124 VEGETABLE GARDENING 



larvae and not the flying form of these insects that do 

 serious injury. (2) Few persons are so far sighted that 

 they can be persuaded to attack insect enemies until they 

 are suffering from their ravages, and the benefits of this 

 method will not be felt until perhaps the following year. 

 (3) The observations of Dr. Otto Lugger show that insects 

 have generally laid their eggs before they fly much, and 

 only the male insects of some species fly, and the females are 

 nearly or quite wingless. It is obvious that in such cases 

 catching the flying insects will do little if any good. 



Applications of Insecticides. In applying insecticides it 

 is generally important to begin their use as soon as the 

 insects appear and not wait until the plants have been 

 weakened and set back by their attacks. There are many 

 and various machines for distributing insecticides. The 

 machine best adapted to this purpose will depend much on 

 the insecticide used and the extent of the operations con- 

 templated. For applying liquid compounds some of the 

 many forms of spray pumps will be found best. For the 

 small garden where there is a variety of crops grown, per- 

 haps what is known as the knapsack spray pump is as con- 

 venient as any general-purpose machine. Where potatoes 

 are grown on a large scale some special spray pump that can 

 be geared to the wheels of a wagon may often be the best to 

 use. Where insecticides are used in powder form, it is a 

 good plan to scatter them on the plants through a coarse 

 linen bag or fine wire cloth. When such material needs to 

 be ejected with force, a fan or bellows may be used. It is 

 always best to use poisons in a liquid form when practicable, 

 since it is the most economical and effective method of 

 applying them. No insecticide should ever be used in a 

 large way until it has been tried on a small scale to see what 

 its effect will be on the crop to be treated, since plants may 



