60 INSECTICIDES AND SPRAYING 



tribute pyrethrum in cracks and crevices which might conceal 

 fleas or bedbugs. A larger bellows is made for use with plants, and 

 a still more complete machine for field use is shown in figure 67. 

 With these one can distribute lime or a mixture of lime and Paris 

 green, dry Bordeaux and like material. More recently, at least 

 two firms have manufactured dust sprayers on a larger scale, to 

 be placed on wagons, and intended for use in large nurseries or 

 orchards. One called the " Cyclone Sprayer," and made in Kansas 

 City, is shown in figure 68. This machine and a smaller one made 

 by the same firm are shown in use on pages 47 and 48. A dry 

 Bordeaux and certain caustic compounds are used with these 

 sprayers, or a combination of dry Bordeaux and Paris green is 

 manufactured, though directions are given to purchasers whereby 

 many of these compounds may be made at home. 



QUESTIONS 



1. What two practical divisions of insects can be made by the farmer and 



orchardisi;, independent of scientific classification, and what bearing have 

 these upon the use of insecticides? 



2. Describe Paris green and its uses. How can*one distinguish between good 



and bad Paris green? 



3. Describe and discuss the use of arsenate of lead. 



4. Why is the use of London purple undesirable? 



5. How can we treat a tree for a plant disease and insect pest at the same 



time? 



6. Describe poison baits and their uses. 



7. Name in order of importance three insecticides for use against sucking 



insects. 



8. What are some of the leading mechanical measures against insects? 



9. Enumerate the uses of tobacco derivatives in sprays. 



10. What is the chief objection to the use of kerosene emulsion? 



11. Give a recipe for a preventive wash to apply to the trunks and branches 



of fruit trees. 



12. Compare liquid and dust spraying. 



13. W T hat points are to be desired in a spray pump, and what features are to 



be avoided? 



14. Discuss nozzles, good and bad. 



