8 BULLETIN 1229, U. S. DEPARTMENT OF AGRICULTURE. 
that became affected as a result of such inoculations. Attempts to 
inoculate other hosts with the Hypochaeris strain have thus far 
failed. Further inoculation experiments, designed to get some in- 
formation as to the possibility of these wild strains passing over to 
cultivated hosts, are under way at the present time. 
ECONOMIC SIGNIFICANCE. 
Many different crops are subject to infection by the stem nematode, 
according to foreign literature. Among these are alfalfa, barley, 
beans, buckwheat, flax, garlic, hyacinth, narcissus, oats, onion, peas, 
potato, rye, strawberry, and manj 7 others of less importance. Many 
of these crops are cultivated in western Oregon and Washington. The 
general belief in Europe is that there are distinct biological strains 
of the nematode. It is not known at the present time whether or 
not the American strains can adapt themselves to new hosts. The 
mere fact of the existence of the disease in so many hosts seems to 
imply this possibility. 
SUMMARY. 
The stem nematode Tylenchus dipsaei has been found rather abun- 
dantly in the Pacific Northwest on the wild strawberry (Frag aria 
chUoensis) and on the false dandelion (Hypochaeris radicata). 
The wild-strawberry strain of nemas occurs along the west coast 
of Oregon near the seashore, from Coos County to northern Tilla- 
mook County. The Hypochaeris strain was found from the south- 
ern part of Lincoln County, Oreg., to Long Beach, Wash., being 
almost universally present in western Oregon. 
Judging from natural occurrence, the two strains appear to be 
entirely independent of one another. 
The symptoms of the disease on either host are swelling and 
crinkling of the leaves and stems, resulting in extreme cases in 
marked twisting and bending. Where an abundance of infection is 
present in the crowns the plants are often killed. In strawberry 
plants the stolons and the flowering parts are swollen and distorted 
also. 
Several species of Fragaria are capable of becoming infested. The 
strawberry strain can be transmitted to red-clover seedlings. At 
tempts to transmit the Hypochaeris strain to other hosts have failed 
thus far. 
