7 



The Ohio V^aturalu 



PUBLISHED BY 



The Biological Club of the Ohio State Uni'versity. 



LIBRARY 



Volume X. 



NOVEMBER. 1909. 



No. 1. 



TABLE OF CONTENTS. 



Matheny— The Twig Girdler 1 



SCHAFFNER— An Interesting Botrychiiim Hsibitat 8 



SCHAFFNER— The Gymnosperms of Ohio 9 



Jennings— The Labrador Tea in Ohio 13 



Cook— Potato Agar 13 



News and Notes 14 



OsBORN—:Meetings of the Biological Clnli 15 



THE TWIG GIRDLER.* 



W. A. :\Iathkxv. 



Oncideres cingulatus (Say) , Order Coleoptera ; family Cerambycidae. 



"A thick-bodied longicorn, dark gray beetle about .5 inch long, with 

 its wing-covers sprinkled over with faint tawny yellow dots." 



In making a study of the galls of this community during the 

 fall of 1907, I came across the work of the "Twig Girdlers." 

 These singular beetles appear in Ohio from the middle of Augtist 

 until the middle of September. Figure 1 represents the beetle 

 and the incision it makes. According to Slingerland, this beetle 

 alwavs works head downward. This would discredit the draw- 

 ing bv Rilev. Prof. Glenn W. Herrick says, in his paper on "The 

 Pecan Pruner" (O. texana Horn.) that the beetle works head 

 downward. 



Professor Haldeman states that "both sexes are rather rare, 

 particularh- the male, which is rather smaller than the female, 

 but with longer antennae." The female does all the work. 

 She makes perforations (Fig. 1, b) in the branches in which she 

 deposits her eggs (one of which is represented of the natural size 

 at Fig. 1, e.) She then proceeds to gnaw a groove, of about a 

 tenth of an inch wide and deep, around the branch and below 

 the place where the eggs are deposited so the exterior portion dies 

 and the larva feeds upon the dead wood. 



Mr. James Brodie describes the manner of cutting of the 



0. texana as follows: 



"In starting work, a patch the desired width of cut is cleaned and 

 the bark eaten. Then the powerful mandibles are brought to work on 

 the wood. A cut is first inade at the top, then the head moves down to 



* Contribution from Biological Laboratory, Ohio University. 



