BUTTERFLIES OF THE VICINITY OF NEW YORK CITY 



An aberration occurs in the female which is sooty brown, instead of 

 yellow, with the black markings faintly visible (var. glaucus). The 

 female lays her eggs singly on the upper surface of a leaf, and 

 the young caterpillar takes up its abode on the same side, reposing 

 on a bed of silk, which it spins for the purpose of retaining its hold 

 on the smooth surface of the leaf. When disposed, it goes to the 

 edge of the leaf to feed. As the caterpillar increases in size, the 

 leaf is somewhat drawn together, making the animal difficult to dis- 

 cover. It is green, and has on each side of the third segment an 

 irregular oval, greenish-yellow patch edged with black and enclosing 

 a purple spot. At the junctions of the fifth and sixth segments is a 

 transverse, narrow, yellow and black band. It feeds on apple, 

 quince, plum, thorn, cherry, birch, basswood, ash, alder, willow, oak, 

 tulip-tree etc. 



In the Hall of North American Forestry there is a group showing 

 a branch of the tulip-tree bearing male and female butterflies, the 

 caterpillar and the chrysalid of this species, and illustrating the effect 

 the insect has upon the leaves of the tree. 



2. Black Swallowtail {Papilio asterias). 



Very common in open fields, especially where the wild parsnip 

 grows, from May to October, but it is most' common in August. 



