CONTENTS 
PAGE 
Introduction v 
Experiments with Repellents against the Corn Root-aphis, 1903 and 1906 1 
Repellent Applications to the Seed 2 
Plot Experiments, 1905 3 
Tabular Summary 5 
Plot Experiments, 1906 7 
Tabular Summary 12 
A Corn-Field Experiment, 1906 13 
The Experimental Field 14 
Insect Infestation of Field 14 
Description of the Experiment 14 
Results of the Experiment: First Inspection 16 
Second Inspection 17 
Data concerning first two Inspections tabulated and compared 19 
Third Inspection , 19 
Fourth Inspection -. 19 
General Final Result 21 
Comparison of Infested Fields 21 
More Experiments necessary 22 
An Additional Minor Test 22 
General Program of Prevention 24 
Habits and Beliavior of the Corn-Ficld Ant. Lasiiis niger americanus 27 
Contents of the Nests 27 
Beginning of a New Colony 28 
Size of Colonies 30 
Intercolonial Hostilities 31 
Area occupied by a Single Colony ii 
Relations to other Species of Ants 34 
Behavior within the Nest 34 
Adaptation of Behavior to Changing Conditions 36 
An Injury to Corn by Ants 2>7 
Effect of a Change of Crop 38 
The Insect Pests of Clover and Alfalfa 41 
Introduction 41 
Injury to Clover by Insects 41 
The Failure of the Seed Crop 43 
Control of Clover Insects 45 
Clover Seed-midge, Dasyneitra leginnimcola Lint 46 
Clover Seed-chalcid, Bruchophagus funebris How 53 
Clover Seed-caterpillar, Eiiannonia intcrstinetana Clem 61 
Pea-louse, or Clover-louse, Macrosiphum pisi Kalt 66 
Clover Leaf-weevil, Phytonomus ptinctatus Fab 83 
Clover Root-borer, Hylasiinus obsciiriis Marsh 92 
Clover Hay-worm, Hypsopygia costalis Fab 96 
Clover Leaf-midge, Dasyncura trifolii Low 99 
Clover Callipterus, Callipterus trifolii Monell 103 
Clover Stem-borer, Languria viocardi Latr 106 
Clover Sitones, Sitones Havesccns All 112 
Other Species of Sitones as Possible Clover Pests 116 
Clover- Root Mealy Bug, Pseudococcus trifolii Forbes 117 
Literature : General Articles 124 
Lists of Species 124 
