110 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



when the examination was made. I have noticed shallow holes that 

 were made in the apple by the larva?, but in most cases the larvae 

 were found dead in the holes, showing that they had gotten some of 

 the poison in eating through the skin. 



Mr. G. D. Shafer: Did you find any dead larvae in these side 

 injuries? 



Mr. E. p. Felt: No, I did not find any. I did not look closely 

 for them. 



President Glenn W. Herrick: Had the trees been sprayed? 



Mr. E. p. Felt: Yes, they had been sprayed. Observations on 

 habits of the larva hatching after late deposition of eggs was included 

 in the experiment. 



Mr. G. D. Shafer: Two years ago in Michigan I found a great 

 many larvae and in a few cases I was able to find dead larvae in the 

 little cups of the injury. I wondered if the larvae had gotten some 

 poison and thus succumbed to that. 



Mr. E. p. Felt: Lloyd records killing larvae in that way. 



President Glenn W. Herrick: I will now call for a paper by 

 Mr. S. W. Bilsing. 



LIFE-HISTORY OF THE PECAN TWIG GIRDLER 



By S. W. Bilsing, College Station, Texas 



Introduction 



Pecan growing has become an important industry in Texas and the 

 means of controlling the insects which affect both the tree and the nut 

 are of great importance. 



In the autumn of 1913 several of the three-year-old pecan trees in the 

 orchard of the Horticultural Department at College Station were 

 severely damaged by the pecan twig girdler, Oncideres texana. Upon 

 close examination it was found that the damage was caused by a single 

 female. The damage was so great that it was decided to make an in- 

 vestigation of the life-history of this insect. 



This insect was marked by putting a drop of red ink on the right 

 wing cover, and the methods of oviposition and egg-laying habits were 

 closely observed. During the fall of 1913 this one female entirely 

 severed one young tree about two feet from the ground and pruned 

 three other trees. Every limb was pruned on two of these trees and a 

 third was pruned almost as severely. In all, 16 limbs were severed 

 by this single female. In each case the limbs severed were from 8 to 

 10 mm. in diameter. Since then we have noted individuals which cut 



