Genus Anosia 



Chrysalis. — The chrysalis is stout, cylindrical, rapidly taper- 

 ing on the abdomen, and is suspended from a button of silk by 

 a long cremaster. The color of the chrysalis is pale green, orna- 

 mented with golden spots. 



The larvae of the genus Anosia feed for the most part upon 

 the varieties of milkweed (Asclepias), and they are therefore 

 called " milkweed butterflies." There are two species of the 

 genus found in our fauna, one, Anosia plexippus, Linnaeus, which 

 is distributed over the entire continent as far north as southern 

 Canada, and the other, Anosia Berenice, Cramer, which is con- 

 fined to the extreme southwestern portions of the United States, 

 being found in Texas and Arizona. 



(i) Anosia plexippus, Linnaeus, Plate VII, Fig. I, $ (The 

 Monarch). 



Butterfly. —The upper surface of the wings of this butterfly is 

 bright reddish, with the borders and veins broadly black, with 

 two rows of white spots on the outer borders and two rows of 

 pale spots of moderately large size across the apex of the fore 

 wings. The males have the wings less broadly bordered with 

 black than the females, and on the first median nervule of the 

 hind wings there is a black scent-pouch. 



Egg.— The egg is ovate conical, and is well represented in 

 Fig. 4 in the introductory chapter of this book. 



Caterpillar.— -The caterpillar is bright yellow or greenish-yel- 

 low, banded with shining black, and furnished with black fleshy 

 thread-like appendages before and behind. It likewise is well 

 delineated in Fig. 16, as well as in Plate III, Fig. 5. 



Chrysalis.— The chrysalis is about an inch in length, pale 

 green, spotted with gold (see Fig. 24, and Plate IV, Figs. 1-3). 



The butterfly is believed to be polygoneutic, that is to say, 

 many broods are produced annually; and it is believed by writers 

 that with the advent of cold weather these butterflies migrate 

 to the South, the chrysalids and caterpillars which may be un- 

 developed at the time of the frosts are destroyed, and that 

 when these insects reappear, as they do every summer, they 

 represent a wave of migration coming northward from the 

 warmer regions of the Gulf States. It is not believed that any 

 of them hibernate in any stage of their existence. This insect 

 sometimes appears in great swarms on the eastern and southern 

 coasts of New Jersey in late autumn. The swarms pressing 



82 



