DISEASES DUE TO NEMATODES (EELWORMS) 6i 



activity the indications are that the worms cannot exist more 

 than a few months without food. 



For active hfe nematodes in general are dependent on the 

 presence of moisture or a high degree of humidity. The rice 

 nematode has been found able to move over a water-free surface 

 in a saturated atmosphere, and to travel on the surface of the 



Fig. 1. 



After N. A. Cobb 



Fig. 14 Tylenchus musicola. Fig. 15 Tylenchus musicola, 

 Male Female 



living plant at humidities below go but not below 75 per cent, 

 of saturation. The same species can survive about a month of 

 total immersion in water, but according to Cobb many soil- 

 inhabiting and plant-infesting nematodes succumb after a sub- 

 mergence of a few days. 



The quality of resistance to nematode attack is shown in 

 certain cases by species or strains of plants related to those 

 infested. Thus Liberian coffee is reported to be definitely re- 

 sistant to nematode troubles experienced in Java and the French 



