IV PAPERS OX IXSECTS AFFECTING VEGETABLES. 



Page 



A little-known cutworm (Porosagrotis vetusta Walk.) F. H. Chittenden. . 47 



Injurious occurrence 47 



Results from applications of arsenate of lead 49 



Description 50 



The moth 50 



The larva 50 



Distribution , 50 



Natural enemies 51 



Arsenite of zinc and lead chromate as remedies against the Colorado potato 



beetle Fred A . Johnston . . 53 



Spraying experiments with arsenite of zinc and lead chromate in compari- 

 son with other arsenicals. 53 



Spraying experiments with arsenite of zinc of different strengths 55 



A report of progress regarding the sugar-beet web worm {Loxostege sticticalis L.), 



E. 0. Marsh.. 57 



Introduction 57 



General appearance of the sugar-beet webworm and nature of attack 58 



Life history and habits 59 



Character of injury ' 61 



Natural enemies 62 



Other checks 63 



Experiments with remedies 63 



Spraying machinery 66 



Cost of spraying 69 



Conclusion 70 



The horse-radish webworm (Plutella armoracia Busck) H. O. Marsh. . 71 



Introduction 71 



Occurrence in Colorado 71 



General appearance and habits • 72 



Life history , 73 



Rearing records 73 



L^gg-laying record 75 



Natural enemies 75 



Experiments with insecticides 76 



Recommendations for control 76 



Conclusion 76 



Index 77 



