18 



BULLETIN 554, U. S. DEPARTMENT OF AGRICULTURE. 



For those who undertake the sanding method of controlling 

 girdlers it should be borne in mind that there is some risk, attendant 

 upon this practice, of increasing the fungous troubles of the fruit, 

 and one should be prepared to spray sanded bogs with a fungicide 

 such as Bordeaux mixture. 



Experimental work is not altogether conclusive as to the thickness 

 of the coat of sand which will prevent emergence of the moths from 

 cocoons. Franklin (11, p. 19) found that an even covering of sand 

 1 inch in thickness effectually prevented moth emergence in small 

 cages, while the writer's data, obtained in a mosquito-bar cage 

 placed on a cranberry bog, lead him to conclude that an even coat, 

 1 inch in thickness, will not be obtained by the grower in the actual 

 practice of sanding and that considerable numbers of moths will 

 emerge through the sand. 



The sanding experiment performed at Whitesbog, X. J., was 

 essentially as follows: Three plats were laid off where the vines 

 showed severe injury and where, in fact, they had been killed over 

 a considerable extent. Two of the plats were sanded fairly evenly 

 on November 23, 1914, the depth varying from an inch to an inch 

 and a half. The winter flowage was put on in December and re- 

 moved May 8, 1915. The same day three cocoons were removed 

 from beneath the sand in plat 2, and on May 10 two cocoons were 

 dug out, all of which contained live larvae. A tight mosquito-bar 

 cage (PI. II, B) was built over the three plats a few days later, 

 and emergence of moths was first noted June 10, 1915. 



Table VII. — Emergence of moths of the cranberry girdler in sanding experi- 

 ment at WJiitesbog, N. J., 1915. 





Number of moths emerged. 



Date. 



Plat 1, 



area, 173 



square feet, 



sanded. 



Plat 2, 



area, 248 



square feet, 



check. 



Plat 3, 



area, 222 



square feet, 



sanded. 





4 



10 

 41 

 18 

 21 

 4 

 

 1 



12 



41 



34 



64 



3 



8 



1 























1 





12 





3 



June 18 - - 



9 





5 



Ju'y 2 



1 



July 8 











Total 



106 



160 



31 







Owing to the distance of the cage from the field laboratory it 

 was not practicable to remove and count the moths each day. The 

 data show that the greatest number of moths emerged from the un- 

 sanded plat, which was also the largest plat, but that 1.55 moths 



