24 BULLETIN 1232, U. S. DEPARTMENT OF AGRICULTURE. 



mound nests or which have underground galleries with well-defined 

 openings. This chemical is a coal-tar product made by combining 

 benzol and chlorine gas. Crystals could be placed in the openings 

 of the nests or mounds and thus kill subterranean termites. How- 

 ever,' where a large number of termite mounds occur on land intended 

 for cultivation, the land can be cleared by the use of steam shov- 

 els or by exploding the mounds with dynamite and crushing them 

 by a heavy gasoline caterpillar tractor. The soil can then be 

 sprayed with sodium C}<anid to kill the termites, using 160 pounds 

 of granular sodium cyanid per acre with 12,000 gallons of water, as 

 recommended for the Japanese beetle {Popillia japonica Newm.), 

 or quicklime, wood ash, or lye used. 



Species in the family Kalotermitidae probably can be practically 

 controlled by the use of dry heat. In the attic of the Royal Palm 

 Hotel, a large, high, frame structure at Miami, Fla., the temperature 

 becomes very high, due to the subtropical heat and also to the fact 

 that the sun's raj^s beat down on the roof; the temperature in the attic 

 was from 17° to 24° F. higher than the maximum temperature re- 

 corded by the United States Weather Bureau. Oak and maple 

 furniture infested with the destructive West Indian termite Orypto- 

 termes hrevis Walker, which had been removed from guest rooms 

 and placed in this attic directly under the roof, contained no living 

 termites when examined in the latter part of January and early part 

 of February, 1922. by T. E. Snyder. Small piles of pellets under 

 this furniture indicated that the termites had continued to work in 

 the infested furniture for a short period after having been removed 

 to the attic, where undoubtedly the temperature became too great 

 even for a termite that normally lives in hard dry wood, i. e., in 

 wood which probably contains normally only about 10 per cent of 

 moisture. 



O'Kane and Osgood (5) were successful in killing the earth-in- 

 habiting termite Rcticulitermes favipes Kol. which was infesting the 

 woodwork of a large hospital at Dover, N. H., by the use of supple- 

 mentary steam piping and maintaining a temperature of 135° F. for 

 24 hours. 



Fumigation with hydrocyanic-acid gas will kill species of Kalo- 

 termitidae infesting woodwork of buildings or furniture. Twelve 

 ounces of sodium cyanid per 1.000 cubic feet was successfully used 

 in killing Cryptotermes hrevis Walker infesting woodwork and fur- 

 niture in case of the Royal Palm Hotel at Miami, after the building 

 had been sealed; the gas remained in the building for about 48 

 hours. 



In order to kill termites of the family Kalotermitidae which 

 work in dry wood and have no connection with the ground, various 

 mixtures can be used. A 20 to 30 per cent solution of paradichloro- • 

 benzene in kerosene (or orthodichlorobenzene, a similar chemical) 

 can be used effectively. 



The infested wood is saturated with this liquid by swabbing it 

 with a mop. Several treatments may be necessary to enable the 

 chemicals to penetrate the wood and kill the insects therein. A 

 poisoned kerosene-emulsion mixture can be similarly used by dissolv- 

 ing 1 ounce of sodium arsenite in each gallon of the water used for 

 diluting stock mixtures of kerosene emulsion or miscible oil. 



