401 



Severin (H. H. p.). Practical Use of Curly Leaf Symptoms. — Facts 

 about Sugar, New York, xii, nos. 9 and 11, 26th February & 12th 

 March 1921, pp. 170-171, 173, and 212-214, 217, 25 figs. 



The symptoms of curly leaf disease of beet conveyed by Eutcttix 

 icnella are discussed and compared with cases of abnormal beet fohage 

 and insect injury such as is caused by Empoasca viridescens. The most 

 constant and reliable symptom is a transparent network of minute 

 veins, generally occurring on the youngest leaves. 



During an outbreak of the disease in 1918-19 observations were 

 made in California on such conditions as environmental factors and the 

 effects of drought. During this outbreak the percentage of curly 

 leaf was not in proportion to the leaf-hoppers present, the condition 

 being attributed to the shortage of rainfall. 



The beet leaf-hopper, Eutettix tenella, was also taken on Atriplex 

 €xpansa and A. rosea [of. R.A.E., A. vii, 474]. 



Pettit (R. H.). The European Corn Borer. — Michigan Agric. 



Expt. Sta., East Lansing, Circ. Bull. 44, November 1920, 3 pp., 



4 figs. [Received 21st June 1921.] 

 To prevent the establishment of the European corn borer [Pyrausia 

 nubilalis, Hb.] in Michigan all suspected occurrences of the pest should 

 be at once reported. The effects of the borer on various parts of the 

 maize plant are illustrated. 



Prorogation de I'Emploi des Sels arsenicaux dans la Vigne. (Decision 

 ministerielle du 27 avril 1921.) — Rev. Agric. Afr. Nord., Algiers, 

 xix, no. 98, 17th June 1921, pp. 461-462. 



The use of soluble arsenical salts for protecting fruit trees and 

 vines is permitted from the end of the vintage season of 1921 up to 

 the beginning of the vegetative period in 1922. Such arsenicals may 

 be delivered and used only if dyed a blue colour according to the 

 following formula: soluble arsenicals 1,000 gms., pure diamin blue 

 3gms.' 



Jegen (G.). Die Blutlaus. [The Woolly Aphis, Eriosoma lani- 

 gerttm.] — Schiveiz. Zeitschr. Obst- u. Weinbau, Frauenfeld, xxx, 

 no. 12, 18th June 1921, pp. 182-185. 



General measures against Eriosoma lanigerum comprise the selection 

 for given localities of those varieties of apple that are found to be 

 free from infestation there, and the proper nourishment of the trees, 

 especially of young ones. 



Combative measures include a summer treatment, consisting in 

 spraying the trunk and branches with a 2^ per cent, solution of soft- 

 soap, beginning as soon as patches of the Aphid appear, and a winter 

 treatment — the more important one — in which spraying is done with 

 a 7 per cent, solution of soft-soap, applied freely, so that the drippings 

 may soak the ground around the trunk. 



PicARD (F.). Sur deux Scolytides des Arbres fruitiers et leurs Parasites. 



■ — Bull. Soc. Path. Veg. France, Paris, viii, no. 1, January-March 

 1921, pp. 15-20. [Received 22nd June 1921.] 



In the south of France fruit trees are attacked by several Scolytid 

 beetles, including Scolyttts rugulosus, Ratz., S. aniygdali, Guer., 

 Xyleborns dispar, ¥., and X. xylographus, Say {saxeseni, Ratz.). 



