1920 



ENTOMOLOGICAL SOCIETY 



37 



Checks. Sixteen batches of eggs were left untreated at various times while 

 the foregoing experiments were being conducted. These served as checks. Out. 

 of a total of 1,346 eggs, 93 per cent. -hatched. 



Effects ox Xymphs. The few tests which were made with lime-sulphur, etc., 

 on recently hatched nymphs were sufficient to shoAV that 1st and 2nd instar nymphs 

 are readily destroyed by lime-sulphur 1-8 and 1-9, with or without starch. 



Table X — Effect of Spray Mixtures ox Recently Hatched Psylla Nymphs. 



Treatment. 



No, of 

 Tests 

 made. 



Total 



No. of 



Nymphs 



his tar. 



Average 



per cent. 



killed. 



Actual 



per cent. 



killed. 



Lime-Sulphur, 1-8 • 



Lime-Sulphur, 1-9 



Lime-Sulphur, 1-9 ..) 



Starch, 2 lbs. to 40 i 



Lime-Sulphur, 1-10 



Lime-Sulphur, 1 to 10 > 



Starch, 2 lbs. to 40 ] 



Total 



12 



47 

 107 

 371 



88 



85 



85 



271 



1,054 



1st 



2nd 

 1st 

 2ud 



1st 



1st 



1st 



100 



100 



98 



100 



100 



91 



96 



100 

 100 

 95.2 

 100 



100 



91 



96 



OnCHAED ExPEr.i:XIEXTS. 



S. M. Gulp's Orchard. Our orchard experiments on the control of psylla 

 were conducted at Beamsville in S. M. Gulp's thirteen-acre orchard of Bartlett, 

 Duchess, Kieffer, Flemish Beauty, Bosc, Winter Nelis and Anjou pears. The mild 

 winter of 1918-19 was very favorable for the hibernating adults and in the spring 

 they emerged in large numbers and a large deposition of eggs was made. 



First Application. The first application, i.e. the application to destroy 

 the eggs, was put on by means of a spray gun at the usual time,* and the following 

 spray mixtures were used : 



1-7 



1-9 



2 lbs. to 40 gallons 



1-10 



2 lbs. to 40 gallons 



(1) Lime-sulphur 

 Lime-sulphur 



(2) Starch 



(3) Lime-sulphur 

 Starch 



(4) Soluble sulphur 12i^ lbs. 

 Hydrated lime 10 lbs. 

 Water 40 gals. 



No one spray mixture, so far as we could judge, proved superior to the others. 

 Each destroyed practically all the eggs and exposed nymphs. The nymphs which 

 had hatched out before the sprays were applied and had sought shelter in the leaf 

 buds beneath the bud scales were uninjured. These averaged about 1.5 to a leaf- 

 bud on all varieties other than Kieffer. On the Kieffer trees the infestation was 

 about .18 to a leaf cluster. This difference no doubt was due to the fact that 

 the Kieffer trees were out in leaf when the spray was applied and therefore did 

 not afford the nymphs much protection. 



* The Pear Psylla in Ontario— Report of the Ent. Soc. of Ont., 1918, pp. 81-90. 



