IMPORTANT PECAN INSECTS AND THEIR CONTROL. 



31 



molting, and these should 

 be destroyed by ci"usliing or 

 some other suitable means. 

 Pecan orchards sprayed 

 with arsenicaJs will rarely 

 suffer serious damage by 

 this insect. 



THE mCKORY PHYLLOXERA.i 



Pecan growers are 



alarmed occasionally by 



the presence of tumor-hke 



swellings or galls (fig. 39) 



which sometimes occur on 



the leaves, leafstalks, and 



succulent shoots. These 



gaUs 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 gaUs wiU reveal 



the true culprit in both 



winged and wingless or im- 



matm-e forms. Before the 



maturity of the inhabitants 



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



it cracks open, aUow^ing the fuHy developed migrants or apliids 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 injm-y is much 

 more prevalent to the seed- 

 lings. It is not uncommon 



Fig. 36. — The walnut catcrjjillar: Colony ollan'se on pecan. 



-The walnut caterpillar: Adult, or moll 

 enlarged. 



Slightly 1 rhylloict 



'. caryaccaulis Fitch, and other 

 species. 



