I've noticed that several butterfly folks out there are calling the
azures flying around right now (April & May) "Spring Azures" (celastrina
ladon) and entering them as such in iNaturalist. It used to be that all
early spring azures in the northeast were called "Spring Azures", but
current research suggests that there are between 2 and 3 species of
Azures in April and May in New Hampshire. These include the confusingly
named (and possibly non-occurring) Spring Azure (celastrina ladon), the
Northern Azure (celastrina lucia), and the enigmatic Cherry Gall Azure
(celastrina serotina). Identification of these three azures is close to
impossible based on just photos. It's a real mess out there right now!
Specimens collected in Vermont during their 1st butterfly atlas showed
only Northern Azure and Cherry Gall Azure, but DID NOT show any records
of "Spring Azure"! The common early spring flying azure in Vermont is
now called the Northern Azure (c. lucia). This is also the case in
Maine where the most recent publication "Butterflies of Maine and the
Canadian Maritime Provinces" only indicates one species of Azure in the
spring and that is the Northern Azure (they don't show any records of
Cherry Gall Azure). They state that "Spring Azure" has NOT BEEN
CONFIRMED IN MAINE! Both Maine and Vermont now treat nearly all April
and May celastrinas (azures) as Northern Azure (C. lucuia).....with a
few Cherry Gall Azures in Vermont.
Based on this information, it seems likely (or at least possible) that
Spring Azures (C. ladon) do not occur at all in NH!!!! And everything
flying right now may in fact best be called Northern Azure!! The key
problem is that Spring Azure is almost impossible to ID from Northern
Azure without a specimen! ONLY MALES CAN BE SAFELY IDENTIFIED BY
OVERLAPPING SCALE PATTERN UNDER A MICROSCOPE. Yikes! Based on this
alone, we have no idea if "Spring Azures" occur in NH.
THE MAPS IN THE CURRENT FIELD GUIDES (Swift and Kauffman) DON'T REFLECT
THIS. They show Spring Azures (C. ladon) as occurring throughout the
northeast and into southeastern Canada. THIS IS FALSE as specimens from
Canada have shown that Spring Azures don't occur there except for a
couple of records.
The taxonomy is still evolving and the range of the Spring Azure is
still a mystery and it's actually possible there may be other hidden
species out there. I've decided to call my early spring azures as just
"Azure" and enter all of my early spring records from April and May in
iNaturalist as "Holarctic Azures" (Celastrina sp.). If you post to this
list or submit azure photos to iNaturalist during these months, you may
want to follow this procedure until we figure this mess out! Summer
sightings in late June and July are likely a different species "Summer
Azure" (c. neglecta), but that's another problem to sort out, and
another story...
If anyone out there has any more recent updates on research or opinions,
it would be interesting to know about.
Bryan Pfeiffer does a GREAT JOB in discussing this complex on his web
site. Highly recommended. Click on the download PDF file in the first
paragraph.
https://bryanpfeiffer.com/2018/04/02/getting-the-blues/
And if you want to dig deeper, here are some other articles for review:
https://zookeys.pensoft.net/articles.php?id=7882
https://bugguide.net/node/view/41017
Steve Mirick
Bradford, MA