742 



THE MONTHLY BULLETIN. 



of many orchards where thorough pruning, cultivation, irrigation, and 

 fertilization have proven of no avail in restoring the productivity of 

 numerous groves that are known to the writer. 



Pig. 39.3. — -Pig rootlets containing the root- 

 knot eelworm. Young figs aie often Icilled by 

 tliis pest when planted in a worm-infested 

 area. (Original.) 



Life History and Description of the Eelworm. 



The eelworm is a very small organism, seldom exceeding one twenty- 

 fifth of an inch in length, is semi-transparent and rather difficult to 

 detect by the untrained eye. When examining a knot for this minute 

 worm always endeavor to break the rootlet ; do not cut, as very 

 little pressure brought to bear upon this small creature ruptures the 

 thin epidermal covering and its presence is overlooked. Close exami- 

 nation will usually reveal two types of the nematodes : a spindle-shaped 

 form which is either the male worm or the larvte (Fig. 894-4) (which 

 can not be differentiated by the naked eye), and the adult female. 

 The mature gravid female (Fig. 394-5) has lost her worm-like appear- 

 ance and will appear as a pearly w^hite, pear-shaped organism, firmly 

 embedded in the plant tissue. This change takes place soon after the 

 last moult in the larval growth. This transformation is the result of 

 the development of the egg masses within the body. 



The Egg. — The female is very prolific (Fig. 394-6), depositing no 

 less than 400 or .500 eggs during her lifetime. These eggs are whitish, 

 semi-transparent, bean-shaped bodies which are too small to be noticed 

 without the aid of a lens or microscope. The time required in hatch- 

 ing the eggs depends largely upon weather conditions ; in warm 



