480 



its food-plant being the common snowberry {Syinphoricarptts race- 

 mosus). A list is also given of the mere uncommon insects taken in 

 British Columbia during the vear under review. 



Gibson (E. H.)- A Review of the Leafhoppers of the Genus Gypona 

 North of MexicOc — Proc. U.S. National Mas., Washington, Ivi, 

 1919, pp. 87-100. 



A key to the Genus Gypona is given, with descriptions of eight 

 new species. These leaf-ho])pers often occur in considerable numbers 

 in limited areas, assuming the proportions of a concentrated outbreak. 



Eegan (W. S.). Late Dormant versus Delayed Dormant or Green 

 Tip Treatment for the Control of Apple Aphids. — Massachusetts 

 Agric. Expt. Sfa., Amherst, Bull. no. 18-J, July 1918, pp. 47-57. 

 [Received 3rd September 1919.] 



The results obtained in these experiments are summarised by the 

 author as follows : — The delayed dormant period is usually indicative 

 of the complete hatching of apple Aphid eggs. At this time the 

 buds have expanded from a quarter to half an inch. Lime-sulphur 

 solution at full dormant-season strength is less than 10 per cent, 

 effective against the living Aphids when applied at the delayed dormant 

 period. Lune-sulphur applied at the late dormant period, before 

 the buds split open and just before the hatching of the eggs, appears 

 to be highly effective under favourable conditions in destroying the 

 eggs, but the elements of thoroughness of application and unfavourable 

 meteorological conditions present such uncertainty as to results that 

 this treatment can hardly be recommended as an effective control. 

 If lime-sulphur is to be used as a control for San Jose scale [Aspidiotus 

 pcrniciosvs] and no special treatment for ap])le Aphids is to be made 

 later, the best results against Aphids are likely to be obtained by a 

 late dormant-season ap])lication just before the eggs hatch. Treat- 

 ment at this time should also be thoroughly effective against the 

 scale. The application of lime-sulphur (1 to 8) and nicotine sulphur 

 (1 to 800) combination applied at the delayed dormant period gives 

 practically a perfect control for apple Aphids and makes unnecessary 

 a separate earlier application of lime-sulphur for San Jose Scale. 

 The percentage of efficiency will depend mainly upon thoroughness 

 of application. The ordinary dormant-season treatment of apple 

 orchards with miscible oil against San Jose scale, if aj)plied thoroughly 

 at the delayed dormant period, should result in practically a perfect 

 control of apple Aphids also. Delayed dormant applications of full 

 dormant-season strength lime-sulphur, lime-sulphur and nicotine 

 sulphate combined and miscible oils, if perfect, can be made without 

 material injury to apple foliage. Even when the foliage is considerably 

 more advanced, little severe injury usually results. This fact, if 

 taken into account, might make unnecessary separate applications 

 for early and late-budding varieties. As the foliage becomes more 

 advanced, however, the success of the treatment involves greater 

 difficulty, since the Aphids are very hard to reach when they have 

 the spreading leaves for protection. The action of lime-sulphur in 



