544 



]\IcKay (M. B.). Occurrence of Tylcnchus dipsaci on Alfalfa in 

 Oregon. — Phytoi>athology, Lancaster, Pa., xii, no. 2, February 

 1922, p. 105. 



Tylenchus dipsaci, Kiihn, caused serious injury to lucerne in Oregon 

 in 1921. It was found to be readily transferable by inoculation to 

 clover, to which it caused typical injury. It occurs in Oregon on clover 

 and strawberries, and does damage in both irrigated and non-irrigated 

 regions. 



Poole (R. F.). Celery liHosaic.—Phytopathologv, Lancaster, Pa., 

 xii, no. 3, March 1922, pp. 151-154, 1 plate, 1 fig. 



The mosaic disease described, which occurred in 1921 on celery in 

 New Jersey, was possibly transmitted from adjacent tomato plants. 

 Myzus persicae was a common Aphid on the celery plants, and the 

 disease has been experimentally transmitted by it. 



Eyer (J. R.). Notes on the Etiology and Specificity of the Potato Tip 



Bum produced by Empoasca mali, Le Baron. — Phytopathology, 



Lancaster, Pa., xii, no. 4, April 1922, pp. 181-184. 



The results of these observations show that the substance producing 



tipburn is specific and cannot be simulated by inoculations with 



extracts from, or by direct feeding of, insects other than Empoasca mali, 



or by mechanical injury. The active principle is most virulent in the 



nymphal stage. The absence of sunlight does not prevent the disease, 



though it may inhibit its progress. 



Rand (F. V.). Insects as Disseminators of Plant Diseases. I. Results 

 of Past Investigations.^ — Phytopathology, Lancaster, Pa., xii, no. 5, 

 May 1922, pp. 225-228. 



The first demonstration of insect dissemination of any disease was 

 given in 1891, when Waite showed that fireblight [Bacillus amylovonts] 

 of pomaceous fruit trees was brought about almost exclusively by the 

 agency of insects. Subsequent observations along these lines are 

 reviewed, the results of which show that there are 16 or 17 bacterial 

 diseases and about 40 fungous chseases in which insects play a part. 

 In the case of the mosaic group of diseases, insect transmission has been 

 demonstrated for over 59 hosts. 



Ball (E. D.). Insects as Disseminators of Plant Diseases. II. 

 Systematic Relations of Carriers. — Phytopathology, Lancaster, Pa., 

 xii, no. 5, May 1922, pp. 229-231. 



The various methods by which plant diseases may be disseminated 

 by insects are discussed, instances being given of transmission both 

 accidental and otherwise. 



Caesar (L.). Insects as Disseminators of Plant Diseases, in. Control 

 Problems. — Phvtopathology, Lancaster, Pa., xii, no. 5, May 1922, 

 pp. 231-233. 



The general recommendations for the control of plant diseases carried 

 by insects, as outlined by many investigators, require the prompt 

 destruction of all plants showing sjinptoms of infection, of any weeds 



