15 



Cooley reports an injuiT of 95 per cent in small home orchards in 

 Helena, Mont. There are many reg'ions in this faunal area in which 

 the insect does about 25 per cent damage, and for some reason, prob- 

 ably climatic, the injury is reduced to almost nothing for several 

 years, after which the numbers of the insect gradually increase. 

 Professor Aldricli records that in lcSJH> an early snowfall and low tem- 

 perature at Moscow, Idaho, killed a great many of the larvie. There 

 are many other localities in the Pacific Northwest where the codling 

 moth either has not been introduced or has not thrived, and in which 

 the injury is tiominal. 



In many regions where the transition zone is pierced by valleys of 

 the upper Sonoran zone the orchards near the canyons suffer much 

 greater injury than those more remote therefrom. Professor Piper 

 has noted several cases in which this was true, and in one the damage 

 was 75 per cent or over. 



TlUC I'ACIKIC COAST TKANSSITIONAL AKEA. 



This area includes those portions of Oregon and Washington be- 

 tween the Coast Mountains and the Cascade Range, pai'ts of northern 

 ('alifornia, and most of the coast region of the State from near Cape 

 Mendocino southward to the Santa Barbara Mountains. In Oregon 

 varying percentages of injury have been reported, ranging from a nom- 

 inal loss to 75 per cent. In the Hood River Valley in some cases it is 

 greater than this, with an average, perhaps, of about 25 to 90 percent. 



UPPER AUSTRAL ZONE. 



The upper austral zone is divided into two areas by reason of the 

 greater humidity of the eastern portion. 



THE CAKOLIXIAX FAUNAL AREA. 



This area includes the great apple regions of the Central Sta.tes and 

 many smaller portions of the Eastern States. Many entomologists 

 have r(>ported injur}' in these areas as ranging from 80 or 50 percent 

 to practically 100 per cent. 



UPPER SOXORAX FAUNAL AREA. 



This area includes that portion of the upper austral zone west of 

 the one hundredth meridian. From many countings and estimates 

 from various sources we find that in badly infested districts the injury 

 varies from 80 to 95 per cent under normal conditions, and it is very 

 common to find the loss reach 100 per cent. 



LOWER AUSTRAL ZONE. 



In this zone there are onl}' a few localities where apples are grown 

 on a commercial scale. Under normal conditions in badly infested 



