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 ver\- 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 proprietar}- 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 eitective means of destropng cockroaches, as well as 

 other insects. The cockroach is unable to withstand a temperature 

 of I20~ 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 ver}- probable that the comparativeh- simple fumigation 

 adAnsed for fleas would be nearly, if not equally efficacious, against 

 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 lirs: is a ver} 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"'^ 



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 





'oDermestci lardarius Linn. 



