of the wings.  Almost all other lucia individuals (24%) are “lucia” form — which differ mostly from “marginata” by also showing the “lucia” patch in/near the center of hind wing.  Only a few C. lucia are in the lightest-marked “violacea” form (about 2%, 1 in 50).  By contrast, the majority of holly azures, C. idella, (90+%, if I understand the literature) are light below; <6% show the “lucia” patch — and Wright & Pavulaan note those few dark “idella”  might be hybrids of the two sibling species.

C. lucia also emerges earlier (generally 2+ weeks) than C. idella, so wear can be a tip, at least from mid-April on.

Wright & Pavulaan note that the colors are slightly different: males of C. lucia are “violet-blue,” while males of C. idella are “uniform light-blue; some individuals w/distinct purple tint.” C. idella individuals also are “distinctly smaller,” W&P note. Both color and sizes can be hard to evaluate on living butterflies, however — at least for me.

The most certain separation for those of us not collecting specimens is the host plant.  C. lucia does not use holly; C. idella does.  Anyone out there with a good photo of idella ovipositing on its host?  That would be wonderful to post here on our blog.

See the post below “Azures & Others” (3/17/11) for photos of all three forms of C. lucia and a link to Wright & Pavulaan’s original description of C. idella.

I am ignoring here the third newly-split species in our area, Edward’s azure, C. ladon, because it seems either rare or non-existent through most of NJ’s southern eight counties.  Wright & Pavulaan’s maps indicate it is most likely to be found in Salem or Gloucester, away from Pine Barrens soils, where dogwood is common.    If any readers would like to offer some tips  on separating ladon from idella, I’d be very pleased to post them here on this blog.

I am also ignoring a fourth apparently-even-rarer possibility: the spring brood of summer azure, C. neglecta, for which we have at least one recent record in our area — photo’d by Mike Crewe at Cape May Point on March 31 last year, and identified by Dale Schweitzer.

Some words of wisdom from different sources about this complex complex:

Paul Opler & G.O. Krizek, Butterflies East Of The Great Plains (1984) “In recent years, it has been realized that several sibling species are involved [under the name spring azure].  Seasonal and geographic variation confuses matters.”

J.P. Brock & K. Kaufman, Butterflies Of North America (2003), “It now appears certain that there are several species, all very similar.  Their classification is still being studied.  Unless you are a specialist on this group or have access to detailed information for your local area, it may just be best to enjoy them as azures — and marvel at the fact that butterflies can still keep so many secrets from us.”

Rich Cech & Guy Tudor, Butterflies Of The East Coast (2005), “We may be, simply enough, witnessing the fragmentation of an ancestral species.”

David Wright in an email to our club (2009), “Study what’s at hand and take lots of photos.  Eventually, it begins to make sense.”

J.C.

*****

Let’s close with two more photos from Dave Amadio of his idella holly from this week (nectaring on Cardamine hirsuta, a mustard):

Celastrina idella photo #2 Dave Amadio,  Salem WMA April 4, 2011

Celastrina idella photo #3 Dave Amadio,  Salem WMA April 4, 2011

Photo by Harvey Tomlinson, Belleplain State Forest, 3-19-11

Goodness, what a pretty shot of a significant find! Harvey Tomlinson found this Henry’s elfin (Callophrys henrici) on a trail at Belleplain where the species is sometimes common in April, but not in mid-March.

This is a new early date for the species for our SJBF Log — even earlier than last year’s surprising first sighting on 3/25/10.

Celastrina lucia, Mannheim Avenue 3/17/11 in “lucia” form (= ~24% of all C. lucia individuals)

Thanks to some lovely sunshine (and the luck of the Irish?), butterflies are flying now, as of March 17th.

Temperatures climbed into the 60s & 70s yesterday, and we logged more species and more individuals in one afternoon than had been reported all year. Questionmarks, eastern commas, and mourning cloaks were reported in several sites in Cape May, Cumberland, and Atlantic Counties (and an anglewing, sp. from Gloucester Co.) And we added two new species for the year: one Cape May observer spotted our first cabbage white, and four different sets of observers in three different counties found blueberry azures, Celastrina lucia (a.k.a. C. ladon lucia).

You can go to our log (“Here’s Our 2011 Log”) for the specifics.

The earliest azures generally appear in mid-March — as they have again this year — and are presumed (by most of us) to be blueberry azures. What was once considered a single species, the spring azure, is now widely recognized as several sibling species. At least four of them occur in our area: blueberry azure, holly azure, Edward’s azure, and summer azure.

The last, C. neglecta, flies later in the season (usually) and is the one member of the group that goes through multiple broods in a single year, with the last brood still flying into late September and even October. The summer azure seems to shows the lightest underwings, and all in all, seems generally the easiest of the complex to ID.

The three other species fly only in spring and are tough to tell apart by sight or even in photographs, especially because different morphs are possible within each population.

Blueberry azures, C. lucia, are the first to fly, but show much variation in the patterns of dark on undersides of wings. The individual above was the darkest of the individuals we saw on Mannheim Ave (Atlantic County) yesterday. That little patch in the hindwing led us to call it a “lucia” morph.

Below are two differently-colored individuals seen flying nearby. Here’s one that represents the majority pattern yesterday, apparently the “marginata” form, having the dark trailing edge but not a real “patch” in hindwing.

Celastrina lucia, Mannheim Avenue 3/17/11 in “marginata” form (= ~74% of all lucia individuals)

And here’s the lightest individual. It lacks both the dark trailing edge and the discal “patch.” This seems to qualify it as a “violacea” form [correct ?]. Seen a few weeks from now this could make a challenging ID: yes, it’s an spring azure, but which one?

Celastrina lucia, Mannheim Avenue 3/17/11 in “violacea” form (= ~2% of all lucia individuals)

Gochfeld & Burger have an excellent discussion of the spring azure complex (including details of other sibling species in North Jersey) in their Butterflies Of New Jersey, pages 165-172, where they note how the work of David Wright & Harry Pavulaan over 20+ years has sharpened our understanding of the azure complex.

Finally, here’s a link to the Wright & Pavulaan’s original 1999 description of the holly azure, Celastrina idella, naming that species. Their article summarizes how spring azures have been variously understood and includes some very helpful photos and maps. If you are serious about learning how to ID azures, studying this article is a must.

J.C.

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