WASHINGTON 



fy/amoo/r 



STEM NEMATODE ON WILD HOSTS. 6 



of 1922. While these surveys were not by any means exhaustive, 

 they covered typical localities and a considerable range of territory. 

 The results of the various surveys indicate that the stem nematode 

 occurs definitely on one host or the other throughout practically the 

 entire length of the Oregon coast line and in at least Pacific County 

 in Washington. In addition, it occurs inland in Willamette Valley 

 at various points. The 

 southern limit is not 

 definitely known for 

 either host. On Fra- 

 garia chiloensis it is 

 abundant in Coos 

 County and also from 

 there northward to 

 the northern end of Til- 

 lamook County, where 

 it apparently ceases. 

 Hypochaeris radicata 

 was found to be affected 

 in the southern part of 

 Lincoln County and 

 northward, beyond the 

 range of the diseased 

 wild strawberries, into 

 Washington. It was 

 also found at Hillsboro, 

 St. Joseph, McMinn- 

 v i 1 1 e , and Corvallis, 

 Oreg. 2 At the last 

 point it occurred in 

 considerable abundance 

 on the campus of the 

 Oregon Agricultural 

 College. Material from 

 this source was used 

 for photographs (PL 

 II) and for preserving. 

 Cultivated strawberry 

 fields were found in- 

 fested to an extent that 

 was of rather serious 

 economic importance in 

 Coos and Lane Counties and to a minor degree at Corvallis in Benton 

 County. The distribution of the disease on its various hosts is shown 

 on the map. (Fig. 1.) 



APPARENT INDEPENDENCE OF THE TWO HOSTS. 



During the course of these surveys several interesting facts were 

 brought out in connection with an apparent lack of any correlation 



Fig. 1.— Map of western Oregon and southwestern Wash- 

 ington, showing the distribution of the stem nematode 

 (Tylenchus dipsaci) on cultivated strawberries (0)» 

 on wild strawberries (•.)> and on the false dande- 

 lion (X). 



2 During the summer of 1923 the nema disease was found in Hppoehaeris radicata 

 in great abundance at different points on Puget Sound, Wash., throughout the length of 

 Willamette Valley, Oreg., and southward along the coast as far as San Francisco, Calif. 



