176 



Pecan-Growing 



the pupal stage and soon emerge as 

 adult beetles ready to renew the life 

 cycle. Some few of the pupae are 

 thought to remain over winter, and the 

 adults emerge the second year. When 

 twig-girdlers appear in large num- 

 bers they cause serious damage to 

 pecan nursery stock and small trees in 

 the orchard. They do very limited 

 harm to the large bearing trees (Fig. 

 32). 



Cont7^ol. 



Since the girdled or cut-off twigs con- 

 tain the eggs and larvae of this beetle, 

 the most satisfactory method of reduc- 

 ing the numbers for the following sea- 

 son is to collect and destroy the infested 

 twigs. Hickory and persimmon trees 

 growing near should also have the 

 twigs gathered and destroyed. 



Spraying with arsenate of lead has 

 been effective in protecting young 

 pecan trees against the twig-girdler. 

 One and one-half pounds of powdered 

 arsenate of lead to three pounds of 

 lime are used with fifty gallons of water for this spray. The 

 first spraying is given about the 20th of August or just 

 before beetles are known to begin girdling the twigs. The 

 second spraying is about the 20th of September, or about 

 three weeks following the first application. 



Figure 32. — The twig- 

 girdler ; a, beetle ; &, 

 larval tunnels ; c, gir- 

 dling work of adult. 



