The 2016 Azure Blues Article by Schmidt and Layberry: What a Butterfly Watcher Needs to Know

Alan Macnaughton

This is a summary of “What Azure blues occur in Canada? A re-assessment of Celastrina Tutt Species (Lepidoptera, Lycaenidae)” by Chris Schmidt and Ross Layberry, published in ZooKeys, April 2016.

The species

Their main conclusion is that three species of azure blues (genus Celastrina) occur in Ontario:
- C. ladon
- C. neglecta
- C. lucia

The species C. serotina (commonly known as the Cherry Gall Azure) does not occur in Ontario. The species C. ladon has not been previously noted to be found in Canada.

Typical locations

The three species occur in different parts of Ontario. In particular, consider three locations: Ottawa, Kitchener and Long Point.

* Ottawa -- One species occurs: C. lucia. There are two broods.

* Kitchener -- Two species occur: C. lucia and C. neglecta. Each species has two broods. C. lucia is the first to come out in the spring; it may be local rather than widespread. C. neglecta is most common in the summer.

* Long Point -- three species occur: C. ladon, C. lucia and C. neglecta.

Further research is needed to determine exactly where C. ladon is found. Possibly it is found elsewhere in the Carolinian forest zone. The primary larval host is Eastern Flowering Dogwood.

Common names

Schmidt and Layberry use the following common names, which is different from current usage.
- C. ladon: Spring Azure (possibly because this is believed to be the only one of the three species that occurs only in the spring)
- C. lucia: Northern Azure (because this is the only species in the genus that is found in boreal and sub-arctic regions)
- C. neglecta: Summer Azure (possibly because this species is particularly abundant in the summer, although it also occurs in the spring)

Maps of locations of 150 specimens and photographs examined by the authors

Figure 7 from the article: C. ladon map

Figure 8 from the article: C. neglecta map

Figure 9 from the article: C. lucia map

What time of year are the different species expected to be found?

Figure 4 from the article: seasonal abundance of C. lucia in eastern Ontario

Figure 6 from the article: predicted seasonal abundance the 3 azure species in southern Ontario (west of about Kingston)

Photographs of the three species: male specimens

C. neglecta is similar to the summer brood of C. lucia, but has darker, smaller and more sharply defined ventral spots, more reduced marginal markings, a solid white dorsal hindwing fringe, and a less evenly checkered forewing fringe.

C. ladon male specimens (3)

C. lucia male specimens, spring generation (3)

C. lucia male specimens, summer generation (5)

C. neglecta male specimens (4)

Photographs of the three species: female specimens

C. ladon female specimens (2)

C. lucia female specimens, spring generation (3)

C. lucia female specimens, summer generation (3)

C. neglecta female specimens (3)

Using a microscope to tell C. ladon apart from the other two species (which is the best way to do so)

Figure 1a: C. ladon male forewing, showing distinctive overlapping scales and lack of androconial scales

Figure 1b: C. lucia male forewing, showing pale, underlying androconial scales typical of this species and C. neglecta

Conclusions

- C. serotina does not occur in Ontario or Quebec, and probably not in Canada

- C. lucia has at least two flights, spring and summer; it is the most common Celastrina from about Toronto northwards

- C. neglecta also has at least two flights, but each is later than the respective lucia flights; it is the most common Celastrina from Toronto southwards

- C. ladon is a Carolinian forest specialist that has only one spring flight, about the same time as C. lucia.

Research Needs

Voucher specimens are needed from virtually anywhere in southern Ontario. This would go towards assessing variation of the various species and broods, and establishing more accurate ranges.

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