60 BULLETIN 107, U. S. DEPARTMENT OP AGRICULTURE. 



Coleoptera, including May beetles, click beetles, darkling beetles, and 

 a few weevils, made up nearly an eighth of the food. Caterpillars 

 (7.9 per cent), spiders (2.1 per cent), and miscellaneous insects (7.8 

 per cent) composed the bulk of the remaining contents. About half 

 of these stomachs contained varying quantities of vegetable rubbish, 

 doubtless swallowed accidentally along with the insects. 



While the toad destroys a considerable number of beneficial ground 

 beetles, some "ladybirds" (Coccinellidse), carrion and dung beetles 

 (Silphida?, Aphodius, etc.), and spiders, it also destroys even greater 

 quantities of insects highly injurious to man. Among these may be 

 mentioned May beetles (the adults of the white grub) ; click beetles 

 (parents of the wireworm) ; various snout beetles, including the 

 alfalfa weevil ; ants ; and caterpillars, including cutworms and army 

 worms. The function of the toad in nature appears to be a rather 

 indiscriminate reduction of insect life coming within reach. These 

 batrachians therefore are especially valuable in the suppression of a 

 terrestrial insect which has become unduly abundant. As such a 

 condition prevails in Utah, every effort should be made to conserve 

 the numbers of this valuable insect desti^er, whose worth is gen- 

 erally underestimated. 



LEOPARD FROG. 



(Rana pipiens.) 



This alert batrachian often may be found in alfalfa adjacent to 

 water and in low, damp fields. Like the toad, it is highly insectivor- 

 ous, but in its more aquatic environment its diet differs somewhat. 

 Conditions are not so favorable for its becoming as effective an enemy 

 of the alfalfa weevil as the toad, although adult weevils hibernating 

 in the brush along ditches may form an appreciable portion of its 

 food. 



Two of the three frogs secured in May had fed on the weevil, in 

 each case a single insect being taken. In bulk this averaged about 

 1 per cent of the food. Ground beetles, earthworms, flies, spiders, 

 and neuropterous insects were the principal other components. 



In June four of the six collected had eaten weevils, which formed a 

 larger proportion of the diet (2^ per cent). One frog had eaten 

 six adults, and larva? had been taken in three of the four cases. 

 Ground beetles, which again figured prominently in the diet, occurred 

 in five of the six stomachs and formed about 40 per cent of the food. 

 A stink bug {Eudchistus varioiarius) , which has been injurious to 

 vegetation, appeared to be a favorite food. It formed 17 per cent 

 of the stomach contents. Click beetles, caterpillars, and spiders made 

 up the greater portion of the remainder. Vegetable rubbish, as in 

 the case of the toad, was freely taken while swallowing insect food. 



