HOW INSECTS INJURE FRUITS 



(1) Insects destroying foliage ; 



(2) Insects upon the bark or upon the surface of leaf and fruit ; 



(3) Insects boring into the twig, stem or root ; 



(4) Insects boring into the pulp cf fruits. 



INSECTS DESTROYING FOLIAGE 



Cut Worms and Army Worms. These are the larvae of Noctuid 

 moths, which often become abundant over limited areas and do 

 much damage to trees and plants. Cut worms and Army worms are 

 terms applied to the same insects in California. In ordinary years 

 they are not present in sufficient numbers to cause much concern, 

 and in such years they are known simply as cut worms. When all 

 conditions are favorable, however, certain species develop in 

 enormous numbers and having exhausted the food supply where 

 they breed, they begin to migrate or march, commonly in a definite 

 direction, as an army in search of new food. When they thus appear 

 in such large numbers and take on the migrating habit they are 

 called army worms. 



Some of the caterpillars have the habit of climbing up vines and 

 trees and eating off the buds in the early spring. These are called 

 climbing cut worms. Others remain at or near the surface of the 

 ground and feed by cutting off the plants at this point. They are 

 more commonly found in the grass lands, but very frequently attack 

 cultivated crops, particularly on land that was in grass the previous 

 year. 



Of the methods used to protect trees and plants from cut worms, 

 poisoned bait is probably the most common. This consists of bran 

 and molasses or other sweet substance poisoned with arsenic and 

 distributed in handfuls about the plants. The proportions are as 

 follows: forty pounds of bran, two gallons of cheap molasses, and 

 five pounds of arsenic. Cheap glycerine may be used to prevent the 

 mixture from drying . This will be eaten by the worms in preference, 

 usually, to the plants which it is desired to protect. It may be placed 

 in spoonfuls at the base of trees or vines which it is desired to pro- 

 tect or in case of an invasion may be broadcasted over the ground 

 which reduces the danger of poisoning poultry and domestic 

 animals. 



Cut worms and army worms may also be captured by means of 

 traps. Because of their habit of feeding at night and remaining con- 

 cealed during the day, pieces of boards may be placed on the ground 

 around the growth to be protected and these may be turned over 

 during the day and the worms killed. 



In case of outbreaks of army worms the most important and 

 successful means of fighting them is to keep them out of the orchard 

 or vineyard entirely. This can be successfully done if they are dis- 

 covered in time, or if already in one portion, they can be kept from 

 spreading over the rest of the property. They travel in immense 

 numbers in a definite direction, coming generally from an adjoining 

 or nearby grain field. If a furrow is plowed along the side of the 

 place to be protected it will effectively stop their progress. This 



