74 THE CANADIAN ENTOMOLOGIST 



subject to injury. They also state that it is not a serious pest in 

 Holland. In New Jersey, it is customary for owners of bay trees 

 to keep them out of doors during the summer, and cool, storage 

 sheds where the temperature is around 38 and 40 degrees F. during 

 the winter. It is during the summer months, of course, when the 

 trees are either outside or under glass that most of the damage 

 takes place. Sometimes nearly every leaf on a tree is curled and 

 discoloured, but as a rule it is the young, developing leaves which 

 are infested. Trees thus disfigured are not salable, and when one 

 considers that bay trees sell at from $10.00 to $100.00 and more for 

 single specimens it is readily seen that a considerable money loss 

 can be laid at the door of this psyllid. 



Coming to remedies, picking off and destroying the infested 

 leaves is one method, practical only if the infestation is slight or the 

 number of infested trees small. Eight ounces of Black Leaf 40 

 plus eight pounds of whale-oil soap to one hundred gallons of water 

 has been used in New Jersey with a fair degree of success as a sum- 

 mer spray. It is impossible, however, to reach the nymphs pro- 

 tected by the tightly curled edges of the leaves. According to 

 Dafert and Kornauth in the Report on the Work Done at the 

 Imperial and Royal Chemical Research Station in Vienna, 1913, 

 pp. 80-95, a review of which appears in the Review of Applied 

 Entomology, Series A, vol. II, 1914, p. 482, cyanide fumigation 

 was tried against Trioza alacris Flor., on laurel with complete suc- 

 cess. The reviewers state that the American 1-1-3 formula was 

 used, but nothing is said about the cubic contents, temperature, 

 length of exposure, etc. 



At one place in New Jersey, where the infestation was severe 

 during the summer and not completely controlled by the nicotine 

 and soap spray, many last stage nymphs and adults were found 

 on the trees November 15, after they had been placed in a storage 

 shed, and it seems quite probable that fumigation with hydro- 

 cyanic acid gas at this time might be effective, inasmuch as both 

 forms were fairly active. The adults evidently hibernate on the 

 bay trees and become active as the temperature increases. An- 

 other dealer in bay trees in New Jersey allows his trees to remain 

 out of doors until late in the season, taking them in only shortly 



