already occurs in France, and the fact that it does not become a serious 

 pest there indicates that conditions are not favourable to it. On the 

 other hand, there may be some danger in importing from Central 

 Europe individuals that may differ from the indigenous ones in their 

 choice of food-plants. Another pest prevalent in Czecho-Slovakia, 

 the Pyralid, Loxostege {Phlyctaenodes) sticticalis, causes considerable 

 damage to the beet crops, and is beheved to be able to survive on 

 other plants, such as fruit trees or conifers. 



McCoLLocH ( J. W.) . A Method for Studying the Hessian Fly and other 



Insects. — Ann. Ent. Soc. Amer., Columbus, Ohio, xiv, no. 3, 

 September 1921, pp. 227-230, 1 fig. 



A method of growing plants in a nutrient solution instead of in soil 

 to facilitate life-history studies of insects proved so effective when 

 tried in connection with the study of Mayetiola destructor, Say, that 

 it has been successfully adapted in connection with studies on Blissus 

 leucopterus, Say (chinch bug), Toxoptera graminum, Rond. (green 

 bug) and Aphis maidis, Fitch (corn-leaf aphis). The technique of 

 this method and its many advantages are discussed. Pfeffer's 

 solution was used, the preparation of which is described. 



EwiNG (H. E.). New Nearctic Spider Mites of the Family Tetrany- 

 Chidae.— Pwc. U.S. Nat. Miis., Washington, D.C., lix, no. 2394, 

 1921, pp. 659-666, 1 plate. 



The new species described include Oligonychus americanus, which 

 causes considerable damage to leaves of spruce in Canada ; 0. major, 

 on avocado in Maryland ; Bryobia brevicornis, on lucerne in Arizona ; 

 Syncaligus quercus, on leaves of oak in New York ; and Tetranycliina 

 tritici, causing injury to wheat in Idaho. 



A key is given to distinguish the new species of Bryobia from 

 B. practiosa, Koch. 



IsAAKiDEs (C. A). La Lutte contre le Dacns en Chaleidique, dans le 

 Pelion et en Messenie. — Minist. Agric. {Serv. Phytopath.), Athens, 

 4th April 1921, 48 pp., 3 plates. [Received 31st October 1921.] 



The loss caused to the olive industry by Dacus oleae (olive fly) in 

 parts of Greece is estimated as being about 30 per cent., not only the 

 oil production but also the crop of olives for table use being seriously 

 affected. The early efforts, begun about 15 years ago, to check these 

 depredations are reviewed. In 1918 a law was passed, which is 

 appended to the present report, establishing a Commission for the 

 purpose of protecting olive trees from insect pests and diseases 

 or providing for their treatment when infested. A tax is imposed 

 upon infested districts for this purpose, and, in return, ingredients 

 and implements for treatment will be distributed, with instructions 

 for their use. The organisation and supervision of the technical 

 work of the Commission are entrusted to the Phytopathological 

 Service. 



Treatment was carried out during 1920 on a large scale, the spray 

 chosen as having given indications of the best results being composed 

 of 3 parts (by weight) of sodium arsenite to 100 parts of molasses 

 and 900 parts of water. Any larger proportion of sodium arsenite 

 resulted in injury to the trees, and the mixture even at this dilution 



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