348 The Principles of Fruit-growing. 
7. 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 edueating 
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 inseet, whieh perhaps docs not. 
weigh a grain, will set a whole community of able- 
hodicd 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. 
