45i 



Province of Don, where this disease is prevalent. These confirm the 

 view that infection may take place through the food as well as through 

 contact with infested silkworm eggs ; cockroaches and similar insects 

 are also liable to this disease and may act as carriers of it amongst 

 silkworms. 



Prostosserdov (N. N.). Kyjibiypa h o6pa6oTKa nan bi» 3aKaBKa3bt. 



[The Cultivation and Treatment of Tea in Transcaucasia]. 

 Petrograd, 1917, 60 pp., 29 figs. 



The tea-mite [Teiranychus hioculatvs], scale-insects and the mole- 

 cricket {GryUoivd'pa], the latter especially injuring young plants, are 

 here recorded as pests of tea in Transcaucasia. 



Pliginsky (V.). PacTMTenbHbie KnemMKM, epeflflmie caflOBOflCTBy. 



[Plant-Mites injurious to Horticulture.] — «CaflOBOA"b.» [The 

 Horticulturist], Rostov-on-Don, xvi, no. 1, January 1917, pp. 40- 

 45, 9 figs. [Received 27th August 1917.] 



The author is of opinion that the spread of Eriophyid mites, which 

 he studied in the government of Kursk, where they are very common, 

 is efiected through the medium of seedling plants. 



In the case of Eriophyes pyri, Pag., which is common on pear trees, 

 this view is borne out by the fact that all the large nurseries throughout 

 Russia are seriously infested with this mite, and it is thought that 

 90% of the trees in nurseries are thus attacked. This species is found 

 practically all over the orchard-region in Russia. Though in this area 

 wild pear trees suffer from this pest to the same extent as cultivated 

 ones, the infection from these sources can only take place very slowly 

 and then chiefly through the medium of wind or fallen leaves. The 

 control of this mite should therefore be effected mainly in the nurseries, 

 for which purpose fumigation with hydrocyanic acid is the best 

 remedy ; fumigation of all seedlings ought to be made compulsory. 



E. ribis, Nal., is also very widespread, and though it is believed to 

 be carried by wind, birds and insects, the chief agent of its distribution 

 is provided by cuttings of currants used for propagation. Fumigation 

 with hydrocyanic acid does not always destroy the eggs of this pest 

 inside the bud, and further experiments should lead to the discovery 

 of a more effective method for the application of this gas. Other 

 remedies include the disinfection of seedlings by immersing them in 

 water heated to about 115° F. ten minutes before planting ; the 

 removal and burning in spring of the infested buds ; careful cleaning 

 of the orchard in spring and autumn from fallen leaves, etc. ; 

 powdering the previously wetted plants with a mixture of 2 parts of 

 flowers of sulphur with 1 part of lime, this being done in March and 

 repeated again in April and May. 



Leaves of plums all over Central Russia are infested with E. padi, 

 Nal., and E. senilis, Nal., both of which also live on blackthorn; 

 their life-histories have not been fully worked out ; the best known 

 remedy is the removal and burning of fallen leaves in autumn. The 

 same remedy can also be used against E. tiliae, Pag., occurring on 

 lime trees and E. tnacrochelus, Nal, E. macrorrhynchus, Nal, and 

 Phyllocoptcs gymnaspis, Nal., on maples. 



