IMPORTANT PECAN INSECTS AND THEIR CONTROL. 



27 



apparently do not have sufficient time to inflict serious damage. 

 It has been observed, further, that the larvae feed on the foliage 

 (fig. 31) if compelled to do so by the rapid growth of the tree, and 

 under these conditions they will eat the outer parts of the leaves. 

 During dry seasons, especially in the spring of the year, pecan 

 nursery stock grows very slowly and is seriously injured by Iarv88 

 of the bud moth. As a nursery practice it is strongly recommended 

 that the trees be kept in 

 a vigorous growing con- 

 dition by thorough culti- 

 vation and fertilization. 

 Spraying with arsenicals 

 during the spring just as 

 the buds are opening will 

 help materially to hold 

 this pest in check, but this 

 treatment is not advised 

 unless the infestation is 

 very serious. Observa- 

 tions would indicate that 

 the pecan bud-moth never 

 does sufficient damage in 

 bearing orchards to war- 

 rant special spraying. 



THE FALL WEBWORM.i 



Perhaps the commonest 

 insect coming under the 

 observation of pecan 

 growers is the so-called 

 fall webworm, which con- 

 structs unsightly nests or 

 webs over the twigs and 

 foliage. These webs are 

 more abundant during the late summer and fall, but since this insect 

 has two generations in the South, the webs are to be found on pecan 

 trees as early as May. Trees defoliated in late summer frequently de- 

 velop leaves and flowers to the detriment of the crop the following year. 



The moths (fig. 32) , which usually are pure white but sometimes 

 have black or brown spots on the forewings, emerge in the spring, 

 during April and May. The eggs are deposited in masses on the leaves, 

 are greenish white in color, and hatch in about a week (fig. 32). The 

 larvae are gregarious, and each colony forms a web in which all the 

 caterpillars feed, eating the upper and lower surfaces of the leaves. 

 When they need additional leaves for food they enlarge the web (fig. 

 33), which sometimes becomes very large and conspicuous. 



1 Hyphantria cunea Drury. 



FIG. 31. The pecan bud-moth: Larval injury to pecan foliage. 



