THE PECAN LEAF CASE-BEARER. 5 



to its attacks was noticed. Such varieties as the Frotscher, Van 



Deman, Nelson, Pabst, Schley, Delmas, Stuart, and Success were 



badly infested, while the Mobile, Georgia, Havens, Teche, Waukeenah, 



Moore, Moneymaker, and Curtis were slightly infested. No reason 



can be given for this apparent varietal resistance, but it may be 



stated in general terms that pecan trees with very small leaves seem 



less likely to be heavily infested by this insect. Unfortunately, many 



of the best commercial varieties of pecan are subject to attacks by 



this pest. 



CHARACTER OF INJURY. 



The most serious damage to pecan occurs during the early spring. 

 The larvae feed voraciously upon the unfolding buds and leaves, as 

 is shown in Plate III, figure 1. Just as the buds are bursting, the 

 little overwintering "worms" gnaw their way out of their hibernacula 

 (winter cases), which invariably are to be found snugly packed around 

 the buds. Usually they migrate immediately to the tips of the 

 swelling buds, upon which they partake greedily of their first meal. 

 Upon leaving hibernation quarters some larvae have been observed 

 eating directly through the side of the buds, instead of entering at 

 the tip as is usually the case. As these larva? begin to work very 

 early in the spring it takes but little feeding to inflict serious injury. 

 On badly infested trees it is not uncommon to see from three to five 

 larvae, and sometimes more, entering a single bud. Under these 

 conditions there is little chance for even partial development of the 

 foliage. As the larvae when in sufficient numbers are capable of 

 eating the green foliage as rapidly as it appears, it is not unusual for 

 the trees to remain defoliated for a considerable length of time. The 

 writer has seen pecan trees kept in this condition for several weeks 

 solely because of the attacks of this pest. On such trees the buds 

 turn brown as a result of the feeding of the larvae, and a block of 

 badly infested trees takes on the appearance of blight by fire. (PI. 

 II, fig. 2.) When the infestation is less severe the larvae web and 

 tie the tender leaves together into masses, which soon become 

 unsightly due to the wilting of the leaves and the presence of particles 

 of excrement and larval cases with which they are united. (PI. Ill, 

 figs. 3, 4.) Late in the spring, when about half grown, the larvae 

 attach their cases to the leaf petioles, draw the leaflets together, and 

 feed freely. (PI. II, fig. 3.) 



After having kept the trees in a defoliated condition for some time 

 and, therefore, when pressed for food, these insects occasionally 

 attack both blossom and leaf buds by burrowing directly into the 

 ends. When thus deprived of their foliage the trees are fairly certain 

 to become so devitalized as to be unable to make proper growth 

 during the remainder of the season or to form fruit buds for the 

 following season. Indirectly the trees suffer by becoming much 



