490 



galleries, so that the inner bark is girdled rapidly in thousands of 

 places, and the sap flow effectively checked. The f oUage turns yellow, 

 and by the following June is dead and red. During July, the beetles 

 leave the dead trees to attack other healthy pines in the neighbourhood. 

 In some districts the destruction has been almost as thorough as a 

 forest fire, while the distribution of the insects is wide. 



Although so destructive, the beetles can be effectively controlled 

 by destroying the broods in the infested area. This may be done by 

 modified logging operations, and often without great expense, since 

 in many valleys the trees that are cut may be utilised as lumber. 

 The general principle is to destroy 75 per cent, of the infested bark, 

 selecting the most heavily infested trees so that approximately 75 

 per cent, of the broods of beetles will be destroyed. If the infested 

 district is being logged, the logs are immersed in water in the spring 

 long enough to kill the broods ; or else they are sawn during winter, 

 and the slabs burned ; or they are removed entirely from the neigh- 

 bourhood. 



If logging is not profitable, the trees should be barked, either standing 

 or felled, and the bark burned. 



The progress is described of control work in the Coldwater and 

 adjacent valleys — the first extensive work on these lines ever under- 

 taken in British Columbia, from which hopes are entertained of a 

 great saving of timber. 



Beittain (W. H.). General Results in Spraying and Dusting. — 



56th Ann. Rept. Nova Scotia Fruit Growers' Assoc, Kingston, 1920, 

 pp. 68-82. 



This paper summarises the advances in methods of orchard pest 

 control that have been made since 1914. 



The discovery of the apple- sucker, Psylla mali, in Nova Scotia is 

 noticed [R.A.E., A, vii, 506], and investigations on hme sprays against 

 it, either in late autumn or in the spring, are proposed. It is not 

 however regarded as a very serious pest at present. Poison sprays 

 against the apple maggot [Ehagoletis pomonella] should consist of lead 

 arsenate (21b. to 40 gals, water) without the addition of sweetening 

 materials, which do not greatly attract the flies, and which often injure 

 the foliage. The trees should be covered thoroughly so as to compel 

 the flies to feed on the poison during the egg-laying period [loc. cit, 

 vii, 302]. Two appHcations, one in the middle of July and one about 

 the first of August, were very effective. 



Much of the information on the development of spraying and dusting 

 has already been noticed [loc. cit., vi, 559 ; vii, 304, etc.]. With 

 regard to the danger of the apples falHng owing to the apphcation of 

 lime-sulphur with high capacity machinery, it is advised that lime- 

 sulphur should not be used in a drenching spray, but should be appHed 

 in the form of a mist. It should not be used for the fourth spray, i.e., 

 that apphed ten days or a fortnight after the apple blossoms fall, but 

 modified Bordeaux mixture made on the formula 3-10-40 or 2-10-40 

 should be substituted. In fact the latter mixture may be used for 

 aU the spraying operations, though it will probably cause a shght 

 russetting if used for the third spray. 



