by Larry de March
Question Mark (2 recorded)
Eastern comma (203 recorded)
Satyr comma (49 recorded)
Gray comma (491 recorded)
Green comma (371 recorded)
Hoary comma (1 recorded)
Compton tortoiseshell (1461 recorded)
Milbert’s tortoiseshell (329 recorded)
Mourning cloak (961 recorded)
On a warm day in early April a welcome flash of orange could be one of our overwintering Comma species. The commas, genus Polygonia, comprise a group of similarly-marked medium-sized orange butterflies with black spots and dark, scalloped wing margins. Eastern comma and Question Mark have summer forms with almost completely black hind wings. Gray comma has a summer form with a larger brown area on the hind wings. Ventrally the wings are generally mottled brown, resembling dry leaves. Their common name derives from the small, white comma (or question mark) on the underside of the hind wing; its shape can be helpful in identification. Polygonia caterpillars are covered in sharp, branched spines.
Above: The shape and general pattern of this Green Comma are typical of the group – Whiteshell P.P. 15 July 2007. Photo by Larry de March
The uncommon Question mark migrates to Manitoba in spring and doesn’t overwinter here. Its caterpillars feed primarily on thistles and hops and they can turn up almost anywhere including in Winnipeg. Of the other Commas, Eastern and Satyr commas are also primarily nettle feeders with the former found in forests and near stream edges where nettles grow; the latter species can be found almost anywhere in and near wooded areas and both overwinter as adults. Gray and Green Commas are fairly common in forested areas. Gray comma caterpillars feed on the leaves of birch, elm and currants whereas the Green comma caterpillars favour the foliage of willow, birch and alder among other plants. Both overwinter as adults. Hoary comma, which is annoyingly similar to Gray comma, has a more northerly distribution so is rare in our study area. Its caterpillars likely feed on currant and skunkberry leaves and adults overwinter.
Above: The shape of the wings identifies this butterfly as a Comma; the dorsal pattern and colours identify it a Green Comma. Whiteshell P.P. 18 May, 2016. Photo by Larry de March
Formerly, there were 3 species in Manitoba placed in the genus Nymphalis, all medium sized and widely differing in appearance. Recently Milbert’s tortoiseshell was put in the mostly Eurasian genus Aglais. It is likely that the first butterfly one sees in spring, even when there is snow on the ground in March, will be one of these three beauties. It is amazing that these coldblooded creatures can fly even at a temperature of only 4º C, when in summer many other species stay grounded at much warmer temperatures. Early in spring before plants are flowering they can be found feeding on sap oozing from injured trees. They can also be found puddling on wet sand or dung. Their caterpillars also have threatening spines.
Above: Milbert’s Tortoisehell is arguably one of the most beautiful butterflies found in Manitoba. Sandilands, 11 October, 2011. Photo by Larry de March
The common Compton tortoiseshell is a widely distributed northern species whose range covers not only a large part of Canada and the northeast United States but an area from Eastern Europe to the Asian Pacific coast. It is another mainly orange butterfly which resembles an oversized Comma, complete with a small white punctuation mark on the ventral side of the hind wing. It overwinters as an adult. They are found primarily in forests including riparian forests where the caterpillars feed on alder, willow, poplar and birch. The less common Milbert’s tortoiseshell is easily identifiable with a large brown triangular basal area on its wings bordered by a broad band which shades from yellow to bright orange. This band gave rise to the seldom-used, but more expressive name, Fire-rim tortoiseshell. Another nettle feeder, this species overwinters as a pupa or adult.
Above: Butterflies which overwinter as adults can become extremely worn like this Compton Tortoisehell feeding on tree sap. Winnipeg, 16 April, 2010. Photo by Larry de March
The Mourning cloak is another species we share with Eurasia. Its British name, Camberwell Beauty is far more uplifting than the Mourning Cloak name used by North Americans and speakers of other Germanic languages. A common species, its adults can be seen early in the spring when it comes out of hibernation and late in the fall before they find a place to spend the winter. They are easily identified by their maroon/brown wings bordered with blue spots and a yellow band which can fade to white with age. It is a ubiquitous species which feeds on willow, cottonwood, elm and birch leaves.
Above: This Mourning Cloak caterpillar is typical of the caterpillars of Commas and related species. Whiteshell P.P., 29 June, 2007. Photo by Larry de March
Above: The chrysalis of Mourning Cloak is similar to those of other species in this group. Whiteshell P.P., 05 July, 2007. Photo by Larry de March
Above:The Mourning Cloak is one of our easiest to identify butterflies. Winnipeg, 09 July, 2007. Photo by Larry de March