CONTENTS 



PAGK 



"Recent Illinois Work on the Corn Eoot-aphis and the Control of its Injuries. . 1 



Recent articles in the office reports 4 



List of operations here reported 6 



Effect of a wet planting-time on the action of repellents 7 



The Bloomington Canning Co. experiment 8 



Tests of lemon oil and terpenes 12 



Contributing cause of injury to seed-corn by repellents 16 



Field experiment with repellents, 1907 17 



The spring weather at Lre Roy 20 



Laboratory experiments with the effects of repellents on ants 21 



Additional field experiments with repellents, 1908 41 



Use of repellents combined with fertilizers 44 



Rotation and cultivation methods 48 



Cultivation experiments at Bloomington , 49 



Effects of treatment as shown by nocturnal movements of ants 53 



Effect of disking and subsequent rolling 55 



Effect of fall plowing compared with that of spring plowing 57 



Rotation of crops with fall plowing 58 



Summary 60 



Oliservations and Experiments on the San Jose Scale 63 



The San Jose Scale on fruits 63 



The life history of the San Jose Scale in Illinois 64 



Tests of orchard sprays 68 



Experiments of 1907-08 69 



Grading of the trees 69 



The experimental plots 70 



Insecticides 70 



Final grading 71 



Results of treatment 71 



The transition zone in insecticide experiments 74 



Experiments of 1909 76 



Experiments of 1911 77 



Summary 79 



Life History and Halnts of the Northern Corn Root-worm (Diabrotica longi- 



cornis S.'iy 80> 



Breeding experiments 80i 



The effect of rotation of crops on injury by the Corn Root-worm 83 



The San Jose Scale (Aspidiotus perniciostis Comstock) 87 



Origin and distribution 87 



Dangerous character of the scale 90 



