Butterflies of the Adirondacks:
Cabbage White (Pieris rapae)
The Cabbage White (Pieris rapae) is a small to medium-sized whitish butterfly  which may be seen in the Adirondack Mountains of upstate New York during much of the summer. It is also known as the Small White and European Cabbage. The latter name is apparently a reference to the fact that this insect (reportedly native to Eurasia and North Africa ) was accidentally introduced to North America from Europe.     This butterfly is said to be the most ubiquitous butterfly in the United States.   
The upper side of the wings are white, with a black patch on the fore wing. The female has two submarginal black spots; the male has one. From below, both wings are evenly yellow-green or gray-green.  
Sources conflict on the character of its flight, with some stating that its flight is strong but erratic, while others contending that the flight of this butterfly is straight and constantly fluttering, with minimal gliding. Male Cabbage Whites patrol for females around host plants. Females lay single eggs on the undersides of host leaves. The caterpillar is green with a thin broken yellow line on each side, as well as a thin yellow dorsal line. Caterpillar hosts include many plants in the mustard family. Adult Cabbage Whites consume flower nectar from a wide array of plants including mustards, cabbage, cauliflower, dandelion, red clover, asters, and mints.  
From the ecological standpoint, the Cabbage White is a generalist.  Its habitat includes almost any type of open space, such as bogs, meadows, woods, roadsides, gardens, and suburbs.  The range of this butterfly is from central Canada south through the United States to northwest Mexico. 
The flight period for Cabbage Whites in the New York City area of New York State is from late March to hard frost, although they are most numerous from early June through early September.   In southern Ontario, Cabbage Whites can be found from mid-April to mid-October.  Cabbage White butterflies are present during the summer months in the Adirondack Mountains and were seen in the Paul Smiths VIC Native Species Butterfly House and in the adjacent Butterfly Garden throughout most of the summer of 2012. We had Cabbage Whites in the Butterfly House almost every day that the house was open, except for the first week and one other week. In subsequent years, Cabbage Whites were present from early July through the middle of August.
- Susan Grimm Hanley. Interpretive Naturalist, Paul Smith's College Native Species Butterfly House. Species Logbooks.
- Butterflies and Moths of North American. Species Profiles. Sighting records: 6/16/2012; 6/16/2012; 7/25/2012; 8/8/2012; 9/1/2012; 9/9/2012; 7/6/2013; 7/6/2013; 7/5/2014; 7/19/2014; 8/19/2014.
- Government of Canada. Canadian Biodiversity Information Facility. SpeciesBank.
- Massachusetts Butterfly Club. Massachusetts Butterfly Species List.
- ENature. Field Guides.
- Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. The Butterflies of Canada (University of Toronto Press, 1998), p. 87, Plates 7, 22, and 26.
- National Audubon Society. Field Guide to Butterflies (New York: Alfred A. Knopf, 1981), pp. 360-361.
- Jim P. Brock and Kenn Kaufman. Kaufman Field Guide to Butterflies of North America (Houghton Mifflin, 2003), pp.46-47.
- Paul A. Opler. A Field Guide to Eastern Butterflies (The Peterson Field Guide Series, Houghton Mifflin Company, 1992,1998), pp. 46-47, 50-51, 56-57, 149.
- Jeffrey Glassberg. Butterflies of North America (Michael Friedman Publishing, 2002), pp. 70-71.
- James A. Scott. The Butterflies of North America. A Natural History and Field Guide (Stanford University Press, 1986), p. 216-217.
- Donald and Lillian Stokes. Stokes Butterfly Book. The Complete Guide to Butterfly Gardening, Identification, and Behavior (Little, Brown and Company, 1991), pp. 50-53.
- Jeffrey Glassberg. Butterflies through Binoculars. The East. A Field Guide to the Butterflies of Eastern North America (Oxford University Press, 1999), p. 54, Plate 6.
- Paul A. Opler and George O. Krizek. Butterflies East of the Great Plains: An Illustrated Natural History (The Johns Hopkins University Press, 1984), pp. 59-60.
- Rick Cech and Guy Tudor. Butterflies of the East Coast. An Observer's Guide (Princeton University Press, 2005), p. 77.
- Jeffrey Glassberg. Butterflies through Binoculars. A Field Guide to the Butterflies in the Boston-New York-Washington Region (Oxford University Press, 1993), pp. 28-29, Plates 4 and 5.