348 The Principles of Fruit -growing. 



1. The necessity of spraying must create a greater 

 watchfulness on the part of the fruit-grower for new 

 pests, for these pests are all the time appearing from 

 foreign countries, from adjacent states or geograph- 

 ical regions, or from the wild. 



8. Inasmuch as every new subject of inquiry 

 awakens new thoughts and expands one's sympathies, 

 so it becomes a means of enlarging and educating 

 the man. A concentrated invasion of the army -worm 

 is one of the very best means of waking up any 

 farming community and of setting every man, woman 

 and child to asking questions of every passer-by, every 

 agricultural editor and teacher, and experiment sta- 

 tion. The good effects of such an invasion are likely 

 to last for a number of years. It is surprising, as 

 one thinks of it, how easily people are scared by a 

 bug! A strange insect, which perhaps does not 

 weigh a grain, will set a whole community of able- 

 bodied men agog, and may cause as much down- 

 right fear and discussion as a political revolution. 



There are three general types of difficulties which 

 are germane to the discussion in this chapter. A 

 classification of these troubles might be made as fol- 

 lows : 



1. Attacks by insects. 



(a) The injuries of those insects which eat 

 or chew the parts of the plant, and which, 

 therefore, are killed by the application of poi- 

 sons like Paris green. Such insects are the 

 whole tribe of caterpillars, worms and beetles. 



