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THE CANADIAN ENTOMOLOGIST. 



plied to the interior and exterior of the tree, so that the droplets 

 adhered to the upper and lower surfaces of the leaves. The time 

 required to spray one tree was estimated at half a minute to a 

 minute. 



Non-isolated orchards. — During a number of years spraying 

 experiments were carried on in a number of olive gardens which 

 were adjacent to one or more untreated olive plantations, and con- 

 sequently more intimately exposed to the invasion of the fly. In 

 1908 three small orchards encircled by neighbouring olive groves 

 were treated. In 1909 a number of orchards composed of about 

 2,000 trees, and in contact at numerous places with neighbouring 

 olive gardens, was sprayed. In 1907 two non-isolated orchards 

 were sprayed. The first contained about 2,500 trees, and was en- 

 circled by olive groves. The second was composed of about 3,000 

 trees, grouped in a score of orchards, and was situated at the junc- 

 tion of two rivers and rose in a succession of terraces on the side of 

 a hill to an elevation of 600-800 meters. The results obtained are 

 shown in Table III. The two columns of figures under the head- 

 ing, "olives infested in treated orchard," represent different var- 

 ieties of olives, the same variety being used as a check under the 

 heading, "olives infested in untreated orchard." Compare the first 

 column of figures with the third, and the second with the fourth. 



TABLE III. 



From this table it is evident that in the small, non-isolated 

 olive gardens the treatment reduced the infestation between 40 and 

 50 %. According to the authors, by increasing the number of ap- 

 plications of the spray, the infestation could be reduced still more. 



