6 CIRCULAR 82 8 ; U. S. DEPARTMENT OF AGRICULTURE 



Baker (2) concluded that the effect of banding (and scraping) on 

 moth emergence and larval hibernation was much greater than was 

 indicated by the percentage of larvae caught in the bands after emerg- 

 ing from the fruit. 



LARVAE CAUGHT IN TRUNK BANDS AND LIMB BANDS 



Experiments to determine the percentage of larvae leaving the fruit 

 that are caught in bands on trunks only and on both trunk and limbs 

 were made on 139 trees of the Jonathan, Winesap, Delicious, and Rome 

 Beauty varieties. The methods followed were similar to those already 

 described, and involved periodic examinations of the bands and of 

 the fruit on the tree. The results of these tests are summarized in 

 table 3. 



Table 3. — Larvae caught in hands on trunks only and on both trunks 

 and scaffold limbs, 1937-4-1 





Year 



Trees 



Larvae in bands 





On trunks only 



On trunks and scaffold limbs 



1937 



Number 



33 



24 

 32 

 32 



18 



Number 

 2,016 

 1,239 



732 

 2,309 



140 



Percent 



56 

 33 

 36 

 46 

 42 



Number 

 2, 547 

 2,276 

 1,241 

 3,060 

 261 



Percent 



67 



1938__. 



56 



1939 -__. 



52 



1940 



1941 



and average 



65 

 61 



Total 



139 



6,436 



43 



9,385 



61 



In 1936-39 three methods of banding were tried in weekly rota- 

 tion on the same trees — trunk bands, limb bands, and both kinds. 

 In these tests on 357 trees of 4 varieties in 10 orchards, 41,713 larvae 

 were caught in bands on trunks, 53,773 in bands on limbs, or 29 per- 

 cent more than in trunk bands, and 62,734 in a combination of both, or 

 17 percent more than in limb bands alone and 50 percent more than 

 in trunk bands alone. 



In 1939 tests were made to determine the numbers of larvae caught 

 in bands on trunks and on scaffold limbs. On 408 trees in 5 orchards, 

 65,819 larvae were captured, of which 17,871 were in trunk bands and 

 47,948 were in limb bands, or 27 and 73 percent, respectively. In other 

 words, limb bands captured 2.7 times as many larvae as trunk bands. 

 However, limb bands require an average of 2.1 times as much banding- 

 material as trunk bands. 



In two tests in which badly infested trees were banded with 3 bands 

 on each limb, about 1 foot apart, an average of 21 limb bands per tree, 

 73 percent of the total larvae captured were in the upper bands, 18 

 percent in the middle bands, and 10 percent in the lower bands. In 

 another test where two bands were placed on each trunk, the lower 

 band caught 56 percent of the total. Both these tests indicate that 

 not all the larvae stop in the first band they come to. 



