105 



the terminal buds where they remain until the leaves unfold in the 

 spring. 



It is thus seen that the pest is well protected at all seasons from anjr 

 poisonous application which might be made. We found that kerosene 

 emulsion would not reach them while in the galls, and it was thought 

 recourse must be had to mechanical means, such as removing and burn- 

 ing the infested leaves which might be practicable on a few choice 

 trees, or by carefully ])runing and burning the young wood in the 

 winter, thus destroying the hibernating mites. Both these methods 

 would be laborious and impracticable on a large scale. 



While experimenting to learn the effect of pure kerosene on dormant 

 wood, I noticed the thoroughness with which the oil penetrated every 

 crevice of the wood, and at once suspected that it might be used with 

 effectiveness against the Pear Mite while in its winter quarters. Last 

 fall I therefore marked several small trees which were very badly in- 

 fested, and in February two trees were treated with pure kerosene; on 

 another tree kerosene emulsion (Riley-Hubbard formula) diluted with 

 2^ parts of water was applied with a brush. One tree was left untreated 

 as a check. This spring the mites appeared in force on the check tree, 

 but upon the trees treated with the kerosene emulsion not more than a 

 dozen galls have been formed, the pest thus being nearly exterminated. 

 The trees treated with j)ure kerosene were very seriously injured, but 

 the only effect upon the tree treated with the emulsion w^as a slight 

 retardation in the unfolding of the leaves in the spring. 



This single experiment on so small a scale is of course only an indi- 

 cator, but could anyone have seen the check tree and the one treated 

 with the emulsion last season and this, I think he would agree that the 

 result strongly fortifies the statement that in kerosene emulsion con- 

 taining at most 20 per cent of kerosene we have a very practicable rem- 

 edy for this pest when in its winter quarters. 



The coming winter more extensive experiments will be made and next 

 spring I hope to report equal success with even a less percentage of 

 kerosene applied with a common sprayer. 



Mr. Lintner reported the insect as excessively abundant in eastern 

 [New York, and Mr. Webster reported it very abundant in Ohio, and 

 stated that spraying with Bordeaux mixture had not shown any bene- 

 ficial effect. 



Mr. Smith stated that in New Jersey the Phytoptus pyri has been 

 I more than usually abundant. It is, however, very much less trouble- 

 some in sprayed orchards than in those unsprayed. The station rec- 

 ommends for orchard practice a spraying before the flower buds open, 

 using carbonate of copper dissolved in ammonia as the fungicide, and 

 London purple as the insecticide. Two sprayings with the same mixture 

 are made after the fruit has set, and after that the fungicide, alone is 

 used. In orchards so treated no injury was done, while in untreated 



