NO. l8 SENSE ORGANS OF COLEOPTERA — McINDOO 29 



Metzger (53) describes five methods used in testing 430 materials, 

 alone and in combination, as repellents for the Japanese beetle. 

 Under method i, " testing material in comparison with a known 

 attrahent," 306 materials were tested, and 45 of them decreased the 

 attraction of the geraniol-eugenol combination. Beginning with the 

 one most repellent, the first ten in the list are o-cresol, pine-tar oil, 

 phenol, Dippel's oil, high boiling tar acids, coal-tar neutral hydro- 

 carbon oil, trichlorobenzene, crude dichlorobenzene No. i, alpha 

 chloronaphthalene, and crude dichlorobenzene No. 2. 



Another difficult test has been to find a successful repellent for 

 wood-boring beetles. The first object is to prevent them from enter- 

 ing the living trees, lumber, or manufactured wooden articles, and 

 the second object is to kill them or drive them out of their burrows 

 after they have once entered. Little success has yet been accomplished 

 along this line, but it is easier to prevent their entrance than to con- 

 trol them later. In Brazil a mixture consisting of crude carbolineum 

 I part, quicklime 10 parts, and water 40 parts is painted on the trunks 

 of citrus trees to prevent the entrance of borers. In the United States 

 carbolineum and creosote are often applied to the trunks of aspen 

 trees in forests to prevent the entrance of the aspen borer. A suc- 

 cessful repellent has recently been recommended by Pettit (60) 

 against flat-headed borers which do considerable damage to apple 

 trees. Following a special procedure a thick solution is prepared by 

 using 50 pounds of laundry soap, 3 gallons of water, 25 pounds of 

 flake naphthalene, and 2 pounds of flour. After warming and thin- 

 ning this mixture to the consistency of heavy cream, it is applied 

 several times with a brush to the trees. 



The Lyctus powder-{X)st beetles, which cause much dainage to 

 hardwood lumber, implement handles, furniture, etc., throughout the 

 world, may be deterred and repelled by several substances. In the 

 United States, according to Snyder (82), the usual method recom- 

 mended is to immerse the lumber, already infested or liable to in- 

 festation with these borers, in vats of kerosene, or in a mixture of 

 creosote and kerosene, or in one of creosote and naphtha. The writer 

 has recently been told that these beetles may be repelled by using 

 coal-tar creosote and orthodichlorobenzene. The lumber and handles 

 which can not be treated by the vat method may be stored in closed 

 sheds and close-fitting houses and then sprayed at intervals with these 

 chemicals. In Great Britain lumber stacked in the open is often 

 treated with cold paraffin mixed in equal parts with oil of cedar, 

 linseed oil. or a heavy mineral oil. To lumber stored in sheds or- 

 thodichlorobenzene is applied with a brush or sprayer, or paradichlo- 



