417 



QuAiNTANCE (A. L.). The San Jose Scale and its Control. — U.S. Dept. 



Agric, Washington, D.C., Farmers' Bull. no. 650, 30th March 



1915, 27 pp., 17 figs., 2 tables. 

 The San Jose scale, Asjndiotus perniciosus, infests all deciduous 

 fruit trees, as well as many ornamental and shade trees. On peach, 

 the scales usually attack the older branches ; on apple and pear, the 

 terminal twigs are infested, many of the young finding their way to 

 tlie fruit. Once established in a locality, its spread is accomphshed 

 by birds, wind or insects. Numerous natural enemies serve to control 

 the scale. Among predaceous insects the Coccinelids, Microweisea misella 

 and Chilocorns hivnlnerus, are the most important, and the following 

 parasites have beeii reared : Aphelinus fuscipennis, A. nujtilaspidis, 

 Aspidiotiphagus citrinus, Physcus varicornis, ProspalteMa sp., Rhopoi- 

 deus citrinus, etc. A fungus disease, due to Sphaerostilbe coccophila, 

 has been investigated ; its abundance has been found to depend on 

 weather conditions. The only means of artificial control is by spraying 

 after the removal of dead or weakened wood. Three series of sprays 

 are considered : (1) lime-sulphur wash series ; (2) petroleum-oil 

 series (including miscible oils) ; (3) soap washes. Commercial lime- 

 sulphur, if used at the proper strength, has proved satisfactory m 

 controlling the scale. It has been found possible to prepare lime- 

 sulphur concentrates at home for immediate or later use ; 50 U.S. gals, 

 water is brought to the boiling point and to it is added 50 lb. of lime 

 and then 100 lb. sulphur. The mixture is stirred and strained through 

 a 30-mesh strainer. The solution should be stored in air-tight recep- 

 tacles. The strength of the solution thus prepared should be tested 

 with a hygrometer, to determine the amount of concentrate to use in 

 a given quantity of w^ater. A dilution table of concentrated solutions 

 is given. Spraying should be carried out when the trees are dormant ; 

 summer spraying should only be performed if absolutely necessary, 

 and a self-boiled mixture should be used. The latter is made up in 

 the proportions of 8 lb. lime, 8 lb. sulphur to 50 gals, water. The 

 lime is covered with w^ater and sulphur gradually added ; sufficient 

 heat is generated to boil the mixture for several minutes ; the 

 remainder of the water is added, the solution strained, diluted and 

 apphed. Pure kerosene can only be applied to dormant trees ; the 

 same holds for pure cnide petroleum. Kerosene emulsion, consisting 

 of 2 gals, kerosene, h lb. fish-oil soap and 2 gals, water, forms a suitable 

 spray The emulsion is diluted to 10-20 per cent, before using. Cmde 

 petroleum emulsion, prepared as above, should not be used in summer, 

 as it is hkely to cause injury to the foliage. Miscible oils, consisting 

 essentially of petroleum oils with the addition of a vegetable oil and an 

 alkali, are very useful for winter spraying. Fish-oil soap wash, at 

 the rate of 1 lb. to 1 gal. water, is used on dormant trees ; a more 

 dilute solution can be used to spray the foliage. Various kinds of 

 spraying apparatus are described. Severe pruning of infested trees 

 is desirable to simplify the work of treatment. 



IMiDDLETON (W.). U.S. Bureau Entom. Notes on some Sawfly Larvae 



belonging to the Genus Dimorphopteryx.—Proc. U.S. Nat.Mns., 



Washington, D.C, xlviii, 18th March 1915, pp. 497-501, 4 figs., 



1 plate. 



Dimorphopteryx castaneae occurs m the early larva], ^5;t*ges on the 



(C180) Wt. P12/91. 1500.8.15. B.&F.Ltd. Gp. 11/3. y^<'''''' 



