ILLUSTRATIONS. 



Page. 



Fig 1 . Canadian rye grass {Elymus canadensis) 12 



2. A'lrginia r_ye grass (Elyiiius virginicus) , 13 



3. (Greater wheat straw-worm {Isosoma grande Riley), spring generation, 



form mimitttm; stages 14 



4. Greater wlieat straw-worm ( Isosoma grande Riley ) , adult summer form . 14 



5. Head of wheat partly destroyed by Isosoma minutum 18 



6. Method of oviposition of female of summer form (/. grande); b, point 



in straw where egg is placed 20 



7. Pediculoides ventrlcosus Newp., a mite which destroys the larva 22 



8. Isosoma iritici Fitch ; adult of the joint worm 24 



9. Effect of joint worm in wheat straw 25 



10. Isosoma horde'i Harr. ; adult of the barley straw-worm 30 



11. Isosoma capllvum How. ; adult 34 



12. Isosoma websteri How. ; adult female 35 



13. Isosoma Jdrtifrons How. ; adult female 37 



14. Greater wheat stem-maggot. (J/erowy^a americana Fitch); stages and 



effect on young wheat plant 44 



15. Oscinis soror Macq. , stages; (/, head of Osciiiis carbonaria 52 



' 5 



