Xew York Aork ulttiial Experiiment Station. 361 



Nozzles adapted to making a rather coarse, driving spray were 

 then attached to the spraying poles and two power spraying rigs 

 were used to apply the mixtures in order to insure the treatment 

 of all of the orchard during the day. Provision was also made 

 for a test of oil emulsion alone or in combination with the nico- 

 tine extract to determine comparative penetrating properties. See 

 Fig. 5, Plats A, B, C. With the use of the new nozzles and by 

 taking more pains to direct the spray into the ends of the buds a 

 large percentage of the thrips were killed. The reduction in the 

 numbers of the insects resulted in a conspicuous difference be- 

 tween sprayed and unsprayed trees which began to show on the 

 following day and noticeably increased as the days passed by. The 

 contrast was largely due to the unwithered and freshened appear- 

 ance of the blossom and leaf clusters of the sprayed trees in com- 

 parison with those on the untreated trees which were beginning to 

 turn brown and were now wet with sap. These differences were 

 noted and commented on by quite a number of visiting orchard- 

 ists in the community. The spraying mixtures seemed to be 

 equally effective. Nevertheless the oil emulsion possesses superior 

 penetrating properties, and as a result of the day's test it is be- 

 lieved that the use of emulsion with the nicotine should make the 

 combination the most desirable spray for the treatment of par- 

 tially opened buds and compact blossom clusters to reach the hid- 

 den thrips. 



On May 1 the blossom clusters were generally separated at the 

 tips, and the thrips were now feeding mainly at the points of con- 

 tact of two flower buds. The entire orchard was sprayed again 

 as outlined in Fig. 5, Plats A, B, C. The exposed positions of 

 the thrips, due to the spreading of the blossom clusters, rendered 

 them very susceptible to all of the treatments and because of the 

 large percentage that were killed no further spraying was deemed 

 necessary for the adults. 



On ]\ray 10 the larvae were apparently out in their maximum 

 numbers and were most noticeable in the calyx basins of the young 

 fruits and on the under surfaces of the leaves. To prevent in- 



