415 



350 to 400 eggs. On the approach of cold weather or other unfavour- 

 able conditions, the females transform into a brown cyst that forms a 

 protective covering for the eggs. These may hatch a few at a time 

 during a period that may extend over several years. This probably 

 accounts for the fact that eelworms have been known to persist in 

 ground that has been kept free from all food plants for some years. 

 Although cold does not apparently injure the eggs in the cyst, they are 

 destroyed when exposed to a dry heat of 145° F. All other stages 

 succumb to 95° F. This Nematode in all forms may be easily carried 

 from place to place by boots, farm implements, etc. It has also been 

 spread by using, as fertilisers, waste water from the beet washers and 

 mud from the settling pond. Infested plants may be safely given to 

 sheep as fodder, as the Nematodes do not pass through the intestines of 

 sheep alive, but it is not yet known if this is true of other 'domestic 

 animals. 



In addition to feeding on plant juices, this pest causes irritation of 

 the plant cells, giving rise to abnormalities of the roots and spots, etc., 

 on the leaves. These appear about the end of July or in August. The 

 food-plants of H. schachtii include various crops of economic impor- 

 tance as well as weeds, a list of which is given. 



Crop rotation has proved the best means of eradicating this pest. 

 A list of non-susceptible plants is given, and beets and other susceptible 

 plants should only be included once in a rotation of about 6 years. 

 If the infested area is small the Nematodes may be destroyed by a 

 liberal application of unslaked lime, which should be well mixed with 

 the infested soil to a depth of about one foot and frequently turned 

 over during the summer. The method of surveying suspected fields 

 is described. Only the females and the brown cysts are visible to 

 the naked eye. 



Fisher (D. F.) & Newcomer (E. J.). Controlling important Fungous 

 and Insect Enemies of the Pear in the Humid Sections of the 

 Pacific North-west. — U.S. Dejjt. Agric, Washington, D.C., Farmers' 

 Bull. 1056, September 1919, 34 pp., 18 figs. [Received 27th July 

 1920.] 



The portion of this paper dealing with the insect enemies of pears 

 includes Syneta albida, Lee; San Jose Scale {Aspidiotus jjerniciosus, 

 Comst.) ; pear leaf blister mite {Eriophyes pyri, Pag.) ; the bud moth 

 {Eucosma {Tmetocera) ocellana, Schiff.) ; the pear slug {Eriocampoides 

 limacina, Retz.) ; and the pear leaf worm {Gymnonychus calif orniciis, 

 i Marl.). 



The methods of preparing and applying the various sprays advocated 

 ' against these pests are discussed, and a spraying schedule is included. 



Ferris (G. F.). Scale Insects of the Santa Cruz Peninsula. — 



Stanford Univ. California Public, Biol. Sci., i, no. 1, 1920,' 57 pp., 

 35 figs. 



This list of Coccids found at Santa Cruz does not include greenhouse 

 species. Of the 92 species dealt with, 60 are presumably native and 

 the rest imported. 



The new species described include Eriococcus paenulatus on the 

 smaller stems of Artemisia californica ; E. stanfordianus ; E, vHhsus 



