CONTENTS. 



Department Bulletin No. 1026. — Irrigation in Northern Colorado: Pags. 



Introduction 1 



Cache la Poudre Valley 2 



Meteorology 3 



Soils * 5 



Water resources 6 



Seepage return 10 



Drainage conditions 12 



Exchange of water 12 



Water rights. 13 



Distribution from river 19 



Duty of the river 24 



Canal s'v^stems 26 



Gross duty for canals 42 



Farm irrigation 51 



Reservoirs 69 



Summary and conclusions 79 



Department Bulletin No. 1027.- — Poisonous MeTals on Sprayed Fruits 

 AND Vegetables: 



Purpose of investigation 1 



Results of previous investigations 1 



Experimental work 16 



Results of experimental work 18 



Summary 58 



Literature cited 58 



Department Bulletin No. 1028. — Apanteles Melanoscelus, an Imported 

 Parasite of the Gipsy Moth: 



Introduction 1 



Part I — Description and life history 2 



History 2 



Distribution in Europe 3 



Description of species 3 



Methods used in biological work 4 



Life history 5 



Seasonal history 11 



Feeding of parasitized larvae versus nonparasitized larvee 12 



Longevity experiments 12 



Hosts of A . melanoscelus 12 



Part II — Introduction and establishment 14 



European work 14 



Comparison of seasonal history in Sicily and New England 15 



Abundance of A . melanoscelus in Sicily 15 



Secondarv parasitism in Sicily 16 



Colonization in New England 16 



Methods used to obtain material for colonization 18 



Success of colonies and distribution of A . melanoscehis 21 



Dispersion 22 



Secondary parasitism , 23 



The value of A. melanoscelus as a gipsy-moth parasite 23 



Abundance of A. melanoscelus in New England 24 



Conclusion 25 



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