Genus Pieris Schrank (the Whites)
Medium-sized butterflies, generally white in color, marked on both upper and under sides with darker lines and spots. Antennæ clubbed; palpi short, compressed, with the last joint short and pointed. Eggs spindle-shaped, with vertical raised ridges. Caterpillar elongate, head hemispherical, feeding upon cruciferous plants. Chrysalis attached by anal extremity and held in place by a silk girdle; concave on the ventral side, convex on the dorsal side, with a hump-like or keel-shaped eminence on the thorax. Head conical.
An extensive genus, confined principally to the northern hemisphere.
(1) Pieris monuste (Linnæus), Plate XCVI, Fig. 1, ♂; Fig. 2, ♀ (The Great Southern White).
Our figure gives a perfect idea of the upper side of the wings. Hind wing on under side grayish saffron, crossed by a poorly defined pale brown transverse band of spots, the veins pale brown, between them pale brown rays on the interspaces. Expanse 1.65-2.35 inches.
Has a wide range in tropical America. Common in the Gulf States.
(2) Pieris protodice Boisduval & Leconte, Plate XCVII, Fig. 1, ♂; Fig. 2, ♀ (The Common White).
Our illustration of both sexes obviates the necessity for a description. Expanse 1.90-2.15 inches.
Ranges from the Atlantic to the Rocky Mountains, and from southern Canada to the Gulf States.
(3) Pieris napi (Linnæus), variety oleracea (Harris), Plate XCVIII, Fig. 1, ♂; variety pallida Scudder, Plate XCVIII, Fig. 2, ♂; variety bryoniæ (Ochsenheimer), Plate XCVIII, Fig. 3, ♀ (The Mustard White). (See p. 174.)
Occurs throughout temperate and boreal North America, ranging well up to the Arctic Circle; also occurs in the eastern hemisphere, ranging from north Africa to the North Cape, and all over temperate and subarctic Asia. There are a multitude of forms which have been named and described; we give but three of those found in America. Oleracea is a winter form; pallida is the common form; and bryoniæ is a subarctic form found in Alaska, Siberia, and the Alps in Europe.
The species ranges from the Atlantic to the Pacific, and from Alaska to the northern boundaries of the Gulf States. Expanse 1.50-2.00 inches.
(4) Pieris rapæ (Linnæus), Plate XCIX, Fig. 1, ♂; Fig. 2, ♀ (The Cabbage Butterfly). (See p. 174.)
This excessively common insect has been in comparatively recent years introduced from Europe. It first appeared about Quebec in 1860; since then it has come to occupy the continent, and wherever cabbages are grown hundreds of these butterflies may be seen. The loss to gardeners which it causes is estimated to run into millions of dollars annually. It feeds on all the Cruciferæ. The multiplication of P. rapæ has been followed by the partial extinction of our native Pierids just as our birds have disappeared before the English Sparrow. Expanse 2.00 inches.