15 



PAGE 



TWENTY-SECOND REPORT 



Introductory Note VIII 



The Corn Bill-bugs in Illinois 1-26 



Usual Conditions of Injury to Corn 2 



General Features of Life History 2 



General Preventive Measure 3 



The Little Brown Bill-bug; the Blue-grass Bill-bug (Sphenophorus 



parvulus) 3-S 



Sphenophorus placidus 8 



The Clay-colored Bill-bug {Sphenophorus ochreus) 9-17 



Sphenophorus pertinax 17 



Sphenophorus cariosus- •••..••..•• • • 19-21 



Additional Species 21 



Sphenophorus scoparius 21 



Sphenophorus sculpt His 21 



Sphenophorus robust us 22 



Recent Bibliography 23-26 



Methods and Results of Field Insecticide Work against the San Jose 



Scale. 1899-1902 27-66 



Experiments with Lime and Sulphur Washes for the San Jose Scale 67-90 



Experiments and Observations on the Use of Crude Petroleum and Pure 



Kerosene for the San Jose Scale 91-95 



Experiments with Summer Washes for the San Jose Scale 96-97 



On the Principal Nursery Pests likely to be distributed in Trade 98-138 



Classification and Description of the Insect and Fungus Pests of the 



Nursery most Important to the Nursery Trade 99-103 



Injurious to the Roots 99-100 



The Woolly Aphis 99 



The Black Peach-aphis 100 



The Crown-gall 100 



The Root-rot 100 



Injurious to the Bark or Wood 100-lCl 



The Woolly Aphis 100 



Scale Insects or Bark-lice 100 



The Peach-tree Borer 100 



Pear-blight, Apple-blight, Fire-blight, Twig-blight 101 



Black-knot 101 



Peach Fruit-spot 101 



Anthracnose of Raspberry 101 



Injurious to the Leaf or Bud 101-103 



Plant-lice or Aphides 101 



The Apple Leaf-crumpler 101 



The Pear-leaf Blister 102 



The Tent-caterpillar 102 



The Bagworm 102 



The Tussock-moth 102 



The Apple-scab 102 



The Pear-blight 102 



The Leaf-spots 103 



Winter Forms and Appearances of the Principal Nursery Pests 103-104 



Description and Discussion of Species 106-138 



The Woolly Aphis 106 



The Black Peach-aphis 107 



The Crown-gall 110 



The Root-rot Ill 



The Scale Insects 112-121 



The San Jose Scale and its Allies 114 



Additional Nursery Scales wintering partly or fully grown.. 117 



