57 



In the larval state, especially when young, there are many agencies 

 of destruction. I have found tips of branches upon which there was 

 but one apple. On the leaves near by there were half a dozen or so 

 hatched eggs, while the apple contained but one larva. In one case 

 the larva would have to crawl 20 feet before finding another. 



In many cases I have found from 2 to 5 per cent of the larvae dead 

 before they had commenced their burrow to the center of the apple 

 from the mine under the skin. There are very few deaths due to 

 fungus and bacteria in the dry regions. In many orchards, in which 

 the water used for irrigation is allowed to stand around the trees, the 

 number of infested apples is markedly less than in those orchards 

 where irrigation is by ditches. Also one does not, as a general rule, 

 find as many worms under bands on trees which have moist soil around 

 them. The only explanation is that the moisture either causes the 

 insects to die by fungus or bacteria or to seek other places. This 

 method, however, has grave disadvantages, since water allowed to 

 stand in an orchard will sooner or later kill the trees. 



NATURAL ENEMIES. 



I did not succeed in finding any egg parasites, but within a pupa I 

 found a pupa of a Hymenopter, but the parasite did not emerge. It 

 was probably a Pimpla. In another pupa I found many pupas of a 

 Hymenopterous parasite, which died before becoming adults. Under 

 some neglected bands were many silk cocoons, probably of a Micro- 

 gaster. Although they are not bred directly from the codling moth, 

 there is little doubt but that they were from this insect. 



While the larvae are seeking a place to spin their cocoons in the day- 

 time they are preyed upon by ants and birds. Chickens allowed in an 

 orchard eat them readily. Often I have observed holes in the bark, 

 and upon examination found empty cocoons. One evening several 

 bats were noticed flying around apple trees and probably feeding upon 

 the moths. 



PREVENTIVE MEASURES. 



One of the best preventive measures is following the best general 

 horticultural practices, such as keeping the soil and trees in healthy 

 and vigorous condition and keeping a close watch upon the orchard. 

 If a fruit grower has no codling moths, what should he do to keep them 

 out of his orchard? The answer to this question has many conditions, 

 according to location, etc. To begin with, every grower should be 

 familiar with this insect in all its stages and know how to fight it. An 

 orchard may be at such an altitude that the insect will not be a very 

 serious pest. In this case the small amount of damage should not be 

 an excuse for letting it alone. It would be well for the grower to be 



