Part 28

The butterflies of this group are provided in both sexes with six legs adapted to walking. The internal vein of the hind wing is wanting, its place being taken by the submedian. Caterpillars elongate, and in the genus Papilio provided with osmateria or protrusive forking scent-organs, which, when excited, they thrust forth from the pouch back of the head in which they usually lie concealed. Chrysalids in all the genera more or less elongate, attached at anal extremity to a button of silk, and held in place by a silk girdle, but never closely appressed to the supporting surface as is the case in the Erycinidæ and Lycænidæ.

SUBFAMILY PIERINÆ

(THE YELLOWS, SULPHURS, AND WHITES).

For the most part small or medium-sized butterflies, white or yellow in color, with dark marginal markings. The eggs are spindle-shaped, marked with vertical ridges and horizontal cross-lines. The caterpillars are cylindrical, relatively long, generally green in color, with longitudinal stripes. The chrysalids are more or less pointed at the head, with the wing-cases greatly developed on the ventral side, forming a more or less keel-shaped projection upon this surface.

The subfamily is very large, and is well represented in the tropics of both the eastern and western hemispheres. Certain genera are also widely distributed in the colder regions of both the north and the south, among them the genus Colias, species of which occur from Greenland to Patagonia and from the North Cape to the Cape of Good Hope.

GENUS TACHYRIS WALLACE

(THE FLORIDA WHITE).

There are about seventy species in this genus, all of which are found in the Old World, except the one which occurs in our fauna, and which has a very wide range throughout the tropics of the New World.

(1) Tachyris ilaire (Godart), Plate XCV, Fig. 1, ♂; Fig. 2, ♀. Our plate gives such an excellent reproduction of the upper side of the wings of this species that no formal description seems necessary. A melanic form of the female sometimes occurs in which the wings are almost wholly dull blackish on both sides. Normally the under side of the wings in the female is pearly white marked with bright orange at base of fore wings. Expanse 2.50-2.75 inches.

Occurs in southern Florida and throughout tropical America.

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.

GENUS NATHALIS BOISDUVAL

Small yellow butterflies margined with black. Fore wings somewhat narrow and produced; antennæ quite short; upper radial vein in fore wing wanting. There are three species found in the subtropical regions of the New World, one of which invades our territory.

(1) Nathalis iole, Boisduval Plate C, Fig. 1, ♂; Fig. 2, ♀ (The Dwarf Yellow).