THE LEAD-CABLE BORER IN CALIFORNIA. 39 



waxes were heated and poured onto the cable ; the greases were spread 

 on with a paddle, and the tar and paint were applied with a brush. 

 The materials used were (A to E) commercial greases or petroleum 

 compounds; (F) a mixture of refined paraffin, 50 per cent, and tal- 

 low, 60 per cent; (G) refined paraffin; (H and I) two chlorinated 

 naphthalene compounds Nos. 1001 and 1008; (J) pine tar; and (K) 

 P. & B. paint. 



The records indicate that the greases (A-E) with the possible ex- 

 ception of B, do not weather as well as the waxes (F-I) and the 

 paints (J and K). The paraffin (G) appears to have held its orig- 

 inal qualities best, with H, F, K, J, and I following in the order 

 given. 



RESULTS OF EXPERIMENTS IN CALIFORNIA IN 1922. 



During the season of 1922 bitumastic enamel, animal gall, pine 

 tar, sealing wax, turpentine and rosin (1 quart to 1 pound), several 

 preparations of mineral paint, pure rubber, tin foil, copper foil, and 

 thin copper sheeting were experimented with as repellents. The 

 only materials that stopped the beetles were the copper foil and 

 copper sheeting and the rubber. Numerous beetles tried the copper 

 but none succeeded in penetrating it. Six beetles out of 32 pene- 

 trated one thickness of .the rubber and 2 of these emerged. None 

 succeeded in penetrating more than one thickness. 



So far as can be determined none of the substances have any 

 repellent value, for the beetles enter wood through them as well as 

 emerge through them. It was felt that the animal gall would repel 

 them, but they attack the wood through it and also through the 

 mineral paints. 



Acetic acid and tannic acid, as well as the alcohol, show some 

 attraction to the beetles. One of the telephone men brought in some 

 specimens of Scobicia which he found entering a wine cask. 



In the attempt to determine the cause of the beetle's attacking the 

 cable no definite conclusions have been reached. The authors be- 

 lieve that the beetle bores the cable because it finds itself closely 

 confined between the cable and the suspending ring, but they do not 

 believe that it can be proved. If it was drawn to the cable by any 

 other attraction it would have to go to this same point to be able to 

 get a foothold from which to bore, and this makes the proof of the 

 theory difficult. The authors have tried the lead, light, heat, elec- 

 tricity, and color as attractants with negative results ; but when 

 two pieces of lead are brought closely together, as by a fold, or a 

 glass plate is placed on a sheet of lead and beetles put between, 

 boring takes place. 



It was found that adults of Scobicia declivis would attack corks 

 treated with a solution of tannic acid and also those treated with a 



