INSECTS INJURIOUS TO MAN AND IN HOUSEHOLD 651 



For this reason control measures must be kept up persistently so 

 as to kill newly hatched young as they appear from time to time 

 Roaches may be killed with poisons or by fumigating or they 

 may be trapped. A trap described by Mr. C. L. Marlatt, of 

 the Bureau of Entomology, is the acme of simplicity. It consists 



FIG. 570. The German roach (Blattella germanica): a, first stage; 6, second 

 stage; c, third stage; d, fourth stage; e, adult; f, adult female with egg 

 case; g, egg case, enlarged; h, adult with wings spread. All natural 

 size except g. (From Riley, U. S. Dept. of Agr.) 



of an ordinary breadpan with the sides greased with rancid 

 butter. The butter acts as a bait and the roaches fall into the 

 pan and are unable to climb up the greased sides and escape. 



FIG. 571. The American roach (Periplaneta americana} : a, view from above; 

 b, from beneath. Both enlarged one-third. After Marlatt, U. S. Dept. 

 of Agr. 



Roaches may be poisoned with chocolate mixed with borax, 

 about equal parts being used. Plaster of paris mixed with flour 

 or with chocolate has also been recommended. Sodium fluoride 



