36 NEW YORK STATE MUSEUM 



led the Entomologist to study carefully the cases and the behavior 

 of the trees through the season. A comparison was also made 

 between the condition of these trees and injury of earlier years 

 following applications of petroleum. He was unable to note any 

 material difference between the two and, furthermore, observed 

 a marked restriction of the damage to trees or even portions of 

 trees which had received the application. After a careful study 

 of the various phases of the matter he was forced to conclude 

 that a certain measure of risk attaches to the application of min- 

 eral oils or preparations of the same to trees in a dormant con- 

 dition. This matter is discussed in detail in the Entomologist's 

 report. 



Fruit tree pests. The experiments conducted by the Entomol- 

 ogist during the last three years against the codling moth were 

 continued in the orchard of Mr Thomas Albright, of New Bal- 

 timore, and very satisfactory returns obtained. The check or 

 unsprayed tree produced only 38.95 per cent of sound fruit, while 

 sprayed trees of the same variety, less than 100 feet away, yielded 

 over 97 and in some instances more than 98 per cent of worm- 

 free apples. The results of this experiment and those of earlier 

 years were checked by a careful study of representative trees in 

 the orchards of Messrs W. H. Hart, of Poughkeepsie, and Ed- 

 ward Van Alstyne, of Kinderhook. These latter were sprayed 

 under strictly commercial conditions with no expectation at that 

 time of their being subjected to a test later. The results in these 

 commercial orchards were very gratifying. The northern spies 

 belonging to Mr Hart produced an average of over 98 per cent 

 of sound fruit, while the greenings and Baldwins on the Van 

 Alstyne place gave an average of over 96 per cent of worm-free 

 apples. The past four years' experiments go far to show that 

 under normal crop conditions one thorough and timely spraying 

 for the codhng moth should result in producing from 95 to 98 

 per cent of sound fruit. These tests are of great practical value 

 to the fruit grower, since they afford a reliable basis for correctly 

 estimating the value of spray applications. 



The pear thrips, a minute insect which blasted or nearly de- 

 stroyed the pear crop in a few orchards in the Hudson valley, 

 was studied with special reference to conditions favoring injury, 

 and the efficacy of spraying with a tobacco preparation demon- 

 strated. The insect, potentially a very dangerous form, is discussed 



