IV 
PAGE 
The Lime and Sulpliur Mixtures 63 
Major Experiments 63 
General Results of the Experiments 71 
Minor Experiments 72 
Miscellaneous Additional Insecticides j^ 
Cost of Materials 74 
General Summary 76 
Spraying Apples for the Plum-curculio 78 
Some Earlier Experiments 78 
Experiments of 1904 80 
Results of Experiments 82 
Cost of the Operation 91 
Summary of Spraying Results 92 
Poison Tests of Sprayed Apples 92 
The Neutral Zone in Spraying Experiments 94 
Diagram of Spraying Effects with Arsenate of Lead 9K 
The Cottony Maple Scale in Illinois rOD 
Food Plants 103 
The Life History of the Insect 104 
The Hatching Period 106 
Summer Insecticide Measures 106 
Effects of Experimental Summer Spray 109 
Winter Insecticide Measures no 
Injury to Trees II2 
Insect Enemies 114 
Summary 115 
The Elm Twig-girdler, Obcrea ulmicohi Chittenden 118 
Recognition of Injury 119 
Nature and Extent of Injury 120 
Life History and Hal)its 122 
Mode of Oviposition -. 122 
The Egg 123 
The Larva 123 
The Pupa 125 
The Beetle 126 
Distrihution 127 
Natural Checks on Multplication 128 
Euderus lividns Ashmead 128 
Cymatodera balteata Leconte 129 
Description of Larva 130 
Protective Measures 131 
Description 133 
Adult 133 
Egg 133 
Larva 133 
f "pa T34 
On the Life History, Habits, and Economic Relations of the White-gruhs 
and May-beetles (Lacluiostcnui ) 135 
The Economic Species 136 
Life Histories of the Injurious Species 137 
