When butterfly identification was less complicated

Bob Bowles

Northern azure, Celastrina lucia forma violacea, at Mayer’s Marsh near Barrie May 13. Ten years ago, this would have been called a spring azure, Celastrina ladon forma violacea. What will it be called 10 years from now?

JOHN WRIGHT/SUBMITTED Northern azure, Celastrina lucia forma violacea, at Mayer’s Marsh near Barrie May 13. Ten years ago, this would have been called a spring azure, Celastrina ladon forma violacea. What will it be called 10 years from now?

Great naturalists of the past did not have the problems modern naturalists have with all the recent technology changes. Carl von Linnaeus (1707 -78) didn’t have all the subspecies and forms we have today when he first started to document and name the species. Alfred Russel Wallace (1823 to 1913) didn’t have to enter all of his species on eBird as he travelled around the world with his shotgun. Henry Walter Bates (1825-92) didn’t have iNaturalist on his iPhone on his trips down the Amazon River. Charles Robert Darwin (1809-82) didn’t have to worry about DNA analysis on all those finches from the Galapagos Islands.

It is only within the past 20 years things have become harder for the naturalist.

I support my case with my history of the study of butterflies. I first became interested in butterflies in 1980, after being fairly confident with my bird, plant and mushroom identification skills. A Field Guide to the Butterflies of Eastern North America, by Alexander Klots, 1951 copyright and renewed in 1979, was the first butterfly guide purchased for my studies and it still sits in my home library. It had only one species of tiger swallowtail recorded for Ontario, the eastern tiger swallowtail, Papilio glaucus, with two subspecies, Canadensis in the north and glaucus in the south. It listed only two species of crescent for Ontario – the pearl crescent, Phyciodes tharos, and the tawny crescent, Phyciodes batesii. Today we could have two species of tiger swallowtails (maybe) and perhaps three or four species of crescents in Ontario. I doubt if this is the case. I wrote about the crescents last year in this column and the swallowtails two years ago. In this article, I will only cover the several changes for the spring azure.

Klots listed only one species, Lycaenopsis argiolus, with two valid subspecies for Ontario using the old European name. A single early subspecies in the north with only one generation a year, heavily marked beneath with dark brown patches called lucia. A subspecies in the south with two or three generations a year with three different forms, some heavily marked with the patch and margin, some with just the margin and some with no dark marking below at all.

The Butterflies of North America, A Natural History and Field Guide, by James A. Scott, published in 1986, became the standard reference of the time. It made no changes to the tiger swallowtails but listed a larger crescent in the north called orange crescent, Phyciodes morpheus, and the pearl crescent, Phyciodes tharos, in the south, for Ontario. The spring azure was changed from Lycaenopsis to Celastrina and, still, only one species, argiolus, but four subspecies in North America, two in the west, one in the south and only one, ladon, for Ontario. It had several seasonal forms with a dark central patch on the lower hindwing called lucia, only a dark margin but no patch called marginata, both the dark patch and margin called lucimargina or just small black dots called violacea. By late May, there is a second flight with small, dark spots on under hindwing and upper wings mostly white called neglectamajor. Another later flight even whiter called neglecta. See where we are going with these blue azures?

Two articles, Pratt et al., 1994, and Wright, 1995, made a strong case for the existence of six species of azures in North American. Three of these were in Canada. They proposed what we had called the second generation of the spring azure was actually a different species, the summer azure, Celastrina neglecta (the old name for the late-summer form of the spring azure). The third species was just given a common name, the cherry gall azure, which is a late generation, that, as a caterpillar, eats the galls on cherry leaves. It was not formally described until 2005 and given the name Celastrina serotina. It was similar to the spring azures but flies as an adult a few weeks later, after the flight of the spring azure. Now, early azures in late April and May were spring azures, while those recorded in July and August were summer azures and those few in between were cherry gall azures.

Some other references I used at this time were Ontario Butterfly Atlas 1991 by Anthony Holmes, Quimby Hess, Ron Tasker, Allan Hanks, Toronto Entomologists Association Summaries of Lepidoptera Encountered in Ontario from 1987 to 2005, North American Butterfly Association Seasonal Counts Summary Reports from 1996 to 2008, and Butterflies through Binoculars for Eastern North America by Jeffrey Glassberg, 1999, but The Butterflies of Canada by Ross Layberry, Peter Hall and Don Lafontaine published in 1998 became the standard Canadian butterfly reference.

A Catalogue of the Butterflies of the United States and Canada, Journal of Research on the Lepidoptera by Jonathan P. Pelham, published in 2008, made another change to the spring azure. The spring azure, Celastrina ladon, was divided into two species, with our northern subspecies declared to be a species, Celastrina lucia, with Celastrina ladon now occurring only in the U.S.

The ROM Butterflies of Ontario by Peter Hall, Colin Jones, Antonia Guidotti and Brad Hubley, published in 2014, listed three species of Celastrina: spring azure, Celastrina lucia, cherry gall azure, Celastrina serotina, summer azure, Celastrina neglecta.

What Azure blues occur in Canada? A reassessment of Celastrina Tutt species (Lepidoptera, Lycaenidae) by B. Christian Schmidt and Ross A. Layberry published online April 26, 2016, determined larval rearing, phenology and seasonal emergence patterns showed no evidence of Celastrina serotina as a separate gall-feeding species distinct from Celastrina lucia, so removed cherry gall azure as a species. The endangered Celastrina ladon, which feeds on eastern flowering dogwood, is confirmed at only three sites in southwestern Ontario and now recorded as part of the Canadian fauna. The common name for this species is spring azure and the more common and widespread Celastrina lucia, once known as the spring azure, is now called the northern azure.

The Canadian Celastrina fauna is revised to consist of four species: Celastrina lucia, northern azure in all provinces and territories, Celastrina neglecta, summer azure in southern Ontario to eastern Alberta, Celastrina ladon, spring azure in the Carolinian zone of southernmost Ontario, and Celastrina echo in southern British Columbia and southwestern Alberta. It was so much easier a few years ago, when there was only one species: the spring azure.

Bob Bowles is a local naturalist. He can be contacted at

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