34 BULLETIN^ 1107, U. S. DEPAETMENT UE AGEICULTUEE. 



All of these attacks were at the point of contact of the glass with the 

 cork. One cork of an empty vial showed a slight attack well above 

 the glass. 



In another experiment two 30 by 100 millimeter vial corks were 

 soaked in alcohol for three days and then placed in a cage with two 

 untreated similar corks and 10 beetles. No attacks were made on any 

 of the corks. 



In the laboratory a 30 by 100 millimeter vial filled with alcohol 

 fell on its side and remained there for some time. The cork of this 

 vial was riddled with beetle attacks, at least 12 beetles having bored it. 



Oak-hark tea. — Four feet of cable in the " experimental cage " was 

 painted with old oak-bark tea. One hundred beetles were active 

 around it but none appeared to be attracted. 



Yeast. — Sections of oak were dipped into various strengths of a 

 yeast dissolved in warm water. Ten beetles were placed with the 

 sections. Apparently these were slightly attracted to the sections 

 dipped in the strongest mixture (2 cakes to one-half quart) and left 

 for the longest time (48 hours) . 



About all that can be said about these fermentation experi- 

 ments is that they indicate that at certain times under certain con- 

 ditions some beetles are attracted. As the conditions of the ferments 

 vary so much and the beetles themselves vary in the same ratio, it is 

 almost impossible to draw reliable conclusions. 



OCCXTEEENCE EXPERIMENTS. 



In order to determine the normal occurrence of the beetles around 

 the regular commercial cables the following experiments were con- 

 ducted. 



Lgs Gatos. — Four sections of freshly cut oak Avith the ends dippe-.l 

 in hot paraffin were suspended para lei with the cable in two dif- 

 ferent locations in Los Gatos. Tavo sections w^ere suspended near 

 a wood yard which contained beetle-infested wood and the other two 

 about one-half mile away. The sections remained in place from 

 July 25 to October 25. One of the sections suspended near the 

 w^ood yard was attacked by three different females. The other three 

 sections were not attacked. 



Palo Alto, — -Similar sections of wood were suspended in the acacia 

 tree close to the cable cages mentioned under " aerial cage " at Palo 

 Alto. No attack was made on these sections. Beetles placed in a 

 small cage with similar sections attacked the sections, so it is reason- 

 able to suppose that if any beetles had been flying near hy they would 

 have attacked these sections. 



Santa Barhara. — On August 18 about 25 feet of commercial cable 

 at Santa Barbara Avas covered with a commercial stickv niatei'ial 



