IXSECT NOTES FOR 1912. 465 



SPRAY TEST FOR CONIFERS. 



It seems often desirable to recommend sprays for coniferous 

 trees infested by aphides and there is apparently not much data 

 as to spray injury on such trees. For this reason Mr. William 

 0. Woods applied the sprays here indicated upon young healthy 

 conifers at Orono as follows: 



(a) Whale oil soap. One pound in two gallons of water. 



(b) 69-70 Bowker's Lime-sulp'hur (i part of lime-sulphur to 

 40 parts of water). 1-70 Nikoteen (i part of Nikoteen to 400 

 parts of water). 



(c) Scalecide. (i part Pratt's Scalecide to 25 parts of 

 water. ) 



On August 25, 191 1, Red Spruce, WHiite Spruce, White Pine, 

 Balsam Fir, and Larch were sprayed with (a) and (b). On 

 September 5, 191 1, the same species of trees were sprayed 

 with (c). 



About mid July, 191 2, the sprayed trees were visited and 

 careful comparison made between these and the nearest un- 

 sprayed checks. 



(a) (b) (c) • 



Larch Xo injury No injury No injury 



Red Spruce (Trees not located). (Trees not located).- No injury 



White Spruce No injury No injury No injury 



White Pine No injury No injury No injury 



Balsam Fir Slight injury. A few leaves Tree alive. 



Tree had grown dead. No 12 branches 



2 ft. other injury. dead. 38 



branches 

 badly 

 injured. 

 The experiment was not on a large enough scale to permit 

 any sweeping generalizations, but the results certainly indicate 

 no especial susceptibility on the part of these conifers to injury 

 by sprays ordinarily used on other vegetation in combating 

 scale insects and aphides. The sprays were 'heavily applied 

 until the branches were dripping and' a year, later all the trees 

 were in good condition except two of the Balsam Firs and as 

 some unsprayed Balsam Firs in the vicinity selected for checks 

 were also in an unthrifty condition the evidence that the state 

 of these trees was due to the spray was not at all conclusive. 



