94 PRINCIPAL HOUSEHOLD INSECTS. 



There are many proprietary substances which claim to be fairly 

 effective roach poisons. The usefulness of most of these is, however, 

 very problematical, and disappointment will ordinarily follow their 

 application. The only one of these that has given very satisfactory 

 results is a phosphorous paste, also sold in the form of pills. It prob- 

 ably consists of sweetened flour paste containing' phosphorus, and is 

 spread on bits of paper or cardboard and placed in the runways of the 

 roaches. It has been used very successfully in the Department to free 

 desks from Croton bugs, numbers of the dead insects being found in the 

 drawers every day during the time the poison was kept about. 



Fumigation. — Wherever roaches infest small rooms or apartments 

 which may be sealed up nearly air-tight, and also on shipboard, the 

 roach nuisance can be greatly abated by the proper use of poisonous 

 gases, notably bisulphide of carbon. This substance, distributed about 

 a pantry or room in open vessels, will evaporate, and, if used in suffi- 

 cient quantity, will destroy roaches. Unless the room can be very 

 tightly sealed up, however, the vapor dissipates so rapidly that its 

 effect will be lost before the roaches are killed. The hatches of ships, 

 especially of smaller coasting vessels, may be battened down, a very 

 liberal application of bisulphide of carbon having been previously made 

 throughout the interior. If left for twenty-four hours the roaches and 

 all other vermin will unquestionably have been destroyed. In the use 

 of this substance it must be always borne in mind that it is violently 

 explosive in the presence of fire, and every possible precaution should 

 be taken to see that no fire is in or about the premises during the treat- 

 ment. It is also deadly to higher animals, and compartments should 

 be thoroughly aired after fumigation. A safer remedy of the same 

 nature consists in burning pyrethruin in the infested apartment. The 

 smoke and vapors generated by the burning of this insecticide are 

 often more effective in destroying roaches than the application of the 

 substance in the ordinary way as a powder. There is no attendant 

 danger of explosion, and the only precaution necessary is to see that 

 the room is kept tightly closed for from six to twelve hours. The smoke 

 of burning gunpowder is also very obnoxious and deadly to roaches, 

 particularly the black English roach. On the authority of Mr. Theo. 

 Pergande, gunpowder is commonly used in Germany to drive these 

 roaches out of their haunts about fireplaces. The method consists in 

 molding cones of the moistened powder and placing them in the empty 

 fireplace and lighting them. The smoke coming from the burning 

 powder causes the roaches to come out of the crevices about the 

 chimney and fire bricks in great numbers, and rapidly paralyzes or 

 kills them, so that they may be afterwards swept up and destroyed. 

 This remedy will only apply to old houses with large fireplaces, and 

 has no especial significance for the modern house. It is presented, 

 however, as a means applicable wherever* conditions similar to those 

 described occur. 



Trapjnng. — Various forms of traps have been very successfully 



