CONTENTS 



PAGE 



Introduction , 3 



The Species of Plant Lice Concerned 3 



Pink and Green Aphis of the Potato 4 



Green Peach Aphis 5 



Green Pea Louse 6 



Bean Louse 7 



Cabbage Aphis 7 



The False Cabbage Aphis 8 



Melon Aphis 9 



Summary of Important Points in Life History 10 



Control of Vegetable Plant Lice and the Prevention of the In- 

 jury Which They Do 10 



Natural Control 10 



Clean Culture * 13 



Direct Artificial Control 13 



On the Nightshade Family 13 



On Peas and Beans 17 



On Beets and Spinach 17 



On the Cabbage Family 18 



On the Cucurbs , 20 



On Lettuce 20 



Summary of Measures of Control 21 



FIGURES 



FIGURE PAGE 



Frontispiece I 



1 . Pink and Green Aphis of the Potato and Tomato 4 



2. The Green Peach Aphis 5 



3. Green Pea Aphis 6 



4. Cabbage Aphis 7 



5. The False Cabbage Aphis 8 



6. Melon Aphis 9 



7. Diagrammatic Life History of the Plant Louse 11 



8. Adult Parasite Laying an Egg in the Louse's Body 12 



9. The Parasite's Work 12 



10. Field Sprayer in Operaton 15 



11. Engine-Driven Potato Sprayer Showing Details of Nozzle 



Arrangement, etc 16 



12. Engine-Driven Potato Sprayer Adapted to Spinach 17 



13. A Lifting Device Attached to a Potato Sprayer 19 



14. Knapsack and Compressed Air Sprayers With Proper 



Sort of Extension Rod 20 



(2) 



