440 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 14 



tection. the species succumbs to a much less vigorous temperature. 

 With the approach of spring, the overwintering forms on plantain 

 become more active, and winged form.s are produced to spread the in- 

 festation. 



Economic Considerations 



The effects of regional variation in the behavior of apple aphids are of 

 direct significance to the commercial fruit grower. The more severe in- 

 jur}- to apple orchards normalh' resulting from attacks of Aphis sorbi in 

 Western Oregon, makes the control of this pest in this section even more 

 imperative than in regions where injury is less pronounced. 



As a rvle. Aphis pomi is less injurious in orchards of Western Oregon 

 than in the New York fruit districts, and in normal seasons causes the 

 Western Oregon orchardist little concern. 



Aphis avenae is of no importance as an apple pest in Western Oregon. 



By wintering on plantain, Aphis sorbi becomes independent of apple 

 in Western Oregon. The continuous breeding on plantain produces a 

 source of supply of these insects, which serves as a reservoir for the spe- 

 cies, and which accounts in part for the greater infestation of apples in 

 this region. Any campaign which might be undertaken for the actual 

 eradication of the species from Western Oregon would have to be waged 

 against the plantain forrns as well as the infestation on apple. 



In Western Oregon the greater capacity of Aphis pomi for dispersal in 

 the later generations would probably greatly interfere with the control of 

 this species during seasons of unusual abundance. 



The most unfortunate effect, however, of the regional variations noted 

 is the failure of the standard "delayed dormant" treatment to success- 

 fully control Aphis sorbi in Western Oregon in spite of the success with 

 which this treatment is applied in the East. The unsatisfactory results 

 which are attending the use of the "delayed dormant" spray of nicotine 

 sulphate for the control of Aphis sorbi in the Willamette Valley are prob- 

 ably due to the long-drawn-out hatching period more than to any other 

 factor. 



LIFE HISTORY OF THE CODLING MOTH IN WALNUTS 

 AT SANTA ANA, CALIFORNIA 



By H. J. Qu.WLE 



Life History 



Wintering Larvae. The larvae winter in cocoons beneath the loose 

 bark of walnut trees, in old pruning cuts, under bands, if such are present, 



