62 



NEW YORK STATE MUSEUM 



Sodium fluoride, pure or diluted with equal parts of plaster of 

 Paris or similar material and strewn about the haunts of these 

 insects, is a simple and very effective method of controlling these 

 pests. Powdered borax, or borax diluted with equal parts of 

 naphthalene flakes, can be used in the same way. The distribution 

 of these insecticides or proprietary remedies should be supple- 

 mented by persistent cleanliness in the elimination of inaccessible 

 haunts so far as possible. 



Superheating, where this is possible, is a comparatively simple 

 and very effective means of destroying cockroaches, as well as 

 other insects. The cockroach is unable to withstand a temperature 

 of 120 F. for more than a few minutes, and the maintenance of 

 a temperature of 150 to 160 F. in a house for several hours 

 should result in killing all the insects. 



It is very probable that the comparatively simple fumigation 

 advised for fleas would be nearly, if not equally efficacious, againsr 

 these pests. Fumigation with sodium or potassium cyanide, burn- 

 ing sulphur or carbon disulphide will destroy the pests, though it 

 should be remembered that the first is a very active poison, that 

 the second is liable to injure fabrics and tarnish metals, and that 

 the third when diluted with air is a dangerous explosive. 



Larder Beetle 70 



The parent insect, a stout, dark-brown beetle with. the base of 

 the wing covers mostly yellowish, is frequently rather common 

 about houses in May and June. This insect breeds by preference 



lug. 24 Larder beetle, 

 seen from above, enlarged. 

 (Authos's illustration) 



76 Dermestes lardarius Linn. 



