IMPORTANT PECAN INSKCTS AND THEIR CONTROL. 



31 



and these should 

 he dest roved 1) y crushing or 

 sonic other suitable means. 

 Pecan, orchards sprayed 

 with arsenic als will rarely 

 suffer serious damage by 

 this insect. 



THE HICKORY PHYLLOXERA.! 



Pecan growers are 

 alarmed occasionally by 

 the presence of tumor-like 

 swellings or galls (fig. 39) 

 which sometimes occur on 

 the leaves, leafstalks, and 

 succulent shoots. These 

 galls are caused by the at- 

 tacks of an insect and are 

 in no way to be associated 

 with a disease organism, as 

 seems to be a more or less 

 prevalent notion among pe- 

 can growers. An examina- 

 tion of one of the newly 

 matured galls will reveal 

 the true culprit in both 

 winged and wingless or im- 

 mature forms. Before the 

 maturity of the inhabitants 



FIG. 36. The walnut caterpillar: Colony ol larvae on pecan. 



the gall is closed, but by the time the inmates have acquired wings 

 it cracks open, allowing the fully developed migrants or aphids to 

 escape, and is left for the younger individuals. 



The formation of galls is more pronounced during the early spring 



than at any other time, al- 

 though galls maybe found on 

 the trees during the greater 

 part of the growing season. 

 Both the seedling and im- 

 proved varieties of pecan 

 are subjected to the attacks 

 of these aphids, but it ap- 

 pears that injury is much 

 more prevalent to the seed- 

 lings. It is not uncommon 



FIG. 37. The walnut caterpillar: Adult, or moth. Slightly 

 enlarged. 



1 Phylloziri carjaccaxlis Fitch, and other 

 species. 



