EELWORMS 557 



that is especially susceptible. Clover should not follow, neither 

 should oats follow clover that has been subject to eelworm 

 disease. Barley is practically safe to follow. 



In oats the base of the stem is often somewhat swollen, 

 when attacked by the frit fly ( Oscinis frit, L.), but in this 

 case the minute larva or the chrysalis may be found when the 

 stem is split open. The chrysalis is brownish and not more 

 that the eighth of an inch long. Somewhat similar symptoms 

 are produced in wheat by a fly called Hylemyia coarctata 

 (Fallen). 



Strawberry root eelworm (Tylenchus devastatrix, Kiihn), 

 is stated by Theobold to cause great mortality amongst straw- 

 berries. The plants rot and decay at ground level. There are 

 no marked symptoms as when plants are attacked by 

 Aphelenchus ; the plants simply rot away, the leaves are some- 

 times crinkled and deformed. 



Dressings of lime and sulphate of potash are recommended. 

 Diseased plants should be removed. 



Theobold, F. V., Insect Pests of Fruit, p. 474 (1909). 



* Ear-cockles ' of wheat (Tylenchus tritici, Bastian) is 

 sometimes responsible for a considerable amount of shortage 

 in the wheat crop. The grain is the part attacked, and 

 becomes changed into a roundish, purple-black body, some- 

 what smaller than a normal grain. As a rule almost every 

 grain in the ear is attacked. If an infected grain is crushed 

 and the contents examined under the microscope, myriads of 

 eelworms will be seen, and even when the grains are fifty 

 years old, and have been kept dry all the time, on the 

 addition of water the eelworms will soon begin to wriggle 

 about in a characteristic manner. This was at one time 

 one of the stock experiments supposed to demonstrate the 

 extreme vitality of life under dessication. Such eelworms, 

 however, are in reality dead, and the wriggling is due to the 

 absorption of water by their dessicated bodies, which causes 

 them to expand and resume a life-like appearance. When 

 the body of an eelworm is once properly saturated with water 

 and expanded all movement ceases. 



. The disease is erratic in appearance, and as a rule does 

 little harm, although Miss Ormerod mentions an instance 

 where about twenty-seven acres of wheat was badly infected. 

 According to Bastian, when infected grains are sown along 



