“Spring” Azures are Springing — With ID Notes

Celastrina neglecta ("spring form" Summer Azure) was flying already yesterday along the high ridges along Oldtown-Orleans Road in Green Ridge State Forest (MD: Allegany Co.).  All males showing that bright sky-blue dorsal aspect when flushed from their roadside puddling. [2016 March 18, MD: Allegany Co., Green Ridge State Forest]

REB notes:  Celastrina neglecta (“spring form” Summer Azure) was flying already yesterday along the high ridges along Oldtown-Orleans Road in Green Ridge State Forest (MD: Allegany Co.). All males showing that bright sky-blue dorsal aspect when flushed from their roadside puddling. [2016 March 18, MD: Allegany Co., Green Ridge State Forest]

With the coming of early spring, Harry Pavulaan always has great info to share about our confusing azure complex here in the mid-Atlantic. I’ve taken the liberty of posting a recent exchange on local butterfly listservs that I’m sure all regional butterfliers will find incredibly helpful.

Note particularly the discussion about identifying C. ladon and C. neglecta from ventral shots only. In my brief time as eButterfly regional editor, by far the most common request for inclusion in the database was for an azure (variously identified as some variation on ladon or neglecta or forms thereof) supported only by VHW pictures and no documentation of the dorsal view (of males) by picture or sight record. I routinely changed all these to “azure sp.” as Harry notes; there may be others more confident about their ID skills but I think this is still the best approach.

Harry recommends this publication for ID help on the mid-Atlantic azures.

Harry writes:

Reporting here from Leesburg, VA. 3/17/2016:

The spring brood of Summer Azure (Celastrina neglecta) is fully underway here along the Potomac River woodlands.  During a half hour at noon, I observed well over 100 Summer Azures.  Interesting behavior:  In areas where dried stalks of last fall’s Wingstem (Verbesina alternifolia) remained, countless fresh males were swarming on the forest floor, obviously just emerged from around stands of their fall hostplants.  In areas where Wingstem is not present, males were flying high and fast, obviously dispersing into the surrounding area.  First female was confirmed, a week after males were first observed.  Random individuals were netted/released (unharmed for those concerned), all confirmed neglecta.  These are easier to identify in flight (yes!) than resting.  The undersides are highly variable, ranging from individuals nearing the summer phenotype (white beneath with spots reduced to mere pinpoints) to darker gray ones with large, dark spots;  to heavily-margined variants with “checkered” wing margins appearing like Northern Azures (Celastrina lucia).  Males are easy to identify in flight by their glowing bright blue appearance. 

It will be interesting to see how these fare with this weekend’s predicted snow and sub-freezing temps!  I’ll continue to monitor the colony.

No candidate Spring Azures (Celastrina ladon) have yet been observed in the same area this season.  These first emerge in response to different cues than Summer Azures.  Summer Azures (C. neglecta) are capable of eclosing at any time during winter and have been observed emerging in a full brood as early as the last week of February in this region.  Spring Azures (C. ladon) always wait until around April 1, regardless of mild weather throughout the month of March.  I net Azures to confirm the first emergence of ladon in this region, though most are easily identified in flight by having a weaker flight in general, and being a duller violet color than the Summer Azures.  The two species simply CANNOT reliably be distinguished by their undersides!  Spring Azures have become very scarce in the area immediately around Washington D.C. as a consequence of the demise of their host, Flowering Dogwood (Cornus florida).  They are still common in the mountain region to the west, feeding primarily on Wild Black Cherry (Prunus serotina) and in the region along the west side of the Chesapeake Bay where they have switched over to feeding on American Holly (Ilex opaca).  Interestingly, they share the host American Holly with Summer Azures and both species have seemingly replaced the Holly Azure in that region.  Competition for the ecological niche among Azures? – but interestingly not with Henry’s Elfin (Incisalia henrici).

Other species observed in Veterans Memorial Park and surrounding neighborhood in Leesburg:

Cabbage White (Pieris rapae) – 2 observed.

Orange Sulphur (Colias eurytheme) – 1 observed.

Eastern Comma (Polygonia comma) – 1 observed.

Mourning Cloak (Nymphalis antiopa) – same 1 observed at same spot for a week now.

Interestingly, no Zebra Swallowtails (Eurytides marcellus) observed since two seen earlier this week.  One large unidentified black Swallowtail was seen flying across a neighborhood street in front of my car, possibly a Spicebush Swallowtail (Papilio troilus).

As a side note here.  Many NABA members have inquired over the years about the status of my “Summer Azure” reports in spring.  NABA lists C. neglecta as “C. ladon neglecta (‘Summer’ Spring Azure).  It must be noted that NABA has not yet updated their Checklist since 2001 and there is no indication that the editorial board will accept two recent papers that highlight the very obvious wing-scale structural differences between Celastrina ladon and C. neglecta.  NABA apparently freezes taxonomy in place between Checklist editions, despite a great many name changes, realignments and new species/subspecies since 2001, and insists on strict adherence to using outdated taxonomy until the next Checklist is published.  There is no mechanism within NABA for accepting taxonomic changes annually nor are changes announced.  As a result, many NABA members unfortunately do not know of ongoing taxonomic research resulting in such new taxa as Papilio rumiko or Hermeuptychia intricata.  Thus, the most recent NABA checklist (2001) considers C. neglecta a subspecies of C. ladon, which is an outdated concept and has been proven to not be the case.  

The traditional view that C. ladon has a spring brood (“Spring Azure”) that produces a summer brood (“Summer Azure”) is strong anchored in what is considered to be the authoritative work of William Henry Edwards.  Edwards performed extensive rearing of Celastrina in West Virginia but did not realize that ANY univoltine species of Azure (ladon and neglectamajor, but also nigra, idella and lucia) reared indoors will usually produce non-diapausing chrysalids that eclose as a second annual generation.  It is difficult to get any Azure chrysalis to diapause through winter.  The right combination of temperature, temperature fluctuation, daylight and humidity, as well as other unknown factors, strongly influence the ability to diapause.  Thus, “lab”-generated summer broods of ladon, neglectamajor, nigra and lucia produce unique, artificially-produced phenotypes that DO NOT occur in nature, nor are they =C. neglecta.  This confused Edwards’ results and he eventually (erroneously) considered ladon, neglecta and neglectamajor all the same species.  Fact is that ladon males bear a unique wing scale structure different from ALL other Celastrina (except sister species C. nigra).  This wing scale structure transfers over to false (lab-produced) summer generation. 

Thus, we have learned that there are TWO types of “spring” Azures in this region:

1) C. ladon – univoltine species flying in April in this region that does NOT produce a summer form.

2) C. neglecta – multivoltine species first emerging in late winter in this region, that produces multiple summer generations. 

Ladon and neglecta may fly together at any one location in our region, or one to the exclusion of the other.  This confuses many people.  These species (also nigra, lucia, idella and neglectamajor) cannot reliably be differentiated by their undersides.  The uppersides are key.  Unfortunately, sight records cannot be accepted in most cases, though in the immediate area around Washington D.C. odds are that any spring-flying Azure will be Summer Azure.  With extensive practice and “quality control” (netting for confirmation or lucky photos of dorsal views), one can, however, learn to confidently differentiate them based on a combination of subtle wing characters (general “look”), flight behavior, hostplant association, habitat, or known location.

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