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CONTENTS 



PAGE 



On the Life History of the Codling-moth 1 



Diagram 1. Illustrating the life history of codling-moth at Olney, 111., in 

 1915, and temperature and rainfall records from April to October. . . . 



opposite 5 



Seasonal history of the codling-moth as observed at Olney, 111., in 1915... 6 

 Diagram 2. Monthly mean temperatures at Olney for 1914 and 1915, and 



for an average or normal year 11 



Figures 15-21 



A General Survey of the May-beetles (Phyllophaga) of Illinois 23 



Location of the collections 23 



Number of species and of specimens 24 



Methods of collection 26 



Acknowledgments 27 



Discussion of the species 27 



The species by sections of the state 43 



Comparison of the sections of the state 45 



Seasonal succession of the species 48 



Varying abundance of the species in different years 57 



Relative attractiveness of different kinds of trees and shrubs to May-beetles 58 



Summary 64 



The Influence of Trees and Crops on Injury by White-grubs 66 



White-grubs most abundant in the neighborhood of trees 66 



The kinds of crops in which May-beetles prefer to lay their eggs 67 



The Chinch-bug Outbreak of 1910 to 1915 71 



Detailed computation of losses 72 



Secondary economic consequences 75 



The progress and development of the outbreak 76 



Illustrative maps 7S-83 



Local and general causes of the outbreak 84 



The arrest of the outbreak in 1915 94 



Effect of the weather 94 



Effect of predaceous insects ' 96 



Effect of the egg parasite 96 



Artificial measures of control 97 



Burning out in winter 98 



Destruction of chinch-bugs at the wheat harvest ! 99 



Experiments with coal-tar mixtures and petroleum products 100 



Petroleum road oils 101 



Failure of the 1913 road oil 103 



Crude creosote as a repellent 104 



