Genus Anosia Hübner
Butterfly, large or medium-sized; fore wings triangular, produced; hind wings rounded, the inner margins clasping the abdomen when at rest; apex, outer margins, and veins, dark; male with sex-mark on first median nervule of hind wing. Egg ovate conical, ribbed perpendicularly and horizontally. Larva cylindrical, with long, dark, fleshy filaments before and behind; body usually pale in color, ringed with dark bands. Chrysalis pendant, stout, cylindrical, abdomen rapidly tapering, and ending in long cremaster; pale, with metallic spots.
A large genus, many species being found in the tropics of both hemispheres, but only two in the United States. The insects are “protected,” being distasteful to other animals, thus escaping attack.
(1) Anosia plexippus (Linnæus), The Monarch, Plate I, ♂; Plate C, Fig. g, egg; Figs. a-c, larva pupating; Fig. d, chrysalis.
Upper side of wings reddish brown, apex, margins, and veins black, under side paler; a double row of whitish spots on outer borders, apex crossed by two bands of light spots. Expanse of wings 3.25 to 4.25 inches. Egg pale green. Caterpillar feeds on milkweeds, and is found in Pennsylvania from June onward. Chrysalis pale green spotted with gold.
Breeds continuously. As summer comes the butterflies move north, laying eggs. The insect spreads until it reaches its northern limit in the Dominion of Canada. In fall it returns. Swarms of the retreating butterflies gather on the northern shores of Lakes Erie and Ontario and in southern New Jersey. Recently the Monarch has become domiciled in many parts of the Old World.
(2) Anosia berenice (Cramer), The Queen, Plate II, ♀.
Smaller than the Monarch; the ground-color of the wings livid brown. The markings, as shown by the Plate, are somewhat different from those of the preceding species. Expanse 2.5 to 3 inches.
This butterfly does not occur in the North, but ranges through New Mexico, Texas, Arizona, and southward.