394 ANNUAL REPORT SMITHSONIAN INSTITUTION, 193 5 



vary greatly in abundance. Some are very common, others are 

 frequent, but never common, and a few are always rare. 



The caterpillars feed on a very great variety of different plants, 

 though mostly on shrubs or trees; only a few feed on herbaceous 

 plants. The orange family (Rutaceae) is especially the favorite, 

 and in every region where oranges are grown one or more kinds 

 of fluted swallowtails are more or less a pest upon them. More or 

 less strongly aromatic plants belonging to the laurel, magnolia, 

 carrot, and aster families (Lauraceae, Magnoliaceae, Apiaceae, and 

 Asteraceae) are also favored, and a few species are more or less of 

 a pest upon parsley, parsnips, celery, and related plants (Apia- 

 ceae). But, besides these aromatic plants, very many other kinds 

 in a great number of different families are also fed upon by the 

 caterpillars of the fluted swallowtails. 



Many species feed only on a single kind of plant, some will feed 

 on several closely related or chemically similar plants, and a few 

 are general feeders. One of the most remarkable is our yellow 

 swallowtail {Papilio glaucus), which is equally at home on a great 

 variety of plants belonging to more than a dozen different families. 



Fluted swallow-tails are cosmopolitan, and range much farther 

 to the northward than the species of the other sections. In Europe 

 one and in North America two cross the Arctic Circle. But the 

 great majority are tropical. 



Though none are so large as the giant Aristolochia swallowtails 

 of New Guinea and adjacent islands, some of the fluted swallow- 

 tails are of imposing size. The largest of all {Papilio antiniachus) ^ 

 from 9 to 12 inches in maximum expanse, is found in tropical west 

 Africa. This is a curious-looking butterfly, with the fore wings 

 very long and narrow. The female, which is very rare, is much 

 smaller than the male, just under 6 inches in expanse. The largest 

 swallowtail in America, Papilio homeims of Jamaica, nearly 7 inches 

 in expanse and with very broad wings, is a member of this section. 

 But this section also includes some of the smallest species of Papilio. 



A number of fluted swallowtails are more or less perfect imita- 

 tions of various other kinds of butterflies. Some are imitations of 

 Aristolochia swallowtails, others of milkweed butterflies or their 

 allies, or of heliconians. This imitation may be confined to the 

 females, or it may include both sexes. 



OUR NATIVE FLUTED SWALLOWTAILS 



Nature has treated us exceptionally well in the matter of fluted 

 swallowtails, for no less than 18 different lands occur within our 

 borders — if we include Alaska. And some of these are unusually 

 interesting. 



