February, '16] ENTOMOLOGISTS' DISCUSSIONS 113 



larvse eat a great number of small holes through to the outside. The 

 larval burrow is also stopped with grass before the larva pupates. 



Pupation takes place during the latter part of August and the first 

 part of September. The pupal stage lasts from 12 to 14 days, and is 

 passed in the larval burrow. 



Control Methods 

 The method which had been recommended in the past, that of 

 gathering up the fallen twigs and burning them in order to kill the larvse, 

 is practicable where a pecan orchard is not located in the vicinity of 

 other trees. When forests are located near a pecan orchard there is 

 always more or less migration from other trees to pecan trees. To 

 meet such conditions we tried out a series of experiments with arsenate 

 of lead and found it entirelv effectual. 



President Glenn W. Herrick: Is there any discussion? 



Mr. S. J. Hunter: I would like to ask if Mr. Bilsing noticed any 

 tendency of the female ovipositing at the base of the minor twigs? 

 In the case of the elm twig girdler they invariably select the base of 

 the twigs. I also wish to ask if the twig falls after being attacked by 

 the girdler? 



Mr. S. W. Bilsing: Regarding the first question I have seen 

 females oviposit many times at the base of minor twigs. The damage 

 is very much less to older trees as they are not injured to any great 

 extent because the beetles do not cut off enough limbs to be of any 

 consequence. Most of the limbs are cut two feet from the trunks of 

 the smaller trees, and they are usually 10 mm. in diameter. As a 

 rule the ovipositing is done in the main twigs. Many times the twig 

 falls after being girdled by the female and she falls with it. This 

 is especially so in windy weather. 



President Glenn W. Herrick: Never at the base? 



Mr. S. W. Bilsing: Yes, sometimes they deposit eggs at the 

 base of the twigs. Occasionally the eggs are deposited in the middle 

 of the twig. 



Mr. W. C. O'Kane: I would hke to ask if Mr. Bilsing maintained 

 check cages in his experiment where other individuals were similarly 

 confined, but without access to sprayed material? In other words did 

 the specimens all die because of eating poison? 



Mr. S. W. Bilsing: I will say that in the experiments shown in 

 the chart I think all of them died from the spray material. I made 

 several experiments later in the fall but could not consider the re- 

 sults accurate because of the beetles in the field dying under the 



