26 



FARMERS BULLETIN 843. 



its semitransparcnt skin can be seen the brownish contents of the 

 alimentary canal. The head and cervical shield, or neck, are shiny 



dark brown in color in full-grown larvae, 

 but on very young- larvse they are jet 

 black. 



The pupa (fig. 29, at left) is of the 

 usual light-brown color. The size 

 varies somewhat, but the length rarely 

 is more than a third of an inch. The 

 pupa? usually are formed in rolled-up 

 leaves or infested buds, but occasionally 

 they can be' founo! under bark scales 

 or at the crown of the tree. 



SEASONAL HISTORY. 



The number of generations a year 

 varies somewhat in different sec- 

 tions. In the extreme southern por- 

 tion of its distribution five or six 

 occur during the course of a season. 

 The pecan bud -mouth passes the 

 winter in the adult stage. As soon 

 as the buds on- the pecan trees begin 

 to open, the moths commence to lay 

 eggs, which usually are deposited on 

 the branches near the buds, but after 

 the foliage appears the eggs are laid 

 invariably on the upper surface of the 

 leaves. (Fig. 30.) The eggs hatch in 

 from 3 to 6 days, depending upon the 

 temperature. The larvas feed from 21 

 to 29 days, the average being about 25 

 days. The pupa stage lasts from 8 to 13 days, but the average period 

 is about 10 days. Ths average life-cycle period is 40 days 5 days 

 being spent in the egg stage, 25 days as larva, and 10 days as pupa. 



CONTROL MEASURES. 



Ordinarily this bud-moth does not occur in sufficient numbers to 

 be ranked as a serious pest of the pecan. In bearing pecan orchards 

 it is rarely troublesome, but during some seasons it is responsible 

 for considerable damage to the pecan nursery trees. This species 

 is primarily a bud feeder, and in attacking the terminal buds on the 

 young trees it causes a stunted growth as well as excessive branching. 

 This feature is especially objectionable from the nurseryman's point 

 of view, since the pecan nursery stock is sold according to its height. 

 It has been observed that nursery trees growing vigorously usually 

 open and unfold their terminal buds so rapidly that the larvae 



FIG. 30. The pecan Imd-moth: Eggs oil 

 pecan leaflet. 



