lie 



CONTENTS, 



Page. 



List of Descriptions V 



Letter of Transmittal VII 



<Jeneral Record for 1887 and 1888 IX 



Studies on the Chinch Bug. II 1 



Chinch-Bug Injury Reported by Townships, 1887 3 



Influence of Excessive Drouth 5 



Effect of Abandoning Corn as a Crop 5 



Successive Abandonment of Corn and Wheat 6 



Secondary Effects of the Abandonment of Wheat 6 



Relations of the Area of Wheat and other Crops to Chinch-Bug Injury 7 



Collection of Data 8 



Study of Data 9 



General Remarks upon the Tables 10 



Injury to Corn as Compared with Acreage in Wheat and other Grains (Tables I-IV) — 11 



Injury to Grass as Compared with Areas in Wheat and other Crops (Tables V-VIII) 16' 



Damage to Small Grain as Compared with the Area in Wheat and other Crops (Tables 



IX-XII) 19 



g Comparison of the Crops for 1886 and 1887 21 



^ Injury to all Crops combined, compared with average of each (Diagrams I-VI) 22 



^ Discussion of Diagrams 29 



P Summary of Current Opinion , 32 



Experiments 35 



O Insecticides 37 



Barriers to Migration 43 



Starvation Experiments 44 



i". Contagious Disease 45 



Miscellaneous Notes and Observations 50 



f7 Summary and Conclusions 53 



The Corn Bill Bugs 5S 



Analysis of Literature 59 



Description of Genus 63 



Key to Illinois Species 63 



Immature Stages 65 



-y-^ Distribution 67 



Life Histories , 67 



jj Injuries to Vegetation 69 



• Natural Enemies 71 



Remedies 71 



Economic Bibliography 73 



^ /Dbservations of the Food of the Snout Beetles (Rhynchophora) 75 



CO 



I 431897 



