36 



BULLETIN 265, U. S. DEPARTMENT OP AGRICULTURE. 



this orchard. The owner found it necessary to prop some of the 

 more heavily loaded limbs, and these props were not banded. Some 

 of the lower limbs, too, became so heavy that they were practically 

 lying on the ground. This prevented the bands from forming an 

 absolute protection against the worms, but there was sufficient pro- 

 tection to make a decided difference. The results of the apple 

 counts made on October 5 are given in Table XXV. 



Table XXV. — Number and percentage of apples injured by the dock false-worm in the 

 experimental plats, Entiat, Wash., 1915. 



Condition of 



Plat A (commercial sticky substance). 



Plat B (cotton). 



fruit. 



Tree 1. 



Tree 2. 



Tree 3. 



Tree 4. 



Plat. 



Tree 1. 



Tree 2. 



Tree 3. 



Tree 4. 



Plat. 



Injured 



298 



19 

 510 



7 

 628 



4 

 700 



37 

 2,136 





 170 



2 

 332 



11 



466 



4 

 620 



17 



1,588 





Total 



305 



529 



635 



704 



2,173 



170 



334 



477 



624 



1,605 



Per cent injured. . 



2.30 



3.59 



1.10 



0.57 



1.70 



0.00 



0.60 



. 2.30 



0.64 



1.06 



Condition of 





Plat C (weeds cleared). 





Plat D (check). 



fruit. 



Tree 1. 



Tree 2. 



Tree 3. 



Tree 4. 



Plat. 



Tree 1. 



Tree 2. 



Tree 3. 



Tree 4. 



Plat. 





5 



185 



23 

 535 



14 

 272 



4 

 133 



46 

 1,125 



25 

 351 



22 

 531 



38 

 556 



22 

 483 



107 





1,921 







Total 



190 



558 



286 



137 



1,171 



376 



553 



594 



505 



2,028 



Per cent injured.. 



2.63 



4.12 



4.90 



2.92 



3.93 



6.65 



3.98 



6.40 



4.36 



5.27 



This period was almost rainless, and the bands of cotton and com- 

 mercial sticky substance were in perfect condition on October 5. No 

 difference in effectiveness can be ascribed to the two materials used 

 for bands, the average infestation for the two plats being 1.43 per 

 cent. This is an infestation of only a little over one-fourth that of 

 the check plat. The slightly greater infestation in Plat A (1.70 per 

 cent, as against 1.06 per cent in Plat B) was due to the fact that five 

 props were used in this plat, while only one was used in Plat B, 

 giving the worms more opportunity of reaching the fruit in the former. 

 It was noticed in picking the fruit in these plats that most of the 

 injured apples were on the lower limbs and the limbs that were 

 propped. Practically none were found in the tops of the trees. 



The results in Plat C show that merely clearing away the weeds 

 and clipping off the lower branches is of some value, the infestation 

 being about three-fourths that of the check plat. This method may 

 be recommended where banding materials are not at hand. 



In general, it may be stated that efficient protection will be secured 

 from the dock false-worm by banding the trees with cotton batting 



