6o SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 85 



best protected forms. Nymphalidae and Hesperiidae are most numer- 

 ously represented among the adults taken. 



The 87 records of imago butterflies are distributed among 15 species 

 of birds, but all save 18 of them pertain to a single hhxl, the pigeon 

 hawk. The specimens of this hawk examined were taken on their 

 southward migration at a point that is in the migration path of butter- 

 flies also, so that opportunities for catching these insects were at the 

 best. (It is worth noting here that dragonflies, swallows, swifts, and 

 bats also using this same migration track were preyed upon by the 

 pigeon hawk.) In this case as in many others the al)undance and 

 availability of prey is shown to have great influence upon the choice 

 of food by birds. Amid the butterflies, this hawk preyed upon them ; 

 elsewhere we have no record of its doing so. Clearly the other birds 

 (14 species) in whose stomachs butterflies have been found (18 

 records) are only occasional predators upon them. This is only what 

 would be expected, for ordinarily butterflies, numerically, are no 

 considerable part of the insect fauna ; when under extraordinary cir- 

 cumstances they do become over-abundant they are more frequently 

 devoured by birds. Thus Bryant found Brewer's blackbird eating 

 large numbers, and three other species of birds smaller numbers, of 

 Eugonia calif ornica during an unusual outbreak of the species. (Con- 

 dor, vol. 13, pp. 195-208, Nov. 191 1.) 



Summary of identifications of Lepidoptera : Total number 18,487 ; 

 percentage of identifications among those of all insects, 9.6831 ; per- 

 centage of species in this group among the whole number of insect 

 species, 15.6180. 



Other enemies. — For the most part fishes are only casual devourers 

 of Lepidoptera, getting chiefly larvae which fall into the water, most 

 of which would perish anyway. However, gamy fishes such as trout 

 snap up adults that incautiously fly near the surface of the water. 



Bullfrogs have been observed feeding freely on Papilio tiirnus 

 adults (Mallonee, Science, 1916, pp. 386-387) and half a dozen leopard 

 frogs have been noted as eating 500 Argyniiis aphrodite in a week 

 (Shiras, Nat. Geogr. Mag., 1921, p. 174). Kirkland found cutworms. 

 tent and other caterpillars to compose 28 per cent of the total food of 

 149 toad stomachs examined by him, and Munz found lepidopterous 

 larvae in stomachs of four species of frogs. In 209 leopard frogs, 

 Drake found one imago, one chrysalid, and 121 larvae of Lepidoptera. 

 Surface reports remains of Lepidoptera in stomachs of eight species 

 of salamanders, one toad, and nine frogs. In the Tropics lizards are 

 said to be important enemies of adults of this order and our lizards 



