452 The Moths and Butterflies 



cosmopolitan distribution of its food-plant, and finally and most important 

 its inedibility to birds. It secretes in its body an ill-tasting acrid fluid, 

 and birds soon learn to let these disagreeable butterfly morsels alone. For 

 the sake of this immunity another butterfly species, the viceroy, Basilarchia 

 archippus (PI. XI, Fig. i; also Fig. 641), which is not ill-tasting, mimics in 

 extraordinary degree the color pattern of the monarch, so that it must be 

 constantly mistaken for the disagreeable monarch and is passed unmolested 

 by experienced birds. The monarch in the eastern states has a migratory 

 habit not unlike that of birds, great swarms flying south in the autumn to the 

 Gulf states and West Indies, returning north again in the spring, not in swarms, 

 however, but singly. It ranges as far north as Canada. It has, too, a curious 

 habit of assembling in great numbers in a few trees, like blackbirds or crows 

 in a "roost," and hanging there quietly in masses and festoons, many indi- 

 viduals clinging only to each other and not to the branches at all. On cer- 

 tain great pine trees near the Bay of Monterey on the Californian coast I 

 have seen myriads of monarchs thus "sembled." The eggs are laid singly 

 on the leaves of various milkweed species, Asclepias cornuti the favored 

 kind, and hatch in about four days. The larva (Fig. 791) attains its full 

 growth in two or three weeks and is a conspicuous object with its greenish- 

 white body regularly banded with narrow black and yellow stripes; it has 

 two pairs of slender black filaments, one on the second thoracic and the other 

 on the eighth abdominal segment. The beautiful plump chrysalid is pea- 

 green, smooth, and rounded with a few black and gilt spots and bands. The 

 pupal stage lasts from nine to fifteen days. There is but one generation a 

 year in the north, but two appear in the south. The winter is passed by 

 the adult butterfly in the warm region of the subtropics. 



Although the viceroy, Basilarchia archippus, closely resembles the 

 monarch in its red-brown ground-color, black -bordered veins, and small 

 white spots, only one of the half-dozen other species of the same genus is 

 at all like it. This one is B. ftoridensis found in the southern states. The 

 others have a blackish ground-color with the hind wings suffused with 

 greenish blue and a few conspicuous reddish blotches on the under side 

 of both wings, as in the red-spotted purple, B. astyanax, common in the East, 

 or broadly banded with white, as in the banded purple, B. arthemis (PI. X, 

 Fig. 6), of the northeastern states, or have a blackish-brown ground with 

 broad white band and red-brown apex of the fore wings, as in Lorquins 

 Admiral, B. lorquini, of the Pacific states. The larvae of Basilarchia 

 feed on oaks, birches, willows, currants, and various other trees and shrubs, 

 and are odd-appearing caterpillars with numerous prominent tubercles or 

 bosses on the back. 



Beautiful and abundant Nymphalids are the angle-wings, tawny above 

 with black markings, dead-leaf-like below and often with a little silvery 



