60 BULLETIN 15 7, U. S. NATIONAL MUSEUM 



ticularly grapes, have an irresistible attraction for them, and on 

 these they sometimes feed to a state of advanced intoxication. 



Many kinds of butterflies tend to gather and to remain in certain 

 areas of limited extent. Boggy hollows in open country which are 

 more or less protected from the wind, especially when they support 

 an abundance of such plants as the red milkweed {Asclepias in- 

 carnata)^ buttonbush {G efhalanthm ocddentalis) , honeset {Eupa- 

 torium perfoUatum), and joe-pye-weed {E. purpurewm) always are 

 productive. Butterflies stray into these and are induced to remain 

 by the dampness and the flowers. 



Clover fields on exposed hillsides, especially if the crest of the hill 

 be wooded, are particularly favorable. The butterflies of the open 

 country drift up the hill and tend to remain more or less near the 

 woods, which, however, they do not enter. The woodland butter- 

 flies stray into the field in order to feed upon the clover or play 

 about the bushes along the borders of the woods. The borders of 

 woodlands are a favorite mating ground for many different kinds of 

 butterflies. 



Roadsides, whether in open country or in woods, are always good 

 collecting grounds, though yielding mostly males. Many woodland 

 species, which ordinarily remain high in the trees or which are 

 exceedingly active and difficult to catch, delight in sunning them- 

 selves on the leaves of bushes growing along the roads and in the 

 glades and clearings, or even on the ground. Especially is this true 

 early in the morning or after a sudden shower. 



In spring the best days for collecting butterflies are warm and 

 sunny days with little wind. In summer the best results are to be 

 obtained on sunny days following evening thunderstorms. 



Certain butterflies are to be found most readily by looking for 

 their food plants and then visiting these at the proper season. Hack- 

 berry trees {Celtis occidentalis) support the hackberry butterfly 

 {Ghlorippe celtis), the tawny emperor {Chlorippe clyton), and the 

 snout or beaked butterfly {Lihythea hachnianii) , and also, together 

 with other mostly related plants, the common angle wings {PoJy- 

 go7iia comma and P. interrogationis) and the Camber well beauty 

 {Vanessa antiopa). Small willows in moist meadows support the 

 viceroy {Basilarchia arcMppus) and sometimes the Camberwell 

 beauty, and both of these are often to be found about small poplars 

 growing on hillsides. An extensive growth of sheep sorrel {Rutnex 

 acetosella) in a barren field is a certain indication of the occurrence 

 of the little copper {Ghrysophanus phlaeas hypophlaeas) . 



The redcedar {Juniperus mrginiatius) supports the olive hair- 

 streak {Mitoura gryneus), while the banded elfin {Incisalia niphon) 

 is only to be found near pines. The turtlehead or balmony [Ghelone 



