Butterflies of the Adirondack Mountains:
Pink-edged Sulphur (Colias interior)

Butterflies of the Adirondacks: Pink-edged Sulphur in the Paul Smiths VIC Butterfly House (6 July 2013)

This page is no longer being updated.  For an updated version of this material, see: Pink-edged Sulphur (Colias interior).

Identification: The Pink-edged Sulphur (Colias interior) is a medium-sized yellow butterfly that may be seen in the Adirondack Mountains of upstate New York in June and July. It is a member of the Pieridae family. ^{[1] [2]} The wings are rounded. ^[3] Both males and females have conspicuous pink wing edges. ^{[4] [5] [6]} The upper side is bright yellow with a black border. ^{[7] [8]} However, this butterfly normally rests with its wings closed, so the upper side is rarely seen. The underside of the hind wing is a clear yellow with a single silver cell spot circled in pink. ^{[9] [10]} It has no postmedian spots. ^[11] The wing span 1 1/2 to 2 5/8 inches.

The Pink-edged Sulphur is easily confused with the very similar Clouded Sulphur and the Orange Sulphur, both of which are also seen in our part of the Adirondacks.

• The Clouded Sulphur normally has dark spots on the underside of the hind wing. ^{[12] [13]} In addition, the center spot on the underside of the hind wing is usually double. ^[14]
• The Orange Sulphur also has a series of dark spots on the underside of both wings. However, there is normally an orange patch on the fore wing, which distinguishes it from the Clouded Sulphur.
• The Pink-edged Sulphur has conspicuous pink wing edges and lacks the dark spots on the underside of the wings.^{[15] [16]} The center spot on the hind wing is single, rather than double. ^{[17] [18] [19] [20]}

Life History: Males patrol with a slow flight for females. ^[21] The female Pink-edged Sulphur lays her eggs in midsummer on blueberry leaves. ^{[22] [23]} The eggs are white, turning orange or greenish yellow soon after being laid. ^{[24] [25]} The larva is yellow-green with light stripes on the back and a white lateral stripe with a red link through it. ^{[26] [27]} The young caterpillars hibernate and overwinter. ^{[28] [29]} Most feeding occurs the following spring. ^{[30] [31]} Caterpillar hosts include various blueberry plants in the heath family. ^{[32] [33] [34]} The adults sip flower nectar and mud. ^{[35] [36]}

Butterflies of the Adirondacks: Pink-edged Sulphur in the Paul Smiths VIC Butterfly House (12 July 2013)

Habitat and Range: Pink-edged Sulphurs make their homes in shrubby openings in woods, bogs, meadow edges, forest openings, or scrub areas where plants of the heath family grow. ^{[37] [38] [39]} This butterfly may often be found in recovering burns or logged sites. ^[40] The Pink-edged Sulphur is a boreal zone species which occurs in Canada and the northern parts of the US. ^{[41] [42]} The range of this butterfly is much more limited than that of the Clouded Sulphur. ^[43] It may be found from British Columbia and eastern Oregon east through the Great Lakes area to northern New England and the Adirondack Mountains. ^{[44] [45] [46]}

Flight: The flight period for Pink-fringed Sulphurs throughout its range is from late May into early September, ^{[47] [48]} peaking in early July to early August. ^[49] There is only one brood. ^{[50] [51] [52] [53]} This butterfly's flight period in the Adirondack Park has not been established. It is, however, a fairly frequent guest in the Paul Smiths VIC Native Species Butterfly House. in 2012, The Pink-edged Sulphur was recorded as present from the day of the Butterfly House opening (9 June) to 25 July. ^[54] In 2013, Pink-edged Sulphurs were present in the Butterfly House during the month of July. ^[55]

References

• Susan Grimm Hanley. Interpretive Naturalist, Paul Smith's College Native Species Butterfly House. Species Logbooks.
• Butterflies and Moths of North American. Species Profiles. Confirmed sightings: 7/6/13, 7/12/13, 7/12/13
• Government of Canada. Canadian Biodiversity Information Facility. SpeciesBank
• ENature. Field Guides.
• Iowa State University. Department of Entomology. BugGuide.
• University of Alberta. Department of Biological Sciences. E.H. Strickland Entomological Museum. Colias interior.
• Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. The Butterflies of Canada (University of Toronto Press, 1998), pp. 113, Plate 9.
• National Audubon Society. Field Guide to Butterflies (New York: Alfred A. Knopf, 1981), pp. 380-381.
• Jim P. Brock and Kenn Kaufman. Kaufman Field Guide to Butterflies of North America (Houghton Mifflin, 2003), pp.62-63.
• Paul A. Opler. A Field Guide to Eastern Butterflies (The Peterson Field Guide Series, Houghton Mifflin Company, 1992,1998), pp. 60-61, 159.
• James A. Scott. The Butterflies of North America. A Natural History and Field Guide (Stanford University Press, 1986), pp. 199-200.
• Jeffrey Glassberg. Butterflies through Binoculars. The East. A Field Guide to the Butterflies of Eastern North America (Oxford University Press, 1999), p. 104, Plate 28.
• Paul A. Opler and George O. Krizek. Butterflies East of the Great Plains: An Illustrated Natural History (The Johns Hopkins University Press, 1984), p. 67, Plate 8.
• Jeffrey Glassberg. Butterflies through Binoculars. A Field Guide to the Butterflies in the Boston-New York-Washington Region (Oxford University Press, 1993), p. 30, Plate 40.