2 CIRCULAR 82 8, IT. S. DEPARTMENT OF AGRICULTURE 



lubricating oil. The chemical kills the larvae that enter. The older 

 types of band, consisting of burlap, building paper, or other material, 

 had to be removed at intervals of 10 to 11 days, so that the larvae 

 might be destroyed by mechanical means. The new chemical bands 

 work automatically and are allowed to remain undisturbed until well 

 after fruit harvest or until the following spring. 



The bands are applied to the trees in June, just before the first 

 larvae leave the fruit. 



All but a few of the larvae caught before the end of July would have 

 produced a second brood of moths during the current season. Only a 

 few of the larvae caught after the third week in August, however, 

 would have changed into moths. Banding, therefore, is immediately 

 effective during the fore part of the season in reducing the second- 

 brood population the same season, but late in the summer the effect 

 is greatest in reducing the overwintering larvae. 



It is necessary to scrape the rough bark thoroughly from the trees 

 to obtain the maximum benefit from banding. Scraping serves a two- 

 fold purpose : (1) To remove and destroy the hibernating larvae and 

 thereby reduce the potential moth population for the following sea- 

 son, and (2) to eliminate the cocooning quarters for the later full- 

 grown larvae after they leave the fruit, thus inducing a greater pro- 

 portion of them to enter the bands and be destroyed. In this way 

 scraping and banding constitute one supplementary control measure, 

 although either will afford some benefit if used alone. 



Experimental scraping and banding and related studies have been 

 carried on in different parts of the country under a great variety of 

 conditions. Some of this work is discussed in the following refer- 

 ences : Baker (1, 2), Gould and Geissler (4), Marshall (J), New- 

 comer (7). Xewcomer et al. (8). Steiner (13. li). Steiner and Acker- 

 man (IS), Steiner and Marshall (16). YTooclsicle (17, 18). Worthlev 

 (19), Yothers (20,21, 22), and Yothers and Carlson (&£, 25, 26). 



This circular brings together work done by the present authors in 

 the Northwest during the period 1935-43, after which this phase of 

 the work was discontinued. Comparatively little emphasis is now 

 being placed on scraping and banding for codling moth control, be- 

 cause of the use of the highly effective insecticide DDT, the greatly 

 increased cost of labor and the development by the authors (Yothers 

 and Carlson 27) of trunk sprays, which are about as effective as 

 scraping and banding and are less expensive and require less labor. 



LOCATION OF OVERWINTERING LARVAE 



Over a period of 6 years near Yakima, Wash., the location of the 

 larvae on or near 80 trees in 8 orchards that had never been scraped, 

 and on 101 trees in 11 orchards that had been scraped and banded the 

 preceding season, was recorded after minute examination. Larvae on 

 trunks, in the lower crotches, and in the soil at the base of the trees 

 were classed as on the trunks ; those on the scaffold limbs above their 

 union with the trunk and as far up -as the rough bark extended, or to 

 secondary limbs, were classed as on scaffold limbs; while those on 

 secondary and smaller branches beyond scaffold limbs were classed 

 as on the branches. 



The trash and soil were sampled as follows : The surface trash from 

 one-fourth of the area (a 90° sector) under a tree, for a distance of 



