10 



FARMERS BULLETIN 843. 



prevents the natural separation of the shucks from the nutshells. 

 Nuts attacked by the shuckworm during the late fall usually will 

 mature in fairly good condition for the market, but if the injury takes 

 place early.it will result in inferior or unmarketable fruit. Sooty 

 trails on the shell of the nuts often result from the attack of the 

 larvae, the nuts sometimes being so discolored as to lessen their market 

 value. The damage is not restricted entirely to the matured nuts, for 

 during the summer the early generations of larvae attack the small, green 



nuts by eating out the interior, 

 causing them to fall to the ground. 

 (Fig. 8.) Injury of this type is 

 not so noticeable or so widespread 

 as that which takes place in the 

 fall, but it plays no small part in 

 the reduction of the nut crop. 



Besides attacking the pecan , this 

 insect feeds upon the nuts of the 

 various species of hickory, where 

 the injury it does is precisely like 

 thatdone to the pecan, except that 

 the destruction of the small, green 

 nuts seems to be greater. Occa- 

 sionally the larvae will be found 

 subsisting on the galls formed 

 by a certain species of aphid. 1 



Before nuts have set on pecan 

 trees larvae sometimes will be 

 found boring into and tunneling 

 the succulent shoots, but this 

 form of injury is very uncom- 

 mon, as this species is primarily 

 a nut-infesting insect. 



DESCRIPTION. 



FIG. 8. The pecan shuckworm: Larva in shuck of 

 nearly matured pecan nut. Enlarged. 



This insect passes through four 

 stages: The egg, the larva, the 

 pupa, and the adult or moth. 

 The moth of the shuckworm (fig. 

 9) is smoky black, mixed with iri- 

 descent bluish and purplish tinges, and the forewings have a series of 

 short, yellowish streaks across their front margins. The moths are rather 

 variable in size, but the maximum expanse of wings is rarely more than 

 three-fifths of an inch. Because of their protective coloration the 

 moths are seldom observed in pecan orchards, even by keen observers. 

 The egg is small, w^hitish, and more or less oval, and under high 

 magnification its surface is seen to be wrinkled. The eggs are de- 



Phylloxera caryaecaulis Fitch. 



