pr/v' C(hM.]/()\ nrri i-:iaLiJS 



The Viceroy is extremely interesting. Although related to the 

 species just mentioned, it resembles to an astonishing degree the com- 

 nu)n and \vide-si)rea(l but only distant!)' related Milkweed or Monarcli 

 lUitterfly. Its general color is a tawny red; the wing veins are out- 

 lined in black, and there is a white-spotted black margin to the wings. 

 vSo far, the description will fit either species but the \"iceroy has a nar- 

 row black band across the middle of the hind wings which the Monarcli 

 lacks. Like other members of its genus it hibernates as a larva. 



During early autumn the Monarch assembles in great swarms 

 in the northeastern I'nited States, large numbers hanging quietly from 

 the leaves and branches of trees and shrubs. These flocks then move 

 southward, suggesting the migration of birds. It is believed, but not 

 positively established, that there are return migrants in the spring. 

 At any rate, none of us have ever found the Monarch in the North 

 during the winter, although its black and yellow banded larvae with 

 their long flexible "horns" and its gold-dotted delicate bluisli-green 

 chrysalids are as easily recognized as is the adult. 



A group in the Museum's Insect Hall represents a portion of one 

 of these autumnal swarms and gives a slight idea of the ^vonderful 

 spectacle they present. The cover design of this leaflet is from 

 a photograph of this group. If the IMonarch were a favorite food of 

 birds it is clear that such a gathering would be dangerous to the species 

 concerned, as birds would find their pre}' ver3^eas3' to catch. The fact 

 that birds do not follow up these swarms has given rise to the belief 

 that the Monarch is distasteful to them. Its larvae feed on the leaves 

 of milkweed, and the acrid juices of their food plant are supposed to 

 impart an acrid flavor not only to the larvae but through the pupae to 

 the adults. This is the wa}^ in which the ^lonarch is supposed to be 

 protected from the birds. 



The bright red color of the adult Monarch is believed to be a notice 

 to birds that it is inedible. On the other hand the Viceroy' is con- 

 sidered suitable bird food but it has acquired — by natural selection 

 or othei^vise — a color very similar to that of the Monarch, and the 

 birds are usually unable to tell the difference so that the Viceroy is 

 protected by mimicking the Monarch. It is interesting in this connec- 

 tion that Viceroys have been found in which the distinguishing black 

 band on the hind wing is nearly or quite absent. 



17 



