DEPARTMENT OF AGRICULTURE BULS. 926-950. 



Department Bulletin No. 936. — Wild Ducks and Duck Foods of the 



Beak River Marshes, Utah : Page. 



Introduction 1 



General account of the Bear River marshes ; 2 



Discussion of waterfowl 3 



Breeding species and their abundance 3 



Habits and activities after the nesting season 6 



Fall migration 9 



The shooting season 10 



Food supplies attractive to wild ducks 10 



Vegetable foods 10 



Animal foods 14- 



Other conditions affecting waterfowl 16 



Agricultural operations 16 



Natural enemies 16 



Conclusions 18 



Department Bulletin No. 937. — Cooperative Grain Marketing : 



Introduction 1 



The farmers' elevator movement 2 



Early development 2 



Marketing conditions 4 



The United Farmers' Association 5 



Examples of farmers' organizations in Canada 6 



The Saskatchewan Cooperative Elevator Co. (Ltd.) 8 



United Grain Growers (Ltd.) 11 



Terminal elevators 12 



Examples of farmers' organizations in the United States 15 



Local farmers' elevators 15 



Terminal activities 17 



Functions of cooperative grain marketing organizations 18 



Comparisons and conclusions 20 



Department Bulletin No. 938. — Effects of Nicotine Sulphate as an 

 Ovicide and Larvicide on the Codling Moth and Three Other 

 Insects : 



Introduction 1 



Experiments conducted in the laboratory 2 



Effects of nicotine sulphate on eggs and newly hatched larvae of 



the silkworm moth 2 



Effects of nicotine sulphate on eggs and newly hatched larvae of 



the codling moth 4 



Effects of nicotine sulphate on eggs of two other insects _ 8 



Discussion as to how nicotine sulphate acts as an ovicide and 



larvicide 10 



Summary of experiments conducted in laboratory 14 



Experiments conducted in orchards 15 



Experiments performed at Benton Harbor, Mich 15 



Experiments performed at Grand Junction, Colo 16 



Experiments performed at Roswell, N. Mex 17 



Conclusions from field experiments 18 



Literature cited 19 



Department Bulletin No. 939. — The Turkey an Important Factor in 

 the Spread of Gape worms : 



Examination of market chickens and turkeys 1 



Experimental work 3 



Factors in the spread of gapeworms 7 



Investigations on Maryland farms 8 



Significance of turkeys in relation to gapes formerly unrecognized 10 



Turkey the preferred host of the gapeworm 10 



How to avoid losses in chickens 11 



Conclusions 12 



List of references 13 



