144 PROTECTION OF PLANTS. 1916-17 



The males are microscopic in size and resemble miniature eels, hence the 

 name eelworms. The females are white and pear-shaped or rounded. 



Life-History. — The eggs are oval shaped and are produced by the females 

 in great numbers in the knots or galls. They hatch in a short time and the 

 young eelworms seek new quarters and feed upon the roots of plants pro- 

 ducing the characteristic deformities. They may pass the winter in their 

 host, or it may be on other plants. The young forms may even encyst 

 themselves in the soil. 



Control. — Infested soil in greenhouses may be sterilized by steam, 

 carbolic acid (1 to 20) or formalin; mix the soil intimately with gas-lime; 

 rotation of crops ; summer fallow ; plant clean nursery stock. 



The following plants are liable to be severely injured by Nematode 

 attacks (Gilbert, Farmers' Bull. 625) : — Soy bean, beet, carrot, celery, 

 cow pea, crimson clover, cucumber, lettuce, peach, potato, squash, tobacco, 

 tomato, watermelon; less severely: — alfalfa, asparagus, lima bean, cabbage, 

 sweet clover, cotton, onion, garden pea, radish, spinach, strawberry, vetch. 

 The following plants are largely immune: — barley, corn, grasses, oats, rye, 

 wheat and cow peas (some varieties). 



