58 BULLETIN 107, U. S. DEPARTMENT OF AGKICULTUKE. 



On June 29 the writer made the photographs reproduced in Plate V. 

 Figure 1 shows the growth at a point in the field where the chickens 

 were allowed to do their first work after the cutting of the crop. 

 The second crop responded immediately, and some of the stalks were 

 9 to 10 inches high. The stake shown in the foreground is about 

 3 inches high. Figure 2, taken on the same day, shows the bare and 

 apparently dead stubble of the first crop at a place farthest from the 

 colony houses where the chickens had not been feeding. 



There may be danger when a limited area is overstocked with 

 chickens that their feeding on the growing crop will impair its prog- 

 ress, but by a judicious scattering and moving of the broods these 

 young birds may be used to excellent advantage. They not only 

 materially benefit the subsequent crop of alfalfa, but also find an 

 abundant supply of animal food. 



OTHER VERTEBRATE ENEMIES OF THE WEEVIL. 



As toads (Bufo lentiginosus woodhousei) were abundant in well- 

 watered fields, and frogs (Rana pipiens) were often found in alfalfa 

 adjacent to ditches, an investigation was made of their food habits, 

 and it was found that both were feeding on the weevil. A sala- 

 mander (Ambystoma tigrinum) collected in 1911 had eaten one adult. 

 A blue racer (Zamenis constrictor flaviventris) collected north of 

 Salt Lake City, and another taken near Bountiful, had failed to eat 

 any. Mr. E. G. Titus records 1 horned "toads" (Phrynosoma spp.), 

 swifts (Lacertilia), and a small garter snake (Eutcenia sp.) as 

 enemies. He also mentions having found a shrew (Soreos sp.) which 

 had fed on a single weevil. The stomach of one of these, a Sorex 

 obscurus, collected by the writer near Midvale contained none. 



As a fairly good series of stomachs of both the Rocky Mountain 

 toad and the leopard frog were secured, a detailed account of their 

 relation to the weevil follows. 



ROCKY MOUNTAIN TOAD. 



(Bufo lentiginosus woodhousei.) 



Toads are essentially nocturnal, especially during the hot, dry 

 months of summer at the altitude of the Salt Lake Valley. Although 

 on cool, cloudy days they may be abroad in alfalfa fields, ordinarily 

 they seldom feed much before sundown or after the morning sun has 

 dried the dew. 



As an enemy of the alfalfa weevil the Eocky Mountain toad ren- 

 ders its best service in the destruction of breeding adults during 

 spring and early summer. Later in the year the bulk of the larvaa 



iBull. 110, Utah Agr. Coll. Exp. Sta., p. 49, Sept., 1910. 



