12 



INSECTS INJURIOUS TO SUBTROPICAL FRUITS. 



The sprayed bldck containecl 121 beariuii- tive.s. These yielded 165 

 loose boxes of onuiiics. The iinsprayed block conlained l^y2 bearing 

 trees, which yielded 1<'>'J loose boxes of oranges. The sprayed block, 

 therefore, [produced three more boxes of fruit, though containing lU 

 less trees, than the unsprayeil block. 



Expoimcnt Xo. II. — A block of Washington Navel oranges em- 

 bracing about 5 acres was .selected in the s[)ring of I'.'IO and treated 

 three times with a spray of connnercial lime-sulphur (.'i;]° Baume). 

 1 pai't to 75 of water, combined with blackleaf tobacco extract. 1 to 

 150. A gasoline power sprayer was used and a pressure of •_*()() 

 pounds maintained. The first ai)plication Avas made May 4, the 

 second May IT. and the third June 14. The fir.st application was 

 timed at a dale when most of the petals had fallen. The second and 

 third applications were made when the thrips l)ecaine sulliciently 

 numerous. An effort was made to keep the young fruii free from 

 thrips until it was the size of an English walnut, as it appeared that 

 this would insure a high percentage of clean fruit. 



Examinations and counts made of *.>'i loose boxes of sprayed fruit 

 and 20 loose boxes of uns|)raye(l fruit from an a^ljoining iinsprayed 

 "check" block gave the results shown in Table III. 



T.vBLK III. — I II i til 11 to .siiiai/cd (111(1 iiii.sjndjKd fruit hii ontiif/c tliritts. 



SPRAYKD. 



UNSPRAYED. 



The sprayed fruit shoAvs a total of 40.9 per cent marked, while 71 

 per cent of the unsprayed fruit was marked, and more severely. The 

 amount of benefit due to the spraying Avas 30.1 pei- cent, which was 

 considerably less than in 1001), due to the fact that the thrii)s were 

 more numerous and infestation Avorse in ll)0i>. The total output of 

 oranges from Tulare County in 1010 Avas 50 per cent freer from 

 thrips markings than in 1009. 



EXPKKIMKNTS WITH NCRSKRY TRKES. 



SeA'eral blocks of young nnr'-ery trees Avere sprayed in the fall of 

 1000 with commercial lime-suli)hiir. 1 to 75, combined with black- 

 leaf tobacco extract. 1 to 150. By two thorough applications it Avas 



