20 



CIRCULAR 82 8, TJ. S. DEPARTMENT OF AGRICULTURE 



harm than good bv furnishing the best possible cocooning quarters 

 (% 7). 



The most practical time to remove and destroy the bands is at 

 scraping time, when they are a convenient aid in burning the scrapings. 



Examination of the beta-naphthol bands after they have been on 

 the trees a few months in badly infested orchards will show consid- 

 erable numbers of dead and live larvae attached to the bands (fig. 8), 

 to the bark between the band and the tree, and inside the corrugations. 

 The live worms ar e recent entrants, but most of them will be killed 





Figure 7.- — An old beta-naphthol band that has lost all its value but is allowed 

 to remain on the tree affords highly suitable quarters for the larvae. Empty 

 pupal cases are shown at the edges of this old band. 



■Z'< 



* 



* 



Figure 8. — Section of beta-naphthol band showing dead larvae. 



within a few days. The larvae entering late in the fall after cool 

 weather has set in will be killed during the winter, but it will take 

 longer to kill them at that time. 



COST OF SCRAPING AND BANDING 



The cost of scraping and banding depends on so many variable 

 factors that it is impossible to set a definite figure. Some of the fac- 

 tors are the size, age. variety, and general physical condition of the 

 trees, and the prevailing wage and cost of materials (bands, tacks, 

 scraping tools, and tarpaulins). 



The most important factors are the size of the trees and the per hour 

 cost of labor. The approximate cost of the two operations for small, 



